Merge branch 'master' into pr/3938

155 files changed, 2800 insertions, 1581 deletions

diff --git a/.github/ISSUE_TEMPLATE b/.github/ISSUE_TEMPLATE
new file mode 100644
index 000000000..1e432aeef
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE
@@ -0,0 +1,14 @@
+You are opening a _bug report_ against the libgit2 project.  If you have a
+question about an API or usage, please ask on StackOverflow:
+http://stackoverflow.com/questions/tagged/libgit2.  Please fill out the
+reproduction steps (below) and delete this introductory paragraph.  Thanks!
+
+### Reproduction steps
+
+### Expected behavior
+
+### Actual behavior
+
+### Version of libgit2 (release number or SHA1)
+
+### Operating system(s) tested
diff --git a/.travis.yml b/.travis.yml
index bfc0fac48..af38252ce 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -47,9 +47,6 @@ matrix:
      os: linux
  allow_failures:
    - env: COVERITY=1
-   - env:
-       - VALGRIND=1
-         OPTIONS="-DBUILD_CLAR=ON -DBUILD_EXAMPLES=OFF -DDEBUG_POOL=ON -DCMAKE_BUILD_TYPE=Debug"
 
 install:
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then ./script/install-deps-${TRAVIS_OS_NAME}.sh; fi
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b65e498f1..34c5d8424 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,19 @@
-v0.24 + 1
+v0.25 + 1
+-------
+
+### Changes or improvements
+
+* `GIT_MERGE_OPTIONS_INIT` now includes a setting to perform rename detection.
+  This aligns this structure with the default by `git_merge` and
+  `git_merge_trees` when `NULL` was provided for the options.
+
+### API additions
+
+### API removals
+
+### Breaking API changes
+
+v0.25
 -------
 
 ### Changes or improvements
@@ -17,14 +32,37 @@ v0.24 + 1
 
 * Improve the performance of the revwalk and bring us closer to git's code.
 
+* The reference db has improved support for concurrency and returns `GIT_ELOCKED`
+  when an operation could not be performed due to locking.
+
+* Nanosecond resolution is now activated by default, following git's change to
+  do this.
+
+* We now restrict the set of ciphers we let OpenSSL use by default.
+
+* Users can now register their own merge drivers for use with `.gitattributes`.
+  The library also gained built-in support for the union merge driver.
+
+* The default for creating references is now to validate that the object does
+  exist.
+
+* Add `git_proxy_options` which is used by the different networking
+  implementations to let the caller specify the proxy settings instead of
+  relying on the environment variables.
+
 ### API additions
 
 * You can now get the user-agent used by libgit2 using the
   `GIT_OPT_GET_USER_AGENT` option with `git_libgit2_opts()`.
   It is the counterpart to `GIT_OPT_SET_USER_AGENT`.
 
+* The `GIT_OPT_SET_SSL_CIPHERS` option for `git_libgit2_opts()` lets you specify
+  a custom list of ciphers to use for OpenSSL.
+
 * `git_commit_create_buffer()` creates a commit and writes it into a
-  user-provided buffer instead of writing it into the object db.
+  user-provided buffer instead of writing it into the object db. Combine it with
+  `git_commit_create_with_signature()` in order to create a commit with a
+  cryptographic signature.
 
 * `git_blob_create_fromstream()` and
   `git_blob_create_fromstream_commit()` allow you to create a blob by
@@ -50,12 +88,48 @@ v0.24 + 1
       `git_repository_open_ext` with this flag will error out if either
       `$GIT_WORK_TREE` or `$GIT_COMMON_DIR` is set.
 
-* `git_diff_from_buffer` can create a `git_diff` object from the contents
+* `git_diff_from_buffer()` can create a `git_diff` object from the contents
   of a git-style patch file.
 
 * `git_index_version()` and `git_index_set_version()` to get and set
   the index version
 
+* `git_odb_expand_ids()` lets you check for the existence of multiple
+  objects at once.
+
+* The new `git_blob_dup()`, `git_commit_dup()`, `git_tag_dup()` and
+  `git_tree_dup()` functions provide type-specific wrappers for
+  `git_object_dup()` to reduce noise and increase type safety for callers.
+
+* `git_reference_dup()` lets you duplicate a reference to aid in ownership
+  management and cleanup.
+
+* `git_signature_from_buffer()` lets you create a signature from a string in the
+  format that appear in objects.
+
+* `git_tree_create_updated()` lets you create a tree based on another one
+  together with a list of updates. For the covered update cases, it's more
+  efficient than the `git_index` route.
+
+* `git_apply_patch()` applies hunks from a `git_patch` to a buffer.
+
+* `git_diff_to_buf()` lets you print an entire diff directory to a buffer,
+  similar to how `git_patch_to_buf()` works.
+
+* `git_proxy_init_options()` is added to initialize a `git_proxy_options`
+  structure at run-time.
+
+* `git_merge_driver_register()`, `git_merge_driver_unregister()` let you
+  register and unregister a custom merge driver to be used when `.gitattributes`
+  specifies it.
+
+* `git_merge_driver_lookup()` can be used to look up a merge driver by name.
+
+* `git_merge_driver_source_repo()`, `git_merge_driver_source_ancestor()`,
+  `git_merge_driver_source_ours()`, `git_merge_driver_source_theirs()`,
+  `git_merge_driver_source_file_options()` added as accessors to
+  `git_merge_driver_source`.
+
 ### API removals
 
 * `git_blob_create_fromchunks()` has been removed in favour of
@@ -84,6 +158,13 @@ v0.24 + 1
   If this is `NULL`, then it will not be called and the `exists` function
   will be used instead.
 
+* `git_remote_connect()` now accepts `git_proxy_options` argument, and
+  `git_fetch_options` and `git_push_options` each have a `proxy_opts` field.
+
+* `git_merge_options` now provides a `default_driver` that can be used
+  to provide the name of a merge driver to be used to handle files changed
+  during a merge.
+
 v0.24
 -------
 
@@ -159,10 +240,6 @@ v0.24
 
 ### Breaking API changes
 
-* `git_merge_options` now provides a `default_driver` that can be used
-  to provide the name of a merge driver to be used to handle files changed
-  during a merge.
-
 * The `git_merge_tree_flag_t` is now `git_merge_flag_t`.  Subsequently,
   its members are no longer prefixed with `GIT_MERGE_TREE_FLAG` but are
   now prefixed with `GIT_MERGE_FLAG`, and the `tree_flags` field of the
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f26f46879..4bfd1b499 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -237,8 +237,6 @@ ENDIF()
 
 IF (WIN32 AND WINHTTP)
 	ADD_DEFINITIONS(-DGIT_WINHTTP)
-	INCLUDE_DIRECTORIES(deps/http-parser)
-	FILE(GLOB SRC_HTTP deps/http-parser/*.c deps/http-parser/*.h)
 
 	# Since MinGW does not come with headers or an import library for winhttp,
 	# we have to include a private header and generate our own import library
@@ -291,17 +289,6 @@ ELSE ()
 		LINK_LIBRARIES(${CURL_LIBRARIES})
 		LIST(APPEND LIBGIT2_PC_LIBS ${CURL_LDFLAGS})
 	ENDIF()
-
-	FIND_PACKAGE(HTTP_Parser)
-	IF (HTTP_PARSER_FOUND AND HTTP_PARSER_VERSION_MAJOR EQUAL 2)
-		INCLUDE_DIRECTORIES(${HTTP_PARSER_INCLUDE_DIRS})
-		LINK_LIBRARIES(${HTTP_PARSER_LIBRARIES})
-		LIST(APPEND LIBGIT2_PC_LIBS "-lhttp_parser")
-	ELSE()
-		MESSAGE(STATUS "http-parser was not found or is too old; using bundled 3rd-party sources.")
-		INCLUDE_DIRECTORIES(deps/http-parser)
-		FILE(GLOB SRC_HTTP deps/http-parser/*.c deps/http-parser/*.h)
-	ENDIF()
 ENDIF()
 
 # Specify sha1 implementation
@@ -332,6 +319,18 @@ IF(WIN32 OR AMIGA OR CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
 	SET(SRC_REGEX deps/regex/regex.c)
 ENDIF()
 
+# Optional external dependency: http-parser
+FIND_PACKAGE(HTTP_Parser)
+IF (HTTP_PARSER_FOUND AND HTTP_PARSER_VERSION_MAJOR EQUAL 2)
+	INCLUDE_DIRECTORIES(${HTTP_PARSER_INCLUDE_DIRS})
+	LINK_LIBRARIES(${HTTP_PARSER_LIBRARIES})
+	LIST(APPEND LIBGIT2_PC_LIBS "-lhttp_parser")
+ELSE()
+	MESSAGE(STATUS "http-parser version 2 was not found; using bundled 3rd-party sources.")
+	INCLUDE_DIRECTORIES(deps/http-parser)
+	FILE(GLOB SRC_HTTP deps/http-parser/*.c deps/http-parser/*.h)
+ENDIF()
+
 # Optional external dependency: zlib
 FIND_PACKAGE(ZLIB)
 IF (ZLIB_FOUND)
diff --git a/PROJECTS.md b/PROJECTS.md
index 87ce78f02..f53a2e120 100644
--- a/PROJECTS.md
+++ b/PROJECTS.md
@@ -5,7 +5,7 @@ So, you want to start helping out with `libgit2`? That's fantastic! We
 welcome contributions and we promise we'll try to be nice.
 
 This is a list of libgit2 related projects that new contributors can take
-on.  It includes a number of good starter projects and well as some larger
+on.  It includes a number of good starter projects as well as some larger
 ideas that no one is actively working on.
 
 ## Before You Start
@@ -70,11 +70,11 @@ some incremental steps listed towards the larger goal.  Those steps
 might make good smaller projects by themselves.
 
 * Port part of the Git test suite to run against the command line emulation
-  in examples/
-    * Pick a Git command that is emulated in our examples/ area
+  in `examples/`
+    * Pick a Git command that is emulated in our `examples/` area
     * Extract the Git tests that exercise that command
     * Convert the tests to call our emulation
-    * These tests could go in examples/tests/...
+    * These tests could go in `examples/tests/`...
 * Add hooks API to enumerate and manage hooks (not run them at this point)
     * Enumeration of available hooks
     * Lookup API to see which hooks have a script and get the script
diff --git a/README.md b/README.md
index e656a460c..19d24dea1 100644
--- a/README.md
+++ b/README.md
@@ -43,9 +43,17 @@ We ask that you not open a GitHub Issue for help, only for bug reports.
 What It Can Do
 ==============
 
-`libgit2` is already very usable and is being used in production for many
-applications including the GitHub.com site, in Plastic SCM and also powering
-Microsoft's Visual Studio tools for Git.  The library provides:
+The goal of this library is to allow its users the ability to handle Git data in
+their applications from their programming language of choice, as is used in
+production for many applications including the GitHub.com site, in Plastic SCM
+and also powering Microsoft's Visual Studio tools for Git.
+
+It does not aim to replace the git tool or its user-facing commands. Some APIs
+resemble the plumbing commands as those align closely with the concepts of the
+Git system, but most commands a user would type are out of scope for this
+library to implement directly.
+
+The library provides:
 
 * SHA conversions, formatting and shortening
 * abstracted ODB backend system
@@ -236,7 +244,7 @@ Here are the bindings to libgit2 that are currently available:
 * Rust
     * git2-rs <https://github.com/alexcrichton/git2-rs>
 * Swift
-    * Gift <https://github.com/modocache/Gift>
+    * SwiftGit2 <https://github.com/SwiftGit2/SwiftGit2>
 * Vala
     * libgit2.vapi <https://github.com/apmasell/vapis/blob/master/libgit2.vapi>
 
diff --git a/THREADING.md b/THREADING.md
index 0b9e50286..430bca858 100644
--- a/THREADING.md
+++ b/THREADING.md
@@ -62,33 +62,38 @@ general case still affects you if you use ssh.
 General Case
 ------------
 
-By default we use libcurl, which has its own ![recommendations for
-thread safety](http://curl.haxx.se/libcurl/c/libcurl-tutorial.html#Multi-threading).
-
-If libcurl was not found or was disabled, libgit2 uses OpenSSL to be
-able to use HTTPS as a transport. This library is made to be
-thread-implementation agnostic, and the users of the library must set
-which locking function it should use. This means that libgit2 cannot
-know what to set as the user of libgit2 may use OpenSSL independently
-and the locking settings must survive libgit2 shutting down.
-
-Even if libgit2 doesn't use OpenSSL directly, OpenSSL can still be used
-by libssh2 depending on the configuration.  If OpenSSL is used both by
-libgit2 and libssh2, you only need to set up threading for OpenSSL once.
-
-libgit2 does provide a last-resort convenience function
+If it's available, by default we use libcurl to provide HTTP tunneling support,
+which may be linked against a number of cryptographic libraries and has its
+own
+[recommendations for thread safety](https://curl.haxx.se/libcurl/c/threadsafe.html).
+
+If there are no alternative TLS implementations (currently only
+SecureTransport), libgit2 uses OpenSSL in order to use HTTPS as a transport.
+OpenSSL is thread-safe starting at version 1.1.0. If your copy of libgit2 is
+linked against that version, you do not need to take any further steps.
+
+Older versions of OpenSSL are made to be thread-implementation agnostic, and the
+users of the library must set which locking function it should use. libgit2
+cannot know what to set as the user of libgit2 may also be using OpenSSL independently and
+the locking settings must then live outside the lifetime of libgit2.
+
+Even if libgit2 doesn't use OpenSSL directly, OpenSSL can still be used by
+libssh2 or libcurl depending on the configuration. If OpenSSL is used by
+more than one library, you only need to set up threading for OpenSSL once.
+
+If libgit2 is linked against OpenSSL, it provides a last-resort convenience function
 `git_openssl_set_locking()` (available in `sys/openssl.h`) to use the
-platform-native mutex mechanisms to perform the locking, which you may
-rely on if you do not want to use OpenSSL outside of libgit2, or you
-know that libgit2 will outlive the rest of the operations. It is not
+platform-native mutex mechanisms to perform the locking, which you can use
+if you do not want to use OpenSSL outside of libgit2, or you
+know that libgit2 will outlive the rest of the operations. It is then not
 safe to use OpenSSL multi-threaded after libgit2's shutdown function
 has been called.  Note `git_openssl_set_locking()` only works if
 libgit2 uses OpenSSL directly - if OpenSSL is only used as a dependency
-of libssh2 as described above, `git_openssl_set_locking()` is a no-op.
+of libssh2 or libcurl as described above, `git_openssl_set_locking()` is a no-op.
 
 If your programming language offers a package/bindings for OpenSSL,
 you should very strongly prefer to use that in order to set up
-locking, as they provide a level of coördination which is impossible
+locking, as they provide a level of coordination which is impossible
 when using this function.
 
 See the
@@ -96,13 +101,10 @@ See the
 on threading for more details, and http://trac.libssh2.org/wiki/MultiThreading
 for a specific example of providing the threading callbacks.
 
-Be also aware that libgit2 does not always link against OpenSSL
-if there are alternatives provided by the system.
-
 libssh2 may be linked against OpenSSL or libgcrypt. If it uses OpenSSL,
 see the above paragraphs. If it uses libgcrypt, then you need to
 set up its locking before using it multi-threaded. libgit2 has no
-direct connection to libgcrypt and thus has not convenience functions for
+direct connection to libgcrypt and thus has no convenience functions for
 it (but libgcrypt has macros). Read libgcrypt's
 [threading documentation for more information](http://www.gnupg.org/documentation/manuals/gcrypt/Multi_002dThreading.html)
 
diff --git a/examples/add.c b/examples/add.c
index 0101ab9ae..e5849892e 100644
--- a/examples/add.c
+++ b/examples/add.c
@@ -75,15 +75,14 @@ int print_matched_cb(const char *path, const char *matched_pathspec, void *paylo
 {
 	struct print_payload p = *(struct print_payload*)(payload);
 	int ret;
-	git_status_t status;
+	unsigned status;
 	(void)matched_pathspec;
 
-	if (git_status_file((unsigned int*)(&status), p.repo, path)) {
-		return -1; //abort
+	if (git_status_file(&status, p.repo, path)) {
+		return -1;
 	}
 
-	if (status & GIT_STATUS_WT_MODIFIED ||
-	         status & GIT_STATUS_WT_NEW) {
+	if (status & GIT_STATUS_WT_MODIFIED || status & GIT_STATUS_WT_NEW) {
 		printf("add '%s'\n", path);
 		ret = 0;
 	} else {
diff --git a/examples/common.c b/examples/common.c
index 0f25f3787..96f5eaa8e 100644
--- a/examples/common.c
+++ b/examples/common.c
@@ -146,6 +146,25 @@ int match_uint16_arg(
 	return 1;
 }
 
+int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint32_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
 static int match_int_internal(
 	int *out, const char *str, int allow_negative, const char *opt)
 {
diff --git a/examples/common.h b/examples/common.h
index b9fa37ce9..adea0d318 100644
--- a/examples/common.h
+++ b/examples/common.h
@@ -73,6 +73,15 @@ extern int match_uint16_arg(
 	uint16_t *out, struct args_info *args, const char *opt);
 
 /**
+ * Check current `args` entry against `opt` string parsing as uint32.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint32_t value; otherwise return 0.
+ */
+extern int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt);
+
+/**
  * Check current `args` entry against `opt` string parsing as int.  If
  * `opt` matches exactly, take the next arg as an int value; if it matches
  * as a prefix (equal sign optional), take the remainder of the arg as a
diff --git a/examples/diff.c b/examples/diff.c
index b69cb2218..9a4f7a59f 100644
--- a/examples/diff.c
+++ b/examples/diff.c
@@ -293,11 +293,11 @@ static void parse_opts(struct opts *o, int argc, char *argv[])
 		else if (is_prefixed(a, "-B") || is_prefixed(a, "--break-rewrites"))
 			/* TODO: parse thresholds */
 			o->findopts.flags |= GIT_DIFF_FIND_REWRITES;
-		else if (!match_uint16_arg(
+		else if (!match_uint32_arg(
 				&o->diffopts.context_lines, &args, "-U") &&
-			!match_uint16_arg(
+			!match_uint32_arg(
 				&o->diffopts.context_lines, &args, "--unified") &&
-			!match_uint16_arg(
+			!match_uint32_arg(
 				&o->diffopts.interhunk_lines, &args, "--inter-hunk-context") &&
 			!match_uint16_arg(
 				&o->diffopts.id_abbrev, &args, "--abbrev") &&
diff --git a/examples/general.c b/examples/general.c
index 32fdaf407..cc0cf1b42 100644
--- a/examples/general.c
+++ b/examples/general.c
@@ -12,39 +12,58 @@
  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
 
-// [**libgit2**][lg] is a portable, pure C implementation of the Git core
-// methods provided as a re-entrant linkable library with a solid API,
-// allowing you to write native speed custom Git applications in any
-// language which supports C bindings.
-//
-// This file is an example of using that API in a real, compilable C file.
-// As the API is updated, this file will be updated to demonstrate the new
-// functionality.
-//
-// If you're trying to write something in C using [libgit2][lg], you should
-// also check out the generated [API documentation][ap]. We try to link to
-// the relevant sections of the API docs in each section in this file.
-//
-// **libgit2** (for the most part) only implements the core plumbing
-// functions, not really the higher level porcelain stuff. For a primer on
-// Git Internals that you will need to know to work with Git at this level,
-// check out [Chapter 10][pg] of the Pro Git book.
-//
-// [lg]: http://libgit2.github.com
-// [ap]: http://libgit2.github.com/libgit2
-// [pg]: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain
-
-// ### Includes
-
-// Including the `git2.h` header will include all the other libgit2 headers
-// that you need.  It should be the only thing you need to include in order
-// to compile properly and get all the libgit2 API.
+/**
+ * [**libgit2**][lg] is a portable, pure C implementation of the Git core
+ * methods provided as a re-entrant linkable library with a solid API,
+ * allowing you to write native speed custom Git applications in any
+ * language which supports C bindings.
+ *
+ * This file is an example of using that API in a real, compilable C file.
+ * As the API is updated, this file will be updated to demonstrate the new
+ * functionality.
+ *
+ * If you're trying to write something in C using [libgit2][lg], you should
+ * also check out the generated [API documentation][ap]. We try to link to
+ * the relevant sections of the API docs in each section in this file.
+ *
+ * **libgit2** (for the most part) only implements the core plumbing
+ * functions, not really the higher level porcelain stuff. For a primer on
+ * Git Internals that you will need to know to work with Git at this level,
+ * check out [Chapter 10][pg] of the Pro Git book.
+ *
+ * [lg]: http://libgit2.github.com
+ * [ap]: http://libgit2.github.com/libgit2
+ * [pg]: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain
+ */
+
+/**
+ * ### Includes
+ *
+ * Including the `git2.h` header will include all the other libgit2 headers
+ * that you need.  It should be the only thing you need to include in order
+ * to compile properly and get all the libgit2 API.
+ */
 #include <git2.h>
 #include <stdio.h>
-
-// Almost all libgit2 functions return 0 on success or negative on error.
-// This is not production quality error checking, but should be sufficient
-// as an example.
+#include <string.h>
+
+static void oid_parsing(git_oid *out);
+static void object_database(git_repository *repo, git_oid *oid);
+static void commit_writing(git_repository *repo);
+static void commit_parsing(git_repository *repo);
+static void tag_parsing(git_repository *repo);
+static void tree_parsing(git_repository *repo);
+static void blob_parsing(git_repository *repo);
+static void revwalking(git_repository *repo);
+static void index_walking(git_repository *repo);
+static void reference_listing(git_repository *repo);
+static void config_files(const char *repo_path, git_repository *repo);
+
+/**
+ * Almost all libgit2 functions return 0 on success or negative on error.
+ * This is not production quality error checking, but should be sufficient
+ * as an example.
+ */
 static void check_error(int error_code, const char *action)
 {
 	const git_error *error = giterr_last();
@@ -52,479 +71,647 @@ static void check_error(int error_code, const char *action)
 		return;
 
 	printf("Error %d %s - %s\n", error_code, action,
-		   (error && error->message) ? error->message : "???");
+			(error && error->message) ? error->message : "???");
 
 	exit(1);
 }
 
 int main (int argc, char** argv)
 {
-  // Initialize the library, this will set up any global state which libgit2 needs
-  // including threading and crypto
-  git_libgit2_init();
-
-  // ### Opening the Repository
-
-  // There are a couple of methods for opening a repository, this being the
-  // simplest.  There are also [methods][me] for specifying the index file
-  // and work tree locations, here we assume they are in the normal places.
-	//
-	// (Try running this program against tests/resources/testrepo.git.)
-  //
-  // [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository
-  int error;
-  const char *repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
-  git_repository *repo;
-
-  error = git_repository_open(&repo, repo_path);
-  check_error(error, "opening repository");
-
-  // ### SHA-1 Value Conversions
-
-  // For our first example, we will convert a 40 character hex value to the
-  // 20 byte raw SHA1 value.
-  printf("*Hex to Raw*\n");
-  char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
-
-  // The `git_oid` is the structure that keeps the SHA value. We will use
-  // this throughout the example for storing the value of the current SHA
-  // key we're working with.
-  git_oid oid;
-  git_oid_fromstr(&oid, hex);
-
-  // Once we've converted the string into the oid value, we can get the raw
-  // value of the SHA by accessing `oid.id`
-
-  // Next we will convert the 20 byte raw SHA1 value to a human readable 40
-  // char hex value.
-  printf("\n*Raw to Hex*\n");
-  char out[GIT_OID_HEXSZ+1];
-  out[GIT_OID_HEXSZ] = '\0';
-
-  // If you have a oid, you can easily get the hex value of the SHA as well.
-  git_oid_fmt(out, &oid);
-  printf("SHA hex string: %s\n", out);
-
-  // ### Working with the Object Database
-
-  // **libgit2** provides [direct access][odb] to the object database.  The
-  // object database is where the actual objects are stored in Git. For
-  // working with raw objects, we'll need to get this structure from the
-  // repository.
-  //
-  // [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb
-  git_odb *odb;
-  git_repository_odb(&odb, repo);
-
-  // #### Raw Object Reading
-
-  printf("\n*Raw Object Read*\n");
-  git_odb_object *obj;
-  git_otype otype;
-  const unsigned char *data;
-  const char *str_type;
-
-  // We can read raw objects directly from the object database if we have
-  // the oid (SHA) of the object.  This allows us to access objects without
-  // knowing their type and inspect the raw bytes unparsed.
-  error = git_odb_read(&obj, odb, &oid);
-  check_error(error, "finding object in repository");
-
-  // A raw object only has three properties - the type (commit, blob, tree
-  // or tag), the size of the raw data and the raw, unparsed data itself.
-  // For a commit or tag, that raw data is human readable plain ASCII
-  // text. For a blob it is just file contents, so it could be text or
-  // binary data. For a tree it is a special binary format, so it's unlikely
-  // to be hugely helpful as a raw object.
-  data = (const unsigned char *)git_odb_object_data(obj);
-  otype = git_odb_object_type(obj);
-
-  // We provide methods to convert from the object type which is an enum, to
-  // a string representation of that value (and vice-versa).
-  str_type = git_object_type2string(otype);
-  printf("object length and type: %d, %s\n",
-      (int)git_odb_object_size(obj),
-      str_type);
-
-  // For proper memory management, close the object when you are done with
-  // it or it will leak memory.
-  git_odb_object_free(obj);
-
-  // #### Raw Object Writing
-
-  printf("\n*Raw Object Write*\n");
-
-  // You can also write raw object data to Git. This is pretty cool because
-  // it gives you direct access to the key/value properties of Git.  Here
-  // we'll write a new blob object that just contains a simple string.
-  // Notice that we have to specify the object type as the `git_otype` enum.
-  git_odb_write(&oid, odb, "test data", sizeof("test data") - 1, GIT_OBJ_BLOB);
-
-  // Now that we've written the object, we can check out what SHA1 was
-  // generated when the object was written to our database.
-  git_oid_fmt(out, &oid);
-  printf("Written Object: %s\n", out);
-
-  // ### Object Parsing
-
-  // libgit2 has methods to parse every object type in Git so you don't have
-  // to work directly with the raw data. This is much faster and simpler
-  // than trying to deal with the raw data yourself.
-
-  // #### Commit Parsing
-
-  // [Parsing commit objects][pco] is simple and gives you access to all the
-  // data in the commit - the author (name, email, datetime), committer
-  // (same), tree, message, encoding and parent(s).
-  //
-  // [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit
-
-  printf("\n*Commit Parsing*\n");
-
-  git_commit *commit;
-  git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
-
-  error = git_commit_lookup(&commit, repo, &oid);
-  check_error(error, "looking up commit");
-
-  const git_signature *author, *cmtter;
-  const char *message;
-  time_t ctime;
-  unsigned int parents, p;
-
-  // Each of the properties of the commit object are accessible via methods,
-  // including commonly needed variations, such as `git_commit_time` which
-  // returns the author time and `git_commit_message` which gives you the
-  // commit message (as a NUL-terminated string).
-  message  = git_commit_message(commit);
-  author   = git_commit_author(commit);
-  cmtter   = git_commit_committer(commit);
-  ctime    = git_commit_time(commit);
-
-  // The author and committer methods return [git_signature] structures,
-  // which give you name, email and `when`, which is a `git_time` structure,
-  // giving you a timestamp and timezone offset.
-  printf("Author: %s (%s)\n", author->name, author->email);
-
-  // Commits can have zero or more parents. The first (root) commit will
-  // have no parents, most commits will have one (i.e. the commit it was
-  // based on) and merge commits will have two or more.  Commits can
-  // technically have any number, though it's rare to have more than two.
-  parents  = git_commit_parentcount(commit);
-  for (p = 0;p < parents;p++) {
-    git_commit *parent;
-    git_commit_parent(&parent, commit, p);
-    git_oid_fmt(out, git_commit_id(parent));
-    printf("Parent: %s\n", out);
-    git_commit_free(parent);
-  }
-
-  // Don't forget to close the object to prevent memory leaks. You will have
-  // to do this for all the objects you open and parse.
-  git_commit_free(commit);
-
-  // #### Writing Commits
-
-  // libgit2 provides a couple of methods to create commit objects easily as
-  // well. There are four different create signatures, we'll just show one
-  // of them here.  You can read about the other ones in the [commit API
-  // docs][cd].
-  //
-  // [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit
-
-  printf("\n*Commit Writing*\n");
-  git_oid tree_id, parent_id, commit_id;
-  git_tree *tree;
-  git_commit *parent;
-
-  // Creating signatures for an authoring identity and time is simple.  You
-  // will need to do this to specify who created a commit and when.  Default
-  // values for the name and email should be found in the `user.name` and
-  // `user.email` configuration options.  See the `config` section of this
-  // example file to see how to access config values.
-  git_signature_new((git_signature **)&author,
-      "Scott Chacon", "schacon@gmail.com", 123456789, 60);
-  git_signature_new((git_signature **)&cmtter,
-      "Scott A Chacon", "scott@github.com", 987654321, 90);
-
-  // Commit objects need a tree to point to and optionally one or more
-  // parents.  Here we're creating oid objects to create the commit with,
-  // but you can also use
-  git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
-  git_tree_lookup(&tree, repo, &tree_id);
-  git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
-  git_commit_lookup(&parent, repo, &parent_id);
-
-  // Here we actually create the commit object with a single call with all
-  // the values we need to create the commit.  The SHA key is written to the
-  // `commit_id` variable here.
-  git_commit_create_v(
-    &commit_id, /* out id */
-    repo,
-    NULL, /* do not update the HEAD */
-    author,
-    cmtter,
-    NULL, /* use default message encoding */
-    "example commit",
-    tree,
-    1, parent);
-
-  // Now we can take a look at the commit SHA we've generated.
-  git_oid_fmt(out, &commit_id);
-  printf("New Commit: %s\n", out);
-
-  // #### Tag Parsing
-
-  // You can parse and create tags with the [tag management API][tm], which
-  // functions very similarly to the commit lookup, parsing and creation
-  // methods, since the objects themselves are very similar.
-  //
-  // [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag
-  printf("\n*Tag Parsing*\n");
-  git_tag *tag;
-  const char *tmessage, *tname;
-  git_otype ttype;
-
-  // We create an oid for the tag object if we know the SHA and look it up
-  // the same way that we would a commit (or any other object).
-  git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
-
-  error = git_tag_lookup(&tag, repo, &oid);
-  check_error(error, "looking up tag");
-
-  // Now that we have the tag object, we can extract the information it
-  // generally contains: the target (usually a commit object), the type of
-  // the target object (usually 'commit'), the name ('v1.0'), the tagger (a
-  // git_signature - name, email, timestamp), and the tag message.
-  git_tag_target((git_object **)&commit, tag);
-  tname = git_tag_name(tag);		// "test"
-  ttype = git_tag_target_type(tag);	// GIT_OBJ_COMMIT (otype enum)
-  tmessage = git_tag_message(tag);	// "tag message\n"
-  printf("Tag Message: %s\n", tmessage);
-
-  git_commit_free(commit);
-
-  // #### Tree Parsing
-
-  // [Tree parsing][tp] is a bit different than the other objects, in that
-  // we have a subtype which is the tree entry.  This is not an actual
-  // object type in Git, but a useful structure for parsing and traversing
-  // tree entries.
-  //
-  // [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree
-  printf("\n*Tree Parsing*\n");
-
-  const git_tree_entry *entry;
-  git_object *objt;
-
-  // Create the oid and lookup the tree object just like the other objects.
-  git_oid_fromstr(&oid, "2a741c18ac5ff082a7caaec6e74db3075a1906b5");
-  git_tree_lookup(&tree, repo, &oid);
-
-  // Getting the count of entries in the tree so you can iterate over them
-  // if you want to.
-  size_t cnt = git_tree_entrycount(tree); // 3
-  printf("tree entries: %d\n", (int)cnt);
-
-  entry = git_tree_entry_byindex(tree, 0);
-  printf("Entry name: %s\n", git_tree_entry_name(entry)); // "hello.c"
-
-  // You can also access tree entries by name if you know the name of the
-  // entry you're looking for.
-  entry = git_tree_entry_byname(tree, "README");
-  git_tree_entry_name(entry); // "hello.c"
-
-  // Once you have the entry object, you can access the content or subtree
-  // (or commit, in the case of submodules) that it points to.  You can also
-  // get the mode if you want.
-  git_tree_entry_to_object(&objt, repo, entry); // blob
-
-  // Remember to close the looked-up object once you are done using it
-  git_object_free(objt);
-
-  // #### Blob Parsing
-
-  // The last object type is the simplest and requires the least parsing
-  // help. Blobs are just file contents and can contain anything, there is
-  // no structure to it. The main advantage to using the [simple blob
-  // api][ba] is that when you're creating blobs you don't have to calculate
-  // the size of the content.  There is also a helper for reading a file
-  // from disk and writing it to the db and getting the oid back so you
-  // don't have to do all those steps yourself.
-  //
-  // [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob
-
-  printf("\n*Blob Parsing*\n");
-  git_blob *blob;
-
-  git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
-  git_blob_lookup(&blob, repo, &oid);
-
-  // You can access a buffer with the raw contents of the blob directly.
-  // Note that this buffer may not be contain ASCII data for certain blobs
-  // (e.g. binary files): do not consider the buffer a NULL-terminated
-  // string, and use the `git_blob_rawsize` attribute to find out its exact
-  // size in bytes
-  printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); // 8
-  git_blob_rawcontent(blob); // "content"
-
-  // ### Revwalking
-
-  // The libgit2 [revision walking api][rw] provides methods to traverse the
-  // directed graph created by the parent pointers of the commit objects.
-  // Since all commits point back to the commit that came directly before
-  // them, you can walk this parentage as a graph and find all the commits
-  // that were ancestors of (reachable from) a given starting point.  This
-  // can allow you to create `git log` type functionality.
-  //
-  // [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk
-
-  printf("\n*Revwalking*\n");
-  git_revwalk *walk;
-  git_commit *wcommit;
-
-  git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
-
-  // To use the revwalker, create a new walker, tell it how you want to sort
-  // the output and then push one or more starting points onto the walker.
-  // If you want to emulate the output of `git log` you would push the SHA
-  // of the commit that HEAD points to into the walker and then start
-  // traversing them.  You can also 'hide' commits that you want to stop at
-  // or not see any of their ancestors.  So if you want to emulate `git log
-  // branch1..branch2`, you would push the oid of `branch2` and hide the oid
-  // of `branch1`.
-  git_revwalk_new(&walk, repo);
-  git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE);
-  git_revwalk_push(walk, &oid);
-
-  const git_signature *cauth;
-  const char *cmsg;
-
-  // Now that we have the starting point pushed onto the walker, we start
-  // asking for ancestors. It will return them in the sorting order we asked
-  // for as commit oids.  We can then lookup and parse the committed pointed
-  // at by the returned OID; note that this operation is specially fast
-  // since the raw contents of the commit object will be cached in memory
-  while ((git_revwalk_next(&oid, walk)) == 0) {
-    error = git_commit_lookup(&wcommit, repo, &oid);
-	check_error(error, "looking up commit during revwalk");
-
-    cmsg  = git_commit_message(wcommit);
-    cauth = git_commit_author(wcommit);
-    printf("%s (%s)\n", cmsg, cauth->email);
-
-    git_commit_free(wcommit);
-  }
-
-  // Like the other objects, be sure to free the revwalker when you're done
-  // to prevent memory leaks.  Also, make sure that the repository being
-  // walked it not deallocated while the walk is in progress, or it will
-  // result in undefined behavior
-  git_revwalk_free(walk);
-
-  // ### Index File Manipulation
-
-  // The [index file API][gi] allows you to read, traverse, update and write
-  // the Git index file (sometimes thought of as the staging area).
-  //
-  // [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index
-
-  printf("\n*Index Walking*\n");
-
-  git_index *index;
-  unsigned int i, ecount;
-
-  // You can either open the index from the standard location in an open
-  // repository, as we're doing here, or you can open and manipulate any
-  // index file with `git_index_open_bare()`. The index for the repository
-  // will be located and loaded from disk.
-  git_repository_index(&index, repo);
-
-  // For each entry in the index, you can get a bunch of information
-  // including the SHA (oid), path and mode which map to the tree objects
-  // that are written out.  It also has filesystem properties to help
-  // determine what to inspect for changes (ctime, mtime, dev, ino, uid,
-  // gid, file_size and flags) All these properties are exported publicly in
-  // the `git_index_entry` struct
-  ecount = git_index_entrycount(index);
-  for (i = 0; i < ecount; ++i) {
-    const git_index_entry *e = git_index_get_byindex(index, i);
-
-    printf("path: %s\n", e->path);
-    printf("mtime: %d\n", (int)e->mtime.seconds);
-    printf("fs: %d\n", (int)e->file_size);
-  }
-
-  git_index_free(index);
-
-  // ### References
-
-  // The [reference API][ref] allows you to list, resolve, create and update
-  // references such as branches, tags and remote references (everything in
-  // the .git/refs directory).
-  //
-  // [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference
-
-  printf("\n*Reference Listing*\n");
-
-  // Here we will implement something like `git for-each-ref` simply listing
-  // out all available references and the object SHA they resolve to.
-  git_strarray ref_list;
-  git_reference_list(&ref_list, repo);
-
-  const char *refname;
-  git_reference *ref;
-
-  // Now that we have the list of reference names, we can lookup each ref
-  // one at a time and resolve them to the SHA, then print both values out.
-  for (i = 0; i < ref_list.count; ++i) {
-    refname = ref_list.strings[i];
-    git_reference_lookup(&ref, repo, refname);
-
-    switch (git_reference_type(ref)) {
-    case GIT_REF_OID:
-      git_oid_fmt(out, git_reference_target(ref));
-      printf("%s [%s]\n", refname, out);
-      break;
-
-    case GIT_REF_SYMBOLIC:
-      printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
-      break;
-    default:
-      fprintf(stderr, "Unexpected reference type\n");
-      exit(1);
-    }
-  }
-
-  git_strarray_free(&ref_list);
-
-  // ### Config Files
-
-  // The [config API][config] allows you to list and updatee config values
-  // in any of the accessible config file locations (system, global, local).
-  //
-  // [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
+	int error;
+	git_oid oid;
+	char *repo_path;
+	git_repository *repo;
+
+	/**
+	 * Initialize the library, this will set up any global state which libgit2 needs
+	 * including threading and crypto
+	 */
+	git_libgit2_init();
+
+	/**
+	 * ### Opening the Repository
+	 *
+	 * There are a couple of methods for opening a repository, this being the
+	 * simplest.  There are also [methods][me] for specifying the index file
+	 * and work tree locations, here we assume they are in the normal places.
+	 *
+	 * (Try running this program against tests/resources/testrepo.git.)
+	 *
+	 * [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository
+	 */
+	repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
+
+	error = git_repository_open(&repo, repo_path);
+	check_error(error, "opening repository");
+
+	oid_parsing(&oid);
+	object_database(repo, &oid);
+	commit_writing(repo);
+	commit_parsing(repo);
+	tag_parsing(repo);
+	tree_parsing(repo);
+	blob_parsing(repo);
+	revwalking(repo);
+	index_walking(repo);
+	reference_listing(repo);
+	config_files(repo_path, repo);
+
+	/**
+	 * Finally, when you're done with the repository, you can free it as well.
+	 */
+	git_repository_free(repo);
+
+	return 0;
+}
+
+/**
+ * ### SHA-1 Value Conversions
+ */
+static void oid_parsing(git_oid *oid)
+{
+	char out[GIT_OID_HEXSZ+1];
+	char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
+
+	printf("*Hex to Raw*\n");
+
+	/**
+	 * For our first example, we will convert a 40 character hex value to the
+	 * 20 byte raw SHA1 value.
+	 *
+	 * The `git_oid` is the structure that keeps the SHA value. We will use
+	 * this throughout the example for storing the value of the current SHA
+	 * key we're working with.
+	 */
+	git_oid_fromstr(oid, hex);
+
+	// Once we've converted the string into the oid value, we can get the raw
+	// value of the SHA by accessing `oid.id`
+
+	// Next we will convert the 20 byte raw SHA1 value to a human readable 40
+	// char hex value.
+	printf("\n*Raw to Hex*\n");
+	out[GIT_OID_HEXSZ] = '\0';
+
+	/**
+	 * If you have a oid, you can easily get the hex value of the SHA as well.
+	 */
+	git_oid_fmt(out, oid);
+
+	/**
+	 * If you have a oid, you can easily get the hex value of the SHA as well.
+	 */
+	git_oid_fmt(out, oid);
+	printf("SHA hex string: %s\n", out);
+}
+
+/**
+ * ### Working with the Object Database
+ *
+ * **libgit2** provides [direct access][odb] to the object database.  The
+ * object database is where the actual objects are stored in Git. For
+ * working with raw objects, we'll need to get this structure from the
+ * repository.
+ *
+ * [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb
+ */
+static void object_database(git_repository *repo, git_oid *oid)
+{
+	char oid_hex[GIT_OID_HEXSZ+1] = { 0 };
+	const unsigned char *data;
+	const char *str_type;
+	int error;
+	git_odb_object *obj;
+	git_odb *odb;
+	git_otype otype;
+
+	git_repository_odb(&odb, repo);
+
+	/**
+	 * #### Raw Object Reading
+	 */
+
+	printf("\n*Raw Object Read*\n");
+
+	/**
+	 * We can read raw objects directly from the object database if we have
+	 * the oid (SHA) of the object.  This allows us to access objects without
+	 * knowing their type and inspect the raw bytes unparsed.
+	 */
+	error = git_odb_read(&obj, odb, oid);
+	check_error(error, "finding object in repository");
+
+	/**
+	 * A raw object only has three properties - the type (commit, blob, tree
+	 * or tag), the size of the raw data and the raw, unparsed data itself.
+	 * For a commit or tag, that raw data is human readable plain ASCII
+	 * text. For a blob it is just file contents, so it could be text or
+	 * binary data. For a tree it is a special binary format, so it's unlikely
+	 * to be hugely helpful as a raw object.
+	 */
+	data = (const unsigned char *)git_odb_object_data(obj);
+	otype = git_odb_object_type(obj);
+
+	/**
+	 * We provide methods to convert from the object type which is an enum, to
+	 * a string representation of that value (and vice-versa).
+	 */
+	str_type = git_object_type2string(otype);
+	printf("object length and type: %d, %s\nobject data: %s\n",
+			(int)git_odb_object_size(obj),
+			str_type, data);
+
+	/**
+	 * For proper memory management, close the object when you are done with
+	 * it or it will leak memory.
+	 */
+	git_odb_object_free(obj);
+
+	/**
+	 * #### Raw Object Writing
+	 */
+
+	printf("\n*Raw Object Write*\n");
+
+	/**
+	 * You can also write raw object data to Git. This is pretty cool because
+	 * it gives you direct access to the key/value properties of Git.  Here
+	 * we'll write a new blob object that just contains a simple string.
+	 * Notice that we have to specify the object type as the `git_otype` enum.
+	 */
+	git_odb_write(oid, odb, "test data", sizeof("test data") - 1, GIT_OBJ_BLOB);
+
+	/**
+	 * Now that we've written the object, we can check out what SHA1 was
+	 * generated when the object was written to our database.
+	 */
+	git_oid_fmt(oid_hex, oid);
+	printf("Written Object: %s\n", oid_hex);
+}
 
-  printf("\n*Config Listing*\n");
+/**
+ * #### Writing Commits
+ *
+ * libgit2 provides a couple of methods to create commit objects easily as
+ * well. There are four different create signatures, we'll just show one
+ * of them here.  You can read about the other ones in the [commit API
+ * docs][cd].
+ *
+ * [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_writing(git_repository *repo)
+{
+	git_oid tree_id, parent_id, commit_id;
+	git_tree *tree;
+	git_commit *parent;
+	const git_signature *author, *cmtter;
+	char oid_hex[GIT_OID_HEXSZ+1] = { 0 };
+
+	printf("\n*Commit Writing*\n");
+
+	/**
+	 * Creating signatures for an authoring identity and time is simple.  You
+	 * will need to do this to specify who created a commit and when.  Default
+	 * values for the name and email should be found in the `user.name` and
+	 * `user.email` configuration options.  See the `config` section of this
+	 * example file to see how to access config values.
+	 */
+	git_signature_new((git_signature **)&author,
+			"Scott Chacon", "schacon@gmail.com", 123456789, 60);
+	git_signature_new((git_signature **)&cmtter,
+			"Scott A Chacon", "scott@github.com", 987654321, 90);
+
+	/**
+	 * Commit objects need a tree to point to and optionally one or more
+	 * parents.  Here we're creating oid objects to create the commit with,
+	 * but you can also use
+	 */
+	git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_tree_lookup(&tree, repo, &tree_id);
+	git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+	git_commit_lookup(&parent, repo, &parent_id);
+
+	/**
+	 * Here we actually create the commit object with a single call with all
+	 * the values we need to create the commit.  The SHA key is written to the
+	 * `commit_id` variable here.
+	 */
+	git_commit_create_v(
+			&commit_id, /* out id */
+			repo,
+			NULL, /* do not update the HEAD */
+			author,
+			cmtter,
+			NULL, /* use default message encoding */
+			"example commit",
+			tree,
+			1, parent);
+
+	/**
+	 * Now we can take a look at the commit SHA we've generated.
+	 */
+	git_oid_fmt(oid_hex, &commit_id);
+	printf("New Commit: %s\n", oid_hex);
+}
+
+/**
+ * ### Object Parsing
+ *
+ * libgit2 has methods to parse every object type in Git so you don't have
+ * to work directly with the raw data. This is much faster and simpler
+ * than trying to deal with the raw data yourself.
+ */
+
+/**
+ * #### Commit Parsing
+ *
+ * [Parsing commit objects][pco] is simple and gives you access to all the
+ * data in the commit - the author (name, email, datetime), committer
+ * (same), tree, message, encoding and parent(s).
+ *
+ * [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_parsing(git_repository *repo)
+{
+	const git_signature *author, *cmtter;
+	git_commit *commit, *parent;
+	git_oid oid;
+	char oid_hex[GIT_OID_HEXSZ+1];
+	const char *message;
+	unsigned int parents, p;
+	int error;
+	time_t time;
+
+	printf("\n*Commit Parsing*\n");
+
+	git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
+
+	error = git_commit_lookup(&commit, repo, &oid);
+	check_error(error, "looking up commit");
+
+	/**
+	 * Each of the properties of the commit object are accessible via methods,
+	 * including commonly needed variations, such as `git_commit_time` which
+	 * returns the author time and `git_commit_message` which gives you the
+	 * commit message (as a NUL-terminated string).
+	 */
+	message  = git_commit_message(commit);
+	author   = git_commit_author(commit);
+	cmtter   = git_commit_committer(commit);
+	time    = git_commit_time(commit);
+
+	/**
+	 * The author and committer methods return [git_signature] structures,
+	 * which give you name, email and `when`, which is a `git_time` structure,
+	 * giving you a timestamp and timezone offset.
+	 */
+	printf("Author: %s (%s)\nCommitter: %s (%s)\nDate: %s\nMessage: %s\n",
+		author->name, author->email,
+		cmtter->name, cmtter->email,
+		ctime(&time), message);
+
+	/**
+	 * Commits can have zero or more parents. The first (root) commit will
+	 * have no parents, most commits will have one (i.e. the commit it was
+	 * based on) and merge commits will have two or more.  Commits can
+	 * technically have any number, though it's rare to have more than two.
+	 */
+	parents  = git_commit_parentcount(commit);
+	for (p = 0;p < parents;p++) {
+		memset(oid_hex, 0, sizeof(oid_hex));
+
+		git_commit_parent(&parent, commit, p);
+		git_oid_fmt(oid_hex, git_commit_id(parent));
+		printf("Parent: %s\n", oid_hex);
+		git_commit_free(parent);
+	}
+
+	git_commit_free(commit);
+}
 
-  const char *email;
-  int32_t j;
+/**
+ * #### Tag Parsing
+ *
+ * You can parse and create tags with the [tag management API][tm], which
+ * functions very similarly to the commit lookup, parsing and creation
+ * methods, since the objects themselves are very similar.
+ *
+ * [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag
+ */
+static void tag_parsing(git_repository *repo)
+{
+	git_commit *commit;
+	git_otype type;
+	git_tag *tag;
+	git_oid oid;
+	const char *name, *message;
+	int error;
+
+	printf("\n*Tag Parsing*\n");
+
+	/**
+	 * We create an oid for the tag object if we know the SHA and look it up
+	 * the same way that we would a commit (or any other object).
+	 */
+	git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
+
+	error = git_tag_lookup(&tag, repo, &oid);
+	check_error(error, "looking up tag");
+
+	/**
+	 * Now that we have the tag object, we can extract the information it
+	 * generally contains: the target (usually a commit object), the type of
+	 * the target object (usually 'commit'), the name ('v1.0'), the tagger (a
+	 * git_signature - name, email, timestamp), and the tag message.
+	 */
+	git_tag_target((git_object **)&commit, tag);
+	name = git_tag_name(tag);		/* "test" */
+	type = git_tag_target_type(tag);	/* GIT_OBJ_COMMIT (otype enum) */
+	message = git_tag_message(tag);		/* "tag message\n" */
+	printf("Tag Name: %s\nTag Type: %s\nTag Message: %s\n",
+		name, git_object_type2string(type), message);
+
+	git_commit_free(commit);
+}
 
-  git_config *cfg;
+/**
+ * #### Tree Parsing
+ *
+ * [Tree parsing][tp] is a bit different than the other objects, in that
+ * we have a subtype which is the tree entry.  This is not an actual
+ * object type in Git, but a useful structure for parsing and traversing
+ * tree entries.
+ *
+ * [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree
+ */
+static void tree_parsing(git_repository *repo)
+{
+	const git_tree_entry *entry;
+	size_t cnt;
+	git_object *obj;
+	git_tree *tree;
+	git_oid oid;
+
+	printf("\n*Tree Parsing*\n");
+
+	/**
+	 * Create the oid and lookup the tree object just like the other objects.
+	 */
+	git_oid_fromstr(&oid, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_tree_lookup(&tree, repo, &oid);
+
+	/**
+	 * Getting the count of entries in the tree so you can iterate over them
+	 * if you want to.
+	 */
+	cnt = git_tree_entrycount(tree); /* 2 */
+	printf("tree entries: %d\n", (int) cnt);
+
+	entry = git_tree_entry_byindex(tree, 0);
+	printf("Entry name: %s\n", git_tree_entry_name(entry)); /* "README" */
+
+	/**
+	 * You can also access tree entries by name if you know the name of the
+	 * entry you're looking for.
+	 */
+	entry = git_tree_entry_byname(tree, "README");
+	git_tree_entry_name(entry); /* "README" */
+
+	/**
+	 * Once you have the entry object, you can access the content or subtree
+	 * (or commit, in the case of submodules) that it points to.  You can also
+	 * get the mode if you want.
+	 */
+	git_tree_entry_to_object(&obj, repo, entry); /* blob */
+
+	/**
+	 * Remember to close the looked-up object once you are done using it
+	 */
+	git_object_free(obj);
+}
 
-  // Open a config object so we can read global values from it.
-  char config_path[256];
-  sprintf(config_path, "%s/config", repo_path);
-  check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
+/**
+ * #### Blob Parsing
+ *
+ * The last object type is the simplest and requires the least parsing
+ * help. Blobs are just file contents and can contain anything, there is
+ * no structure to it. The main advantage to using the [simple blob
+ * api][ba] is that when you're creating blobs you don't have to calculate
+ * the size of the content.  There is also a helper for reading a file
+ * from disk and writing it to the db and getting the oid back so you
+ * don't have to do all those steps yourself.
+ *
+ * [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob
+ */
+static void blob_parsing(git_repository *repo)
+{
+	git_blob *blob;
+	git_oid oid;
+
+	printf("\n*Blob Parsing*\n");
+
+	git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
+	git_blob_lookup(&blob, repo, &oid);
+
+	/**
+	 * You can access a buffer with the raw contents of the blob directly.
+	 * Note that this buffer may not be contain ASCII data for certain blobs
+	 * (e.g. binary files): do not consider the buffer a NULL-terminated
+	 * string, and use the `git_blob_rawsize` attribute to find out its exact
+	 * size in bytes
+	 * */
+	printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); /* 8 */
+	git_blob_rawcontent(blob); /* "content" */
+}
 
-  git_config_get_int32(&j, cfg, "help.autocorrect");
-  printf("Autocorrect: %d\n", j);
+/**
+ * ### Revwalking
+ *
+ * The libgit2 [revision walking api][rw] provides methods to traverse the
+ * directed graph created by the parent pointers of the commit objects.
+ * Since all commits point back to the commit that came directly before
+ * them, you can walk this parentage as a graph and find all the commits
+ * that were ancestors of (reachable from) a given starting point.  This
+ * can allow you to create `git log` type functionality.
+ *
+ * [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk
+ */
+static void revwalking(git_repository *repo)
+{
+	const git_signature *cauth;
+	const char *cmsg;
+	int error;
+	git_revwalk *walk;
+	git_commit *wcommit;
+	git_oid oid;
+
+	printf("\n*Revwalking*\n");
+
+	git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+
+	/**
+	 * To use the revwalker, create a new walker, tell it how you want to sort
+	 * the output and then push one or more starting points onto the walker.
+	 * If you want to emulate the output of `git log` you would push the SHA
+	 * of the commit that HEAD points to into the walker and then start
+	 * traversing them.  You can also 'hide' commits that you want to stop at
+	 * or not see any of their ancestors.  So if you want to emulate `git log
+	 * branch1..branch2`, you would push the oid of `branch2` and hide the oid
+	 * of `branch1`.
+	 */
+	git_revwalk_new(&walk, repo);
+	git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE);
+	git_revwalk_push(walk, &oid);
+
+	/**
+	 * Now that we have the starting point pushed onto the walker, we start
+	 * asking for ancestors. It will return them in the sorting order we asked
+	 * for as commit oids.  We can then lookup and parse the committed pointed
+	 * at by the returned OID; note that this operation is specially fast
+	 * since the raw contents of the commit object will be cached in memory
+	 */
+	while ((git_revwalk_next(&oid, walk)) == 0) {
+		error = git_commit_lookup(&wcommit, repo, &oid);
+		check_error(error, "looking up commit during revwalk");
+
+		cmsg  = git_commit_message(wcommit);
+		cauth = git_commit_author(wcommit);
+		printf("%s (%s)\n", cmsg, cauth->email);
+
+		git_commit_free(wcommit);
+	}
+
+	/**
+	 * Like the other objects, be sure to free the revwalker when you're done
+	 * to prevent memory leaks.  Also, make sure that the repository being
+	 * walked it not deallocated while the walk is in progress, or it will
+	 * result in undefined behavior
+	 */
+	git_revwalk_free(walk);
+}
 
-  git_config_get_string(&email, cfg, "user.email");
-  printf("Email: %s\n", email);
+/**
+ * ### Index File Manipulation *
+ * The [index file API][gi] allows you to read, traverse, update and write
+ * the Git index file (sometimes thought of as the staging area).
+ *
+ * [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index
+ */
+static void index_walking(git_repository *repo)
+{
+	git_index *index;
+	unsigned int i, ecount;
+
+	printf("\n*Index Walking*\n");
+
+	/**
+	 * You can either open the index from the standard location in an open
+	 * repository, as we're doing here, or you can open and manipulate any
+	 * index file with `git_index_open_bare()`. The index for the repository
+	 * will be located and loaded from disk.
+	 */
+	git_repository_index(&index, repo);
+
+	/**
+	 * For each entry in the index, you can get a bunch of information
+	 * including the SHA (oid), path and mode which map to the tree objects
+	 * that are written out.  It also has filesystem properties to help
+	 * determine what to inspect for changes (ctime, mtime, dev, ino, uid,
+	 * gid, file_size and flags) All these properties are exported publicly in
+	 * the `git_index_entry` struct
+	 */
+	ecount = git_index_entrycount(index);
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		printf("path: %s\n", e->path);
+		printf("mtime: %d\n", (int)e->mtime.seconds);
+		printf("fs: %d\n", (int)e->file_size);
+	}
+
+	git_index_free(index);
+}
 
-  // Finally, when you're done with the repository, you can free it as well.
-  git_repository_free(repo);
+/**
+ * ### References
+ *
+ * The [reference API][ref] allows you to list, resolve, create and update
+ * references such as branches, tags and remote references (everything in
+ * the .git/refs directory).
+ *
+ * [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference
+ */
+static void reference_listing(git_repository *repo)
+{
+	git_strarray ref_list;
+	const char *refname;
+	git_reference *ref;
+	unsigned i;
+	char oid_hex[GIT_OID_HEXSZ+1];
+
+	printf("\n*Reference Listing*\n");
+
+	/**
+	 * Here we will implement something like `git for-each-ref` simply listing
+	 * out all available references and the object SHA they resolve to.
+	 *
+	 * Now that we have the list of reference names, we can lookup each ref
+	 * one at a time and resolve them to the SHA, then print both values out.
+	 */
+
+	git_reference_list(&ref_list, repo);
+
+	for (i = 0; i < ref_list.count; ++i) {
+		memset(oid_hex, 0, sizeof(oid_hex));
+		refname = ref_list.strings[i];
+		git_reference_lookup(&ref, repo, refname);
+
+		switch (git_reference_type(ref)) {
+			case GIT_REF_OID:
+				git_oid_fmt(oid_hex, git_reference_target(ref));
+				printf("%s [%s]\n", refname, oid_hex);
+				break;
+
+			case GIT_REF_SYMBOLIC:
+				printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
+				break;
+			default:
+				fprintf(stderr, "Unexpected reference type\n");
+				exit(1);
+		}
+	}
+
+	git_strarray_free(&ref_list);
+}
 
-  return 0;
+/**
+ * ### Config Files
+ *
+ * The [config API][config] allows you to list and updatee config values
+ * in any of the accessible config file locations (system, global, local).
+ *
+ * [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
+ */
+static void config_files(const char *repo_path, git_repository* repo)
+{
+	const char *email;
+	char config_path[256];
+	int32_t j;
+	git_config *cfg;
+	git_config *snap_cfg;
+
+	printf("\n*Config Listing*\n");
+
+	/**
+	 * Open a config object so we can read global values from it.
+	 */
+	sprintf(config_path, "%s/config", repo_path);
+	check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
+
+	git_config_get_int32(&j, cfg, "help.autocorrect");
+	printf("Autocorrect: %d\n", j);
+
+	check_error(git_repository_config_snapshot(&snap_cfg, repo), "config snapshot");
+	git_config_get_string(&email, snap_cfg, "user.email");
+	printf("Email: %s\n", email);
 }
diff --git a/examples/network/clone.c b/examples/network/clone.c
index caf41cca8..540000bfd 100644
--- a/examples/network/clone.c
+++ b/examples/network/clone.c
@@ -50,7 +50,7 @@ static int sideband_progress(const char *str, int len, void *payload)
 {
 	(void)payload; // unused
 
-	printf("remote: %*s", len, str);
+	printf("remote: %.*s", len, str);
 	fflush(stdout);
 	return 0;
 }
diff --git a/examples/network/fetch.c b/examples/network/fetch.c
index 177359b88..10974a9f1 100644
--- a/examples/network/fetch.c
+++ b/examples/network/fetch.c
@@ -55,6 +55,8 @@ static int update_cb(const char *refname, const git_oid *a, const git_oid *b, vo
  */
 static int transfer_progress_cb(const git_transfer_progress *stats, void *payload)
 {
+	(void)payload;
+
 	if (stats->received_objects == stats->total_objects) {
 		printf("Resolving deltas %d/%d\r",
 		       stats->indexed_deltas, stats->total_deltas);
@@ -71,7 +73,6 @@ int fetch(git_repository *repo, int argc, char **argv)
 {
 	git_remote *remote = NULL;
 	const git_transfer_progress *stats;
-	struct dl_data data;
 	git_fetch_options fetch_opts = GIT_FETCH_OPTIONS_INIT;
 
 	if (argc < 2) {
@@ -79,14 +80,13 @@ int fetch(git_repository *repo, int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
-	// Figure out whether it's a named remote or a URL
+	/* Figure out whether it's a named remote or a URL */
 	printf("Fetching %s for repo %p\n", argv[1], repo);
-	if (git_remote_lookup(&remote, repo, argv[1]) < 0) {
+	if (git_remote_lookup(&remote, repo, argv[1]) < 0)
 		if (git_remote_create_anonymous(&remote, repo, argv[1]) < 0)
-			return -1;
-	}
+			goto on_error;
 
-	// Set up the callbacks (only update_tips for now)
+	/* Set up the callbacks (only update_tips for now) */
 	fetch_opts.callbacks.update_tips = &update_cb;
 	fetch_opts.callbacks.sideband_progress = &progress_cb;
 	fetch_opts.callbacks.transfer_progress = transfer_progress_cb;
@@ -98,7 +98,7 @@ int fetch(git_repository *repo, int argc, char **argv)
 	 * "fetch".
 	 */
 	if (git_remote_fetch(remote, NULL, &fetch_opts, "fetch") < 0)
-		return -1;
+		goto on_error;
 
 	/**
 	 * If there are local objects (we got a thin pack), then tell
diff --git a/include/git2/common.h b/include/git2/common.h
index a8d698fa4..99c99812b 100644
--- a/include/git2/common.h
+++ b/include/git2/common.h
@@ -109,9 +109,27 @@ GIT_EXTERN(void) git_libgit2_version(int *major, int *minor, int *rev);
  * was compiled
  */
 typedef enum {
+  /**
+   * If set, libgit2 was built thread-aware and can be safely used from multiple
+   * threads.
+   */
 	GIT_FEATURE_THREADS	= (1 << 0),
+  /**
+   * If set, libgit2 was built with and linked against a TLS implementation.
+   * Custom TLS streams may still be added by the user to support HTTPS
+   * regardless of this.
+   */
 	GIT_FEATURE_HTTPS	= (1 << 1),
+  /**
+   * If set, libgit2 was built with and linked against libssh2. A custom
+   * transport may still be added by the user to support libssh2 regardless of
+   * this.
+   */
 	GIT_FEATURE_SSH		= (1 << 2),
+  /**
+   * If set, libgit2 was built with support for sub-second resolution in file
+   * modification times.
+   */
 	GIT_FEATURE_NSEC	= (1 << 3),
 } git_feature_t;
 
diff --git a/include/git2/describe.h b/include/git2/describe.h
index 3044d9165..971eb350c 100644
--- a/include/git2/describe.h
+++ b/include/git2/describe.h
@@ -44,8 +44,8 @@ typedef enum {
 typedef struct git_describe_options {
 	unsigned int version;
 
-	unsigned int max_candidates_tags; /** default: 10 */
-	unsigned int describe_strategy; /** default: GIT_DESCRIBE_DEFAULT */
+	unsigned int max_candidates_tags; /**< default: 10 */
+	unsigned int describe_strategy; /**< default: GIT_DESCRIBE_DEFAULT */
 	const char *pattern;
 	/**
 	 * When calculating the distance from the matching tag or
@@ -105,6 +105,9 @@ typedef struct {
 
 GIT_EXTERN(int) git_describe_init_format_options(git_describe_format_options *opts, unsigned int version);
 
+/**
+ * A struct that stores the result of a describe operation.
+ */
 typedef struct git_describe_result git_describe_result;
 
 /**
diff --git a/include/git2/merge.h b/include/git2/merge.h
index c6f6cba6c..94ac8b5c5 100644
--- a/include/git2/merge.h
+++ b/include/git2/merge.h
@@ -290,7 +290,8 @@ typedef struct {
 } git_merge_options;
 
 #define GIT_MERGE_OPTIONS_VERSION 1
-#define GIT_MERGE_OPTIONS_INIT {GIT_MERGE_OPTIONS_VERSION}
+#define GIT_MERGE_OPTIONS_INIT { \
+	GIT_MERGE_OPTIONS_VERSION, GIT_MERGE_FIND_RENAMES }
 
 /**
  * Initializes a `git_merge_options` with default values. Equivalent to
diff --git a/include/git2/patch.h b/include/git2/patch.h
index 790cb74fc..4eb9f0263 100644
--- a/include/git2/patch.h
+++ b/include/git2/patch.h
@@ -191,7 +191,7 @@ GIT_EXTERN(int) git_patch_get_hunk(
  *
  * @param patch The git_patch object
  * @param hunk_idx Index of the hunk
- * @return Number of lines in hunk or -1 if invalid hunk index
+ * @return Number of lines in hunk or GIT_ENOTFOUND if invalid hunk index
  */
 GIT_EXTERN(int) git_patch_num_lines_in_hunk(
 	const git_patch *patch,
diff --git a/include/git2/proxy.h b/include/git2/proxy.h
index dcd615633..194cbb651 100644
--- a/include/git2/proxy.h
+++ b/include/git2/proxy.h
@@ -19,7 +19,7 @@ typedef enum {
 	/**
 	 * Do not attempt to connect through a proxy
 	 *
-	 * If built against lbicurl, it itself may attempt to connect
+	 * If built against libcurl, it itself may attempt to connect
 	 * to a proxy if the environment variables specify it.
 	 */
 	GIT_PROXY_NONE,
diff --git a/include/git2/remote.h b/include/git2/remote.h
index c459f42cc..691114172 100644
--- a/include/git2/remote.h
+++ b/include/git2/remote.h
@@ -26,8 +26,6 @@
  */
 GIT_BEGIN_DECL
 
-typedef int (*git_remote_rename_problem_cb)(const char *problematic_refspec, void *payload);
-
 /**
  * Add a remote with the default fetch refspec to the repository's configuration.
  *
@@ -360,6 +358,8 @@ typedef struct {
 } git_push_update;
 
 /**
+ * Callback used to inform of upcoming updates.
+ *
  * @param updates an array containing the updates which will be sent
  * as commands to the destination.
  * @param len number of elements in `updates`
@@ -403,7 +403,7 @@ struct git_remote_callbacks {
 	 * connection to proceed. Returns 1 to allow the connection, 0
 	 * to disallow it or a negative value to indicate an error.
 	 */
-        git_transport_certificate_check_cb certificate_check;
+	git_transport_certificate_check_cb certificate_check;
 
 	/**
 	 * During the download of new data, this will be regularly
@@ -569,7 +569,7 @@ typedef struct {
  * Initializes a `git_fetch_options` with default values. Equivalent to
  * creating an instance with GIT_FETCH_OPTIONS_INIT.
  *
- * @param opts the `git_push_options` instance to initialize.
+ * @param opts the `git_fetch_options` instance to initialize.
  * @param version the version of the struct; you should pass
  *        `GIT_FETCH_OPTIONS_VERSION` here.
  * @return Zero on success; -1 on failure.
diff --git a/include/git2/sys/repository.h b/include/git2/sys/repository.h
index 800396c86..0c9142143 100644
--- a/include/git2/sys/repository.h
+++ b/include/git2/sys/repository.h
@@ -135,6 +135,35 @@ GIT_EXTERN(void) git_repository_set_index(git_repository *repo, git_index *index
  */
 GIT_EXTERN(int) git_repository_set_bare(git_repository *repo);
 
+/**
+ * Load and cache all submodules.
+ *
+ * Because the `.gitmodules` file is unstructured, loading submodules is an
+ * O(N) operation.  Any operation (such as `git_rebase_init`) that requires
+ * accessing all submodules is O(N^2) in the number of submodules, if it
+ * has to look each one up individually.  This function loads all submodules
+ * and caches them so that subsequent calls to `git_submodule_lookup` are O(1).
+ *
+ * @param repo the repository whose submodules will be cached.
+ */
+GIT_EXTERN(int) git_repository_submodule_cache_all(
+	git_repository *repo);
+
+/**
+ * Clear the submodule cache.
+ *
+ * Clear the submodule cache populated by `git_repository_submodule_cache_all`.
+ * If there is no cache, do nothing.
+ *
+ * The cache incorporates data from the repository's configuration, as well
+ * as the state of the working tree, the index, and HEAD.  So any time any
+ * of these has changed, the cache might become invalid.
+ *
+ * @param repo the repository whose submodule cache will be cleared
+ */
+GIT_EXTERN(int) git_repository_submodule_cache_clear(
+	git_repository *repo);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/transaction.h b/include/git2/transaction.h
index 64abb0c69..00ca13993 100644
--- a/include/git2/transaction.h
+++ b/include/git2/transaction.h
@@ -8,6 +8,14 @@
 #define INCLUDE_git_transaction_h__
 
 #include "common.h"
+
+/**
+ * @file git2/transaction.h
+ * @brief Git transactional reference routines
+ * @defgroup git_transaction Git transactional reference routines
+ * @ingroup Git
+ * @{
+ */
 GIT_BEGIN_DECL
 
 /**
@@ -107,5 +115,6 @@ GIT_EXTERN(int) git_transaction_commit(git_transaction *tx);
  */
 GIT_EXTERN(void) git_transaction_free(git_transaction *tx);
 
+/** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/version.h b/include/git2/version.h
index 66a6623cd..0df191f4f 100644
--- a/include/git2/version.h
+++ b/include/git2/version.h
@@ -7,12 +7,12 @@
 #ifndef INCLUDE_git_version_h__
 #define INCLUDE_git_version_h__
 
-#define LIBGIT2_VERSION "0.24.0"
+#define LIBGIT2_VERSION "0.25.0"
 #define LIBGIT2_VER_MAJOR 0
-#define LIBGIT2_VER_MINOR 24
+#define LIBGIT2_VER_MINOR 25
 #define LIBGIT2_VER_REVISION 0
 #define LIBGIT2_VER_PATCH 0
 
-#define LIBGIT2_SOVERSION 24
+#define LIBGIT2_SOVERSION 25
 
 #endif
diff --git a/script/cibuild.sh b/script/cibuild.sh
index b13ad88c4..403df223e 100755
--- a/script/cibuild.sh
+++ b/script/cibuild.sh
@@ -20,7 +20,7 @@ java -jar poxyproxy.jar -d --port 8080 --credentials foo:bar &
 mkdir _build
 cd _build
 # shellcheck disable=SC2086
-cmake .. -DCMAKE_INSTALL_PREFIX=../_install $OPTIONS || exit $?
+cmake .. -DBUILD_EXAMPLES=ON -DCMAKE_INSTALL_PREFIX=../_install $OPTIONS || exit $?
 make -j2 install || exit $?
 
 # If this platform doesn't support test execution, bail out now
diff --git a/script/coverity.sh b/script/coverity.sh
index 7fe9eb4c7..5fe16c031 100755
--- a/script/coverity.sh
+++ b/script/coverity.sh
@@ -1,23 +1,22 @@
 #!/bin/bash
 set -e
 
-# Environment check
-[ -z "$COVERITY_TOKEN" ] && echo "Need to set a coverity token" && exit 1
-
 # Only run this on our branches
-echo "Pull request: $TRAVIS_PULL_REQUEST  |  Slug: $TRAVIS_REPO_SLUG"
-if [ "$TRAVIS_PULL_REQUEST" != "false" -o "$TRAVIS_REPO_SLUG" != "libgit2/libgit2" ];
+echo "Branch: $TRAVIS_BRANCH  |  Pull request: $TRAVIS_PULL_REQUEST  |  Slug: $TRAVIS_REPO_SLUG"
+if [ "$TRAVIS_BRANCH" != "master" -o "$TRAVIS_PULL_REQUEST" != "false" -o "$TRAVIS_REPO_SLUG" != "libgit2/libgit2" ];
 then
-	echo "Only analyzing 'development' on the main repo."
+	echo "Only analyzing the 'master' brach of the main repository."
 	exit 0
 fi
 
-COV_VERSION=6.6.1
+# Environment check
+[ -z "$COVERITY_TOKEN" ] && echo "Need to set a coverity token" && exit 1
+
 case $(uname -m) in
 	i?86)				BITS=32 ;;
 	amd64|x86_64)	BITS=64 ;;
 esac
-SCAN_TOOL=https://scan.coverity.com/download/linux-${BITS}
+SCAN_TOOL=https://scan.coverity.com/download/cxx/linux${BITS}
 TOOL_BASE=$(pwd)/_coverity-scan
 
 # Install coverity tools
diff --git a/src/apply.c b/src/apply.c
index f70172469..595f5f300 100644
--- a/src/apply.c
+++ b/src/apply.c
@@ -173,7 +173,7 @@ static int apply_hunk(
 		git_diff_line *line = git_array_get(patch->lines, linenum);
 
 		if (!line) {
-			error = apply_err("Preimage does not contain line %d", linenum);
+			error = apply_err("preimage does not contain line %"PRIuZ, linenum);
 			goto done;
 		}
 
@@ -193,7 +193,7 @@ static int apply_hunk(
 	line_num = hunk->hunk.new_start ? hunk->hunk.new_start - 1 : 0;
 
 	if (!find_hunk_linenum(&line_num, image, &preimage, line_num)) {
-		error = apply_err("Hunk at line %d did not apply",
+		error = apply_err("hunk at line %d did not apply",
 			hunk->hunk.new_start);
 		goto done;
 	}
diff --git a/src/attr_file.c b/src/attr_file.c
index 11d149358..0bb761d04 100644
--- a/src/attr_file.c
+++ b/src/attr_file.c
@@ -30,7 +30,7 @@ int git_attr_file__new(
 	GITERR_CHECK_ALLOC(attrs);
 
 	if (git_mutex_init(&attrs->lock) < 0) {
-		giterr_set(GITERR_OS, "Failed to initialize lock");
+		giterr_set(GITERR_OS, "failed to initialize lock");
 		git__free(attrs);
 		return -1;
 	}
@@ -49,7 +49,7 @@ int git_attr_file__clear_rules(git_attr_file *file, bool need_lock)
 	git_attr_rule *rule;
 
 	if (need_lock && git_mutex_lock(&file->lock) < 0) {
-		giterr_set(GITERR_OS, "Failed to lock attribute file");
+		giterr_set(GITERR_OS, "failed to lock attribute file");
 		return -1;
 	}
 
@@ -140,7 +140,7 @@ int git_attr_file__load(
 		break;
 	}
 	default:
-		giterr_set(GITERR_INVALID, "Unknown file source %d", source);
+		giterr_set(GITERR_INVALID, "unknown file source %d", source);
 		return -1;
 	}
 
@@ -212,7 +212,7 @@ int git_attr_file__out_of_date(
 	}
 
 	default:
-		giterr_set(GITERR_INVALID, "Invalid file type %d", file->source);
+		giterr_set(GITERR_INVALID, "invalid file type %d", file->source);
 		return -1;
 	}
 }
@@ -238,7 +238,7 @@ int git_attr_file__parse_buffer(
 		context = attrs->entry->path;
 
 	if (git_mutex_lock(&attrs->lock) < 0) {
-		giterr_set(GITERR_OS, "Failed to lock attribute file");
+		giterr_set(GITERR_OS, "failed to lock attribute file");
 		return -1;
 	}
 
diff --git a/src/attrcache.c b/src/attrcache.c
index a57110684..0ade38c7c 100644
--- a/src/attrcache.c
+++ b/src/attrcache.c
@@ -12,7 +12,7 @@ GIT_INLINE(int) attr_cache_lock(git_attr_cache *cache)
 	GIT_UNUSED(cache); /* avoid warning if threading is off */
 
 	if (git_mutex_lock(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to get attr cache lock");
+		giterr_set(GITERR_OS, "unable to get attr cache lock");
 		return -1;
 	}
 	return 0;
@@ -365,7 +365,7 @@ int git_attr_cache__do_init(git_repository *repo)
 
 	/* set up lock */
 	if (git_mutex_init(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to initialize lock for attr cache");
+		giterr_set(GITERR_OS, "unable to initialize lock for attr cache");
 		git__free(cache);
 		return -1;
 	}
@@ -430,7 +430,7 @@ int git_attr_cache__insert_macro(git_repository *repo, git_attr_rule *macro)
 		return 0;
 
 	if (git_mutex_lock(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to get attr cache lock");
+		giterr_set(GITERR_OS, "unable to get attr cache lock");
 		error = -1;
 	} else {
 		git_strmap_insert(macros, macro->match.pattern, macro, error);
diff --git a/src/blob.c b/src/blob.c
index 1926c9e58..cd5df3537 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -96,7 +96,7 @@ static int write_file_stream(
 	p_close(fd);
 
 	if (written != file_size || read_len < 0) {
-		giterr_set(GITERR_OS, "Failed to read file into stream");
+		giterr_set(GITERR_OS, "failed to read file into stream");
 		error = -1;
 	}
 
@@ -142,7 +142,7 @@ static int write_symlink(
 
 	read_len = p_readlink(path, link_data, link_size);
 	if (read_len != (ssize_t)link_size) {
-		giterr_set(GITERR_OS, "Failed to create blob.  Can't read symlink '%s'", path);
+		giterr_set(GITERR_OS, "failed to create blob: cannot read symlink '%s'", path);
 		git__free(link_data);
 		return -1;
 	}
@@ -186,7 +186,7 @@ int git_blob__create_from_paths(
 		goto done;
 
 	if (S_ISDIR(st.st_mode)) {
-		giterr_set(GITERR_ODB, "cannot create blob from '%s'; it is a directory", content_path);
+		giterr_set(GITERR_ODB, "cannot create blob from '%s': it is a directory", content_path);
 		error = GIT_EDIRECTORY;
 		goto done;
 	}
diff --git a/src/branch.c b/src/branch.c
index 51c35d7ff..7ddcb3da7 100644
--- a/src/branch.c
+++ b/src/branch.c
@@ -33,7 +33,7 @@ static int retrieve_branch_reference(
 		/* OOM */;
 	else if ((error = git_reference_lookup(&branch, repo, ref_name.ptr)) < 0)
 		giterr_set(
-			GITERR_REFERENCE, "Cannot locate %s branch '%s'",
+			GITERR_REFERENCE, "cannot locate %s branch '%s'",
 			is_remote ? "remote-tracking" : "local", branch_name);
 
 	*branch_reference_out = branch; /* will be NULL on error */
@@ -46,7 +46,7 @@ static int not_a_local_branch(const char *reference_name)
 {
 	giterr_set(
 		GITERR_INVALID,
-		"Reference '%s' is not a local branch.", reference_name);
+		"reference '%s' is not a local branch.", reference_name);
 	return -1;
 }
 
@@ -58,16 +58,17 @@ static int create_branch(
 	const char *from,
 	int force)
 {
-	int is_head = 0;
+	int is_unmovable_head = 0;
 	git_reference *branch = NULL;
 	git_buf canonical_branch_name = GIT_BUF_INIT,
 			  log_message = GIT_BUF_INIT;
 	int error = -1;
+	int bare = git_repository_is_bare(repository);
 
 	assert(branch_name && commit && ref_out);
 	assert(git_object_owner((const git_object *)commit) == repository);
 
-	if (force && git_branch_lookup(&branch, repository, branch_name, GIT_BRANCH_LOCAL) == 0) {
+	if (force && !bare && git_branch_lookup(&branch, repository, branch_name, GIT_BRANCH_LOCAL) == 0) {
 		error = git_branch_is_head(branch);
 		git_reference_free(branch);
 		branch = NULL;
@@ -75,11 +76,11 @@ static int create_branch(
 		if (error < 0)
 			goto cleanup;
 
-		is_head = error;
+		is_unmovable_head = error;
 	}
 
-	if (is_head && force) {
-		giterr_set(GITERR_REFERENCE, "Cannot force update branch '%s' as it is "
+	if (is_unmovable_head && force) {
+		giterr_set(GITERR_REFERENCE, "cannot force update branch '%s' as it is "
 			"the current HEAD of the repository.", branch_name);
 		error = -1;
 		goto cleanup;
@@ -134,7 +135,7 @@ int git_branch_delete(git_reference *branch)
 	assert(branch);
 
 	if (!git_reference_is_branch(branch) && !git_reference_is_remote(branch)) {
-		giterr_set(GITERR_INVALID, "Reference '%s' is not a valid branch.",
+		giterr_set(GITERR_INVALID, "reference '%s' is not a valid branch.",
 			git_reference_name(branch));
 		return GIT_ENOTFOUND;
 	}
@@ -143,7 +144,7 @@ int git_branch_delete(git_reference *branch)
 		return is_head;
 
 	if (is_head) {
-		giterr_set(GITERR_REFERENCE, "Cannot delete branch '%s' as it is "
+		giterr_set(GITERR_REFERENCE, "cannot delete branch '%s' as it is "
 			"the current HEAD of the repository.", git_reference_name(branch));
 		return -1;
 	}
@@ -305,7 +306,7 @@ int git_branch_name(
 		branch_name += strlen(GIT_REFS_REMOTES_DIR);
 	} else {
 		giterr_set(GITERR_INVALID,
-				"Reference '%s' is neither a local nor a remote branch.", ref->name);
+				"reference '%s' is neither a local nor a remote branch.", ref->name);
 		return -1;
 	}
 	*out = branch_name;
@@ -435,7 +436,7 @@ int git_branch_remote_name(git_buf *buf, git_repository *repo, const char *refna
 
 	/* Verify that this is a remote branch */
 	if (!git_reference__is_remote(refname)) {
-		giterr_set(GITERR_INVALID, "Reference '%s' is not a remote branch.",
+		giterr_set(GITERR_INVALID, "reference '%s' is not a remote branch.",
 			refname);
 		error = GIT_ERROR;
 		goto cleanup;
@@ -462,7 +463,7 @@ int git_branch_remote_name(git_buf *buf, git_repository *repo, const char *refna
 				git_remote_free(remote);
 
 				giterr_set(GITERR_REFERENCE,
-					"Reference '%s' is ambiguous", refname);
+					"reference '%s' is ambiguous", refname);
 				error = GIT_EAMBIGUOUS;
 				goto cleanup;
 			}
@@ -476,7 +477,7 @@ int git_branch_remote_name(git_buf *buf, git_repository *repo, const char *refna
 		error = git_buf_puts(buf, remote_name);
 	} else {
 		giterr_set(GITERR_REFERENCE,
-			"Could not determine remote for '%s'", refname);
+			"could not determine remote for '%s'", refname);
 		error = GIT_ENOTFOUND;
 	}
 
@@ -565,7 +566,7 @@ int git_branch_set_upstream(git_reference *branch, const char *upstream_name)
 		local = 0;
 	else {
 		giterr_set(GITERR_REFERENCE,
-			"Cannot set upstream for branch '%s'", shortname);
+			"cannot set upstream for branch '%s'", shortname);
 		return GIT_ENOTFOUND;
 	}
 
diff --git a/src/buffer.c b/src/buffer.c
index d135ebe4a..fdb732d9e 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -962,14 +962,14 @@ int git_buf_unquote(git_buf *buf)
 			case '0': case '1': case '2': case '3':
 				if (j == buf->size-3) {
 					giterr_set(GITERR_INVALID,
-						"Truncated quoted character \\%c", ch);
+						"truncated quoted character \\%c", ch);
 					return -1;
 				}
 
 				if (buf->ptr[j+1] < '0' || buf->ptr[j+1] > '7' ||
 					buf->ptr[j+2] < '0' || buf->ptr[j+2] > '7') {
 					giterr_set(GITERR_INVALID,
-						"Truncated quoted character \\%c%c%c",
+						"truncated quoted character \\%c%c%c",
 						buf->ptr[j], buf->ptr[j+1], buf->ptr[j+2]);
 					return -1;
 				}
@@ -981,7 +981,7 @@ int git_buf_unquote(git_buf *buf)
 				break;
 
 			default:
-				giterr_set(GITERR_INVALID, "Invalid quoted character \\%c", ch);
+				giterr_set(GITERR_INVALID, "invalid quoted character \\%c", ch);
 				return -1;
 			}
 		}
@@ -995,6 +995,6 @@ int git_buf_unquote(git_buf *buf)
 	return 0;
 
 invalid:
-	giterr_set(GITERR_INVALID, "Invalid quoted line");
+	giterr_set(GITERR_INVALID, "invalid quoted line");
 	return -1;
 }
diff --git a/src/cache.c b/src/cache.c
index ca5173c0d..16ae9b397 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -70,7 +70,7 @@ int git_cache_init(git_cache *cache)
 	cache->map = git_oidmap_alloc();
 	GITERR_CHECK_ALLOC(cache->map);
 	if (git_rwlock_init(&cache->lock)) {
-		giterr_set(GITERR_OS, "Failed to initialize cache rwlock");
+		giterr_set(GITERR_OS, "failed to initialize cache rwlock");
 		return -1;
 	}
 	return 0;
diff --git a/src/checkout.c b/src/checkout.c
index b3427fb7c..b70d5ab35 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -1021,13 +1021,13 @@ static int checkout_conflicts_load_byname_entry(
 	*theirs_out = NULL;
 
 	if (!name_entry->ancestor) {
-		giterr_set(GITERR_INDEX, "A NAME entry exists without an ancestor");
+		giterr_set(GITERR_INDEX, "a NAME entry exists without an ancestor");
 		error = -1;
 		goto done;
 	}
 
 	if (!name_entry->ours && !name_entry->theirs) {
-		giterr_set(GITERR_INDEX, "A NAME entry exists without an ours or theirs");
+		giterr_set(GITERR_INDEX, "a NAME entry exists without an ours or theirs");
 		error = -1;
 		goto done;
 	}
@@ -1035,7 +1035,7 @@ static int checkout_conflicts_load_byname_entry(
 	if ((ancestor = checkout_conflicts_search_ancestor(data,
 		name_entry->ancestor)) == NULL) {
 		giterr_set(GITERR_INDEX,
-			"A NAME entry referenced ancestor entry '%s' which does not exist in the main index",
+			"a NAME entry referenced ancestor entry '%s' which does not exist in the main index",
 			name_entry->ancestor);
 		error = -1;
 		goto done;
@@ -1047,7 +1047,7 @@ static int checkout_conflicts_load_byname_entry(
 		else if ((ours = checkout_conflicts_search_branch(data, name_entry->ours)) == NULL ||
 			ours->ours == NULL) {
 			giterr_set(GITERR_INDEX,
-				"A NAME entry referenced our entry '%s' which does not exist in the main index",
+				"a NAME entry referenced our entry '%s' which does not exist in the main index",
 				name_entry->ours);
 			error = -1;
 			goto done;
@@ -1062,7 +1062,7 @@ static int checkout_conflicts_load_byname_entry(
 		else if ((theirs = checkout_conflicts_search_branch(data, name_entry->theirs)) == NULL ||
 			theirs->theirs == NULL) {
 			giterr_set(GITERR_INDEX,
-				"A NAME entry referenced their entry '%s' which does not exist in the main index",
+				"a NAME entry referenced their entry '%s' which does not exist in the main index",
 				name_entry->theirs);
 			error = -1;
 			goto done;
@@ -1161,7 +1161,7 @@ static int checkout_conflicts_mark_directoryfile(
 		if ((error = git_index_find(&j, index, path)) < 0) {
 			if (error == GIT_ENOTFOUND)
 				giterr_set(GITERR_INDEX,
-					"Index inconsistency, could not find entry for expected conflict '%s'", path);
+					"index inconsistency, could not find entry for expected conflict '%s'", path);
 
 			goto done;
 		}
@@ -1169,7 +1169,7 @@ static int checkout_conflicts_mark_directoryfile(
 		for (; j < len; j++) {
 			if ((entry = git_index_get_byindex(index, j)) == NULL) {
 				giterr_set(GITERR_INDEX,
-					"Index inconsistency, truncated index while loading expected conflict '%s'", path);
+					"index inconsistency, truncated index while loading expected conflict '%s'", path);
 				error = -1;
 				goto done;
 			}
@@ -1254,14 +1254,14 @@ static int checkout_verify_paths(
 
 	if (action & CHECKOUT_ACTION__REMOVE) {
 		if (!git_path_isvalid(repo, delta->old_file.path, flags)) {
-			giterr_set(GITERR_CHECKOUT, "Cannot remove invalid path '%s'", delta->old_file.path);
+			giterr_set(GITERR_CHECKOUT, "cannot remove invalid path '%s'", delta->old_file.path);
 			return -1;
 		}
 	}
 
 	if (action & ~CHECKOUT_ACTION__REMOVE) {
 		if (!git_path_isvalid(repo, delta->new_file.path, flags)) {
-			giterr_set(GITERR_CHECKOUT, "Cannot checkout to invalid path '%s'", delta->new_file.path);
+			giterr_set(GITERR_CHECKOUT, "cannot checkout to invalid path '%s'", delta->new_file.path);
 			return -1;
 		}
 	}
@@ -1430,7 +1430,7 @@ static int mkpath2file(
 			 */
 			error = git_futils_rmdir_r(path, NULL, GIT_RMDIR_REMOVE_FILES);
 		} else if (errno != ENOENT) {
-			giterr_set(GITERR_OS, "Failed to stat file '%s'", path);
+			giterr_set(GITERR_OS, "failed to stat '%s'", path);
 			return GIT_EEXISTS;
 		} else {
 			giterr_clear();
@@ -1454,7 +1454,7 @@ static int checkout_stream_write(
 	int ret;
 
 	if ((ret = p_write(stream->fd, buffer, len)) < 0)
-		giterr_set(GITERR_OS, "Could not write to '%s'", stream->path);
+		giterr_set(GITERR_OS, "could not write to '%s'", stream->path);
 
 	return ret;
 }
@@ -1503,7 +1503,7 @@ static int blob_content_to_file(
 		mode = GIT_FILEMODE_BLOB;
 
 	if ((fd = p_open(path, flags, mode)) < 0) {
-		giterr_set(GITERR_OS, "Could not open '%s' for writing", path);
+		giterr_set(GITERR_OS, "could not open '%s' for writing", path);
 		return fd;
 	}
 
@@ -1540,7 +1540,7 @@ static int blob_content_to_file(
 		data->perfdata.stat_calls++;
 
 		if ((error = p_stat(path, st)) < 0) {
-			giterr_set(GITERR_OS, "Error statting '%s'", path);
+			giterr_set(GITERR_OS, "failed to stat '%s'", path);
 			return error;
 		}
 
@@ -1567,7 +1567,7 @@ static int blob_content_to_link(
 
 	if (data->can_symlink) {
 		if ((error = p_symlink(git_buf_cstr(&linktarget), path)) < 0)
-			giterr_set(GITERR_OS, "Could not create symlink %s", path);
+			giterr_set(GITERR_OS, "could not create symlink %s", path);
 	} else {
 		error = git_futils_fake_symlink(git_buf_cstr(&linktarget), path);
 	}
@@ -1576,7 +1576,7 @@ static int blob_content_to_link(
 		data->perfdata.stat_calls++;
 
 		if ((error = p_lstat(path, st)) < 0)
-			giterr_set(GITERR_CHECKOUT, "Could not stat symlink %s", path);
+			giterr_set(GITERR_CHECKOUT, "could not stat symlink %s", path);
 
 		st->st_mode = GIT_FILEMODE_LINK;
 	}
@@ -1621,7 +1621,7 @@ static int checkout_submodule_update_index(
 	data->perfdata.stat_calls++;
 	if (p_stat(fullpath->ptr, &st) < 0) {
 		giterr_set(
-			GITERR_CHECKOUT, "Could not stat submodule %s\n", file->path);
+			GITERR_CHECKOUT, "could not stat submodule %s\n", file->path);
 		return GIT_ENOTFOUND;
 	}
 
@@ -1694,7 +1694,7 @@ static int checkout_safe_for_update_only(
 			return 0;
 
 		/* otherwise, stat error and no update */
-		giterr_set(GITERR_OS, "Failed to stat file '%s'", path);
+		giterr_set(GITERR_OS, "failed to stat '%s'", path);
 		return -1;
 	}
 
@@ -1966,7 +1966,7 @@ static int checkout_path_suffixed(git_buf *path, const char *suffix)
 	if (i == INT_MAX) {
 		git_buf_truncate(path, path_len);
 
-		giterr_set(GITERR_CHECKOUT, "Could not write '%s': working directory file exists", path);
+		giterr_set(GITERR_CHECKOUT, "could not write '%s': working directory file exists", path->ptr);
 		return GIT_EEXISTS;
 	}
 
@@ -2097,7 +2097,7 @@ static int checkout_write_merge(
 		goto done;
 
 	if (result.path == NULL || result.mode == 0) {
-		giterr_set(GITERR_CHECKOUT, "Could not merge contents of file");
+		giterr_set(GITERR_CHECKOUT, "could not merge contents of file");
 		error = GIT_ECONFLICT;
 		goto done;
 	}
@@ -2345,7 +2345,7 @@ static int checkout_data_init(
 	memset(data, 0, sizeof(*data));
 
 	if (!repo) {
-		giterr_set(GITERR_CHECKOUT, "Cannot checkout nothing");
+		giterr_set(GITERR_CHECKOUT, "cannot checkout nothing");
 		return -1;
 	}
 
@@ -2469,7 +2469,7 @@ static int checkout_data_init(
 			data->opts.checkout_strategy |= GIT_CHECKOUT_CONFLICT_STYLE_DIFF3;
 		else {
 			giterr_set(GITERR_CHECKOUT, "unknown style '%s' given for 'merge.conflictstyle'",
-				conflict_style);
+				conflict_style->value);
 			error = -1;
 			git_config_entry_free(conflict_style);
 			goto cleanup;
@@ -2553,6 +2553,10 @@ int git_checkout_iterator(
 		GIT_ITERATOR_IGNORE_CASE : GIT_ITERATOR_DONT_IGNORE_CASE;
 	baseline_opts.start = data.pfx;
 	baseline_opts.end = data.pfx;
+	if (opts && (opts->checkout_strategy & GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH)) {
+		baseline_opts.pathlist.count = opts->paths.count;
+		baseline_opts.pathlist.strings = opts->paths.strings;
+	}
 
 	if (data.opts.baseline_index) {
 		if ((error = git_iterator_for_index(
@@ -2647,7 +2651,7 @@ int git_checkout_index(
 
 	if (!index && !repo) {
 		giterr_set(GITERR_CHECKOUT,
-			"Must provide either repository or index to checkout");
+			"must provide either repository or index to checkout");
 		return -1;
 	}
 
@@ -2655,7 +2659,7 @@ int git_checkout_index(
 		git_index_owner(index) &&
 		git_index_owner(index) != repo) {
 		giterr_set(GITERR_CHECKOUT,
-			"Index to checkout does not match repository");
+			"index to checkout does not match repository");
 		return -1;
 	} else if(index && repo && !git_index_owner(index)) {
 		GIT_REFCOUNT_OWN(index, repo);
@@ -2694,12 +2698,12 @@ int git_checkout_tree(
 
 	if (!treeish && !repo) {
 		giterr_set(GITERR_CHECKOUT,
-			"Must provide either repository or tree to checkout");
+			"must provide either repository or tree to checkout");
 		return -1;
 	}
 	if (treeish && repo && git_object_owner(treeish) != repo) {
 		giterr_set(GITERR_CHECKOUT,
-			"Object to checkout does not match repository");
+			"object to checkout does not match repository");
 		return -1;
 	}
 
@@ -2709,7 +2713,7 @@ int git_checkout_tree(
 	if (treeish) {
 		if (git_object_peel((git_object **)&tree, treeish, GIT_OBJ_TREE) < 0) {
 			giterr_set(
-				GITERR_CHECKOUT, "Provided object cannot be peeled to a tree");
+				GITERR_CHECKOUT, "provided object cannot be peeled to a tree");
 			return -1;
 		}
 	}
diff --git a/src/cherrypick.c b/src/cherrypick.c
index c92975194..ab067339e 100644
--- a/src/cherrypick.c
+++ b/src/cherrypick.c
@@ -130,13 +130,13 @@ int git_cherrypick_commit(
 	if (git_commit_parentcount(cherrypick_commit) > 1) {
 		if (!mainline)
 			return cherrypick_seterr(cherrypick_commit,
-				"Mainline branch is not specified but %s is a merge commit");
+				"mainline branch is not specified but %s is a merge commit");
 
 		parent = mainline;
 	} else {
 		if (mainline)
 			return cherrypick_seterr(cherrypick_commit,
-				"Mainline branch specified but %s is not a merge commit");
+				"mainline branch specified but %s is not a merge commit");
 
 		parent = git_commit_parentcount(cherrypick_commit);
 	}
diff --git a/src/commit.c b/src/commit.c
index 76e6dcbc9..87ab2ab60 100644
--- a/src/commit.c
+++ b/src/commit.c
@@ -468,7 +468,7 @@ int git_commit__parse(void *_commit, git_odb_object *odb_obj)
 	return 0;
 
 bad_buffer:
-	giterr_set(GITERR_OBJECT, "Failed to parse bad commit object");
+	giterr_set(GITERR_OBJECT, "failed to parse bad commit object");
 	return -1;
 }
 
@@ -598,7 +598,7 @@ int git_commit_parent(
 
 	parent_id = git_commit_parent_id(commit, n);
 	if (parent_id == NULL) {
-		giterr_set(GITERR_INVALID, "Parent %u does not exist", n);
+		giterr_set(GITERR_INVALID, "parent %u does not exist", n);
 		return GIT_ENOTFOUND;
 	}
 
diff --git a/src/commit_list.c b/src/commit_list.c
index a1681ffae..3bba58c27 100644
--- a/src/commit_list.c
+++ b/src/commit_list.c
@@ -61,7 +61,7 @@ static int commit_error(git_commit_list_node *commit, const char *msg)
 	git_oid_fmt(commit_oid, &commit->oid);
 	commit_oid[GIT_OID_HEXSZ] = '\0';
 
-	giterr_set(GITERR_ODB, "Failed to parse commit %s - %s", commit_oid, msg);
+	giterr_set(GITERR_ODB, "failed to parse commit %s - %s", commit_oid, msg);
 
 	return -1;
 }
@@ -191,7 +191,7 @@ int git_commit_list_parse(git_revwalk *walk, git_commit_list_node *commit)
 		return error;
 
 	if (obj->cached.type != GIT_OBJ_COMMIT) {
-		giterr_set(GITERR_INVALID, "Object is no commit object");
+		giterr_set(GITERR_INVALID, "object is no commit object");
 		error = -1;
 	} else
 		error = commit_quick_parse(
diff --git a/src/common.h b/src/common.h
index 51fb9186e..e566aeabd 100644
--- a/src/common.h
+++ b/src/common.h
@@ -103,7 +103,8 @@
 /**
  * Set the error message for this thread, formatting as needed.
  */
-void giterr_set(int error_class, const char *string, ...);
+
+void giterr_set(int error_class, const char *string, ...) GIT_FORMAT_PRINTF(2, 3);
 
 /**
  * Set the error message for a regex failure, using the internal regex
@@ -187,7 +188,7 @@ GIT_INLINE(int) giterr__check_version(const void *structure, unsigned int expect
 	if (actual > 0 && actual <= expected_max)
 		return 0;
 
-	giterr_set(GITERR_INVALID, "Invalid version %d on %s", actual, name);
+	giterr_set(GITERR_INVALID, "invalid version %d on %s", actual, name);
 	return -1;
 }
 #define GITERR_CHECK_VERSION(S,V,N) if (giterr__check_version(S,V,N) < 0) return -1
diff --git a/src/config.c b/src/config.c
index 403b7090d..0d73ad2cc 100644
--- a/src/config.c
+++ b/src/config.c
@@ -109,7 +109,7 @@ int git_config_add_file_ondisk(
 
 	res = p_stat(path, &st);
 	if (res < 0 && errno != ENOENT) {
-		giterr_set(GITERR_CONFIG, "Error stat'ing config file '%s'", path);
+		giterr_set(GITERR_CONFIG, "failed to stat '%s'", path);
 		return -1;
 	}
 
@@ -203,7 +203,7 @@ static int find_internal_file_by_level(
 
 	if (pos == -1) {
 		giterr_set(GITERR_CONFIG,
-			"No config file exists for the given level '%i'", (int)level);
+			"no config file exists for the given level '%i'", (int)level);
 		return GIT_ENOTFOUND;
 	}
 
@@ -218,7 +218,7 @@ static int duplicate_level(void **old_raw, void *new_raw)
 
 	GIT_UNUSED(new_raw);
 
-	giterr_set(GITERR_CONFIG, "A file with the same level (%i) has already been added to the config", (int)(*old)->level);
+	giterr_set(GITERR_CONFIG, "a file with the same level (%i) has already been added to the config", (int)(*old)->level);
 	return GIT_EEXISTS;
 }
 
@@ -579,7 +579,7 @@ int git_config_foreach_match(
 static int config_error_nofiles(const char *name)
 {
 	giterr_set(GITERR_CONFIG,
-		"Cannot set value for '%s' when no config files exist", name);
+		"cannot set value for '%s' when no config files exist", name);
 	return GIT_ENOTFOUND;
 }
 
@@ -620,7 +620,7 @@ int git_config_set_string(git_config *cfg, const char *name, const char *value)
 	file_internal *internal;
 
 	if (!value) {
-		giterr_set(GITERR_CONFIG, "The value to set cannot be NULL");
+		giterr_set(GITERR_CONFIG, "the value to set cannot be NULL");
 		return -1;
 	}
 
@@ -674,7 +674,7 @@ int git_config__update_entry(
 
 static int config_error_notfound(const char *name)
 {
-	giterr_set(GITERR_CONFIG, "Config value '%s' was not found", name);
+	giterr_set(GITERR_CONFIG, "config value '%s' was not found", name);
 	return GIT_ENOTFOUND;
 }
 
@@ -1236,7 +1236,7 @@ int git_config_lookup_map_value(
 	}
 
 fail_parse:
-	giterr_set(GITERR_CONFIG, "Failed to map '%s'", value);
+	giterr_set(GITERR_CONFIG, "failed to map '%s'", value);
 	return -1;
 }
 
@@ -1270,7 +1270,7 @@ int git_config_parse_bool(int *out, const char *value)
 		return 0;
 	}
 
-	giterr_set(GITERR_CONFIG, "Failed to parse '%s' as a boolean value", value);
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as a boolean value", value);
 	return -1;
 }
 
@@ -1313,7 +1313,7 @@ int git_config_parse_int64(int64_t *out, const char *value)
 	}
 
 fail_parse:
-	giterr_set(GITERR_CONFIG, "Failed to parse '%s' as an integer", value ? value : "(null)");
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as an integer", value ? value : "(null)");
 	return -1;
 }
 
@@ -1333,7 +1333,7 @@ int git_config_parse_int32(int32_t *out, const char *value)
 	return 0;
 
 fail_parse:
-	giterr_set(GITERR_CONFIG, "Failed to parse '%s' as a 32-bit integer", value ? value : "(null)");
+	giterr_set(GITERR_CONFIG, "failed to parse '%s' as a 32-bit integer", value ? value : "(null)");
 	return -1;
 }
 
@@ -1398,7 +1398,7 @@ int git_config__normalize_name(const char *in, char **out)
 
 invalid:
 	git__free(name);
-	giterr_set(GITERR_CONFIG, "Invalid config item name '%s'", in);
+	giterr_set(GITERR_CONFIG, "invalid config item name '%s'", in);
 	return GIT_EINVALIDSPEC;
 }
 
@@ -1461,7 +1461,7 @@ int git_config_rename_section(
 			replace.ptr, strchr(replace.ptr, '.'))) < 0)
 	{
 		giterr_set(
-			GITERR_CONFIG, "Invalid config section '%s'", new_section_name);
+			GITERR_CONFIG, "invalid config section '%s'", new_section_name);
 		goto cleanup;
 	}
 
diff --git a/src/config_file.c b/src/config_file.c
index 9ff021e7e..2e3d568bb 100644
--- a/src/config_file.c
+++ b/src/config_file.c
@@ -126,7 +126,7 @@ static int config_snapshot(git_config_backend **out, git_config_backend *in);
 
 static void set_parse_error(struct reader *reader, int col, const char *error_str)
 {
-	giterr_set(GITERR_CONFIG, "Failed to parse config file: %s (in %s:%d, column %d)",
+	giterr_set(GITERR_CONFIG, "failed to parse config file: %s (in %s:%d, column %d)",
 		error_str, reader->file_path, reader->line_number, col);
 }
 
@@ -233,7 +233,7 @@ static refcounted_strmap *refcounted_strmap_take(diskfile_header *h)
 	refcounted_strmap *map;
 
 	if (git_mutex_lock(&h->values_mutex) < 0) {
-	    giterr_set(GITERR_OS, "Failed to lock config backend");
+	    giterr_set(GITERR_OS, "failed to lock config backend");
 	    return NULL;
 	}
 
@@ -322,7 +322,7 @@ static int config__refresh(git_config_backend *cfg)
 		goto out;
 
 	if ((error = git_mutex_lock(&b->header.values_mutex)) < 0) {
-		giterr_set(GITERR_OS, "Failed to lock config backend");
+		giterr_set(GITERR_OS, "failed to lock config backend");
 		goto out;
 	}
 
@@ -479,7 +479,7 @@ static int config_set(git_config_backend *cfg, const char *name, const char *val
 		cvar_t *existing = git_strmap_value_at(values, pos);
 
 		if (existing->next != NULL) {
-			giterr_set(GITERR_CONFIG, "Multivar incompatible with simple set");
+			giterr_set(GITERR_CONFIG, "multivar incompatible with simple set");
 			ret = -1;
 			goto out;
 		}
@@ -611,7 +611,7 @@ static int config_delete(git_config_backend *cfg, const char *name)
 
 	if (!git_strmap_valid_index(values, pos)) {
 		refcounted_strmap_free(map);
-		giterr_set(GITERR_CONFIG, "Could not find key '%s' to delete", name);
+		giterr_set(GITERR_CONFIG, "could not find key '%s' to delete", name);
 		return GIT_ENOTFOUND;
 	}
 
@@ -619,7 +619,7 @@ static int config_delete(git_config_backend *cfg, const char *name)
 	refcounted_strmap_free(map);
 
 	if (var->next != NULL) {
-		giterr_set(GITERR_CONFIG, "Cannot delete multivar with a single delete");
+		giterr_set(GITERR_CONFIG, "cannot delete multivar with a single delete");
 		return -1;
 	}
 
@@ -651,7 +651,7 @@ static int config_delete_multivar(git_config_backend *cfg, const char *name, con
 	if (!git_strmap_valid_index(values, pos)) {
 		refcounted_strmap_free(map);
 		git__free(key);
-		giterr_set(GITERR_CONFIG, "Could not find key '%s' to delete", name);
+		giterr_set(GITERR_CONFIG, "could not find key '%s' to delete", name);
 		return GIT_ENOTFOUND;
 	}
 
@@ -1325,7 +1325,7 @@ static int unescape_line(
 				*fixed++ = escaped[esc - escapes];
 			} else {
 				git__free(str);
-				giterr_set(GITERR_CONFIG, "Invalid escape at %s", ptr);
+				giterr_set(GITERR_CONFIG, "invalid escape at %s", ptr);
 				return -1;
 			}
 		}
@@ -1639,7 +1639,7 @@ static int config_read(git_strmap *values, diskfile_backend *cfg_file, struct re
 	struct parse_data parse_data;
 
 	if (depth >= MAX_INCLUDE_DEPTH) {
-		giterr_set(GITERR_CONFIG, "Maximum config include depth reached");
+		giterr_set(GITERR_CONFIG, "maximum config include depth reached");
 		return -1;
 	}
 
diff --git a/src/crlf.c b/src/crlf.c
index 11895b19f..b8ae5cda1 100644
--- a/src/crlf.c
+++ b/src/crlf.c
@@ -218,7 +218,7 @@ static const char *line_ending(struct crlf_attrs *ca)
 		return "\r\n";
 
 line_ending_error:
-	giterr_set(GITERR_INVALID, "Invalid input to line ending filter");
+	giterr_set(GITERR_INVALID, "invalid input to line ending filter");
 	return NULL;
 }
 
diff --git a/src/curl_stream.c b/src/curl_stream.c
index 98de187dd..4e0455cca 100644
--- a/src/curl_stream.c
+++ b/src/curl_stream.c
@@ -15,6 +15,16 @@
 #include "vector.h"
 #include "proxy.h"
 
+/* This is for backwards compatibility with curl<7.45.0. */
+#ifndef CURLINFO_ACTIVESOCKET
+# define CURLINFO_ACTIVESOCKET CURLINFO_LASTSOCKET
+# define GIT_CURL_BADSOCKET -1
+# define git_activesocket_t long
+#else
+# define GIT_CURL_BADSOCKET CURL_SOCKET_BAD
+# define git_activesocket_t curl_socket_t
+#endif
+
 typedef struct {
 	git_stream parent;
 	CURL *handle;
@@ -87,7 +97,8 @@ static int ask_and_apply_proxy_creds(curl_stream *s)
 static int curls_connect(git_stream *stream)
 {
 	curl_stream *s = (curl_stream *) stream;
-	long sockextr, connect_last = 0;
+	git_activesocket_t sockextr;
+	long connect_last = 0;
 	int failed_cert = 0, error;
 	bool retry_connect;
 	CURLcode res;
@@ -117,10 +128,15 @@ static int curls_connect(git_stream *stream)
 	if (res == CURLE_PEER_FAILED_VERIFICATION)
 		failed_cert = 1;
 
-	if ((res = curl_easy_getinfo(s->handle, CURLINFO_LASTSOCKET, &sockextr)) != CURLE_OK) {
+	if ((res = curl_easy_getinfo(s->handle, CURLINFO_ACTIVESOCKET, &sockextr)) != CURLE_OK) {
 		return seterr_curl(s);
 	}
 
+	if (sockextr == GIT_CURL_BADSOCKET) {
+		giterr_set(GITERR_NET, "curl socket is no longer valid");
+		return -1;
+	}
+
 	s->socket = sockextr;
 
 	if (s->parent.encrypted && failed_cert)
@@ -198,6 +214,7 @@ static int wait_for(curl_socket_t fd, bool reading)
 	FD_ZERO(&outfd);
 	FD_ZERO(&errfd);
 
+	assert(fd >= 0);
 	FD_SET(fd, &errfd);
 	if (reading)
 		FD_SET(fd, &infd);
diff --git a/src/delta.c b/src/delta.c
index dc45697b6..073cba7c6 100644
--- a/src/delta.c
+++ b/src/delta.c
@@ -131,7 +131,7 @@ static int lookup_index_alloc(
 	GITERR_CHECK_ALLOC_ADD(&index_len, index_len, hash_len);
 
 	if (!git__is_ulong(index_len)) {
-		giterr_set(GITERR_NOMEMORY, "Overly large delta");
+		giterr_set(GITERR_NOMEMORY, "overly large delta");
 		return -1;
 	}
 
@@ -544,12 +544,12 @@ int git_delta_apply(
 	* base object, resulting in data corruption or segfault.
 	*/
 	if ((hdr_sz(&base_sz, &delta, delta_end) < 0) || (base_sz != base_len)) {
-		giterr_set(GITERR_INVALID, "Failed to apply delta. Base size does not match given data");
+		giterr_set(GITERR_INVALID, "failed to apply delta: base size does not match given data");
 		return -1;
 	}
 
 	if (hdr_sz(&res_sz, &delta, delta_end) < 0) {
-		giterr_set(GITERR_INVALID, "Failed to apply delta. Base size does not match given data");
+		giterr_set(GITERR_INVALID, "failed to apply delta: base size does not match given data");
 		return -1;
 	}
 
@@ -614,6 +614,6 @@ fail:
 	*out = NULL;
 	*out_len = 0;
 
-	giterr_set(GITERR_INVALID, "Failed to apply delta");
+	giterr_set(GITERR_INVALID, "failed to apply delta");
 	return -1;
 }
diff --git a/src/describe.c b/src/describe.c
index fc48fbde4..16e195542 100644
--- a/src/describe.c
+++ b/src/describe.c
@@ -335,14 +335,14 @@ static int display_name(git_buf *buf, git_repository *repo, struct commit_name *
 {
 	if (n->prio == 2 && !n->tag) {
 		if (git_tag_lookup(&n->tag, repo, &n->sha1) < 0) {
-			giterr_set(GITERR_TAG, "Annotated tag '%s' not available", n->path);
+			giterr_set(GITERR_TAG, "annotated tag '%s' not available", n->path);
 			return -1;
 		}
 	}
 
 	if (n->tag && !n->name_checked) {
 		if (!git_tag_name(n->tag)) {
-			giterr_set(GITERR_TAG, "Annotated tag '%s' has no embedded name", n->path);
+			giterr_set(GITERR_TAG, "annotated tag '%s' has no embedded name", n->path);
 			return -1;
 		}
 
@@ -471,7 +471,7 @@ static int describe(
 	if (!data->opts->max_candidates_tags) {
 		error = describe_not_found(
 			git_commit_id(commit),
-			"Cannot describe - no tag exactly matches '%s'");
+			"cannot describe - no tag exactly matches '%s'");
 
 		goto cleanup;
 	}
@@ -564,15 +564,15 @@ static int describe(
 		}
 		if (unannotated_cnt) {
 			error = describe_not_found(git_commit_id(commit), 
-				"Cannot describe - "
-				"No annotated tags can describe '%s'."
-			    "However, there were unannotated tags.");
+				"cannot describe - "
+				"no annotated tags can describe '%s'; "
+			    "however, there were unannotated tags.");
 			goto cleanup;
 		}
 		else {
 			error = describe_not_found(git_commit_id(commit), 
-				"Cannot describe - "
-				"No tags can describe '%s'.");
+				"cannot describe - "
+				"no tags can describe '%s'.");
 			goto cleanup;
 		}
 	}
@@ -695,8 +695,8 @@ int git_describe_commit(
 				goto cleanup;
 
 	if (git_oidmap_size(data.names) == 0 && !opts->show_commit_oid_as_fallback) {
-		giterr_set(GITERR_DESCRIBE, "Cannot describe - "
-			"No reference found, cannot describe anything.");
+		giterr_set(GITERR_DESCRIBE, "cannot describe - "
+			"no reference found, cannot describe anything.");
 		error = -1;
 		goto cleanup;
 	}
@@ -793,7 +793,7 @@ int git_describe_format(git_buf *out, const git_describe_result *result, const g
 
 
 	if (opts.always_use_long_format && opts.abbreviated_size == 0) {
-		giterr_set(GITERR_DESCRIBE, "Cannot describe - "
+		giterr_set(GITERR_DESCRIBE, "cannot describe - "
 			"'always_use_long_format' is incompatible with a zero"
 			"'abbreviated_size'");
 		return -1;
diff --git a/src/diff_driver.c b/src/diff_driver.c
index 1a7f09a44..0adf704fb 100644
--- a/src/diff_driver.c
+++ b/src/diff_driver.c
@@ -151,7 +151,7 @@ static git_diff_driver_registry *git_repository_driver_registry(
 	}
 
 	if (!repo->diff_drivers)
-		giterr_set(GITERR_REPOSITORY, "Unable to create diff driver registry");
+		giterr_set(GITERR_REPOSITORY, "unable to create diff driver registry");
 
 	return repo->diff_drivers;
 }
diff --git a/src/diff_file.c b/src/diff_file.c
index cc1029038..d5fc5e940 100644
--- a/src/diff_file.c
+++ b/src/diff_file.c
@@ -304,7 +304,7 @@ static int diff_file_content_load_workdir_symlink(
 
 	read_len = p_readlink(git_buf_cstr(path), fc->map.data, alloc_len);
 	if (read_len < 0) {
-		giterr_set(GITERR_OS, "Failed to read symlink '%s'", fc->file->path);
+		giterr_set(GITERR_OS, "failed to read symlink '%s'", fc->file->path);
 		return -1;
 	}
 
diff --git a/src/diff_generate.c b/src/diff_generate.c
index 06f9b19c7..f6cc04fed 100644
--- a/src/diff_generate.c
+++ b/src/diff_generate.c
@@ -624,7 +624,7 @@ int git_diff__oid_for_entry(
 		error = git_odb__hashlink(out, full_path.ptr);
 		diff->base.perf.oid_calculations++;
 	} else if (!git__is_sizet(entry.file_size)) {
-		giterr_set(GITERR_OS, "File size overflow (for 32-bits) on '%s'",
+		giterr_set(GITERR_OS, "file size overflow (for 32-bits) on '%s'",
 			entry.path);
 		error = -1;
 	} else if (!(error = git_filter_list_load(&fl,
@@ -1587,7 +1587,7 @@ int git_diff__commit(
 		char commit_oidstr[GIT_OID_HEXSZ + 1];
 
 		error = -1;
-		giterr_set(GITERR_INVALID, "Commit %s is a merge commit",
+		giterr_set(GITERR_INVALID, "commit %s is a merge commit",
 			git_oid_tostr(commit_oidstr, GIT_OID_HEXSZ + 1, git_commit_id(commit)));
 		goto on_error;
 	}
diff --git a/src/diff_print.c b/src/diff_print.c
index fd1a186c1..5aa8a37e6 100644
--- a/src/diff_print.c
+++ b/src/diff_print.c
@@ -222,7 +222,7 @@ static int diff_print_one_raw(
 
 	if (pi->id_strlen > id_abbrev) {
 		giterr_set(GITERR_PATCH,
-			"The patch input contains %d id characters (cannot print %d)",
+			"the patch input contains %d id characters (cannot print %d)",
 			id_abbrev, pi->id_strlen);
 		return -1;
 	}
@@ -273,7 +273,7 @@ static int diff_print_oid_range(
 	if (delta->old_file.mode &&
 			id_strlen > delta->old_file.id_abbrev) {
 		giterr_set(GITERR_PATCH,
-			"The patch input contains %d id characters (cannot print %d)",
+			"the patch input contains %d id characters (cannot print %d)",
 			delta->old_file.id_abbrev, id_strlen);
 		return -1;
 	}
@@ -281,7 +281,7 @@ static int diff_print_oid_range(
 	if ((delta->new_file.mode &&
 			id_strlen > delta->new_file.id_abbrev)) {
 		giterr_set(GITERR_PATCH,
-			"The patch input contains %d id characters (cannot print %d)",
+			"the patch input contains %d id characters (cannot print %d)",
 			delta->new_file.id_abbrev, id_strlen);
 		return -1;
 	}
@@ -680,7 +680,7 @@ int git_diff_print(
 		print_file = diff_print_one_name_status;
 		break;
 	default:
-		giterr_set(GITERR_INVALID, "Unknown diff output format (%d)", format);
+		giterr_set(GITERR_INVALID, "unknown diff output format (%d)", format);
 		return -1;
 	}
 
@@ -708,7 +708,7 @@ int git_diff_print_callback__to_buf(
 	GIT_UNUSED(delta); GIT_UNUSED(hunk);
 
 	if (!output) {
-		giterr_set(GITERR_INVALID, "Buffer pointer must be provided");
+		giterr_set(GITERR_INVALID, "buffer pointer must be provided");
 		return -1;
 	}
 
diff --git a/src/diff_tform.c b/src/diff_tform.c
index e8848bd45..f2ff147d1 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -131,7 +131,7 @@ int git_diff__merge(
 	if (ignore_case != ((from->opts.flags & GIT_DIFF_IGNORE_CASE) != 0) ||
 		reversed    != ((from->opts.flags & GIT_DIFF_REVERSE) != 0)) {
 		giterr_set(GITERR_INVALID,
-			"Attempt to merge diffs created with conflicting options");
+			"attempt to merge diffs created with conflicting options");
 		return -1;
 	}
 
diff --git a/src/diff_xdiff.c b/src/diff_xdiff.c
index 5bd6381b5..60c4d85cb 100644
--- a/src/diff_xdiff.c
+++ b/src/diff_xdiff.c
@@ -50,7 +50,7 @@ static int git_xdiff_parse_hunk(git_diff_hunk *hunk, const char *header)
 	return 0;
 
 fail:
-	giterr_set(GITERR_INVALID, "Malformed hunk header from xdiff");
+	giterr_set(GITERR_INVALID, "malformed hunk header from xdiff");
 	return -1;
 }
 
@@ -99,7 +99,7 @@ static int diff_update_lines(
 		info->new_lineno += (int)line->num_lines;
 		break;
 	default:
-		giterr_set(GITERR_INVALID, "Unknown diff line origin %02x",
+		giterr_set(GITERR_INVALID, "unknown diff line origin %02x",
 			(unsigned int)line->origin);
 		return -1;
 	}
diff --git a/src/fetch.c b/src/fetch.c
index 4d895752c..f408a5174 100644
--- a/src/fetch.c
+++ b/src/fetch.c
@@ -113,7 +113,7 @@ int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts)
 	remote->need_pack = 0;
 
 	if (filter_wants(remote, opts) < 0) {
-		giterr_set(GITERR_NET, "Failed to filter the reference list for wants");
+		giterr_set(GITERR_NET, "failed to filter the reference list for wants");
 		return -1;
 	}
 
diff --git a/src/fetchhead.c b/src/fetchhead.c
index a95ea4ca4..0d9ab2c25 100644
--- a/src/fetchhead.c
+++ b/src/fetchhead.c
@@ -149,7 +149,7 @@ static int fetchhead_ref_parse(
 
 	if (!*line) {
 		giterr_set(GITERR_FETCHHEAD,
-			"Empty line in FETCH_HEAD line %d", line_num);
+			"empty line in FETCH_HEAD line %"PRIuZ, line_num);
 		return -1;
 	}
 
@@ -163,15 +163,15 @@ static int fetchhead_ref_parse(
 
 	if (strlen(oid_str) != GIT_OID_HEXSZ) {
 		giterr_set(GITERR_FETCHHEAD,
-			"Invalid object ID in FETCH_HEAD line %d", line_num);
+			"invalid object ID in FETCH_HEAD line %"PRIuZ, line_num);
 		return -1;
 	}
 
 	if (git_oid_fromstr(oid, oid_str) < 0) {
 		const git_error *oid_err = giterr_last();
-		const char *err_msg = oid_err ? oid_err->message : "Invalid object ID";
+		const char *err_msg = oid_err ? oid_err->message : "invalid object ID";
 
-		giterr_set(GITERR_FETCHHEAD, "%s in FETCH_HEAD line %d",
+		giterr_set(GITERR_FETCHHEAD, "%s in FETCH_HEAD line %"PRIuZ,
 			err_msg, line_num);
 		return -1;
 	}
@@ -180,7 +180,7 @@ static int fetchhead_ref_parse(
 	if (*line) {
 		if ((is_merge_str = git__strsep(&line, "\t")) == NULL) {
 			giterr_set(GITERR_FETCHHEAD,
-				"Invalid description data in FETCH_HEAD line %d", line_num);
+				"invalid description data in FETCH_HEAD line %"PRIuZ, line_num);
 			return -1;
 		}
 
@@ -190,13 +190,13 @@ static int fetchhead_ref_parse(
 			*is_merge = 0;
 		else {
 			giterr_set(GITERR_FETCHHEAD,
-				"Invalid for-merge entry in FETCH_HEAD line %d", line_num);
+				"invalid for-merge entry in FETCH_HEAD line %"PRIuZ, line_num);
 			return -1;
 		}
 
 		if ((desc = line) == NULL) {
 			giterr_set(GITERR_FETCHHEAD,
-				"Invalid description in FETCH_HEAD line %d", line_num);
+				"invalid description in FETCH_HEAD line %"PRIuZ, line_num);
 			return -1;
 		}
 
@@ -213,7 +213,7 @@ static int fetchhead_ref_parse(
 			if ((desc = strstr(name, "' ")) == NULL ||
 				git__prefixcmp(desc, "' of ") != 0) {
 				giterr_set(GITERR_FETCHHEAD,
-					"Invalid description in FETCH_HEAD line %d", line_num);
+					"invalid description in FETCH_HEAD line %"PRIuZ, line_num);
 				return -1;
 			}
 
@@ -277,7 +277,7 @@ int git_repository_fetchhead_foreach(git_repository *repo,
 	}
 
 	if (*buffer) {
-		giterr_set(GITERR_FETCHHEAD, "No EOL at line %d", line_num+1);
+		giterr_set(GITERR_FETCHHEAD, "no EOL at line %"PRIuZ, line_num+1);
 		error = -1;
 		goto done;
 	}
diff --git a/src/filebuf.c b/src/filebuf.c
index 582399470..ef68b16f4 100644
--- a/src/filebuf.c
+++ b/src/filebuf.c
@@ -23,7 +23,7 @@ static int verify_last_error(git_filebuf *file)
 {
 	switch (file->last_error) {
 	case BUFERR_WRITE:
-		giterr_set(GITERR_OS, "Failed to write out file");
+		giterr_set(GITERR_OS, "failed to write out file");
 		return -1;
 
 	case BUFERR_MEM:
@@ -48,7 +48,7 @@ static int lock_file(git_filebuf *file, int flags, mode_t mode)
 		else {
 			giterr_clear(); /* actual OS error code just confuses */
 			giterr_set(GITERR_OS,
-				"Failed to lock file '%s' for writing", file->path_lock);
+				"failed to lock file '%s' for writing", file->path_lock);
 			return GIT_ELOCKED;
 		}
 	}
@@ -75,7 +75,7 @@ static int lock_file(git_filebuf *file, int flags, mode_t mode)
 		source = p_open(file->path_original, O_RDONLY);
 		if (source < 0) {
 			giterr_set(GITERR_OS,
-				"Failed to open file '%s' for reading",
+				"failed to open file '%s' for reading",
 				file->path_original);
 			return -1;
 		}
@@ -90,10 +90,10 @@ static int lock_file(git_filebuf *file, int flags, mode_t mode)
 		p_close(source);
 
 		if (read_bytes < 0) {
-			giterr_set(GITERR_OS, "Failed to read file '%s'", file->path_original);
+			giterr_set(GITERR_OS, "failed to read file '%s'", file->path_original);
 			return -1;
 		} else if (error < 0) {
-			giterr_set(GITERR_OS, "Failed to write file '%s'", file->path_lock);
+			giterr_set(GITERR_OS, "failed to write file '%s'", file->path_lock);
 			return -1;
 		}
 	}
@@ -316,7 +316,7 @@ int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mo
 	if (compression != 0) {
 		/* Initialize the ZLib stream */
 		if (deflateInit(&file->zs, compression) != Z_OK) {
-			giterr_set(GITERR_ZLIB, "Failed to initialize zlib");
+			giterr_set(GITERR_ZLIB, "failed to initialize zlib");
 			goto cleanup;
 		}
 
@@ -426,14 +426,14 @@ int git_filebuf_commit(git_filebuf *file)
 	file->fd_is_open = false;
 
 	if (p_close(file->fd) < 0) {
-		giterr_set(GITERR_OS, "Failed to close file at '%s'", file->path_lock);
+		giterr_set(GITERR_OS, "failed to close file at '%s'", file->path_lock);
 		goto on_error;
 	}
 
 	file->fd = -1;
 
 	if (p_rename(file->path_lock, file->path_original) < 0) {
-		giterr_set(GITERR_OS, "Failed to rename lockfile to '%s'", file->path_original);
+		giterr_set(GITERR_OS, "failed to rename lockfile to '%s'", file->path_original);
 		goto on_error;
 	}
 
@@ -571,7 +571,7 @@ int git_filebuf_stats(time_t *mtime, size_t *size, git_filebuf *file)
 		res = p_stat(file->path_original, &st);
 
 	if (res < 0) {
-		giterr_set(GITERR_OS, "Could not get stat info for '%s'",
+		giterr_set(GITERR_OS, "could not get stat info for '%s'",
 			file->path_original);
 		return res;
 	}
diff --git a/src/fileops.c b/src/fileops.c
index fcc0301f9..7a8733209 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -37,13 +37,13 @@ int git_futils_mktmp(git_buf *path_out, const char *filename, mode_t mode)
 
 	if ((fd = p_mkstemp(path_out->ptr)) < 0) {
 		giterr_set(GITERR_OS,
-			"Failed to create temporary file '%s'", path_out->ptr);
+			"failed to create temporary file '%s'", path_out->ptr);
 		return -1;
 	}
 
 	if (p_chmod(path_out->ptr, (mode & ~mask))) {
 		giterr_set(GITERR_OS,
-			"Failed to set permissions on file '%s'", path_out->ptr);
+			"failed to set permissions on file '%s'", path_out->ptr);
 		return -1;
 	}
 
@@ -59,7 +59,7 @@ int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode
 
 	fd = p_creat(path, mode);
 	if (fd < 0) {
-		giterr_set(GITERR_OS, "Failed to create file '%s'", path);
+		giterr_set(GITERR_OS, "failed to create file '%s'", path);
 		return -1;
 	}
 
@@ -72,8 +72,16 @@ int git_futils_creat_locked(const char *path, const mode_t mode)
 		O_EXCL | O_BINARY | O_CLOEXEC, mode);
 
 	if (fd < 0) {
-		giterr_set(GITERR_OS, "Failed to create locked file '%s'", path);
-		return errno == EEXIST ? GIT_ELOCKED : -1;
+		int error = errno;
+		giterr_set(GITERR_OS, "failed to create locked file '%s'", path);
+		switch (error) {
+		case EEXIST:
+			return GIT_ELOCKED;
+		case ENOENT:
+			return GIT_ENOTFOUND;
+		default:
+			return -1;
+		}
 	}
 
 	return fd;
@@ -100,7 +108,7 @@ git_off_t git_futils_filesize(git_file fd)
 	struct stat sb;
 
 	if (p_fstat(fd, &sb)) {
-		giterr_set(GITERR_OS, "Failed to stat file descriptor");
+		giterr_set(GITERR_OS, "failed to stat file descriptor");
 		return -1;
 	}
 
@@ -129,7 +137,7 @@ int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
 	git_buf_clear(buf);
 
 	if (!git__is_ssizet(len)) {
-		giterr_set(GITERR_INVALID, "Read too large.");
+		giterr_set(GITERR_INVALID, "read too large");
 		return -1;
 	}
 
@@ -141,7 +149,7 @@ int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
 	read_size = p_read(fd, buf->ptr, len);
 
 	if (read_size != (ssize_t)len) {
-		giterr_set(GITERR_OS, "Failed to read descriptor");
+		giterr_set(GITERR_OS, "failed to read descriptor");
 		git_buf_free(buf);
 		return -1;
 	}
@@ -176,7 +184,7 @@ int git_futils_readbuffer_updated(
 	}
 
 	if (!git__is_sizet(st.st_size+1)) {
-		giterr_set(GITERR_OS, "Invalid regular file stat for '%s'", path);
+		giterr_set(GITERR_OS, "invalid regular file stat for '%s'", path);
 		return -1;
 	}
 
@@ -237,18 +245,18 @@ int git_futils_writebuffer(
 		mode = GIT_FILEMODE_BLOB;
 
 	if ((fd = p_open(path, flags, mode)) < 0) {
-		giterr_set(GITERR_OS, "Could not open '%s' for writing", path);
+		giterr_set(GITERR_OS, "could not open '%s' for writing", path);
 		return fd;
 	}
 
 	if ((error = p_write(fd, git_buf_cstr(buf), git_buf_len(buf))) < 0) {
-		giterr_set(GITERR_OS, "Could not write to '%s'", path);
+		giterr_set(GITERR_OS, "could not write to '%s'", path);
 		(void)p_close(fd);
 		return error;
 	}
 
 	if ((error = p_close(fd)) < 0)
-		giterr_set(GITERR_OS, "Error while closing '%s'", path);
+		giterr_set(GITERR_OS, "error while closing '%s'", path);
 
 	return error;
 }
@@ -259,7 +267,7 @@ int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmod
 		return -1;
 
 	if (p_rename(from, to) < 0) {
-		giterr_set(GITERR_OS, "Failed to rename '%s' to '%s'", from, to);
+		giterr_set(GITERR_OS, "failed to rename '%s' to '%s'", from, to);
 		return -1;
 	}
 
@@ -282,7 +290,7 @@ int git_futils_mmap_ro_file(git_map *out, const char *path)
 
 	len = git_futils_filesize(fd);
 	if (!git__is_sizet(len)) {
-		giterr_set(GITERR_OS, "File `%s` too large to mmap", path);
+		giterr_set(GITERR_OS, "file `%s` too large to mmap", path);
 		return -1;
 	}
 
@@ -306,14 +314,14 @@ GIT_INLINE(int) mkdir_validate_dir(
 	/* with exclusive create, existing dir is an error */
 	if ((flags & GIT_MKDIR_EXCL) != 0) {
 		giterr_set(GITERR_FILESYSTEM,
-			"Failed to make directory '%s': directory exists", path);
+			"failed to make directory '%s': directory exists", path);
 		return GIT_EEXISTS;
 	}
 
 	if ((S_ISREG(st->st_mode) && (flags & GIT_MKDIR_REMOVE_FILES)) ||
 		(S_ISLNK(st->st_mode) && (flags & GIT_MKDIR_REMOVE_SYMLINKS))) {
 		if (p_unlink(path) < 0) {
-			giterr_set(GITERR_OS, "Failed to remove %s '%s'",
+			giterr_set(GITERR_OS, "failed to remove %s '%s'",
 				S_ISLNK(st->st_mode) ? "symlink" : "file", path);
 			return GIT_EEXISTS;
 		}
@@ -321,7 +329,7 @@ GIT_INLINE(int) mkdir_validate_dir(
 		opts->perfdata.mkdir_calls++;
 
 		if (p_mkdir(path, mode) < 0) {
-			giterr_set(GITERR_OS, "Failed to make directory '%s'", path);
+			giterr_set(GITERR_OS, "failed to make directory '%s'", path);
 			return GIT_EEXISTS;
 		}
 	}
@@ -331,14 +339,14 @@ GIT_INLINE(int) mkdir_validate_dir(
 		opts->perfdata.stat_calls++;
 
 		if (p_stat(path, st) < 0) {
-			giterr_set(GITERR_OS, "Failed to make directory '%s'", path);
+			giterr_set(GITERR_OS, "failed to make directory '%s'", path);
 			return GIT_EEXISTS;
 		}
 	}
 
 	else if (!S_ISDIR(st->st_mode)) {
 		giterr_set(GITERR_FILESYSTEM,
-			"Failed to make directory '%s': directory exists", path);
+			"failed to make directory '%s': directory exists", path);
 		return GIT_EEXISTS;
 	}
 
@@ -561,7 +569,7 @@ int git_futils_mkdir_relative(
 retry_lstat:
 		if (p_lstat(make_path.ptr, &st) < 0) {
 			if (mkdir_attempted || errno != ENOENT) {
-				giterr_set(GITERR_OS, "Cannot access component in path '%s'", make_path.ptr);
+				giterr_set(GITERR_OS, "cannot access component in path '%s'", make_path.ptr);
 				error = -1;
 				goto done;
 			}
@@ -572,7 +580,7 @@ retry_lstat:
 			if (p_mkdir(make_path.ptr, mode) < 0) {
 				if (errno == EEXIST)
 					goto retry_lstat;
-				giterr_set(GITERR_OS, "Failed to make directory '%s'", make_path.ptr);
+				giterr_set(GITERR_OS, "failed to make directory '%s'", make_path.ptr);
 				error = -1;
 				goto done;
 			}
@@ -613,7 +621,7 @@ retry_lstat:
 		opts->perfdata.stat_calls++;
 
 		if (p_stat(make_path.ptr, &st) < 0 || !S_ISDIR(st.st_mode)) {
-			giterr_set(GITERR_OS, "Path is not a directory '%s'",
+			giterr_set(GITERR_OS, "path is not a directory '%s'",
 				make_path.ptr);
 			error = GIT_ENOTFOUND;
 		}
@@ -636,10 +644,10 @@ typedef struct {
 static int futils__error_cannot_rmdir(const char *path, const char *filemsg)
 {
 	if (filemsg)
-		giterr_set(GITERR_OS, "Could not remove directory. File '%s' %s",
+		giterr_set(GITERR_OS, "could not remove directory '%s': %s",
 				   path, filemsg);
 	else
-		giterr_set(GITERR_OS, "Could not remove directory '%s'", path);
+		giterr_set(GITERR_OS, "could not remove directory '%s'", path);
 
 	return -1;
 }
@@ -807,7 +815,7 @@ static int cp_by_fd(int ifd, int ofd, bool close_fd_when_done)
 		error = p_write(ofd, buffer, len);
 
 	if (len < 0) {
-		giterr_set(GITERR_OS, "Read error while copying file");
+		giterr_set(GITERR_OS, "read error while copying file");
 		error = (int)len;
 	}
 
@@ -863,14 +871,14 @@ static int cp_link(const char *from, const char *to, size_t link_size)
 
 	read_len = p_readlink(from, link_data, link_size);
 	if (read_len != (ssize_t)link_size) {
-		giterr_set(GITERR_OS, "Failed to read symlink data for '%s'", from);
+		giterr_set(GITERR_OS, "failed to read symlink data for '%s'", from);
 		error = -1;
 	}
 	else {
 		link_data[read_len] = '\0';
 
 		if (p_symlink(link_data, to) < 0) {
-			giterr_set(GITERR_OS, "Could not symlink '%s' as '%s'",
+			giterr_set(GITERR_OS, "could not symlink '%s' as '%s'",
 				link_data, to);
 			error = -1;
 		}
@@ -966,7 +974,7 @@ static int _cp_r_callback(void *ref, git_buf *from)
 			return 0;
 
 		if (p_unlink(info->to.ptr) < 0) {
-			giterr_set(GITERR_OS, "Cannot overwrite existing file '%s'",
+			giterr_set(GITERR_OS, "cannot overwrite existing file '%s'",
 				info->to.ptr);
 			return GIT_EEXISTS;
 		}
diff --git a/src/fileops.h b/src/fileops.h
index 54e3bd4e4..65c96a6f5 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -45,12 +45,12 @@ extern int git_futils_writebuffer(
 extern int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode);
 
 /**
- * Create an open a process-locked file
+ * Create and open a process-locked file
  */
 extern int git_futils_creat_locked(const char *path, const mode_t mode);
 
 /**
- * Create an open a process-locked file, while
+ * Create and open a process-locked file, while
  * also creating all the folders in its path
  */
 extern int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode);
diff --git a/src/filter.c b/src/filter.c
index a0628d779..0d8831e0c 100644
--- a/src/filter.c
+++ b/src/filter.c
@@ -296,7 +296,7 @@ int git_filter_unregister(const char *name)
 
 	/* cannot unregister default filters */
 	if (!strcmp(GIT_FILTER_CRLF, name) || !strcmp(GIT_FILTER_IDENT, name)) {
-		giterr_set(GITERR_FILTER, "Cannot unregister filter '%s'", name);
+		giterr_set(GITERR_FILTER, "cannot unregister filter '%s'", name);
 		return -1;
 	}
 
@@ -306,7 +306,7 @@ int git_filter_unregister(const char *name)
 	}
 
 	if ((fdef = filter_registry_lookup(&pos, name)) == NULL) {
-		giterr_set(GITERR_FILTER, "Cannot find filter '%s' to unregister", name);
+		giterr_set(GITERR_FILTER, "cannot find filter '%s' to unregister", name);
 		error = GIT_ENOTFOUND;
 		goto done;
 	}
@@ -645,7 +645,7 @@ int git_filter_list_push(
 	git_rwlock_rdunlock(&filter_registry.lock);
 
 	if (fdef == NULL) {
-		giterr_set(GITERR_FILTER, "Cannot use an unregistered filter");
+		giterr_set(GITERR_FILTER, "cannot use an unregistered filter");
 		return -1;
 	}
 
@@ -758,7 +758,7 @@ static int buf_from_blob(git_buf *out, git_blob *blob)
 	git_off_t rawsize = git_blob_rawsize(blob);
 
 	if (!git__is_sizet(rawsize)) {
-		giterr_set(GITERR_OS, "Blob is too large to filter");
+		giterr_set(GITERR_OS, "blob is too large to filter");
 		return -1;
 	}
 
diff --git a/src/global.c b/src/global.c
index 45b1ab8f6..e2ad8fe71 100644
--- a/src/global.c
+++ b/src/global.c
@@ -247,6 +247,7 @@ BOOL WINAPI DllMain(HINSTANCE hInstDll, DWORD fdwReason, LPVOID lpvReserved)
 #elif defined(GIT_THREADS) && defined(_POSIX_THREADS)
 
 static pthread_key_t _tls_key;
+static pthread_mutex_t _init_mutex = PTHREAD_MUTEX_INITIALIZER;
 static pthread_once_t _once_init = PTHREAD_ONCE_INIT;
 int init_error = 0;
 
@@ -268,12 +269,19 @@ static void init_once(void)
 
 int git_libgit2_init(void)
 {
-	int ret;
+	int ret, err;
 
 	ret = git_atomic_inc(&git__n_inits);
-	pthread_once(&_once_init, init_once);
 
-	return init_error ? init_error : ret;
+	if ((err = pthread_mutex_lock(&_init_mutex)) != 0)
+		return err;
+	err = pthread_once(&_once_init, init_once);
+	err |= pthread_mutex_unlock(&_init_mutex);
+
+	if (err || init_error)
+		return err | init_error;
+
+	return ret;
 }
 
 int git_libgit2_shutdown(void)
@@ -285,6 +293,9 @@ int git_libgit2_shutdown(void)
 	if ((ret = git_atomic_dec(&git__n_inits)) != 0)
 		return ret;
 
+	if ((ret = pthread_mutex_lock(&_init_mutex)) != 0)
+		return ret;
+
 	/* Shut down any subsystems that have global state */
 	shutdown_common();
 
@@ -298,6 +309,9 @@ int git_libgit2_shutdown(void)
 	git_mutex_free(&git__mwindow_mutex);
 	_once_init = new_once;
 
+	if ((ret = pthread_mutex_unlock(&_init_mutex)) != 0)
+		return ret;
+
 	return 0;
 }
 
@@ -327,7 +341,7 @@ int git_libgit2_init(void)
 {
 	int ret;
 
-	/* Only init SSL the first time */
+	/* Only init subsystems the first time */
 	if ((ret = git_atomic_inc(&git__n_inits)) != 1)
 		return ret;
 
@@ -345,6 +359,7 @@ int git_libgit2_shutdown(void)
 	if ((ret = git_atomic_dec(&git__n_inits)) == 0) {
 		shutdown_common();
 		git__global_state_cleanup(&__state);
+		memset(&__state, 0, sizeof(__state));
 	}
 
 	return ret;
diff --git a/src/global.h b/src/global.h
index 219951525..88f40aad1 100644
--- a/src/global.h
+++ b/src/global.h
@@ -16,6 +16,12 @@ typedef struct {
 	git_error error_t;
 	git_buf error_buf;
 	char oid_fmt[GIT_OID_HEXSZ+1];
+
+	/* On Windows, this is the current child thread that was started by
+	 * `git_thread_create`.  This is used to set the thread's exit code
+	 * when terminated by `git_thread_exit`.  It is unused on POSIX.
+	 */
+	git_thread *current_thread;
 } git_global_st;
 
 #ifdef GIT_OPENSSL
diff --git a/src/graph.c b/src/graph.c
index 8accd808c..948f7d306 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -59,7 +59,7 @@ static int mark_parents(git_revwalk *walk, git_commit_list_node *one,
 	/* as long as there are non-STALE commits */
 	while (interesting(&list, roots)) {
 		git_commit_list_node *commit = git_pqueue_pop(&list);
-		int flags;
+		unsigned int flags;
 
 		if (commit == NULL)
 			break;
diff --git a/src/hashsig.c b/src/hashsig.c
index e99637d8b..bea538349 100644
--- a/src/hashsig.c
+++ b/src/hashsig.c
@@ -214,7 +214,7 @@ static int hashsig_finalize_hashes(git_hashsig *sig)
 	if (sig->mins.size < HASHSIG_HEAP_MIN_SIZE &&
 		!(sig->opt & GIT_HASHSIG_ALLOW_SMALL_FILES)) {
 		giterr_set(GITERR_INVALID,
-			"File too small for similarity signature calculation");
+			"file too small for similarity signature calculation");
 		return GIT_EBUFS;
 	}
 
@@ -286,7 +286,7 @@ int git_hashsig_create_fromfile(
 		if ((buflen = p_read(fd, buf, sizeof(buf))) <= 0) {
 			if ((error = (int)buflen) < 0)
 				giterr_set(GITERR_OS,
-					"Read error on '%s' calculating similarity hashes", path);
+					"read error on '%s' calculating similarity hashes", path);
 			break;
 		}
 
diff --git a/src/ignore.c b/src/ignore.c
index dcbd5c1ca..d1a6c5550 100644
--- a/src/ignore.c
+++ b/src/ignore.c
@@ -175,7 +175,7 @@ static int parse_ignore_file(
 		context = attrs->entry->path;
 
 	if (git_mutex_lock(&attrs->lock) < 0) {
-		giterr_set(GITERR_OS, "Failed to lock ignore file");
+		giterr_set(GITERR_OS, "failed to lock ignore file");
 		return -1;
 	}
 
diff --git a/src/index.c b/src/index.c
index bc15959a8..f27fa16d2 100644
--- a/src/index.c
+++ b/src/index.c
@@ -552,7 +552,7 @@ int git_index_clear(git_index *index)
 
 static int create_index_error(int error, const char *msg)
 {
-	giterr_set(GITERR_INDEX, msg);
+	giterr_set_str(GITERR_INDEX, msg);
 	return error;
 }
 
@@ -570,7 +570,7 @@ int git_index_set_caps(git_index *index, int caps)
 
 		if (!repo)
 			return create_index_error(
-				-1, "Cannot access repository to set index caps");
+				-1, "cannot access repository to set index caps");
 
 		if (!git_repository__cvar(&val, repo, GIT_CVAR_IGNORECASE))
 			index->ignore_case = (val != 0);
@@ -639,7 +639,7 @@ int git_index_read(git_index *index, int force)
 
 	if (!index->index_file_path)
 		return create_index_error(-1,
-			"Failed to read index: The index is in-memory only");
+			"failed to read index: The index is in-memory only");
 
 	index->on_disk = git_path_exists(index->index_file_path);
 
@@ -653,7 +653,7 @@ int git_index_read(git_index *index, int force)
 	    ((updated = compare_checksum(index)) < 0)) {
 		giterr_set(
 			GITERR_INDEX,
-			"Failed to read index: '%s' no longer exists",
+			"failed to read index: '%s' no longer exists",
 			index->index_file_path);
 		return updated;
 	}
@@ -765,7 +765,7 @@ int git_index_set_version(git_index *index, unsigned int version)
 
 	if (version < INDEX_VERSION_NUMBER_LB ||
 	    version > INDEX_VERSION_NUMBER_UB) {
-		giterr_set(GITERR_INDEX, "Invalid version number");
+		giterr_set(GITERR_INDEX, "invalid version number");
 		return -1;
 	}
 
@@ -805,7 +805,7 @@ int git_index_write_tree(git_oid *oid, git_index *index)
 
 	if (repo == NULL)
 		return create_index_error(-1, "Failed to write tree. "
-		  "The index file is not backed up by an existing repository");
+		  "the index file is not backed up by an existing repository");
 
 	return git_tree__write_index(oid, index, repo);
 }
@@ -847,7 +847,7 @@ const git_index_entry *git_index_get_bypath(
 	if (git_idxmap_valid_index(index->entries_map, pos))
 		return git_idxmap_value_at(index->entries_map, pos);
 
-	giterr_set(GITERR_INDEX, "Index does not contain %s", path);
+	giterr_set(GITERR_INDEX, "index does not contain '%s'", path);
 	return NULL;
 }
 
@@ -934,7 +934,7 @@ static int index_entry_init(
 
 	if (INDEX_OWNER(index) == NULL)
 		return create_index_error(-1,
-			"Could not initialize index entry. "
+			"could not initialize index entry. "
 			"Index is not backed up by an existing repository.");
 
 	if (index_entry_create(&entry, INDEX_OWNER(index), rel_path, true) < 0)
@@ -1423,7 +1423,7 @@ int git_index_add_frombuffer(
 
 	if (INDEX_OWNER(index) == NULL)
 		return create_index_error(-1,
-			"Could not initialize index entry. "
+			"could not initialize index entry. "
 			"Index is not backed up by an existing repository.");
 
 	if (!valid_filemode(source_entry->mode)) {
@@ -1637,7 +1637,7 @@ int git_index_remove(git_index *index, const char *path, int stage)
 
 	if (index_find(&position, index, path, 0, stage) < 0) {
 		giterr_set(
-			GITERR_INDEX, "Index does not contain %s at stage %d", path, stage);
+			GITERR_INDEX, "index does not contain %s at stage %d", path, stage);
 		error = GIT_ENOTFOUND;
 	} else {
 		error = index_remove_entry(index, position);
@@ -1709,7 +1709,7 @@ int git_index_find(size_t *at_pos, git_index *index, const char *path)
 
 	if (git_vector_bsearch2(
 			&pos, &index->entries, index->entries_search_path, path) < 0) {
-		giterr_set(GITERR_INDEX, "Index does not contain %s", path);
+		giterr_set(GITERR_INDEX, "index does not contain %s", path);
 		return GIT_ENOTFOUND;
 	}
 
@@ -2153,7 +2153,7 @@ void git_index_reuc_clear(git_index *index)
 
 static int index_error_invalid(const char *message)
 {
-	giterr_set(GITERR_INDEX, "Invalid data in index - %s", message);
+	giterr_set(GITERR_INDEX, "invalid data in index - %s", message);
 	return -1;
 }
 
@@ -3390,7 +3390,7 @@ static int index_apply_to_all(
 				i--; /* back up foreach if we removed this */
 			break;
 		default:
-			giterr_set(GITERR_INVALID, "Unknown index action %d", action);
+			giterr_set(GITERR_INVALID, "unknown index action %d", action);
 			error = -1;
 			break;
 		}
@@ -3475,13 +3475,13 @@ int git_indexwriter_init(
 
 	if (!index->index_file_path)
 		return create_index_error(-1,
-			"Failed to write index: The index is in-memory only");
+			"failed to write index: The index is in-memory only");
 
 	if ((error = git_filebuf_open(
 		&writer->file, index->index_file_path, GIT_FILEBUF_HASH_CONTENTS, GIT_INDEX_FILE_MODE)) < 0) {
 
 		if (error == GIT_ELOCKED)
-			giterr_set(GITERR_INDEX, "The index is locked. This might be due to a concurrent or crashed process");
+			giterr_set(GITERR_INDEX, "the index is locked; this might be due to a concurrent or crashed process");
 
 		return error;
 	}
@@ -3530,7 +3530,7 @@ int git_indexwriter_commit(git_indexwriter *writer)
 
 	if ((error = git_futils_filestamp_check(
 		&writer->index->stamp, writer->index->index_file_path)) < 0) {
-		giterr_set(GITERR_OS, "Could not read index timestamp");
+		giterr_set(GITERR_OS, "could not read index timestamp");
 		return -1;
 	}
 
diff --git a/src/indexer.c b/src/indexer.c
index a3a866989..951d7179c 100644
--- a/src/indexer.c
+++ b/src/indexer.c
@@ -33,7 +33,7 @@ struct entry {
 
 struct git_indexer {
 	unsigned int parsed_header :1,
-		opened_pack :1,
+		pack_committed :1,
 		have_stream :1,
 		have_delta :1;
 	struct git_pack_header hdr;
@@ -83,12 +83,12 @@ static int parse_header(struct git_pack_header *hdr, struct git_pack_file *pack)
 
 	/* Verify we recognize this pack file format. */
 	if (hdr->hdr_signature != ntohl(PACK_SIGNATURE)) {
-		giterr_set(GITERR_INDEXER, "Wrong pack signature");
+		giterr_set(GITERR_INDEXER, "wrong pack signature");
 		return -1;
 	}
 
 	if (!pack_version_ok(hdr->hdr_version)) {
-		giterr_set(GITERR_INDEXER, "Wrong pack version");
+		giterr_set(GITERR_INDEXER, "wrong pack version");
 		return -1;
 	}
 
@@ -151,6 +151,12 @@ cleanup:
 	if (fd != -1)
 		p_close(fd);
 
+	if (git_buf_len(&tmp_path) > 0)
+		p_unlink(git_buf_cstr(&tmp_path));
+
+	if (idx->pack != NULL)
+		p_unlink(idx->pack->pack_name);
+
 	git_buf_free(&path);
 	git_buf_free(&tmp_path);
 	git__free(idx);
@@ -376,7 +382,7 @@ static int hash_and_save(git_indexer *idx, git_rawobj *obj, git_off_t entry_star
 	GITERR_CHECK_ALLOC(entry);
 
 	if (git_odb__hashobj(&oid, obj) < 0) {
-		giterr_set(GITERR_INDEXER, "Failed to hash object");
+		giterr_set(GITERR_INDEXER, "failed to hash object");
 		goto on_error;
 	}
 
@@ -1054,6 +1060,7 @@ int git_indexer_commit(git_indexer *idx, git_transfer_progress *stats)
 
 	/* And don't forget to rename the packfile to its new place. */
 	p_rename(idx->pack->pack_name, git_buf_cstr(&filename));
+	idx->pack_committed = 1;
 
 	git_buf_free(&filename);
 	git_hash_ctx_cleanup(&ctx);
@@ -1074,7 +1081,7 @@ void git_indexer_free(git_indexer *idx)
 
 	git_vector_free_deep(&idx->objects);
 
-	if (idx->pack && idx->pack->idx_cache) {
+	if (idx->pack->idx_cache) {
 		struct git_pack_entry *pentry;
 		kh_foreach_value(
 			idx->pack->idx_cache, pentry, { git__free(pentry); });
@@ -1085,6 +1092,9 @@ void git_indexer_free(git_indexer *idx)
 	git_vector_free_deep(&idx->deltas);
 
 	if (!git_mutex_lock(&git__mwindow_mutex)) {
+		if (!idx->pack_committed)
+			git_packfile_close(idx->pack, true);
+
 		git_packfile_free(idx->pack);
 		git_mutex_unlock(&git__mwindow_mutex);
 	}
diff --git a/src/iterator.c b/src/iterator.c
index 598c69c83..8fc62c01c 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -1311,7 +1311,7 @@ static int filesystem_iterator_frame_push(
 
 	if (iter->frames.size == FILESYSTEM_MAX_DEPTH) {
 		giterr_set(GITERR_REPOSITORY,
-			"directory nesting too deep (%d)", iter->frames.size);
+			"directory nesting too deep (%"PRIuZ")", iter->frames.size);
 		return -1;
 	}
 
diff --git a/src/merge.c b/src/merge.c
index 6934aa731..087178ace 100644
--- a/src/merge.c
+++ b/src/merge.c
@@ -78,7 +78,7 @@ int merge_bases_many(git_commit_list **out, git_revwalk **walk_out, git_reposito
 	unsigned int i;
 
 	if (length < 2) {
-		giterr_set(GITERR_INVALID, "At least two commits are required to find an ancestor. Provided 'length' was %" PRIuZ ".", length);
+		giterr_set(GITERR_INVALID, "at least two commits are required to find an ancestor");
 		return -1;
 	}
 
@@ -104,7 +104,7 @@ int merge_bases_many(git_commit_list **out, git_revwalk **walk_out, git_reposito
 		goto on_error;
 
 	if (!result) {
-		giterr_set(GITERR_MERGE, "No merge base found");
+		giterr_set(GITERR_MERGE, "no merge base found");
 		error = GIT_ENOTFOUND;
 		goto on_error;
 	}
@@ -184,7 +184,7 @@ int git_merge_base_octopus(git_oid *out, git_repository *repo, size_t length, co
 	assert(out && repo && input_array);
 
 	if (length < 2) {
-		giterr_set(GITERR_INVALID, "At least two commits are required to find an ancestor. Provided 'length' was %" PRIuZ ".", length);
+		giterr_set(GITERR_INVALID, "at least two commits are required to find an ancestor");
 		return -1;
 	}
 
@@ -230,7 +230,7 @@ static int merge_bases(git_commit_list **out, git_revwalk **walk_out, git_reposi
 
 	if (!result) {
 		git_revwalk_free(walk);
-		giterr_set(GITERR_MERGE, "No merge base found");
+		giterr_set(GITERR_MERGE, "no merge base found");
 		return GIT_ENOTFOUND;
 	}
 
@@ -574,7 +574,7 @@ int git_repository_mergehead_foreach(
 
 	while ((line = git__strsep(&buffer, "\n")) != NULL) {
 		if (strlen(line) != GIT_OID_HEXSZ) {
-			giterr_set(GITERR_INVALID, "Unable to parse OID - invalid length");
+			giterr_set(GITERR_INVALID, "unable to parse OID - invalid length");
 			error = -1;
 			goto cleanup;
 		}
@@ -591,7 +591,7 @@ int git_repository_mergehead_foreach(
 	}
 
 	if (*buffer) {
-		giterr_set(GITERR_MERGE, "No EOL at line %d", line_num);
+		giterr_set(GITERR_MERGE, "no EOL at line %"PRIuZ, line_num);
 		error = -1;
 		goto cleanup;
 	}
@@ -1713,15 +1713,15 @@ static int merge_normalize_opts(
 	if ((error = git_repository_config__weakptr(&cfg, repo)) < 0)
 		return error;
 
-	if (given != NULL)
+	if (given != NULL) {
 		memcpy(opts, given, sizeof(git_merge_options));
-	else {
+	} else {
 		git_merge_options init = GIT_MERGE_OPTIONS_INIT;
 		memcpy(opts, &init, sizeof(init));
+	}
 
-		opts->flags = GIT_MERGE_FIND_RENAMES;
+	if ((opts->flags & GIT_MERGE_FIND_RENAMES) && !opts->rename_threshold)
 		opts->rename_threshold = GIT_MERGE_DEFAULT_RENAME_THRESHOLD;
-	}
 
 	if (given && given->default_driver) {
 		opts->default_driver = git__strdup(given->default_driver);
@@ -3043,7 +3043,7 @@ int git_merge_analysis(
 	assert(analysis_out && preference_out && repo && their_heads);
 
 	if (their_heads_len != 1) {
-		giterr_set(GITERR_MERGE, "Can only merge a single branch");
+		giterr_set(GITERR_MERGE, "can only merge a single branch");
 		error = -1;
 		goto done;
 	}
@@ -3099,7 +3099,7 @@ int git_merge(
 	assert(repo && their_heads);
 
 	if (their_heads_len != 1) {
-		giterr_set(GITERR_MERGE, "Can only merge a single branch");
+		giterr_set(GITERR_MERGE, "can only merge a single branch");
 		return -1;
 	}
 
diff --git a/src/merge_file.c b/src/merge_file.c
index 3f14a4f63..5ecd8f4d0 100644
--- a/src/merge_file.c
+++ b/src/merge_file.c
@@ -127,7 +127,7 @@ static int merge_file__xdiff(
 
 	if ((xdl_result = xdl_merge(&ancestor_mmfile, &our_mmfile,
 		&their_mmfile, &xmparam, &mmbuffer)) < 0) {
-		giterr_set(GITERR_MERGE, "Failed to merge files.");
+		giterr_set(GITERR_MERGE, "failed to merge files");
 		error = -1;
 		goto done;
 	}
diff --git a/src/mwindow.c b/src/mwindow.c
index 8a5b5caee..520e7685f 100644
--- a/src/mwindow.c
+++ b/src/mwindow.c
@@ -231,7 +231,7 @@ static int git_mwindow_close_lru(git_mwindow_file *mwf)
 	}
 
 	if (!lru_w) {
-		giterr_set(GITERR_OS, "Failed to close memory window. Couldn't find LRU");
+		giterr_set(GITERR_OS, "failed to close memory window; couldn't find LRU");
 		return -1;
 	}
 
diff --git a/src/netops.c b/src/netops.c
index 90326ea59..4b73baa0e 100644
--- a/src/netops.c
+++ b/src/netops.c
@@ -144,7 +144,7 @@ int gitno_connection_data_from_url(
 		default_port = "80";
 
 		if (data->use_ssl) {
-			giterr_set(GITERR_NET, "Redirect from HTTPS to HTTP is not allowed");
+			giterr_set(GITERR_NET, "redirect from HTTPS to HTTP is not allowed");
 			goto cleanup;
 		}
 	} else if (!git__prefixcmp(url, prefix_https)) {
@@ -155,7 +155,7 @@ int gitno_connection_data_from_url(
 		default_port = data->use_ssl ? "443" : "80";
 
 	if (!default_port) {
-		giterr_set(GITERR_NET, "Unrecognized URL prefix");
+		giterr_set(GITERR_NET, "unrecognized URL prefix");
 		goto cleanup;
 	}
 
@@ -187,7 +187,7 @@ int gitno_connection_data_from_url(
 
 		/* Check for errors in the resulting data */
 		if (original_host && url[0] != '/' && strcmp(original_host, data->host)) {
-			giterr_set(GITERR_NET, "Cross host redirect not allowed");
+			giterr_set(GITERR_NET, "cross host redirect not allowed");
 			error = -1;
 		}
 	}
@@ -237,7 +237,7 @@ int gitno_extract_url_parts(
 	const char *_host, *_port, *_path, *_userinfo;
 
 	if (http_parser_parse_url(url, strlen(url), false, &u)) {
-		giterr_set(GITERR_NET, "Malformed URL '%s'", url);
+		giterr_set(GITERR_NET, "malformed URL '%s'", url);
 		return GIT_EINVALIDSPEC;
 	}
 
diff --git a/src/notes.c b/src/notes.c
index fe8d2164f..75108b9c9 100644
--- a/src/notes.c
+++ b/src/notes.c
@@ -15,7 +15,7 @@
 
 static int note_error_notfound(void)
 {
-	giterr_set(GITERR_INVALID, "Note could not be found");
+	giterr_set(GITERR_INVALID, "note could not be found");
 	return GIT_ENOTFOUND;
 }
 
@@ -226,7 +226,7 @@ static int remove_note_in_tree_enotfound_cb(
 	GIT_UNUSED(note_oid);
 	GIT_UNUSED(fanout);
 
-	giterr_set(GITERR_REPOSITORY, "Object '%s' has no note", annotated_object_sha);
+	giterr_set(GITERR_REPOSITORY, "object '%s' has no note", annotated_object_sha);
 	return current_error;
 }
 
@@ -244,7 +244,7 @@ static int insert_note_in_tree_eexists_cb(git_tree **out,
 	GIT_UNUSED(note_oid);
 	GIT_UNUSED(fanout);
 
-	giterr_set(GITERR_REPOSITORY, "Note for '%s' exists already", annotated_object_sha);
+	giterr_set(GITERR_REPOSITORY, "note for '%s' exists already", annotated_object_sha);
 	return current_error;
 }
 
diff --git a/src/object.c b/src/object.c
index 1d45f9f1b..2da36a2ee 100644
--- a/src/object.c
+++ b/src/object.c
@@ -66,12 +66,12 @@ int git_object__from_odb_object(
 	/* Validate type match */
 	if (type != GIT_OBJ_ANY && type != odb_obj->cached.type) {
 		giterr_set(GITERR_INVALID,
-			"The requested type does not match the type in the ODB");
+			"the requested type does not match the type in the ODB");
 		return GIT_ENOTFOUND;
 	}
 
 	if ((object_size = git_object__size(odb_obj->cached.type)) == 0) {
-		giterr_set(GITERR_INVALID, "The requested type is invalid");
+		giterr_set(GITERR_INVALID, "the requested type is invalid");
 		return GIT_ENOTFOUND;
 	}
 
@@ -122,7 +122,7 @@ int git_object_lookup_prefix(
 	assert(repo && object_out && id);
 
 	if (len < GIT_OID_MINPREFIXLEN) {
-		giterr_set(GITERR_OBJECT, "Ambiguous lookup - OID prefix is too short");
+		giterr_set(GITERR_OBJECT, "ambiguous lookup - OID prefix is too short");
 		return GIT_EAMBIGUOUS;
 	}
 
@@ -147,7 +147,7 @@ int git_object_lookup_prefix(
 				if (type != GIT_OBJ_ANY && type != object->cached.type) {
 					git_object_free(object);
 					giterr_set(GITERR_INVALID,
-						"The requested type does not match the type in ODB");
+						"the requested type does not match the type in ODB");
 					return GIT_ENOTFOUND;
 				}
 
@@ -292,7 +292,7 @@ static int peel_error(int error, const git_oid *oid, git_otype type)
 	git_oid_fmt(hex_oid, oid);
 	hex_oid[GIT_OID_HEXSZ] = '\0';
 
-	giterr_set(GITERR_OBJECT, "The git_object of id '%s' can not be "
+	giterr_set(GITERR_OBJECT, "the git_object of id '%s' can not be "
 		"successfully peeled into a %s (git_otype=%i).", hex_oid, type_name, type);
 
 	return error;
diff --git a/src/odb.c b/src/odb.c
index acf4dea71..dc98a6ff7 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -176,7 +176,7 @@ int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_otype type)
 	int error = 0;
 
 	if (!git_object_typeisloose(type)) {
-		giterr_set(GITERR_INVALID, "Invalid object type for hash");
+		giterr_set(GITERR_INVALID, "invalid object type for hash");
 		return -1;
 	}
 
@@ -199,7 +199,7 @@ int git_odb__hashfd(git_oid *out, git_file fd, size_t size, git_otype type)
 	 * If size is not zero, the file was truncated after we originally
 	 * stat'd it, so we consider this a read failure too */
 	if (read_len < 0 || size > 0) {
-		giterr_set(GITERR_OS, "Error reading file for hashing");
+		giterr_set(GITERR_OS, "error reading file for hashing");
 		error = -1;
 
 		goto done;
@@ -251,7 +251,7 @@ int git_odb__hashlink(git_oid *out, const char *path)
 		return -1;
 
 	if (!git__is_int(st.st_size) || (int)st.st_size < 0) {
-		giterr_set(GITERR_FILESYSTEM, "File size overflow for 32-bit systems");
+		giterr_set(GITERR_FILESYSTEM, "file size overflow for 32-bit systems");
 		return -1;
 	}
 
@@ -269,7 +269,7 @@ int git_odb__hashlink(git_oid *out, const char *path)
 		read_len = p_readlink(path, link_data, size);
 		link_data[size] = '\0';
 		if (read_len != size) {
-			giterr_set(GITERR_OS, "Failed to read symlink data for '%s'", path);
+			giterr_set(GITERR_OS, "failed to read symlink data for '%s'", path);
 			git__free(link_data);
 			return -1;
 		}
@@ -295,7 +295,7 @@ int git_odb_hashfile(git_oid *out, const char *path, git_otype type)
 		return fd;
 
 	if ((size = git_futils_filesize(fd)) < 0 || !git__is_sizet(size)) {
-		giterr_set(GITERR_OS, "File size overflow for 32-bit systems");
+		giterr_set(GITERR_OS, "file size overflow for 32-bit systems");
 		p_close(fd);
 		return -1;
 	}
@@ -475,7 +475,7 @@ size_t git_odb_num_backends(git_odb *odb)
 static int git_odb__error_unsupported_in_backend(const char *action)
 {
 	giterr_set(GITERR_ODB,
-		"Cannot %s - unsupported in the loaded odb backends", action);
+		"cannot %s - unsupported in the loaded odb backends", action);
 	return -1;
 }
 
@@ -492,7 +492,7 @@ int git_odb_get_backend(git_odb_backend **out, git_odb *odb, size_t pos)
 		return 0;
 	}
 
-	giterr_set(GITERR_ODB, "No ODB backend loaded at index %" PRIuZ, pos);
+	giterr_set(GITERR_ODB, "no ODB backend loaded at index %" PRIuZ, pos);
 	return GIT_ENOTFOUND;
 }
 
@@ -517,7 +517,7 @@ static int add_default_backends(
 		if (as_alternates)
 			return 0;
 
-		giterr_set(GITERR_ODB, "Failed to load object database in '%s'", objects_dir);
+		giterr_set(GITERR_ODB, "failed to load object database in '%s'", objects_dir);
 		return -1;
 	}
 
@@ -1264,7 +1264,7 @@ static int git_odb_stream__invalid_length(
 	const char *action)
 {
 	giterr_set(GITERR_ODB,
-		"Cannot %s - "
+		"cannot %s - "
 		"Invalid length. %"PRIuZ" was expected. The "
 		"total size of the received chunks amounts to %"PRIuZ".",
 		action, stream->declared_size, stream->received_bytes);		
@@ -1399,17 +1399,17 @@ int git_odb__error_notfound(
 	if (oid != NULL) {
 		char oid_str[GIT_OID_HEXSZ + 1];
 		git_oid_tostr(oid_str, oid_len+1, oid);
-		giterr_set(GITERR_ODB, "Object not found - %s (%.*s)",
-			message, oid_len, oid_str);
+		giterr_set(GITERR_ODB, "object not found - %s (%.*s)",
+			message, (int) oid_len, oid_str);
 	} else
-		giterr_set(GITERR_ODB, "Object not found - %s", message);
+		giterr_set(GITERR_ODB, "object not found - %s", message);
 
 	return GIT_ENOTFOUND;
 }
 
 int git_odb__error_ambiguous(const char *message)
 {
-	giterr_set(GITERR_ODB, "Ambiguous SHA1 prefix - %s", message);
+	giterr_set(GITERR_ODB, "ambiguous SHA1 prefix - %s", message);
 	return GIT_EAMBIGUOUS;
 }
 
diff --git a/src/odb_loose.c b/src/odb_loose.c
index f312b9c9c..b2e2f1fb7 100644
--- a/src/odb_loose.c
+++ b/src/odb_loose.c
@@ -214,7 +214,7 @@ static int finish_inflate(z_stream *s)
 	inflateEnd(s);
 
 	if ((status != Z_STREAM_END) || (s->avail_in != 0)) {
-		giterr_set(GITERR_ZLIB, "Failed to finish ZLib inflation. Stream aborted prematurely");
+		giterr_set(GITERR_ZLIB, "failed to finish zlib inflation; stream aborted prematurely");
 		return -1;
 	}
 
@@ -243,7 +243,7 @@ static int inflate_buffer(void *in, size_t inlen, void *out, size_t outlen)
 	zs.avail_in = (uInt)inlen;
 
 	if (inflateInit(&zs) < Z_OK) {
-		giterr_set(GITERR_ZLIB, "Failed to inflate buffer");
+		giterr_set(GITERR_ZLIB, "failed to inflate buffer");
 		return -1;
 	}
 
@@ -255,7 +255,7 @@ static int inflate_buffer(void *in, size_t inlen, void *out, size_t outlen)
 	if (status != Z_STREAM_END /* || zs.avail_in != 0 */ ||
 		zs.total_out != outlen)
 	{
-		giterr_set(GITERR_ZLIB, "Failed to inflate buffer. Stream aborted prematurely");
+		giterr_set(GITERR_ZLIB, "failed to inflate buffer; stream aborted prematurely");
 		return -1;
 	}
 
@@ -319,7 +319,7 @@ static int inflate_packlike_loose_disk_obj(git_rawobj *out, git_buf *obj)
 	 */
 	if ((used = get_binary_object_header(&hdr, obj)) == 0 ||
 		!git_object_typeisloose(hdr.type)) {
-		giterr_set(GITERR_ODB, "Failed to inflate loose object.");
+		giterr_set(GITERR_ODB, "failed to inflate loose object");
 		return -1;
 	}
 
@@ -366,7 +366,7 @@ static int inflate_disk_obj(git_rawobj *out, git_buf *obj)
 		(used = get_object_header(&hdr, head)) == 0 ||
 		!git_object_typeisloose(hdr.type))
 	{
-		giterr_set(GITERR_ODB, "Failed to inflate disk object.");
+		giterr_set(GITERR_ODB, "failed to inflate disk object");
 		return -1;
 	}
 
@@ -455,7 +455,7 @@ static int read_header_loose(git_rawobj *out, git_buf *loc)
 		|| get_object_header(&header_obj, inflated_buffer) == 0
 		|| git_object_typeisloose(header_obj.type) == 0)
 	{
-		giterr_set(GITERR_ZLIB, "Failed to read loose object header");
+		giterr_set(GITERR_ZLIB, "failed to read loose object header");
 		error = -1;
 	} else {
 		out->len = header_obj.size;
diff --git a/src/odb_mempack.c b/src/odb_mempack.c
index 594a2784c..84ed9c104 100644
--- a/src/odb_mempack.c
+++ b/src/odb_mempack.c
@@ -24,7 +24,7 @@ struct memobject {
 	git_oid oid;
 	size_t len;
 	git_otype type;
-	char data[];
+	char data[GIT_FLEX_ARRAY];
 };
 
 struct memory_packer_db {
@@ -177,6 +177,7 @@ int git_mempack_new(git_odb_backend **out)
 
 	db->objects = git_oidmap_alloc();
 
+	db->parent.version = GIT_ODB_BACKEND_VERSION;
 	db->parent.read = &impl__read;
 	db->parent.write = &impl__write;
 	db->parent.read_header = &impl__read_header;
diff --git a/src/oid.c b/src/oid.c
index 9fe2ebb65..9dc719194 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -16,7 +16,7 @@ static char to_hex[] = "0123456789abcdef";
 
 static int oid_error_invalid(const char *msg)
 {
-	giterr_set(GITERR_INVALID, "Unable to parse OID - %s", msg);
+	giterr_set(GITERR_INVALID, "unable to parse OID - %s", msg);
 	return -1;
 }
 
@@ -380,7 +380,7 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 	node_index idx;
 
 	if (os->full) {
-		giterr_set(GITERR_INVALID, "Unable to shorten OID - OID set full");
+		giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
 		return -1;
 	}
 
@@ -395,7 +395,7 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 		trie_node *node;
 
 		if (c == -1) {
-			giterr_set(GITERR_INVALID, "Unable to shorten OID - invalid hex value");
+			giterr_set(GITERR_INVALID, "unable to shorten OID - invalid hex value");
 			return -1;
 		}
 
@@ -410,7 +410,7 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 			node = push_leaf(os, idx, git__fromhex(tail[0]), &tail[1]);
 			if (node == NULL) {
 				if (os->full)
-					giterr_set(GITERR_INVALID, "Unable to shorten OID - OID set full");
+					giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
 				return -1;
 			}
 		}
@@ -418,7 +418,7 @@ int git_oid_shorten_add(git_oid_shorten *os, const char *text_oid)
 		if (node->children[c] == 0) {
 			if (push_leaf(os, idx, c, &text_oid[i + 1]) == NULL) {
 				if (os->full)
-					giterr_set(GITERR_INVALID, "Unable to shorten OID - OID set full");
+					giterr_set(GITERR_INVALID, "unable to shorten OID - OID set full");
 				return -1;
 			}
 			break;
diff --git a/src/openssl_stream.c b/src/openssl_stream.c
index b8ab21fef..bb9b32c67 100644
--- a/src/openssl_stream.c
+++ b/src/openssl_stream.c
@@ -13,6 +13,7 @@
 #include "posix.h"
 #include "stream.h"
 #include "socket_stream.h"
+#include "openssl_stream.h"
 #include "netops.h"
 #include "git2/transport.h"
 #include "git2/sys/openssl.h"
@@ -71,12 +72,20 @@ static void shutdown_ssl_locking(void)
 
 #endif /* GIT_THREADS */
 
+static BIO_METHOD *git_stream_bio_method;
+static int init_bio_method(void);
+
 /**
  * This function aims to clean-up the SSL context which
  * we allocated.
  */
 static void shutdown_ssl(void)
 {
+	if (git_stream_bio_method) {
+		BIO_meth_free(git_stream_bio_method);
+		git_stream_bio_method = NULL;
+	}
+
 	if (git__ssl_ctx) {
 		SSL_CTX_free(git__ssl_ctx);
 		git__ssl_ctx = NULL;
@@ -121,6 +130,13 @@ int git_openssl_stream_global_init(void)
 		git__ssl_ctx = NULL;
 		return -1;
 	}
+
+	if (init_bio_method() < 0) {
+		SSL_CTX_free(git__ssl_ctx);
+		git__ssl_ctx = NULL;
+		return -1;
+	}
+
 #endif
 
 	git__on_shutdown(shutdown_ssl);
@@ -148,7 +164,7 @@ int git_openssl_set_locking(void)
 	git__on_shutdown(shutdown_ssl_locking);
 	return 0;
 #else
-	giterr_set(GITERR_THREAD, "libgit2 as not built with threads");
+	giterr_set(GITERR_THREAD, "libgit2 was not built with threads");
 	return -1;
 #endif
 }
@@ -156,10 +172,8 @@ int git_openssl_set_locking(void)
 
 static int bio_create(BIO *b)
 {
-	b->init = 1;
-	b->num = 0;
-	b->ptr = NULL;
-	b->flags = 0;
+	BIO_set_init(b, 1);
+	BIO_set_data(b, NULL);
 
 	return 1;
 }
@@ -169,23 +183,22 @@ static int bio_destroy(BIO *b)
 	if (!b)
 		return 0;
 
-	b->init = 0;
-	b->num = 0;
-	b->ptr = NULL;
-	b->flags = 0;
+	BIO_set_data(b, NULL);
 
 	return 1;
 }
 
 static int bio_read(BIO *b, char *buf, int len)
 {
-	git_stream *io = (git_stream *) b->ptr;
+	git_stream *io = (git_stream *) BIO_get_data(b);
+
 	return (int) git_stream_read(io, buf, len);
 }
 
 static int bio_write(BIO *b, const char *buf, int len)
 {
-	git_stream *io = (git_stream *) b->ptr;
+	git_stream *io = (git_stream *) BIO_get_data(b);
+
 	return (int) git_stream_write(io, buf, len, 0);
 }
 
@@ -214,17 +227,22 @@ static int bio_puts(BIO *b, const char *str)
 	return bio_write(b, str, strlen(str));
 }
 
-static BIO_METHOD git_stream_bio_method = {
-	BIO_TYPE_SOURCE_SINK,
-	"git_stream",
-	bio_write,
-	bio_read,
-	bio_puts,
-	bio_gets,
-	bio_ctrl,
-	bio_create,
-	bio_destroy
-};
+static int init_bio_method(void)
+{
+	/* Set up the BIO_METHOD we use for wrapping our own stream implementations */
+	git_stream_bio_method = BIO_meth_new(BIO_TYPE_SOURCE_SINK | BIO_get_new_index(), "git_stream");
+	GITERR_CHECK_ALLOC(git_stream_bio_method);
+
+	BIO_meth_set_write(git_stream_bio_method, bio_write);
+	BIO_meth_set_read(git_stream_bio_method, bio_read);
+	BIO_meth_set_puts(git_stream_bio_method, bio_puts);
+	BIO_meth_set_gets(git_stream_bio_method, bio_gets);
+	BIO_meth_set_ctrl(git_stream_bio_method, bio_ctrl);
+	BIO_meth_set_create(git_stream_bio_method, bio_create);
+	BIO_meth_set_destroy(git_stream_bio_method, bio_destroy);
+
+	return 0;
+}
 
 static int ssl_set_error(SSL *ssl, int error)
 {
@@ -239,10 +257,10 @@ static int ssl_set_error(SSL *ssl, int error)
 	switch (err) {
 	case SSL_ERROR_WANT_CONNECT:
 	case SSL_ERROR_WANT_ACCEPT:
-		giterr_set(GITERR_NET, "SSL error: connection failure\n");
+		giterr_set(GITERR_NET, "SSL error: connection failure");
 		break;
 	case SSL_ERROR_WANT_X509_LOOKUP:
-		giterr_set(GITERR_NET, "SSL error: x509 error\n");
+		giterr_set(GITERR_NET, "SSL error: x509 error");
 		break;
 	case SSL_ERROR_SYSCALL:
 		e = ERR_get_error();
@@ -309,7 +327,7 @@ static int verify_server_cert(SSL *ssl, const char *host)
 	int i = -1,j;
 
 	if (SSL_get_verify_result(ssl) != X509_V_OK) {
-		giterr_set(GITERR_SSL, "The SSL certificate is invalid");
+		giterr_set(GITERR_SSL, "the SSL certificate is invalid");
 		return GIT_ECERTIFICATE;
 	}
 
@@ -339,7 +357,7 @@ static int verify_server_cert(SSL *ssl, const char *host)
 		num = sk_GENERAL_NAME_num(alts);
 		for (i = 0; i < num && matched != 1; i++) {
 			const GENERAL_NAME *gn = sk_GENERAL_NAME_value(alts, i);
-			const char *name = (char *) ASN1_STRING_data(gn->d.ia5);
+			const char *name = (char *) ASN1_STRING_get0_data(gn->d.ia5);
 			size_t namelen = (size_t) ASN1_STRING_length(gn->d.ia5);
 
 			/* Skip any names of a type we're not looking for */
@@ -394,7 +412,7 @@ static int verify_server_cert(SSL *ssl, const char *host)
 		if (size > 0) {
 			peer_cn = OPENSSL_malloc(size + 1);
 			GITERR_CHECK_ALLOC(peer_cn);
-			memcpy(peer_cn, ASN1_STRING_data(str), size);
+			memcpy(peer_cn, ASN1_STRING_get0_data(str), size);
 			peer_cn[size] = '\0';
 		} else {
 			goto cert_fail_name;
@@ -445,11 +463,12 @@ int openssl_connect(git_stream *stream)
 
 	st->connected = true;
 
-	bio = BIO_new(&git_stream_bio_method);
+	bio = BIO_new(git_stream_bio_method);
 	GITERR_CHECK_ALLOC(bio);
-	bio->ptr = st->io;
 
+	BIO_set_data(bio, st->io);
 	SSL_set_bio(st->ssl, bio, bio);
+
 	/* specify the host in case SNI is needed */
 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
 	SSL_set_tlsext_host_name(st->ssl, st->host);
diff --git a/src/openssl_stream.h b/src/openssl_stream.h
index 82b5110c4..f5e59dab1 100644
--- a/src/openssl_stream.h
+++ b/src/openssl_stream.h
@@ -13,4 +13,110 @@ extern int git_openssl_stream_global_init(void);
 
 extern int git_openssl_stream_new(git_stream **out, const char *host, const char *port);
 
+/*
+ * OpenSSL 1.1 made BIO opaque so we have to use functions to interact with it
+ * which do not exist in previous versions. We define these inline functions so
+ * we can program against the interface instead of littering the implementation
+ * with ifdefs.
+ */
+#ifdef GIT_OPENSSL
+# include <openssl/ssl.h>
+# include <openssl/err.h>
+# include <openssl/x509v3.h>
+# include <openssl/bio.h>
+
+
+
+# if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
+
+GIT_INLINE(BIO_METHOD*) BIO_meth_new(int type, const char *name)
+{
+	BIO_METHOD *meth = git__calloc(1, sizeof(BIO_METHOD));
+	if (!meth) {
+		return NULL;
+	}
+
+	meth->type = type;
+	meth->name = name;
+
+	return meth;
+}
+
+GIT_INLINE(void) BIO_meth_free(BIO_METHOD *biom)
+{
+	git__free(biom);
+}
+
+GIT_INLINE(int) BIO_meth_set_write(BIO_METHOD *biom, int (*write) (BIO *, const char *, int))
+{
+	biom->bwrite = write;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_read(BIO_METHOD *biom, int (*read) (BIO *, char *, int))
+{
+	biom->bread = read;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_puts(BIO_METHOD *biom, int (*puts) (BIO *, const char *))
+{
+	biom->bputs = puts;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_gets(BIO_METHOD *biom, int (*gets) (BIO *, char *, int))
+
+{
+	biom->bgets = gets;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_ctrl(BIO_METHOD *biom, long (*ctrl) (BIO *, int, long, void *))
+{
+	biom->ctrl = ctrl;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_create(BIO_METHOD *biom, int (*create) (BIO *))
+{
+	biom->create = create;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy) (BIO *))
+{
+	biom->destroy = destroy;
+	return 1;
+}
+
+GIT_INLINE(int) BIO_get_new_index(void)
+{
+	/* This exists as of 1.1 so before we'd just have 0 */
+	return 0;
+}
+
+GIT_INLINE(void) BIO_set_init(BIO *b, int init)
+{
+	b->init = init;
+}
+
+GIT_INLINE(void) BIO_set_data(BIO *a, void *ptr)
+{
+	a->ptr = ptr;
+}
+
+GIT_INLINE(void*) BIO_get_data(BIO *a)
+{
+	return a->ptr;
+}
+
+GIT_INLINE(const unsigned char *) ASN1_STRING_get0_data(const ASN1_STRING *x)
+{
+	return ASN1_STRING_data((ASN1_STRING *)x);
+}
+
+# endif // OpenSSL < 1.1
+#endif // GIT_OPENSSL
+
 #endif
diff --git a/src/pack-objects.c b/src/pack-objects.c
index 9f62322f7..6dbb6cf6c 100644
--- a/src/pack-objects.c
+++ b/src/pack-objects.c
@@ -162,7 +162,7 @@ int git_packbuilder_new(git_packbuilder **out, git_repository *repo)
 		git_mutex_init(&pb->progress_mutex) ||
 		git_cond_init(&pb->progress_cond))
 	{
-		giterr_set(GITERR_OS, "Failed to initialize packbuilder mutex");
+		giterr_set(GITERR_OS, "failed to initialize packbuilder mutex");
 		goto on_error;
 	}
 
@@ -225,7 +225,7 @@ int git_packbuilder_insert(git_packbuilder *pb, const git_oid *oid,
 		GITERR_CHECK_ALLOC_MULTIPLY(&newsize, newsize, 3 / 2);
 
 		if (!git__is_uint32(newsize)) {
-			giterr_set(GITERR_NOMEMORY, "Packfile too large to fit in memory.");
+			giterr_set(GITERR_NOMEMORY, "packfile too large to fit in memory.");
 			return -1;
 		}
 
@@ -298,7 +298,7 @@ static int get_delta(void **out, git_odb *odb, git_pobject *po)
 		goto on_error;
 
 	if (error == GIT_EBUFS || delta_size != po->delta_size) {
-		giterr_set(GITERR_INVALID, "Delta size changed");
+		giterr_set(GITERR_INVALID, "delta size changed");
 		goto on_error;
 	}
 
@@ -808,7 +808,7 @@ static int try_delta(git_packbuilder *pb, struct unpacked *trg,
 
 		if (sz != trg_size) {
 			giterr_set(GITERR_INVALID,
-				   "Inconsistent target object length");
+				   "inconsistent target object length");
 			return -1;
 		}
 
@@ -830,7 +830,7 @@ static int try_delta(git_packbuilder *pb, struct unpacked *trg,
 
 		if (sz != src_size) {
 			giterr_set(GITERR_INVALID,
-				   "Inconsistent source object length");
+				   "inconsistent source object length");
 			return -1;
 		}
 
diff --git a/src/pack.c b/src/pack.c
index 310f00fa3..243719d9c 100644
--- a/src/pack.c
+++ b/src/pack.c
@@ -45,7 +45,7 @@ static int pack_entry_find_offset(
 
 static int packfile_error(const char *message)
 {
-	giterr_set(GITERR_ODB, "Invalid pack file - %s", message);
+	giterr_set(GITERR_ODB, "invalid pack file - %s", message);
 	return -1;
 }
 
@@ -99,7 +99,7 @@ static int cache_init(git_pack_cache *cache)
 	cache->memory_limit = GIT_PACK_CACHE_MEMORY_LIMIT;
 
 	if (git_mutex_init(&cache->lock)) {
-		giterr_set(GITERR_OS, "Failed to initialize pack cache mutex");
+		giterr_set(GITERR_OS, "failed to initialize pack cache mutex");
 
 		git__free(cache->entries);
 		cache->entries = NULL;
@@ -226,7 +226,7 @@ static int pack_index_check(const char *path, struct git_pack_file *p)
 
 	if (p_fstat(fd, &st) < 0) {
 		p_close(fd);
-		giterr_set(GITERR_OS, "Unable to stat pack index '%s'", path);
+		giterr_set(GITERR_OS, "unable to stat pack index '%s'", path);
 		return -1;
 	}
 
@@ -235,7 +235,7 @@ static int pack_index_check(const char *path, struct git_pack_file *p)
 		(idx_size = (size_t)st.st_size) < 4 * 256 + 20 + 20)
 	{
 		p_close(fd);
-		giterr_set(GITERR_ODB, "Invalid pack index '%s'", path);
+		giterr_set(GITERR_ODB, "invalid pack index '%s'", path);
 		return -1;
 	}
 
@@ -509,8 +509,10 @@ int git_packfile_resolve_header(
 		git_packfile_stream_free(&stream);
 		if (error < 0)
 			return error;
-	} else
+	} else {
 		*size_p = size;
+		base_offset = 0;
+	}
 
 	while (type == GIT_OBJ_OFS_DELTA || type == GIT_OBJ_REF_DELTA) {
 		curpos = base_offset;
@@ -757,8 +759,11 @@ int git_packfile_unpack(
 	}
 
 cleanup:
-	if (error < 0)
+	if (error < 0) {
 		git__free(obj->data);
+		if (cached)
+			git_atomic_dec(&cached->refcount);
+	}
 
 	if (elem)
 		*obj_offset = curpos;
@@ -986,6 +991,18 @@ git_off_t get_delta_base(
  *
  ***********************************************************/
 
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile)
+{
+	if (p->mwf.fd >= 0) {
+		git_mwindow_free_all_locked(&p->mwf);
+		p_close(p->mwf.fd);
+		p->mwf.fd = -1;
+	}
+
+	if (unlink_packfile)
+		p_unlink(p->pack_name);
+}
+
 void git_packfile_free(struct git_pack_file *p)
 {
 	if (!p)
@@ -993,10 +1010,7 @@ void git_packfile_free(struct git_pack_file *p)
 
 	cache_free(&p->bases);
 
-	if (p->mwf.fd >= 0) {
-		git_mwindow_free_all_locked(&p->mwf);
-		p_close(p->mwf.fd);
-	}
+	git_packfile_close(p, false);
 
 	pack_index_free(p);
 
@@ -1077,7 +1091,7 @@ static int packfile_open(struct git_pack_file *p)
 	return 0;
 
 cleanup:
-	giterr_set(GITERR_OS, "Invalid packfile '%s'", p->pack_name);
+	giterr_set(GITERR_OS, "invalid packfile '%s'", p->pack_name);
 
 	if (p->mwf.fd >= 0)
 		p_close(p->mwf.fd);
@@ -1153,7 +1167,7 @@ int git_packfile_alloc(struct git_pack_file **pack_out, const char *path)
 	p->index_version = -1;
 
 	if (git_mutex_init(&p->lock)) {
-		giterr_set(GITERR_OS, "Failed to initialize packfile mutex");
+		giterr_set(GITERR_OS, "failed to initialize packfile mutex");
 		git__free(p);
 		return -1;
 	}
@@ -1268,8 +1282,8 @@ static int pack_entry_find_offset(
 	const git_oid *short_oid,
 	size_t len)
 {
-	const uint32_t *level1_ofs = p->index_map.data;
-	const unsigned char *index = p->index_map.data;
+	const uint32_t *level1_ofs;
+	const unsigned char *index;
 	unsigned hi, lo, stride;
 	int pos, found = 0;
 	git_off_t offset;
@@ -1283,11 +1297,11 @@ static int pack_entry_find_offset(
 		if ((error = pack_index_open(p)) < 0)
 			return error;
 		assert(p->index_map.data);
-
-		index = p->index_map.data;
-		level1_ofs = p->index_map.data;
 	}
 
+	index = p->index_map.data;
+	level1_ofs = p->index_map.data;
+
 	if (p->index_version > 1) {
 		level1_ofs += 2;
 		index += 8;
diff --git a/src/pack.h b/src/pack.h
index 5302db5b7..e2bf165f4 100644
--- a/src/pack.h
+++ b/src/pack.h
@@ -149,6 +149,7 @@ git_off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
 		git_off_t *curpos, git_otype type,
 		git_off_t delta_obj_offset);
 
+void git_packfile_close(struct git_pack_file *p, bool unlink_packfile);
 void git_packfile_free(struct git_pack_file *p);
 int git_packfile_alloc(struct git_pack_file **pack_out, const char *path);
 
diff --git a/src/patch_generate.c b/src/patch_generate.c
index a13f2ff5d..3559cc2b8 100644
--- a/src/patch_generate.c
+++ b/src/patch_generate.c
@@ -284,7 +284,7 @@ static int create_binary(
 	size_t b_datalen)
 {
 	git_buf deflate = GIT_BUF_INIT, delta = GIT_BUF_INIT;
-	size_t delta_data_len;
+	size_t delta_data_len = 0;
 	int error;
 
 	/* The git_delta function accepts unsigned long only */
@@ -417,7 +417,7 @@ static int diff_required(git_diff *diff, const char *action)
 {
 	if (diff)
 		return 0;
-	giterr_set(GITERR_INVALID, "Must provide valid diff to %s", action);
+	giterr_set(GITERR_INVALID, "must provide valid diff to %s", action);
 	return -1;
 }
 
@@ -776,7 +776,7 @@ int git_patch_generated_from_diff(
 
 	delta = git_vector_get(&diff->deltas, idx);
 	if (!delta) {
-		giterr_set(GITERR_INVALID, "Index out of range for delta in diff");
+		giterr_set(GITERR_INVALID, "index out of range for delta in diff");
 		return GIT_ENOTFOUND;
 	}
 
diff --git a/src/patch_parse.c b/src/patch_parse.c
index 5ee09ee27..f5275947d 100644
--- a/src/patch_parse.c
+++ b/src/patch_parse.c
@@ -176,7 +176,7 @@ static int parse_header_mode(uint16_t *mode, git_patch_parse_ctx *ctx)
 	int ret;
 
 	if (ctx->line_len < 1 || !git__isdigit(ctx->line[0]))
-		return parse_err("invalid file mode at line %d", ctx->line_num);
+		return parse_err("invalid file mode at line %"PRIuZ, ctx->line_num);
 
 	if ((ret = git__strntol32(&m, ctx->line, ctx->line_len, &end, 8)) < 0)
 		return ret;
@@ -205,7 +205,7 @@ static int parse_header_oid(
 
 	if (len < GIT_OID_MINPREFIXLEN || len > GIT_OID_HEXSZ ||
 		git_oid_fromstrn(oid, ctx->line, len) < 0)
-		return parse_err("invalid hex formatted object id at line %d",
+		return parse_err("invalid hex formatted object id at line %"PRIuZ,
 			ctx->line_num);
 
 	parse_advance_chars(ctx, len);
@@ -350,7 +350,7 @@ static int parse_header_similarity(
 	git_patch_parsed *patch, git_patch_parse_ctx *ctx)
 {
 	if (parse_header_percent(&patch->base.delta->similarity, ctx) < 0)
-		return parse_err("invalid similarity percentage at line %d",
+		return parse_err("invalid similarity percentage at line %"PRIuZ,
 			ctx->line_num);
 
 	return 0;
@@ -362,7 +362,7 @@ static int parse_header_dissimilarity(
 	uint16_t dissimilarity;
 
 	if (parse_header_percent(&dissimilarity, ctx) < 0)
-		return parse_err("invalid similarity percentage at line %d",
+		return parse_err("invalid similarity percentage at line %"PRIuZ,
 			ctx->line_num);
 
 	patch->base.delta->similarity = 100 - dissimilarity;
@@ -406,15 +406,15 @@ static int parse_header_git(
 
 	/* Parse the diff --git line */
 	if (parse_advance_expected_str(ctx, "diff --git ") < 0)
-		return parse_err("corrupt git diff header at line %d", ctx->line_num);
+		return parse_err("corrupt git diff header at line %"PRIuZ, ctx->line_num);
 
 	if (parse_header_path(&patch->header_old_path, ctx) < 0)
-		return parse_err("corrupt old path in git diff header at line %d",
+		return parse_err("corrupt old path in git diff header at line %"PRIuZ,
 			ctx->line_num);
 
 	if (parse_advance_ws(ctx) < 0 ||
 		parse_header_path(&patch->header_new_path, ctx) < 0)
-		return parse_err("corrupt new path in git diff header at line %d",
+		return parse_err("corrupt new path in git diff header at line %"PRIuZ,
 			ctx->line_num);
 
 	/* Parse remaining header lines */
@@ -447,7 +447,7 @@ static int parse_header_git(
 			parse_advance_expected_str(ctx, "\n");
 
 			if (ctx->line_len > 0) {
-				error = parse_err("trailing data at line %d", ctx->line_num);
+				error = parse_err("trailing data at line %"PRIuZ, ctx->line_num);
 				goto done;
 			}
 
@@ -456,7 +456,7 @@ static int parse_header_git(
 		}
 		
 		if (!found) {
-			error = parse_err("invalid patch header at line %d",
+			error = parse_err("invalid patch header at line %"PRIuZ,
 				ctx->line_num);
 			goto done;
 		}
@@ -536,7 +536,7 @@ static int parse_hunk_header(
 
 	hunk->hunk.header_len = ctx->line - header_start;
 	if (hunk->hunk.header_len > (GIT_DIFF_HUNK_HEADER_SIZE - 1))
-		return parse_err("oversized patch hunk header at line %d",
+		return parse_err("oversized patch hunk header at line %"PRIuZ,
 			ctx->line_num);
 
 	memcpy(hunk->hunk.header, header_start, hunk->hunk.header_len);
@@ -545,7 +545,7 @@ static int parse_hunk_header(
 	return 0;
 
 fail:
-	giterr_set(GITERR_PATCH, "invalid patch hunk header at line %d",
+	giterr_set(GITERR_PATCH, "invalid patch hunk header at line %"PRIuZ,
 		ctx->line_num);
 	return -1;
 }
@@ -570,7 +570,7 @@ static int parse_hunk_body(
 		int prefix = 1;
 
 		if (ctx->line_len == 0 || ctx->line[ctx->line_len - 1] != '\n') {
-			error = parse_err("invalid patch instruction at line %d",
+			error = parse_err("invalid patch instruction at line %"PRIuZ,
 				ctx->line_num);
 			goto done;
 		}
@@ -596,7 +596,7 @@ static int parse_hunk_body(
 			break;
 
 		default:
-			error = parse_err("invalid patch hunk at line %d", ctx->line_num);
+			error = parse_err("invalid patch hunk at line %"PRIuZ, ctx->line_num);
 			goto done;
 		}
 
@@ -672,7 +672,7 @@ static int parse_patch_header(
 				continue;
 			}
 
-			error = parse_err("invalid hunk header outside patch at line %d",
+			error = parse_err("invalid hunk header outside patch at line %"PRIuZ,
 				line_num);
 			goto done;
 		}
@@ -715,12 +715,12 @@ static int parse_patch_binary_side(
 		parse_advance_chars(ctx, 6);
 	} else {
 		error = parse_err(
-			"unknown binary delta type at line %d", ctx->line_num);
+			"unknown binary delta type at line %"PRIuZ, ctx->line_num);
 		goto done;
 	}
 
 	if (parse_number(&len, ctx) < 0 || parse_advance_nl(ctx) < 0 || len < 0) {
-		error = parse_err("invalid binary size at line %d", ctx->line_num);
+		error = parse_err("invalid binary size at line %"PRIuZ, ctx->line_num);
 		goto done;
 	}
 
@@ -736,7 +736,7 @@ static int parse_patch_binary_side(
 			decoded_len = c - 'a' + (('z' - 'a') + 1) + 1;
 
 		if (!decoded_len) {
-			error = parse_err("invalid binary length at line %d", ctx->line_num);
+			error = parse_err("invalid binary length at line %"PRIuZ, ctx->line_num);
 			goto done;
 		}
 
@@ -745,7 +745,7 @@ static int parse_patch_binary_side(
 		encoded_len = ((decoded_len / 4) + !!(decoded_len % 4)) * 5;
 
 		if (encoded_len > ctx->line_len - 1) {
-			error = parse_err("truncated binary data at line %d", ctx->line_num);
+			error = parse_err("truncated binary data at line %"PRIuZ, ctx->line_num);
 			goto done;
 		}
 
@@ -754,14 +754,14 @@ static int parse_patch_binary_side(
 			goto done;
 
 		if (decoded.size - decoded_orig != decoded_len) {
-			error = parse_err("truncated binary data at line %d", ctx->line_num);
+			error = parse_err("truncated binary data at line %"PRIuZ, ctx->line_num);
 			goto done;
 		}
 
 		parse_advance_chars(ctx, encoded_len);
 
 		if (parse_advance_nl(ctx) < 0) {
-			error = parse_err("trailing data at line %d", ctx->line_num);
+			error = parse_err("trailing data at line %"PRIuZ, ctx->line_num);
 			goto done;
 		}
 	}
@@ -785,7 +785,7 @@ static int parse_patch_binary(
 
 	if (parse_advance_expected_str(ctx, "GIT binary patch") < 0 ||
 		parse_advance_nl(ctx) < 0)
-		return parse_err("corrupt git binary header at line %d", ctx->line_num);
+		return parse_err("corrupt git binary header at line %"PRIuZ, ctx->line_num);
 
 	/* parse old->new binary diff */
 	if ((error = parse_patch_binary_side(
@@ -793,7 +793,7 @@ static int parse_patch_binary(
 		return error;
 
 	if (parse_advance_nl(ctx) < 0)
-		return parse_err("corrupt git binary separator at line %d",
+		return parse_err("corrupt git binary separator at line %"PRIuZ,
 			ctx->line_num);
 
 	/* parse new->old binary diff */
@@ -802,7 +802,7 @@ static int parse_patch_binary(
 		return error;
 
 	if (parse_advance_nl(ctx) < 0)
-		return parse_err("corrupt git binary patch separator at line %d",
+		return parse_err("corrupt git binary patch separator at line %"PRIuZ,
 			ctx->line_num);
 
 	patch->base.binary.contains_data = 1;
@@ -820,7 +820,7 @@ static int parse_patch_binary_nodata(
 		parse_advance_expected_str(ctx, patch->header_new_path) < 0 ||
 		parse_advance_expected_str(ctx, " differ") < 0 ||
 		parse_advance_nl(ctx) < 0)
-		return parse_err("corrupt git binary header at line %d", ctx->line_num);
+		return parse_err("corrupt git binary header at line %"PRIuZ, ctx->line_num);
 
 	patch->base.binary.contains_data = 0;
 	patch->base.delta->flags |= GIT_DIFF_FLAG_BINARY;
@@ -912,7 +912,7 @@ static int check_prefix(
 
 	if (remain_len || !*path)
 		return parse_err(
-			"header filename does not contain %d path components",
+			"header filename does not contain %"PRIuZ" path components",
 			prefix_len);
 
 done:
@@ -1014,8 +1014,10 @@ git_patch_parse_ctx *git_patch_parse_ctx_init(
 		return NULL;
 
 	if (content_len) {
-		if ((ctx->content = git__malloc(content_len)) == NULL)
+		if ((ctx->content = git__malloc(content_len)) == NULL) {
+			git__free(ctx);
 			return NULL;
+		}
 
 		memcpy((char *)ctx->content, content, content_len);
 	}
diff --git a/src/path.c b/src/path.c
index e5f04a56a..bffde930b 100644
--- a/src/path.c
+++ b/src/path.c
@@ -341,7 +341,7 @@ int git_path_prettify(git_buf *path_out, const char *path, const char *base)
 	if (p_realpath(path, buf) == NULL) {
 		/* giterr_set resets the errno when dealing with a GITERR_OS kind of error */
 		int error = (errno == ENOENT || errno == ENOTDIR) ? GIT_ENOTFOUND : -1;
-		giterr_set(GITERR_OS, "Failed to resolve path '%s'", path);
+		giterr_set(GITERR_OS, "failed to resolve path '%s'", path);
 
 		git_buf_clear(path_out);
 
@@ -632,20 +632,24 @@ int git_path_set_error(int errno_value, const char *path, const char *action)
 	switch (errno_value) {
 	case ENOENT:
 	case ENOTDIR:
-		giterr_set(GITERR_OS, "Could not find '%s' to %s", path, action);
+		giterr_set(GITERR_OS, "could not find '%s' to %s", path, action);
 		return GIT_ENOTFOUND;
 
 	case EINVAL:
 	case ENAMETOOLONG:
-		giterr_set(GITERR_OS, "Invalid path for filesystem '%s'", path);
+		giterr_set(GITERR_OS, "invalid path for filesystem '%s'", path);
 		return GIT_EINVALIDSPEC;
 
 	case EEXIST:
-		giterr_set(GITERR_OS, "Failed %s - '%s' already exists", action, path);
+		giterr_set(GITERR_OS, "failed %s - '%s' already exists", action, path);
 		return GIT_EEXISTS;
 
+	case EACCES:
+		giterr_set(GITERR_OS, "failed %s - '%s' is locked", action, path);
+		return GIT_ELOCKED;
+
 	default:
-		giterr_set(GITERR_OS, "Could not %s '%s'", action, path);
+		giterr_set(GITERR_OS, "could not %s '%s'", action, path);
 		return -1;
 	}
 }
@@ -754,7 +758,7 @@ int git_path_resolve_relative(git_buf *path, size_t ceiling)
 			/* error out if trying to up one from a hard base */
 			if (to == base && ceiling != 0) {
 				giterr_set(GITERR_INVALID,
-					"Cannot strip root component off url");
+					"cannot strip root component off url");
 				return -1;
 			}
 
@@ -983,7 +987,7 @@ int git_path_iconv(git_path_iconv_t *ic, const char **in, size_t *inlen)
 	return 0;
 
 fail:
-	giterr_set(GITERR_OS, "Unable to convert unicode path data");
+	giterr_set(GITERR_OS, "unable to convert unicode path data");
 	return -1;
 }
 
@@ -1076,7 +1080,7 @@ int git_path_direach(
 	wd_len = git_buf_len(path);
 
 	if ((dir = opendir(path->ptr)) == NULL) {
-		giterr_set(GITERR_OS, "Failed to open directory '%s'", path->ptr);
+		giterr_set(GITERR_OS, "failed to open directory '%s'", path->ptr);
 		if (errno == ENOENT)
 			return GIT_ENOTFOUND;
 
@@ -1141,7 +1145,6 @@ int git_path_diriter_init(
 	unsigned int flags)
 {
 	git_win32_path path_filter;
-	git_buf hack = {0};
 
 	static int is_win7_or_later = -1;
 	if (is_win7_or_later < 0)
@@ -1158,13 +1161,13 @@ int git_path_diriter_init(
 	git_path_trim_slashes(&diriter->path_utf8);
 
 	if (diriter->path_utf8.size == 0) {
-		giterr_set(GITERR_FILESYSTEM, "Could not open directory '%s'", path);
+		giterr_set(GITERR_FILESYSTEM, "could not open directory '%s'", path);
 		return -1;
 	}
 
 	if ((diriter->parent_len = git_win32_path_from_utf8(diriter->path, diriter->path_utf8.ptr)) < 0 ||
 			!git_win32__findfirstfile_filter(path_filter, diriter->path_utf8.ptr)) {
-		giterr_set(GITERR_OS, "Could not parse the directory path '%s'", path);
+		giterr_set(GITERR_OS, "could not parse the directory path '%s'", path);
 		return -1;
 	}
 
@@ -1177,7 +1180,7 @@ int git_path_diriter_init(
 		is_win7_or_later ? FIND_FIRST_EX_LARGE_FETCH : 0);
 
 	if (diriter->handle == INVALID_HANDLE_VALUE) {
-		giterr_set(GITERR_OS, "Could not open directory '%s'", path);
+		giterr_set(GITERR_OS, "could not open directory '%s'", path);
 		return -1;
 	}
 
@@ -1307,14 +1310,14 @@ int git_path_diriter_init(
 	git_path_trim_slashes(&diriter->path);
 
 	if (diriter->path.size == 0) {
-		giterr_set(GITERR_FILESYSTEM, "Could not open directory '%s'", path);
+		giterr_set(GITERR_FILESYSTEM, "could not open directory '%s'", path);
 		return -1;
 	}
 
 	if ((diriter->dir = opendir(diriter->path.ptr)) == NULL) {
 		git_buf_free(&diriter->path);
 
-		giterr_set(GITERR_OS, "Failed to open directory '%s'", path);
+		giterr_set(GITERR_OS, "failed to open directory '%s'", path);
 		return -1;
 	}
 
@@ -1347,7 +1350,7 @@ int git_path_diriter_next(git_path_diriter *diriter)
 				return GIT_ITEROVER;
 
 			giterr_set(GITERR_OS,
-				"Could not read directory '%s'", diriter->path);
+				"could not read directory '%s'", diriter->path.ptr);
 			return -1;
 		}
 	} while (skip_dot && git_path_is_dot_or_dotdot(de->d_name));
diff --git a/src/pathspec.c b/src/pathspec.c
index 361b398b8..00dba4f6b 100644
--- a/src/pathspec.c
+++ b/src/pathspec.c
@@ -487,7 +487,7 @@ static int pathspec_match_from_iterator(
 
 	/* if every pattern failed to match, then we have failed */
 	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_files) {
-		giterr_set(GITERR_INVALID, "No matching files were found");
+		giterr_set(GITERR_INVALID, "no matching files were found");
 		error = GIT_ENOTFOUND;
 	}
 
@@ -658,7 +658,7 @@ int git_pathspec_match_diff(
 
 	/* if every pattern failed to match, then we have failed */
 	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_deltas) {
-		giterr_set(GITERR_INVALID, "No matching deltas were found");
+		giterr_set(GITERR_INVALID, "no matching deltas were found");
 		error = GIT_ENOTFOUND;
 	}
 
diff --git a/src/posix.c b/src/posix.c
index b3f1a1cd3..e68f324f6 100644
--- a/src/posix.c
+++ b/src/posix.c
@@ -240,7 +240,7 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offs
 	out->len = 0;
 
 	if ((prot & GIT_PROT_WRITE) && ((flags & GIT_MAP_TYPE) == GIT_MAP_SHARED)) {
-		giterr_set(GITERR_OS, "Trying to map shared-writeable");
+		giterr_set(GITERR_OS, "trying to map shared-writeable");
 		return -1;
 	}
 
diff --git a/src/pqueue.c b/src/pqueue.c
index 8cfc4390f..9341d1af3 100644
--- a/src/pqueue.c
+++ b/src/pqueue.c
@@ -86,8 +86,9 @@ int git_pqueue_insert(git_pqueue *pq, void *item)
 	if ((pq->flags & GIT_PQUEUE_FIXED_SIZE) != 0 &&
 		pq->length >= pq->_alloc_size)
 	{
-		/* skip this item if below min item in heap */
-		if (pq->_cmp(item, git_vector_get(pq, 0)) <= 0)
+		/* skip this item if below min item in heap or if
+		 * we do not have a comparison function */
+		if (!pq->_cmp || pq->_cmp(item, git_vector_get(pq, 0)) <= 0)
 			return 0;
 		/* otherwise remove the min item before inserting new */
 		(void)git_pqueue_pop(pq);
diff --git a/src/push.c b/src/push.c
index b4901388b..09c234034 100644
--- a/src/push.c
+++ b/src/push.c
@@ -90,7 +90,7 @@ static void free_refspec(push_spec *spec)
 static int check_rref(char *ref)
 {
 	if (git__prefixcmp(ref, "refs/")) {
-		giterr_set(GITERR_INVALID, "Not a valid reference '%s'", ref);
+		giterr_set(GITERR_INVALID, "not a valid reference '%s'", ref);
 		return -1;
 	}
 
@@ -111,7 +111,7 @@ static int check_lref(git_push *push, char *ref)
 		giterr_set(GITERR_REFERENCE,
 			"src refspec '%s' does not match any existing object", ref);
 	else
-		giterr_set(GITERR_INVALID, "Not a valid reference '%s'", ref);
+		giterr_set(GITERR_INVALID, "not a valid reference '%s'", ref);
 	return -1;
 }
 
@@ -321,7 +321,7 @@ static int revwalk(git_vector *commits, git_push *push)
 
 			if (!git_odb_exists(push->repo->_odb, &spec->roid)) {
 				giterr_set(GITERR_REFERENCE, 
-					"Cannot push because a reference that you are trying to update on the remote contains commits that are not present locally.");
+					"cannot push because a reference that you are trying to update on the remote contains commits that are not present locally.");
 				error = GIT_ENONFASTFORWARD;
 				goto on_error;
 			}
@@ -332,7 +332,7 @@ static int revwalk(git_vector *commits, git_push *push)
 			if (error == GIT_ENOTFOUND ||
 				(!error && !git_oid_equal(&base, &spec->roid))) {
 				giterr_set(GITERR_REFERENCE,
-					"Cannot push non-fastforwardable reference");
+					"cannot push non-fastforwardable reference");
 				error = GIT_ENONFASTFORWARD;
 				goto on_error;
 			}
@@ -553,7 +553,7 @@ static int calculate_work(git_push *push)
 			/* This is a create or update.  Local ref must exist. */
 			if (git_reference_name_to_id(
 					&spec->loid, push->repo, spec->refspec.src) < 0) {
-				giterr_set(GITERR_REFERENCE, "No such reference '%s'", spec->refspec.src);
+				giterr_set(GITERR_REFERENCE, "no such reference '%s'", spec->refspec.src);
 				return -1;
 			}
 		}
@@ -579,7 +579,7 @@ static int do_push(git_push *push, const git_remote_callbacks *callbacks)
 	git_transport *transport = push->remote->transport;
 
 	if (!transport->push) {
-		giterr_set(GITERR_NET, "Remote transport doesn't support push");
+		giterr_set(GITERR_NET, "remote transport doesn't support push");
 		error = -1;
 		goto on_error;
 	}
diff --git a/src/rebase.c b/src/rebase.c
index e86312e7e..b2024a439 100644
--- a/src/rebase.c
+++ b/src/rebase.c
@@ -152,7 +152,7 @@ GIT_INLINE(int) rebase_readint(
 		return error;
 
 	if (git__strtol32(&num, asc_out->ptr, &eol, 10) < 0 || num < 0 || *eol) {
-		giterr_set(GITERR_REBASE, "The file '%s' contains an invalid numeric value", filename);
+		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid numeric value", filename);
 		return -1;
 	}
 
@@ -170,7 +170,7 @@ GIT_INLINE(int) rebase_readoid(
 		return error;
 
 	if (str_out->size != GIT_OID_HEXSZ || git_oid_fromstr(out, str_out->ptr) < 0) {
-		giterr_set(GITERR_REBASE, "The file '%s' contains an invalid object ID", filename);
+		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid object ID", filename);
 		return -1;
 	}
 
@@ -316,7 +316,7 @@ int git_rebase_open(
 		goto done;
 
 	if (rebase->type == GIT_REBASE_TYPE_NONE) {
-		giterr_set(GITERR_REBASE, "There is no rebase in progress");
+		giterr_set(GITERR_REBASE, "there is no rebase in progress");
 		error = GIT_ENOTFOUND;
 		goto done;
 	}
@@ -372,14 +372,14 @@ int git_rebase_open(
 
 	switch (rebase->type) {
 	case GIT_REBASE_TYPE_INTERACTIVE:
-		giterr_set(GITERR_REBASE, "Interactive rebase is not supported");
+		giterr_set(GITERR_REBASE, "interactive rebase is not supported");
 		error = -1;
 		break;
 	case GIT_REBASE_TYPE_MERGE:
 		error = rebase_open_merge(rebase);
 		break;
 	case GIT_REBASE_TYPE_APPLY:
-		giterr_set(GITERR_REBASE, "Patch application rebase is not supported");
+		giterr_set(GITERR_REBASE, "patch application rebase is not supported");
 		error = -1;
 		break;
 	default:
@@ -478,7 +478,7 @@ static int rebase_setupfiles(git_rebase *rebase)
 	git_oid_fmt(orig_head, &rebase->orig_head_id);
 
 	if (p_mkdir(rebase->state_path, REBASE_DIR_MODE) < 0) {
-		giterr_set(GITERR_OS, "Failed to create rebase directory '%s'", rebase->state_path);
+		giterr_set(GITERR_OS, "failed to create rebase directory '%s'", rebase->state_path);
 		return -1;
 	}
 
@@ -511,7 +511,7 @@ static int rebase_ensure_not_in_progress(git_repository *repo)
 		return error;
 
 	if (type != GIT_REBASE_TYPE_NONE) {
-		giterr_set(GITERR_REBASE, "There is an existing rebase in progress");
+		giterr_set(GITERR_REBASE, "there is an existing rebase in progress");
 		return -1;
 	}
 
@@ -536,7 +536,7 @@ static int rebase_ensure_not_dirty(
 			goto done;
 
 		if (git_diff_num_deltas(diff) > 0) {
-			giterr_set(GITERR_REBASE, "Uncommitted changes exist in index");
+			giterr_set(GITERR_REBASE, "uncommitted changes exist in index");
 			error = fail_with;
 			goto done;
 		}
@@ -550,7 +550,7 @@ static int rebase_ensure_not_dirty(
 			goto done;
 
 		if (git_diff_num_deltas(diff) > 0) {
-			giterr_set(GITERR_REBASE, "Unstaged changes exist in workdir");
+			giterr_set(GITERR_REBASE, "unstaged changes exist in workdir");
 			error = fail_with;
 			goto done;
 		}
@@ -630,7 +630,7 @@ static int rebase_init_merge(
 	rebase->state_path = git_buf_detach(&state_path);
 	GITERR_CHECK_ALLOC(rebase->state_path);
 
-	if (branch->ref_name) {
+	if (branch->ref_name && strcmp(branch->ref_name, "HEAD")) {
 		rebase->orig_head_name = git__strdup(branch->ref_name);
 		GITERR_CHECK_ALLOC(rebase->orig_head_name);
 	} else {
@@ -731,7 +731,7 @@ int git_rebase_init(
 	if (inmemory)
 		error = rebase_init_inmemory(rebase, repo, branch, upstream, onto);
 	else
-		rebase_init_merge(rebase, repo, branch ,upstream, onto);
+		error = rebase_init_merge(rebase, repo, branch ,upstream, onto);
 
 	if (error == 0)
 		*out = rebase;
@@ -807,7 +807,7 @@ static int rebase_next_merge(
 		goto done;
 
 	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
-		giterr_set(GITERR_REBASE, "Cannot rebase a merge commit");
+		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
 		error = -1;
 		goto done;
 	} else if (parent_count) {
@@ -864,7 +864,7 @@ static int rebase_next_inmemory(
 		goto done;
 
 	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
-		giterr_set(GITERR_REBASE, "Cannot rebase a merge commit");
+		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
 		error = -1;
 		goto done;
 	} else if (parent_count) {
@@ -1259,7 +1259,7 @@ static int rebase_copy_notes(
 	goto done;
 
 on_error:
-	giterr_set(GITERR_REBASE, "Invalid rewritten file at line %d", linenum);
+	giterr_set(GITERR_REBASE, "invalid rewritten file at line %d", linenum);
 	error = -1;
 
 done:
diff --git a/src/refdb.c b/src/refdb.c
index debba1276..1ee0efb31 100644
--- a/src/refdb.c
+++ b/src/refdb.c
@@ -125,13 +125,15 @@ int git_refdb_lookup(git_reference **out, git_refdb *db, const char *ref_name)
 
 int git_refdb_iterator(git_reference_iterator **out, git_refdb *db, const char *glob)
 {
+	int error;
+
 	if (!db->backend || !db->backend->iterator) {
-		giterr_set(GITERR_REFERENCE, "This backend doesn't support iterators");
+		giterr_set(GITERR_REFERENCE, "this backend doesn't support iterators");
 		return -1;
 	}
 
-	if (db->backend->iterator(out, db->backend, glob) < 0)
-		return -1;
+	if ((error = db->backend->iterator(out, db->backend, glob)) < 0)
+		return error;
 
 	GIT_REFCOUNT_INC(db);
 	(*out)->db = db;
diff --git a/src/refdb_fs.c b/src/refdb_fs.c
index f978038e6..e40f48bd5 100644
--- a/src/refdb_fs.c
+++ b/src/refdb_fs.c
@@ -185,7 +185,7 @@ static int packed_reload(refdb_fs_backend *backend)
 	return 0;
 
 parse_failed:
-	giterr_set(GITERR_REFERENCE, "Corrupted packed references file");
+	giterr_set(GITERR_REFERENCE, "corrupted packed references file");
 
 	git_sortedcache_clear(backend->refcache, false);
 	git_sortedcache_wunlock(backend->refcache);
@@ -212,7 +212,7 @@ static int loose_parse_oid(
 		return 0;
 
 corrupted:
-	giterr_set(GITERR_REFERENCE, "Corrupted loose reference file: %s", filename);
+	giterr_set(GITERR_REFERENCE, "corrupted loose reference file: %s", filename);
 	return -1;
 }
 
@@ -326,12 +326,13 @@ static int refdb_fs_backend__exists(
 {
 	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
 	git_buf ref_path = GIT_BUF_INIT;
+	int error;
 
 	assert(backend);
 
-	if (packed_reload(backend) < 0 ||
-		git_buf_joinpath(&ref_path, backend->path, ref_name) < 0)
-		return -1;
+	if ((error = packed_reload(backend)) < 0 ||
+		(error = git_buf_joinpath(&ref_path, backend->path, ref_name)) < 0)
+		return error;
 
 	*exists = git_path_isfile(ref_path.ptr) ||
 		(git_sortedcache_lookup(backend->refcache, ref_name) != NULL);
@@ -348,7 +349,7 @@ static const char *loose_parse_symbolic(git_buf *file_content)
 	refname_start = (const char *)file_content->ptr;
 
 	if (git_buf_len(file_content) < header_len + 1) {
-		giterr_set(GITERR_REFERENCE, "Corrupted loose reference file");
+		giterr_set(GITERR_REFERENCE, "corrupted loose reference file");
 		return NULL;
 	}
 
@@ -397,7 +398,7 @@ static int loose_lookup(
 
 static int ref_error_notfound(const char *name)
 {
-	giterr_set(GITERR_REFERENCE, "Reference '%s' not found", name);
+	giterr_set(GITERR_REFERENCE, "reference '%s' not found", name);
 	return GIT_ENOTFOUND;
 }
 
@@ -409,8 +410,8 @@ static int packed_lookup(
 	int error = 0;
 	struct packref *entry;
 
-	if (packed_reload(backend) < 0)
-		return -1;
+	if ((error = packed_reload(backend)) < 0)
+		return error;
 
 	if (git_sortedcache_rlock(backend->refcache) < 0)
 		return -1;
@@ -615,13 +616,14 @@ static int refdb_fs_backend__iterator_next_name(
 static int refdb_fs_backend__iterator(
 	git_reference_iterator **out, git_refdb_backend *_backend, const char *glob)
 {
+	int error;
 	refdb_fs_iter *iter;
 	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
 
 	assert(backend);
 
-	if (packed_reload(backend) < 0)
-		return -1;
+	if ((error = packed_reload(backend)) < 0)
+		return error;
 
 	iter = git__calloc(1, sizeof(refdb_fs_iter));
 	GITERR_CHECK_ALLOC(iter);
@@ -674,20 +676,22 @@ static int reference_path_available(
 	int force)
 {
 	size_t i;
+	int error;
 
-	if (packed_reload(backend) < 0)
-		return -1;
+	if ((error = packed_reload(backend)) < 0)
+		return error;
 
 	if (!force) {
 		int exists;
 
-		if (refdb_fs_backend__exists(
-				&exists, (git_refdb_backend *)backend, new_ref) < 0)
-			return -1;
+		if ((error = refdb_fs_backend__exists(
+			&exists, (git_refdb_backend *)backend, new_ref)) < 0) {
+			return error;
+		}
 
 		if (exists) {
 			giterr_set(GITERR_REFERENCE,
-				"Failed to write reference '%s': a reference with "
+				"failed to write reference '%s': a reference with "
 				"that name already exists.", new_ref);
 			return GIT_EEXISTS;
 		}
@@ -701,7 +705,7 @@ static int reference_path_available(
 		if (ref && !ref_is_available(old_ref, new_ref, ref->name)) {
 			git_sortedcache_runlock(backend->refcache);
 			giterr_set(GITERR_REFERENCE,
-				"Path to reference '%s' collides with existing one", new_ref);
+				"path to reference '%s' collides with existing one", new_ref);
 			return -1;
 		}
 	}
@@ -718,15 +722,15 @@ static int loose_lock(git_filebuf *file, refdb_fs_backend *backend, const char *
 	assert(file && backend && name);
 
 	if (!git_path_isvalid(backend->repo, name, GIT_PATH_REJECT_FILESYSTEM_DEFAULTS)) {
-		giterr_set(GITERR_INVALID, "Invalid reference name '%s'.", name);
+		giterr_set(GITERR_INVALID, "invalid reference name '%s'", name);
 		return GIT_EINVALIDSPEC;
 	}
 
 	/* Remove a possibly existing empty directory hierarchy
 	 * which name would collide with the reference name
 	 */
-	if (git_futils_rmdir_r(name, backend->path, GIT_RMDIR_SKIP_NONEMPTY) < 0)
-		return -1;
+	if ((error = git_futils_rmdir_r(name, backend->path, GIT_RMDIR_SKIP_NONEMPTY)) < 0)
+		return error;
 
 	if (git_buf_joinpath(&ref_path, backend->path, name) < 0)
 		return -1;
@@ -901,40 +905,62 @@ static int packed_write_ref(struct packref *ref, git_filebuf *file)
 static int packed_remove_loose(refdb_fs_backend *backend)
 {
 	size_t i;
-	git_buf full_path = GIT_BUF_INIT;
-	int failed = 0;
+	git_filebuf lock = GIT_FILEBUF_INIT;
+	git_buf ref_content = GIT_BUF_INIT;
+	int error = 0;
 
 	/* backend->refcache is already locked when this is called */
 
 	for (i = 0; i < git_sortedcache_entrycount(backend->refcache); ++i) {
 		struct packref *ref = git_sortedcache_entry(backend->refcache, i);
+		git_oid current_id;
 
 		if (!ref || !(ref->flags & PACKREF_WAS_LOOSE))
 			continue;
 
-		if (git_buf_joinpath(&full_path, backend->path, ref->name) < 0)
-			return -1; /* critical; do not try to recover on oom */
+		git_filebuf_cleanup(&lock);
 
-		if (git_path_exists(full_path.ptr) && p_unlink(full_path.ptr) < 0) {
-			if (failed)
-				continue;
+		/* We need to stop anybody from updating the ref while we try to do a safe delete */
+		error = loose_lock(&lock, backend, ref->name);
+		/* If someone else is updating it, let them do it */
+		if (error == GIT_EEXISTS || error == GIT_ENOTFOUND)
+			continue;
 
-			giterr_set(GITERR_REFERENCE,
-				"Failed to remove loose reference '%s' after packing: %s",
-				full_path.ptr, strerror(errno));
-			failed = 1;
+		if (error < 0) {
+			git_buf_free(&ref_content);
+			giterr_set(GITERR_REFERENCE, "failed to lock loose reference '%s'", ref->name);
+			return error;
 		}
 
+		error = git_futils_readbuffer(&ref_content, lock.path_original);
+		/* Someone else beat us to cleaning up the ref, let's simply continue */
+		if (error == GIT_ENOTFOUND)
+			continue;
+
+		/* This became a symref between us packing and trying to delete it, so ignore it */
+		if (!git__prefixcmp(ref_content.ptr, GIT_SYMREF))
+			continue;
+
+		/* Figure out the current id; if we find a bad ref file, skip it so we can do the rest */
+		if (loose_parse_oid(&current_id, lock.path_original, &ref_content) < 0)
+			continue;
+
+		/* If the ref moved since we packed it, we must not delete it */
+		if (!git_oid_equal(&current_id, &ref->oid))
+			continue;
+
 		/*
 		 * if we fail to remove a single file, this is *not* good,
 		 * but we should keep going and remove as many as possible.
-		 * After we've removed as many files as possible, we return
-		 * the error code anyway.
+		 * If we fail to remove, the ref is still in the old state, so
+		 * we haven't lost information.
 		 */
+		p_unlink(lock.path_original);
 	}
 
-	git_buf_free(&full_path);
-	return failed ? -1 : 0;
+	git_buf_free(&ref_content);
+	git_filebuf_cleanup(&lock);
+	return 0;
 }
 
 /*
@@ -944,41 +970,42 @@ static int packed_write(refdb_fs_backend *backend)
 {
 	git_sortedcache *refcache = backend->refcache;
 	git_filebuf pack_file = GIT_FILEBUF_INIT;
+	int error;
 	size_t i;
 
 	/* lock the cache to updates while we do this */
-	if (git_sortedcache_wlock(refcache) < 0)
-		return -1;
+	if ((error = git_sortedcache_wlock(refcache)) < 0)
+		return error;
 
 	/* Open the file! */
-	if (git_filebuf_open(&pack_file, git_sortedcache_path(refcache), 0, GIT_PACKEDREFS_FILE_MODE) < 0)
+	if ((error = git_filebuf_open(&pack_file, git_sortedcache_path(refcache), 0, GIT_PACKEDREFS_FILE_MODE)) < 0)
 		goto fail;
 
 	/* Packfiles have a header... apparently
 	 * This is in fact not required, but we might as well print it
 	 * just for kicks */
-	if (git_filebuf_printf(&pack_file, "%s\n", GIT_PACKEDREFS_HEADER) < 0)
+	if ((error = git_filebuf_printf(&pack_file, "%s\n", GIT_PACKEDREFS_HEADER)) < 0)
 		goto fail;
 
 	for (i = 0; i < git_sortedcache_entrycount(refcache); ++i) {
 		struct packref *ref = git_sortedcache_entry(refcache, i);
 		assert(ref);
 
-		if (packed_find_peel(backend, ref) < 0)
+		if ((error = packed_find_peel(backend, ref)) < 0)
 			goto fail;
 
-		if (packed_write_ref(ref, &pack_file) < 0)
+		if ((error = packed_write_ref(ref, &pack_file)) < 0)
 			goto fail;
 	}
 
 	/* if we've written all the references properly, we can commit
 	 * the packfile to make the changes effective */
-	if (git_filebuf_commit(&pack_file) < 0)
+	if ((error = git_filebuf_commit(&pack_file)) < 0)
 		goto fail;
 
 	/* when and only when the packfile has been properly written,
 	 * we can go ahead and remove the loose refs */
-	if (packed_remove_loose(backend) < 0)
+	if ((error = packed_remove_loose(backend)) < 0)
 		goto fail;
 
 	git_sortedcache_updated(refcache);
@@ -991,7 +1018,7 @@ fail:
 	git_filebuf_cleanup(&pack_file);
 	git_sortedcache_wunlock(refcache);
 
-	return -1;
+	return error;
 }
 
 static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, const git_oid *old, const git_oid *new, const git_signature *author, const char *message);
@@ -1143,8 +1170,7 @@ static int refdb_fs_backend__write(
 
 	assert(backend);
 
-	error = reference_path_available(backend, ref->name, NULL, force);
-	if (error < 0)
+	if ((error = reference_path_available(backend, ref->name, NULL, force)) < 0)
 		return error;
 
 	/* We need to perform the reflog append and old value check under the ref's lock */
@@ -1260,15 +1286,14 @@ static int refdb_fs_backend__delete_tail(
 	if (git_buf_joinpath(&loose_path, backend->path, ref_name) < 0)
 		return -1;
 
-	if (git_path_isfile(loose_path.ptr)) {
-		error = p_unlink(loose_path.ptr);
-		loose_deleted = 1;
-	}
-
-	git_buf_free(&loose_path);
 
-	if (error != 0)
+	error = p_unlink(loose_path.ptr);
+	if (error < 0 && errno == ENOENT)
+		error = 0;
+	else if (error < 0)
 		goto cleanup;
+	else if (error == 0)
+		loose_deleted = 1;
 
 	if ((error = packed_reload(backend)) < 0)
 		goto cleanup;
@@ -1291,6 +1316,7 @@ static int refdb_fs_backend__delete_tail(
 	error = packed_write(backend);
 
 cleanup:
+	git_buf_free(&loose_path);
 	git_filebuf_cleanup(file);
 
 	return error;
@@ -1362,14 +1388,15 @@ static int refdb_fs_backend__rename(
 
 static int refdb_fs_backend__compress(git_refdb_backend *_backend)
 {
+	int error;
 	refdb_fs_backend *backend = (refdb_fs_backend *)_backend;
 
 	assert(backend);
 
-	if (packed_reload(backend) < 0 || /* load the existing packfile */
-		packed_loadloose(backend) < 0 || /* add all the loose refs */
-		packed_write(backend) < 0) /* write back to disk */
-		return -1;
+	if ((error = packed_reload(backend)) < 0 || /* load the existing packfile */
+	    (error = packed_loadloose(backend)) < 0 || /* add all the loose refs */
+	    (error = packed_write(backend)) < 0) /* write back to disk */
+		return error;
 
 	return 0;
 }
@@ -1457,7 +1484,7 @@ static int reflog_parse(git_reflog *log, const char *buf, size_t buf_size)
 
 #define seek_forward(_increase) do { \
 	if (_increase >= buf_size) { \
-		giterr_set(GITERR_INVALID, "Ran out of data while parsing reflog"); \
+		giterr_set(GITERR_INVALID, "ran out of data while parsing reflog"); \
 		goto fail; \
 	} \
 	buf += _increase; \
@@ -1673,7 +1700,7 @@ static int lock_reflog(git_filebuf *file, refdb_fs_backend *backend, const char
 	repo = backend->repo;
 
 	if (!git_path_isvalid(backend->repo, refname, GIT_PATH_REJECT_FILESYSTEM_DEFAULTS)) {
-		giterr_set(GITERR_INVALID, "Invalid reference name '%s'.", refname);
+		giterr_set(GITERR_INVALID, "invalid reference name '%s'", refname);
 		return GIT_EINVALIDSPEC;
 	}
 
@@ -1682,7 +1709,7 @@ static int lock_reflog(git_filebuf *file, refdb_fs_backend *backend, const char
 
 	if (!git_path_isfile(git_buf_cstr(&log_path))) {
 		giterr_set(GITERR_INVALID,
-			"Log file for reference '%s' doesn't exist.", refname);
+			"log file for reference '%s' doesn't exist", refname);
 		error = -1;
 		goto cleanup;
 	}
@@ -1789,9 +1816,10 @@ static int reflog_append(refdb_fs_backend *backend, const git_reference *ref, co
 	 * there maybe an obsolete/unused directory (or directory hierarchy) in the way.
 	 */
 	if (git_path_isdir(git_buf_cstr(&path))) {
-		if ((git_futils_rmdir_r(git_buf_cstr(&path), NULL, GIT_RMDIR_SKIP_NONEMPTY) < 0))
-			error = -1;
-		else if (git_path_isdir(git_buf_cstr(&path))) {
+		if ((error = git_futils_rmdir_r(git_buf_cstr(&path), NULL, GIT_RMDIR_SKIP_NONEMPTY)) < 0) {
+			if (error == GIT_ENOTFOUND)
+				error = 0;
+		} else if (git_path_isdir(git_buf_cstr(&path))) {
 			giterr_set(GITERR_REFERENCE, "cannot create reflog at '%s', there are reflogs beneath that folder",
 				ref->name);
 			error = GIT_EDIRECTORY;
@@ -1861,7 +1889,7 @@ static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_
 	p_close(fd);
 
 	if (p_rename(git_buf_cstr(&old_path), git_buf_cstr(&temp_path)) < 0) {
-		giterr_set(GITERR_OS, "Failed to rename reflog for %s", new_name);
+		giterr_set(GITERR_OS, "failed to rename reflog for %s", new_name);
 		error = -1;
 		goto cleanup;
 	}
@@ -1878,7 +1906,7 @@ static int refdb_reflog_fs__rename(git_refdb_backend *_backend, const char *old_
 	}
 
 	if (p_rename(git_buf_cstr(&temp_path), git_buf_cstr(&new_path)) < 0) {
-		giterr_set(GITERR_OS, "Failed to rename reflog for %s", new_name);
+		giterr_set(GITERR_OS, "failed to rename reflog for %s", new_name);
 		error = -1;
 	}
 
diff --git a/src/reflog.c b/src/reflog.c
index 9ce9aee6f..98ef1b669 100644
--- a/src/reflog.c
+++ b/src/reflog.c
@@ -93,7 +93,7 @@ int git_reflog_append(git_reflog *reflog, const git_oid *new_oid, const git_sign
 
 		if (newline) {
 			if (newline[1] != '\0') {
-				giterr_set(GITERR_INVALID, "Reflog message cannot contain newline");
+				giterr_set(GITERR_INVALID, "reflog message cannot contain newline");
 				goto cleanup;
 			}
 
@@ -193,7 +193,7 @@ int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)
 	entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);
 
 	if (entry == NULL) {
-		giterr_set(GITERR_REFERENCE, "No reflog entry at index %"PRIuZ, idx);
+		giterr_set(GITERR_REFERENCE, "no reflog entry at index %"PRIuZ, idx);
 		return GIT_ENOTFOUND;
 	}
 
diff --git a/src/refs.c b/src/refs.c
index bff443ac9..dbc7e5e8e 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -236,7 +236,7 @@ int git_reference_lookup_resolved(
 
 	if (scan_type != GIT_REF_OID && max_nesting != 0) {
 		giterr_set(GITERR_REFERENCE,
-			"Cannot resolve reference (>%u levels deep)", max_nesting);
+			"cannot resolve reference (>%u levels deep)", max_nesting);
 		git_reference_free(ref);
 		return -1;
 	}
@@ -298,7 +298,7 @@ cleanup:
 	if (error && !foundvalid) {
 		/* never found a valid reference name */
 		giterr_set(GITERR_REFERENCE,
-			"Could not use '%s' as valid reference name", git_buf_cstr(&name));
+			"could not use '%s' as valid reference name", git_buf_cstr(&name));
 	}
 
 	if (error == GIT_ENOTFOUND)
@@ -396,7 +396,7 @@ static int reference__create(
 
 		if (!git_object__is_valid(repo, oid, GIT_OBJ_ANY)) {
 			giterr_set(GITERR_REFERENCE,
-				"Target OID for the reference doesn't exist on the repository");
+				"target OID for the reference doesn't exist on the repository");
 			return -1;
 		}
 
@@ -524,7 +524,7 @@ static int ensure_is_an_updatable_direct_reference(git_reference *ref)
 	if (ref->type == GIT_REF_OID)
 		return 0;
 
-	giterr_set(GITERR_REFERENCE, "Cannot set OID on symbolic reference");
+	giterr_set(GITERR_REFERENCE, "cannot set OID on symbolic reference");
 	return -1;
 }
 
@@ -552,7 +552,7 @@ static int ensure_is_an_updatable_symbolic_reference(git_reference *ref)
 	if (ref->type == GIT_REF_SYMBOLIC)
 		return 0;
 
-	giterr_set(GITERR_REFERENCE, "Cannot set symbolic target on a direct reference");
+	giterr_set(GITERR_REFERENCE, "cannot set symbolic target on a direct reference");
 	return -1;
 }
 
@@ -599,7 +599,7 @@ static int reference__rename(git_reference **out, git_reference *ref, const char
 	/* Update HEAD it was pointing to the reference being renamed */
 	if (should_head_be_updated &&
 		(error = git_repository_set_head(ref->db->repo, normalized)) < 0) {
-		giterr_set(GITERR_REFERENCE, "Failed to update HEAD after renaming reference");
+		giterr_set(GITERR_REFERENCE, "failed to update HEAD after renaming reference");
 		return error;
 	}
 
@@ -636,7 +636,7 @@ int git_reference_resolve(git_reference **ref_out, const git_reference *ref)
 		return git_reference_lookup_resolved(ref_out, ref->db->repo, ref->target.symbolic, -1);
 
 	default:
-		giterr_set(GITERR_REFERENCE, "Invalid reference");
+		giterr_set(GITERR_REFERENCE, "invalid reference");
 		return -1;
 	}
 }
@@ -973,7 +973,7 @@ cleanup:
 	if (error == GIT_EINVALIDSPEC)
 		giterr_set(
 			GITERR_REFERENCE,
-			"The given reference name '%s' is not valid", name);
+			"the given reference name '%s' is not valid", name);
 
 	if (error && normalize)
 		git_buf_free(buf);
@@ -1000,7 +1000,7 @@ int git_reference_normalize_name(
 	if (git_buf_len(&buf) > buffer_size - 1) {
 		giterr_set(
 		GITERR_REFERENCE,
-		"The provided buffer is too short to hold the normalization of '%s'", name);
+		"the provided buffer is too short to hold the normalization of '%s'", name);
 		error = GIT_EBUFS;
 		goto cleanup;
 	}
@@ -1046,7 +1046,7 @@ static int get_terminal(git_reference **out, git_repository *repo, const char *r
 	int error = 0;
 
 	if (nesting > MAX_NESTING_LEVEL) {
-		giterr_set(GITERR_REFERENCE, "Reference chain too deep (%d)", nesting);
+		giterr_set(GITERR_REFERENCE, "reference chain too deep (%d)", nesting);
 		return GIT_ENOTFOUND;
 	}
 
@@ -1229,7 +1229,7 @@ static int peel_error(int error, git_reference *ref, const char* msg)
 {
 	giterr_set(
 		GITERR_INVALID,
-		"The reference '%s' cannot be peeled - %s", git_reference_name(ref), msg);
+		"the reference '%s' cannot be peeled - %s", git_reference_name(ref), msg);
 	return error;
 }
 
diff --git a/src/remote.c b/src/remote.c
index c1d7d59ea..8da7346fb 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -283,7 +283,7 @@ static int ensure_remote_doesnot_exist(git_repository *repo, const char *name)
 
 	giterr_set(
 		GITERR_CONFIG,
-		"Remote '%s' already exists.", name);
+		"remote '%s' already exists", name);
 
 	return GIT_EEXISTS;
 }
@@ -476,7 +476,7 @@ int git_remote_lookup(git_remote **out, git_repository *repo, const char *name)
 
 	if (!optional_setting_found) {
 		error = GIT_ENOTFOUND;
-		giterr_set(GITERR_CONFIG, "Remote '%s' does not exist.", name);
+		giterr_set(GITERR_CONFIG, "remote '%s' does not exist", name);
 		goto cleanup;
 	}
 
@@ -1718,7 +1718,7 @@ int git_remote_set_autotag(git_repository *repo, const char *remote, git_remote_
 			error = 0;
 		break;
 	default:
-		giterr_set(GITERR_INVALID, "Invalid value for the tagopt setting");
+		giterr_set(GITERR_INVALID, "invalid value for the tagopt setting");
 		error = -1;
 	}
 
diff --git a/src/repository.c b/src/repository.c
index cf3d18a2d..2185632bf 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -27,6 +27,10 @@
 #include "merge.h"
 #include "diff_driver.h"
 #include "annotated_commit.h"
+#include "submodule.h"
+
+GIT__USE_STRMAP
+#include "strmap.h"
 
 #ifdef GIT_WIN32
 # include "win32/w32_util.h"
@@ -109,6 +113,7 @@ void git_repository__cleanup(git_repository *repo)
 {
 	assert(repo);
 
+	git_repository_submodule_cache_clear(repo);
 	git_cache_clear(&repo->objects);
 	git_attr_cache_flush(repo);
 
@@ -332,7 +337,7 @@ static int read_gitfile(git_buf *path_out, const char *file_path)
 		memcmp(git_buf_cstr(&file), GIT_FILE_CONTENT_PREFIX, prefix_len) != 0)
 	{
 		giterr_set(GITERR_REPOSITORY,
-			"The `.git` file at '%s' is malformed", file_path);
+			"the `.git` file at '%s' is malformed", file_path);
 		error = -1;
 	}
 	else if ((error = git_path_dirname_r(path_out, file_path)) >= 0) {
@@ -410,7 +415,7 @@ static int find_repo(
 					break;
 				}
 			}
-			else if (S_ISREG(st.st_mode)) {
+			else if (S_ISREG(st.st_mode) && git__suffixcmp(path.ptr, "/" DOT_GIT) == 0) {
 				error = read_gitfile(&repo_link, path.ptr);
 				if (error < 0)
 					break;
@@ -459,7 +464,7 @@ static int find_repo(
 	 * to report, report that. */
 	if (!git_buf_len(repo_path) && !error) {
 		giterr_set(GITERR_REPOSITORY,
-			"Could not find repository from '%s'", start_path);
+			"could not find repository from '%s'", start_path);
 		error = GIT_ENOTFOUND;
 	}
 
@@ -481,7 +486,7 @@ int git_repository_open_bare(
 
 	if (!valid_repository_path(&path)) {
 		git_buf_free(&path);
-		giterr_set(GITERR_REPOSITORY, "Path is not a repository: %s", bare_path);
+		giterr_set(GITERR_REPOSITORY, "path is not a repository: %s", bare_path);
 		return GIT_ENOTFOUND;
 	}
 
@@ -613,9 +618,10 @@ static int _git_repository_open_ext_from_env(
 		git_repository_set_odb(repo, odb);
 
 	error = git__getenv(&alts_buf, "GIT_ALTERNATE_OBJECT_DIRECTORIES");
-	if (error == GIT_ENOTFOUND)
+	if (error == GIT_ENOTFOUND) {
 		giterr_clear();
-	else if (error < 0)
+		error = 0;
+	} else if (error < 0)
 		goto error;
         else {
 		const char *end;
@@ -638,9 +644,11 @@ static int _git_repository_open_ext_from_env(
 		}
 	}
 
-	error = git_repository_set_namespace(repo, git_buf_cstr(&namespace_buf));
-	if (error < 0)
-		goto error;
+	if (git_buf_len(&namespace_buf)) {
+		error = git_repository_set_namespace(repo, git_buf_cstr(&namespace_buf));
+		if (error < 0)
+			goto error;
+	}
 
 	git_repository_set_index(repo, index);
 
@@ -1177,7 +1185,7 @@ static int check_repositoryformatversion(git_config *config)
 
 	if (GIT_REPO_VERSION < version) {
 		giterr_set(GITERR_REPOSITORY,
-			"Unsupported repository version %d. Only versions up to %d are supported.",
+			"unsupported repository version %d. Only versions up to %d are supported.",
 			version, GIT_REPO_VERSION);
 		return -1;
 	}
@@ -1271,12 +1279,12 @@ static int create_empty_file(const char *path, mode_t mode)
 	int fd;
 
 	if ((fd = p_creat(path, mode)) < 0) {
-		giterr_set(GITERR_OS, "Error while creating '%s'", path);
+		giterr_set(GITERR_OS, "error while creating '%s'", path);
 		return -1;
 	}
 
 	if (p_close(fd) < 0) {
-		giterr_set(GITERR_OS, "Error while closing '%s'", path);
+		giterr_set(GITERR_OS, "error while closing '%s'", path);
 		return -1;
 	}
 
@@ -1505,7 +1513,7 @@ static int repo_write_template(
 
 	if (error)
 		giterr_set(GITERR_OS,
-			"Failed to initialize repository with template '%s'", file);
+			"failed to initialize repository with template '%s'", file);
 
 	return error;
 }
@@ -1536,7 +1544,7 @@ static int repo_write_gitlink(
 
 	if (!p_stat(buf.ptr, &st) && !S_ISREG(st.st_mode)) {
 		giterr_set(GITERR_REPOSITORY,
-			"Cannot overwrite gitlink file into path '%s'", in_dir);
+			"cannot overwrite gitlink file into path '%s'", in_dir);
 		error = GIT_EEXISTS;
 		goto cleanup;
 	}
@@ -1590,7 +1598,7 @@ static int repo_init_structure(
 	if ((opts->flags & GIT_REPOSITORY_INIT__HAS_DOTGIT) != 0) {
 		if (git_win32__set_hidden(repo_dir, true) < 0) {
 			giterr_set(GITERR_OS,
-				"Failed to mark Git repository folder as hidden");
+				"failed to mark Git repository folder as hidden");
 			return -1;
 		}
 	}
@@ -1744,7 +1752,7 @@ static int repo_init_directories(
 			if (git_path_dirname_r(wd_path, repo_path->ptr) < 0)
 				return -1;
 		} else {
-			giterr_set(GITERR_REPOSITORY, "Cannot pick working directory"
+			giterr_set(GITERR_REPOSITORY, "cannot pick working directory"
 				" for non-bare repository that isn't a '.git' directory");
 			return -1;
 		}
@@ -1864,7 +1872,7 @@ int git_repository_init_ext(
 
 		if ((opts->flags & GIT_REPOSITORY_INIT_NO_REINIT) != 0) {
 			giterr_set(GITERR_REPOSITORY,
-				"Attempt to reinitialize '%s'", given_repo);
+				"attempt to reinitialize '%s'", given_repo);
 			error = GIT_EEXISTS;
 			goto cleanup;
 		}
@@ -2146,7 +2154,7 @@ int git_repository_message(git_buf *out, git_repository *repo)
 	if ((error = p_stat(git_buf_cstr(&path), &st)) < 0) {
 		if (errno == ENOENT)
 			error = GIT_ENOTFOUND;
-		giterr_set(GITERR_OS, "Could not access message file");
+		giterr_set(GITERR_OS, "could not access message file");
 	} else {
 		error = git_futils_readbuffer(out, git_buf_cstr(&path));
 	}
@@ -2224,7 +2232,7 @@ int git_repository_hashfile(
 	}
 
 	if (!git__is_sizet(len)) {
-		giterr_set(GITERR_OS, "File size overflow for 32-bit systems");
+		giterr_set(GITERR_OS, "file size overflow for 32-bit systems");
 		error = -1;
 		goto cleanup;
 	}
@@ -2538,3 +2546,31 @@ int git_repository_set_ident(git_repository *repo, const char *name, const char
 
 	return 0;
 }
+
+int git_repository_submodule_cache_all(git_repository *repo)
+{
+	int error;
+
+	assert(repo);
+
+	if ((error = git_strmap_alloc(&repo->submodule_cache)))
+		return error;
+
+	error = git_submodule__map(repo, repo->submodule_cache);
+	return error;
+}
+
+int git_repository_submodule_cache_clear(git_repository *repo)
+{
+	git_submodule *sm;
+	assert(repo);
+	if (repo->submodule_cache == NULL) {
+		return 0;
+	}
+	git_strmap_foreach_value(repo->submodule_cache, sm, {
+		git_submodule_free(sm);
+	});
+	git_strmap_free(repo->submodule_cache);
+	repo->submodule_cache = 0;
+	return 0;
+}
diff --git a/src/repository.h b/src/repository.h
index fd679b483..9d276f376 100644
--- a/src/repository.h
+++ b/src/repository.h
@@ -143,6 +143,7 @@ struct git_repository {
 	git_atomic attr_session_key;
 
 	git_cvar_value cvar_cache[GIT_CVAR_CACHE_MAX];
+	git_strmap *submodule_cache;
 };
 
 GIT_INLINE(git_attr_cache *) git_repository_attr_cache(git_repository *repo)
@@ -182,7 +183,7 @@ GIT_INLINE(int) git_repository__ensure_not_bare(
 
 	giterr_set(
 		GITERR_REPOSITORY,
-		"Cannot %s. This operation is not allowed against bare repositories.",
+		"cannot %s. This operation is not allowed against bare repositories.",
 		operation_name);
 
 	return GIT_EBAREREPO;
diff --git a/src/reset.c b/src/reset.c
index db0bfb373..066b5dbda 100644
--- a/src/reset.c
+++ b/src/reset.c
@@ -137,7 +137,7 @@ static int reset(
 		(git_repository_state(repo) == GIT_REPOSITORY_STATE_MERGE ||
 		 git_index_has_conflicts(index)))
 	{
-		giterr_set(GITERR_OBJECT, "%s (soft) in the middle of a merge.", ERROR_MSG);
+		giterr_set(GITERR_OBJECT, "%s (soft) in the middle of a merge", ERROR_MSG);
 		error = GIT_EUNMERGED;
 		goto cleanup;
 	}
diff --git a/src/revert.c b/src/revert.c
index c481e7dea..b255245bf 100644
--- a/src/revert.c
+++ b/src/revert.c
@@ -133,13 +133,13 @@ int git_revert_commit(
 	if (git_commit_parentcount(revert_commit) > 1) {
 		if (!mainline)
 			return revert_seterr(revert_commit,
-				"Mainline branch is not specified but %s is a merge commit");
+				"mainline branch is not specified but %s is a merge commit");
 
 		parent = mainline;
 	} else {
 		if (mainline)
 			return revert_seterr(revert_commit,
-				"Mainline branch specified but %s is not a merge commit");
+				"mainline branch specified but %s is not a merge commit");
 
 		parent = git_commit_parentcount(revert_commit);
 	}
diff --git a/src/revparse.c b/src/revparse.c
index aa7e0bd98..d5511b47b 100644
--- a/src/revparse.c
+++ b/src/revparse.c
@@ -46,7 +46,7 @@ static int build_regex(regex_t *regex, const char *pattern)
 	int error;
 
 	if (*pattern == '\0') {
-		giterr_set(GITERR_REGEX, "Empty pattern");
+		giterr_set(GITERR_REGEX, "empty pattern");
 		return GIT_EINVALIDSPEC;
 	}
 
@@ -118,7 +118,7 @@ static int revparse_lookup_object(
 	if ((error = maybe_describe(object_out, repo, spec)) != GIT_ENOTFOUND)
 		return error;
 
-	giterr_set(GITERR_REFERENCE, "Revspec '%s' not found.", spec);
+	giterr_set(GITERR_REFERENCE, "revspec '%s' not found", spec);
 	return GIT_ENOTFOUND;
 }
 
@@ -245,7 +245,7 @@ static int retrieve_oid_from_reflog(git_oid *oid, git_reference *ref, size_t ide
 notfound:
 	giterr_set(
 		GITERR_REFERENCE,
-		"Reflog for '%s' has only %"PRIuZ" entries, asked for %"PRIuZ,
+		"reflog for '%s' has only %"PRIuZ" entries, asked for %"PRIuZ,
 		git_reference_name(ref), numentries, identifier);
 
 	git_reflog_free(reflog);
@@ -757,7 +757,7 @@ int revparse__ext(
 					 * TODO: support merge-stage path lookup (":2:Makefile")
 					 * and plain index blob lookup (:i-am/a/blob)
 					 */
-					giterr_set(GITERR_INVALID, "Unimplemented");
+					giterr_set(GITERR_INVALID, "unimplemented");
 					error = GIT_ERROR;
 					goto cleanup;
 				}
@@ -816,7 +816,7 @@ cleanup:
 	if (error) {
 		if (error == GIT_EINVALIDSPEC)
 			giterr_set(GITERR_INVALID,
-				"Failed to parse revision specifier - Invalid pattern '%s'", spec);
+				"failed to parse revision specifier - Invalid pattern '%s'", spec);
 
 		git_object_free(base_rev);
 		git_reference_free(reference);
diff --git a/src/revwalk.c b/src/revwalk.c
index 0ada5870a..8c370bcc8 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -61,7 +61,7 @@ static int push_commit(git_revwalk *walk, const git_oid *oid, int uninteresting,
 		if (from_glob)
 			return 0;
 
-		giterr_set(GITERR_INVALID, "Object is not a committish");
+		giterr_set(GITERR_INVALID, "object is not a committish");
 		return -1;
 	}
 	if (error < 0)
@@ -198,7 +198,7 @@ int git_revwalk_push_range(git_revwalk *walk, const char *range)
 
 	if (revspec.flags & GIT_REVPARSE_MERGE_BASE) {
 		/* TODO: support "<commit>...<commit>" */
-		giterr_set(GITERR_INVALID, "Symmetric differences not implemented in revwalk");
+		giterr_set(GITERR_INVALID, "symmetric differences not implemented in revwalk");
 		return GIT_EINVALIDSPEC;
 	}
 
@@ -290,7 +290,7 @@ static void mark_parents_uninteresting(git_commit_list_node *commit)
 
 
 	while (parents) {
-		git_commit_list_node *commit = git_commit_list_pop(&parents);
+		commit = git_commit_list_pop(&parents);
 
 		while (commit) {
 			if (commit->uninteresting)
@@ -733,7 +733,7 @@ int git_revwalk_add_hide_cb(
 
 	if (walk->hide_cb) {
 		/* There is already a callback added */
-		giterr_set(GITERR_INVALID, "There is already a callback added to hide commits in revision walker.");
+		giterr_set(GITERR_INVALID, "there is already a callback added to hide commits in revwalk");
 		return -1;
 	}
 
diff --git a/src/settings.c b/src/settings.c
index cb2317f74..980233d88 100644
--- a/src/settings.c
+++ b/src/settings.c
@@ -29,7 +29,9 @@ int git_libgit2_features(void)
 #ifdef GIT_THREADS
 		| GIT_FEATURE_THREADS
 #endif
+#if defined(GIT_OPENSSL) || defined(GIT_WINHTTP) || defined(GIT_SECURE_TRANSPORT)
 		| GIT_FEATURE_HTTPS
+#endif
 #if defined(GIT_SSH)
 		| GIT_FEATURE_SSH
 #endif
@@ -62,7 +64,7 @@ static int config_level_to_sysdir(int config_level)
 		break;
 	default:
 		giterr_set(
-			GITERR_INVALID, "Invalid config path selector %d", config_level);
+			GITERR_INVALID, "invalid config path selector %d", config_level);
 	}
 
 	return val;
diff --git a/src/sha1_lookup.c b/src/sha1_lookup.c
index c6b561340..ead26de06 100644
--- a/src/sha1_lookup.c
+++ b/src/sha1_lookup.c
@@ -206,7 +206,7 @@ int sha1_entry_pos(const void *table,
 #endif
 
 		if (!(lo <= mi && mi < hi)) {
-			giterr_set(GITERR_INVALID, "Assertion failure. Binary search invariant is false");
+			giterr_set(GITERR_INVALID, "assertion failure: binary search invariant is false");
 			return -1;
 		}
 
diff --git a/src/signature.c b/src/signature.c
index dcc379717..e792a52f8 100644
--- a/src/signature.c
+++ b/src/signature.c
@@ -25,7 +25,7 @@ void git_signature_free(git_signature *sig)
 
 static int signature_error(const char *msg)
 {
-	giterr_set(GITERR_INVALID, "Failed to parse signature - %s", msg);
+	giterr_set(GITERR_INVALID, "failed to parse signature - %s", msg);
 	return -1;
 }
 
@@ -251,7 +251,7 @@ int git_signature__parse(git_signature *sig, const char **buffer_out,
 			 * only store timezone if it's not overflowing;
 			 * see http://www.worldtimezone.com/faq.html
 			 */
-			if (hours < 14 && mins < 59) {
+			if (hours <= 14 && mins <= 59) {
 				sig->when.offset = (hours * 60) + mins;
 				if (tz_start[0] == '-')
 					sig->when.offset = -sig->when.offset;
diff --git a/src/socket_stream.c b/src/socket_stream.c
index 71f49118e..fca411717 100644
--- a/src/socket_stream.c
+++ b/src/socket_stream.c
@@ -57,7 +57,7 @@ static int close_socket(GIT_SOCKET s)
 		return -1;
 
 	if (0 != WSACleanup()) {
-		giterr_set(GITERR_OS, "Winsock cleanup failed");
+		giterr_set(GITERR_OS, "winsock cleanup failed");
 		return -1;
 	}
 
@@ -82,13 +82,13 @@ int socket_connect(git_stream *stream)
 	WSADATA wsd;
 
 	if (WSAStartup(MAKEWORD(2,2), &wsd) != 0) {
-		giterr_set(GITERR_OS, "Winsock init failed");
+		giterr_set(GITERR_OS, "winsock init failed");
 		return -1;
 	}
 
 	if (LOBYTE(wsd.wVersion) != 2 || HIBYTE(wsd.wVersion) != 2) {
 		WSACleanup();
-		giterr_set(GITERR_OS, "Winsock init failed");
+		giterr_set(GITERR_OS, "winsock init failed");
 		return -1;
 	}
 #endif
@@ -99,7 +99,7 @@ int socket_connect(git_stream *stream)
 
 	if ((ret = p_getaddrinfo(st->host, st->port, &hints, &info)) != 0) {
 		giterr_set(GITERR_NET,
-			   "Failed to resolve address for %s: %s", st->host, p_gai_strerror(ret));
+			   "failed to resolve address for %s: %s", st->host, p_gai_strerror(ret));
 		return -1;
 	}
 
@@ -121,7 +121,7 @@ int socket_connect(git_stream *stream)
 
 	/* Oops, we couldn't connect to any address */
 	if (s == INVALID_SOCKET && p == NULL) {
-		giterr_set(GITERR_OS, "Failed to connect to %s", st->host);
+		giterr_set(GITERR_OS, "failed to connect to %s", st->host);
 		p_freeaddrinfo(info);
 		return -1;
 	}
diff --git a/src/sortedcache.c b/src/sortedcache.c
index 5c2a167a7..c5e338f75 100644
--- a/src/sortedcache.c
+++ b/src/sortedcache.c
@@ -27,7 +27,7 @@ int git_sortedcache_new(
 		goto fail;
 
 	if (git_rwlock_init(&sc->lock)) {
-		giterr_set(GITERR_OS, "Failed to initialize lock");
+		giterr_set(GITERR_OS, "failed to initialize lock");
 		goto fail;
 	}
 
@@ -162,7 +162,7 @@ int git_sortedcache_wlock(git_sortedcache *sc)
 	GIT_UNUSED(sc); /* prevent warning when compiled w/o threads */
 
 	if (git_rwlock_wrlock(&sc->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to acquire write lock on cache");
+		giterr_set(GITERR_OS, "unable to acquire write lock on cache");
 		return -1;
 	}
 	return 0;
@@ -181,7 +181,7 @@ int git_sortedcache_rlock(git_sortedcache *sc)
 	GIT_UNUSED(sc); /* prevent warning when compiled w/o threads */
 
 	if (git_rwlock_rdlock(&sc->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to acquire read lock on cache");
+		giterr_set(GITERR_OS, "unable to acquire read lock on cache");
 		return -1;
 	}
 	return 0;
@@ -200,6 +200,7 @@ void git_sortedcache_runlock(git_sortedcache *sc)
 int git_sortedcache_lockandload(git_sortedcache *sc, git_buf *buf)
 {
 	int error, fd;
+	struct stat st;
 
 	if ((error = git_sortedcache_wlock(sc)) < 0)
 		return error;
@@ -207,19 +208,27 @@ int git_sortedcache_lockandload(git_sortedcache *sc, git_buf *buf)
 	if ((error = git_futils_filestamp_check(&sc->stamp, sc->path)) <= 0)
 		goto unlock;
 
-	if (!git__is_sizet(sc->stamp.size)) {
-		giterr_set(GITERR_INVALID, "Unable to load file larger than size_t");
+	if ((fd = git_futils_open_ro(sc->path)) < 0) {
+		error = fd;
+		goto unlock;
+	}
+
+	if (p_fstat(fd, &st) < 0) {
+		giterr_set(GITERR_OS, "failed to stat file");
 		error = -1;
+		(void)p_close(fd);
 		goto unlock;
 	}
 
-	if ((fd = git_futils_open_ro(sc->path)) < 0) {
-		error = fd;
+	if (!git__is_sizet(st.st_size)) {
+		giterr_set(GITERR_INVALID, "unable to load file larger than size_t");
+		error = -1;
+		(void)p_close(fd);
 		goto unlock;
 	}
 
 	if (buf)
-		error = git_futils_readbuffer_fd(buf, fd, (size_t)sc->stamp.size);
+		error = git_futils_readbuffer_fd(buf, fd, (size_t)st.st_size);
 
 	(void)p_close(fd);
 
@@ -364,7 +373,7 @@ int git_sortedcache_remove(git_sortedcache *sc, size_t pos)
 	 */
 
 	if ((item = git_vector_get(&sc->items, pos)) == NULL) {
-		giterr_set(GITERR_INVALID, "Removing item out of range");
+		giterr_set(GITERR_INVALID, "removing item out of range");
 		return GIT_ENOTFOUND;
 	}
 
diff --git a/src/stash.c b/src/stash.c
index f5f4f36bf..d13220cdd 100644
--- a/src/stash.c
+++ b/src/stash.c
@@ -27,7 +27,7 @@
 
 static int create_error(int error, const char *msg)
 {
-	giterr_set(GITERR_STASH, "Cannot stash changes - %s", msg);
+	giterr_set(GITERR_STASH, "cannot stash changes - %s", msg);
 	return error;
 }
 
@@ -36,7 +36,7 @@ static int retrieve_head(git_reference **out, git_repository *repo)
 	int error = git_repository_head(out, repo);
 
 	if (error == GIT_EUNBORNBRANCH)
-		return create_error(error, "You do not have the initial commit yet.");
+		return create_error(error, "you do not have the initial commit yet.");
 
 	return error;
 }
@@ -198,7 +198,7 @@ static int stash_update_index_from_diff(
 			/* Unimplemented */
 			giterr_set(
 				GITERR_INVALID,
-				"Cannot update index. Unimplemented status (%d)",
+				"cannot update index. Unimplemented status (%d)",
 				delta->status);
 			return -1;
 		}
@@ -479,7 +479,7 @@ static int ensure_there_are_changes_to_stash(
 		return 0;
 
 	if (!error)
-		return create_error(GIT_ENOTFOUND, "There is nothing to stash.");
+		return create_error(GIT_ENOTFOUND, "there is nothing to stash.");
 
 	return error;
 }
@@ -593,7 +593,7 @@ static int retrieve_stash_commit(
 	max = git_reflog_entrycount(reflog);
 	if (!max || index > max - 1) {
 		error = GIT_ENOTFOUND;
-		giterr_set(GITERR_STASH, "No stashed state at position %" PRIuZ, index);
+		giterr_set(GITERR_STASH, "no stashed state at position %" PRIuZ, index);
 		goto cleanup;
 	}
 
@@ -1036,7 +1036,7 @@ int git_stash_drop(
 
 	if (!max || index > max - 1) {
 		error = GIT_ENOTFOUND;
-		giterr_set(GITERR_STASH, "No stashed state at position %" PRIuZ, index);
+		giterr_set(GITERR_STASH, "no stashed state at position %" PRIuZ, index);
 		goto cleanup;
 	}
 
diff --git a/src/status.c b/src/status.c
index e610f5fe1..6752b5625 100644
--- a/src/status.c
+++ b/src/status.c
@@ -243,13 +243,13 @@ static int status_validate_options(const git_status_options *opts)
 	GITERR_CHECK_VERSION(opts, GIT_STATUS_OPTIONS_VERSION, "git_status_options");
 
 	if (opts->show > GIT_STATUS_SHOW_WORKDIR_ONLY) {
-		giterr_set(GITERR_INVALID, "Unknown status 'show' option");
+		giterr_set(GITERR_INVALID, "unknown status 'show' option");
 		return -1;
 	}
 
 	if ((opts->flags & GIT_STATUS_OPT_NO_REFRESH) != 0 &&
 		(opts->flags & GIT_STATUS_OPT_UPDATE_INDEX) != 0) {
-		giterr_set(GITERR_INVALID, "Updating index from status "
+		giterr_set(GITERR_INVALID, "updating index from status "
 			"is not allowed when index refresh is disabled");
 		return -1;
 	}
@@ -510,13 +510,13 @@ int git_status_file(
 
 	if (error < 0 && sfi.ambiguous) {
 		giterr_set(GITERR_INVALID,
-			"Ambiguous path '%s' given to git_status_file", sfi.expected);
+			"ambiguous path '%s' given to git_status_file", sfi.expected);
 		error = GIT_EAMBIGUOUS;
 	}
 
 	if (!error && !sfi.count) {
 		giterr_set(GITERR_INVALID,
-			"Attempt to get status of nonexistent file '%s'", path);
+			"attempt to get status of nonexistent file '%s'", path);
 		error = GIT_ENOTFOUND;
 	}
 
diff --git a/src/submodule.c b/src/submodule.c
index ac6998603..21e3d45e4 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -124,8 +124,8 @@ static void submodule_set_lookup_error(int error, const char *name)
 		return;
 
 	giterr_set(GITERR_SUBMODULE, (error == GIT_ENOTFOUND) ?
-		"No submodule named '%s'" :
-		"Submodule '%s' has not been added yet", name);
+		"no submodule named '%s'" :
+		"submodule '%s' has not been added yet", name);
 }
 
 typedef struct {
@@ -149,40 +149,53 @@ static int find_by_path(const git_config_entry *entry, void *payload)
 }
 
 /**
- * Find out the name of a submodule from its path
+ * Release the name map returned by 'load_submodule_names'.
  */
-static int name_from_path(git_buf *out, git_config *cfg, const char *path)
+static void free_submodule_names(git_strmap *names)
+{
+	git_buf *name = 0;
+	if (names == NULL)
+		return;
+	git_strmap_foreach_value(names, name, {
+		git__free(name);
+	});
+	git_strmap_free(names);
+	return;
+}
+
+/**
+ * Map submodule paths to names.
+ * TODO: for some use-cases, this might need case-folding on a
+ * case-insensitive filesystem
+ */
+static int load_submodule_names(git_strmap *out, git_config *cfg)
 {
 	const char *key = "submodule\\..*\\.path";
 	git_config_iterator *iter;
 	git_config_entry *entry;
-	int error;
+	git_buf buf = GIT_BUF_INIT;
+	int rval;
+	int error = 0;
 
 	if ((error = git_config_iterator_glob_new(&iter, cfg, key)) < 0)
 		return error;
 
-	while ((error = git_config_next(&entry, iter)) == 0) {
+	while (git_config_next(&entry, iter) == 0) {
 		const char *fdot, *ldot;
-		/* TODO: this should maybe be strcasecmp on a case-insensitive fs */
-		if (strcmp(path, entry->value) != 0)
-			continue;
-
 		fdot = strchr(entry->name, '.');
 		ldot = strrchr(entry->name, '.');
 
-		git_buf_clear(out);
-		git_buf_put(out, fdot + 1, ldot - fdot - 1);
-		goto cleanup;
-	}
-
-	if (error == GIT_ITEROVER) {
-		giterr_set(GITERR_SUBMODULE, "could not find a submodule name for '%s'", path);
-		error = GIT_ENOTFOUND;
+		git_buf_put(&buf, fdot + 1, ldot - fdot - 1);
+		git_strmap_insert(out, entry->value, git_buf_detach(&buf), rval);
+		if (rval < 0) {
+			giterr_set(GITERR_NOMEMORY, "Error inserting submodule into hash table");
+			free_submodule_names(out);
+			return -1;
+		}
 	}
 
-cleanup:
 	git_config_iterator_free(iter);
-	return error;
+	return 0;
 }
 
 int git_submodule_lookup(
@@ -196,6 +209,17 @@ int git_submodule_lookup(
 
 	assert(repo && name);
 
+	if (repo->submodule_cache != NULL) {
+		khiter_t pos = git_strmap_lookup_index(repo->submodule_cache, name);
+		if (git_strmap_valid_index(repo->submodule_cache, pos)) {
+			if (out) {
+				*out = git_strmap_value_at(repo->submodule_cache, pos);
+				GIT_REFCOUNT_INC(*out);
+			}
+			return 0;
+		}
+	}
+
 	if ((error = submodule_alloc(&sm, repo, name)) < 0)
 		return error;
 
@@ -324,89 +348,107 @@ done:
 
 static int submodules_from_index(git_strmap *map, git_index *idx, git_config *cfg)
 {
-       int error;
-       git_iterator *i;
-       const git_index_entry *entry;
-       git_buf name = GIT_BUF_INIT;
-
-       if ((error = git_iterator_for_index(&i, git_index_owner(idx), idx, NULL)) < 0)
-               return error;
-
-       while (!(error = git_iterator_advance(&entry, i))) {
-               khiter_t pos = git_strmap_lookup_index(map, entry->path);
-               git_submodule *sm;
+	int error;
+	git_iterator *i;
+	const git_index_entry *entry;
+	git_strmap *names = 0;
+	git_strmap_alloc(&names);
+	if ((error = load_submodule_names(names, cfg)))
+		goto done;
 
-	       git_buf_clear(&name);
-	       if (!name_from_path(&name, cfg, entry->path)) {
-		       git_strmap_lookup_index(map, name.ptr);
-	       }
+	if ((error = git_iterator_for_index(&i, git_index_owner(idx), idx, NULL)) < 0)
+		goto done;
 
-               if (git_strmap_valid_index(map, pos)) {
-                       sm = git_strmap_value_at(map, pos);
+	while (!(error = git_iterator_advance(&entry, i))) {
+		khiter_t pos = git_strmap_lookup_index(map, entry->path);
+		git_submodule *sm;
+
+		if (git_strmap_valid_index(map, pos)) {
+			sm = git_strmap_value_at(map, pos);
+
+			if (S_ISGITLINK(entry->mode))
+				submodule_update_from_index_entry(sm, entry);
+			else
+				sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
+		} else if (S_ISGITLINK(entry->mode)) {
+			khiter_t name_pos;
+			const char *name;
+
+			name_pos = git_strmap_lookup_index(names, entry->path);
+			if (git_strmap_valid_index(names, name_pos)) {
+				name = git_strmap_value_at(names, name_pos);
+			} else {
+				name = entry->path;
+			}
 
-                       if (S_ISGITLINK(entry->mode))
-                               submodule_update_from_index_entry(sm, entry);
-                       else
-                               sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
-               } else if (S_ISGITLINK(entry->mode)) {
-                       if (!submodule_get_or_create(&sm, git_index_owner(idx), map, name.ptr ? name.ptr : entry->path)) {
-                               submodule_update_from_index_entry(sm, entry);
-                               git_submodule_free(sm);
-                       }
-               }
-       }
+			if (!submodule_get_or_create(&sm, git_index_owner(idx), map, name)) {
+				submodule_update_from_index_entry(sm, entry);
+				git_submodule_free(sm);
+			}
+		}
+	}
 
-       if (error == GIT_ITEROVER)
-               error = 0;
+	if (error == GIT_ITEROVER)
+		error = 0;
 
-       git_buf_free(&name);
-       git_iterator_free(i);
+done:
+	git_iterator_free(i);
+	free_submodule_names(names);
 
-       return error;
+	return error;
 }
 
 static int submodules_from_head(git_strmap *map, git_tree *head, git_config *cfg)
 {
-       int error;
-       git_iterator *i;
-       const git_index_entry *entry;
-       git_buf name = GIT_BUF_INIT;
-
-       if ((error = git_iterator_for_tree(&i, head, NULL)) < 0)
-               return error;
-
-       while (!(error = git_iterator_advance(&entry, i))) {
-               khiter_t pos = git_strmap_lookup_index(map, entry->path);
-               git_submodule *sm;
+	int error;
+	git_iterator *i;
+	const git_index_entry *entry;
+	git_strmap *names = 0;
+	git_strmap_alloc(&names);
+	if ((error = load_submodule_names(names, cfg)))
+		goto done;
 
-	       git_buf_clear(&name);
-	       if (!name_from_path(&name, cfg, entry->path)) {
-		       git_strmap_lookup_index(map, name.ptr);
-	       }
+	if ((error = git_iterator_for_tree(&i, head, NULL)) < 0)
+		goto done;
 
-               if (git_strmap_valid_index(map, pos)) {
-                       sm = git_strmap_value_at(map, pos);
+	while (!(error = git_iterator_advance(&entry, i))) {
+		khiter_t pos = git_strmap_lookup_index(map, entry->path);
+		git_submodule *sm;
+
+		if (git_strmap_valid_index(map, pos)) {
+			sm = git_strmap_value_at(map, pos);
+
+			if (S_ISGITLINK(entry->mode))
+				submodule_update_from_head_data(sm, entry->mode, &entry->id);
+			else
+				sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
+		} else if (S_ISGITLINK(entry->mode)) {
+			khiter_t name_pos;
+			const char *name;
+
+			name_pos = git_strmap_lookup_index(names, entry->path);
+			if (git_strmap_valid_index(names, name_pos)) {
+				name = git_strmap_value_at(names, name_pos);
+			} else {
+				name = entry->path;
+			}
 
-                       if (S_ISGITLINK(entry->mode))
-                               submodule_update_from_head_data(sm, entry->mode, &entry->id);
-                       else
-                               sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
-               } else if (S_ISGITLINK(entry->mode)) {
-                       if (!submodule_get_or_create(&sm, git_tree_owner(head), map, name.ptr ? name.ptr : entry->path)) {
-                               submodule_update_from_head_data(
-                                       sm, entry->mode, &entry->id);
-                               git_submodule_free(sm);
-                       }
-               }
-       }
+			if (!submodule_get_or_create(&sm, git_tree_owner(head), map, name)) {
+				submodule_update_from_head_data(
+					sm, entry->mode, &entry->id);
+				git_submodule_free(sm);
+			}
+		}
+	}
 
-       if (error == GIT_ITEROVER)
-               error = 0;
+	if (error == GIT_ITEROVER)
+		error = 0;
 
-       git_buf_free(&name);
-       git_iterator_free(i);
+done:
+	git_iterator_free(i);
+	free_submodule_names(names);
 
-       return error;
+	return error;
 }
 
 /* If have_sm is true, sm is populated, otherwise map an repo are. */
@@ -416,7 +458,7 @@ typedef struct {
 	git_repository *repo;
 } lfc_data;
 
-static int all_submodules(git_repository *repo, git_strmap *map)
+int git_submodule__map(git_repository *repo, git_strmap *map)
 {
 	int error = 0;
 	git_index *idx = NULL;
@@ -509,7 +551,7 @@ int git_submodule_foreach(
 	if ((error = git_strmap_alloc(&submodules)) < 0)
 		return error;
 
-	if ((error = all_submodules(repo, submodules)) < 0)
+	if ((error = git_submodule__map(repo, submodules)) < 0)
 		goto done;
 
 	if (!(error = git_vector_init(
@@ -618,7 +660,7 @@ int git_submodule_add_setup(
 		giterr_clear();
 	else {
 		giterr_set(GITERR_SUBMODULE,
-			"Attempt to add submodule '%s' that already exists", path);
+			"attempt to add submodule '%s' that already exists", path);
 		return GIT_EEXISTS;
 	}
 
@@ -628,7 +670,7 @@ int git_submodule_add_setup(
 		path += strlen(git_repository_workdir(repo));
 
 	if (git_path_root(path) >= 0) {
-		giterr_set(GITERR_SUBMODULE, "Submodule path must be a relative path");
+		giterr_set(GITERR_SUBMODULE, "submodule path must be a relative path");
 		error = -1;
 		goto cleanup;
 	}
@@ -637,7 +679,7 @@ int git_submodule_add_setup(
 
 	if (!(mods = open_gitmodules(repo, GITMODULES_CREATE))) {
 		giterr_set(GITERR_SUBMODULE,
-			"Adding submodules to a bare repository is not supported");
+			"adding submodules to a bare repository is not supported");
 		return -1;
 	}
 
@@ -758,7 +800,7 @@ int git_submodule_add_to_index(git_submodule *sm, int write_index)
 	/* read stat information for submodule working directory */
 	if (p_stat(path.ptr, &st) < 0) {
 		giterr_set(GITERR_SUBMODULE,
-			"Cannot add submodule without working directory");
+			"cannot add submodule without working directory");
 		error = -1;
 		goto cleanup;
 	}
@@ -771,7 +813,7 @@ int git_submodule_add_to_index(git_submodule *sm, int write_index)
 	/* calling git_submodule_open will have set sm->wd_oid if possible */
 	if ((sm->flags & GIT_SUBMODULE_STATUS__WD_OID_VALID) == 0) {
 		giterr_set(GITERR_SUBMODULE,
-			"Cannot add submodule without HEAD to index");
+			"cannot add submodule without HEAD to index");
 		error = -1;
 		goto cleanup;
 	}
@@ -861,7 +903,7 @@ int git_submodule_resolve_url(git_buf *out, git_repository *repo, const char *ur
 	} else if (strchr(url, ':') != NULL || url[0] == '/') {
 		error = git_buf_sets(out, url);
 	} else {
-		giterr_set(GITERR_SUBMODULE, "Invalid format for submodule URL");
+		giterr_set(GITERR_SUBMODULE, "invalid format for submodule URL");
 		error = -1;
 	}
 
@@ -1133,7 +1175,7 @@ int git_submodule_update(git_submodule *sm, int init, git_submodule_update_optio
 				goto done;
 
 			if (!init) {
-				giterr_set(GITERR_SUBMODULE, "Submodule is not initialized.");
+				giterr_set(GITERR_SUBMODULE, "submodule is not initialized");
 				error = GIT_ERROR;
 				goto done;
 			}
@@ -1214,7 +1256,7 @@ int git_submodule_init(git_submodule *sm, int overwrite)
 
 	if (!sm->url) {
 		giterr_set(GITERR_SUBMODULE,
-			"No URL configured for submodule '%s'", sm->name);
+			"no URL configured for submodule '%s'", sm->name);
 		return -1;
 	}
 
@@ -1258,7 +1300,7 @@ int git_submodule_sync(git_submodule *sm)
 
 	if (!sm->url) {
 		giterr_set(GITERR_SUBMODULE,
-			"No URL configured for submodule '%s'", sm->name);
+			"no URL configured for submodule '%s'", sm->name);
 		return -1;
 	}
 
@@ -1501,13 +1543,22 @@ int git_submodule__status(
 		return 0;
 	}
 
-	/* refresh the index OID */
-	if (submodule_update_index(sm) < 0)
-		return -1;
+	/* If the user has requested caching submodule state, performing these
+	 * expensive operations (especially `submodule_update_head`, which is
+	 * bottlenecked on `git_repository_head_tree`) eliminates much of the
+	 * advantage.  We will, therefore, interpret the request for caching to
+	 * apply here to and skip them.
+	 */
 
-	/* refresh the HEAD OID */
-	if (submodule_update_head(sm) < 0)
-		return -1;
+	if (sm->repo->submodule_cache == NULL) {
+		/* refresh the index OID */
+		if (submodule_update_index(sm) < 0)
+			return -1;
+
+		/* refresh the HEAD OID */
+		if (submodule_update_head(sm) < 0)
+			return -1;
+	}
 
 	/* for ignore == dirty, don't scan the working directory */
 	if (ign == GIT_SUBMODULE_IGNORE_DIRTY) {
@@ -1565,7 +1616,6 @@ int git_submodule_location(unsigned int *location, git_submodule *sm)
 		location, NULL, NULL, NULL, sm, GIT_SUBMODULE_IGNORE_ALL);
 }
 
-
 /*
  * INTERNAL FUNCTIONS
  */
@@ -1577,7 +1627,7 @@ static int submodule_alloc(
 	git_submodule *sm;
 
 	if (!name || !(namelen = strlen(name))) {
-		giterr_set(GITERR_SUBMODULE, "Invalid submodule name");
+		giterr_set(GITERR_SUBMODULE, "invalid submodule name");
 		return -1;
 	}
 
@@ -1629,7 +1679,7 @@ void git_submodule_free(git_submodule *sm)
 static int submodule_config_error(const char *property, const char *value)
 {
 	giterr_set(GITERR_INVALID,
-		"Invalid value for submodule '%s' property: '%s'", property, value);
+		"invalid value for submodule '%s' property: '%s'", property, value);
 	return -1;
 }
 
@@ -1967,7 +2017,7 @@ static int lookup_default_remote(git_remote **remote, git_repository *repo)
 	if (error == GIT_ENOTFOUND)
 		giterr_set(
 			GITERR_SUBMODULE,
-			"Cannot get default remote for submodule - no local tracking "
+			"cannot get default remote for submodule - no local tracking "
 			"branch for HEAD and origin does not exist");
 
 	return error;
diff --git a/src/submodule.h b/src/submodule.h
index 2ef2031b3..456a93979 100644
--- a/src/submodule.h
+++ b/src/submodule.h
@@ -143,4 +143,7 @@ extern int git_submodule_parse_ignore(
 extern int git_submodule_parse_update(
 	git_submodule_update_t *out, const char *value);
 
+extern int git_submodule__map(
+	git_repository *repo,
+	git_strmap *map);
 #endif
diff --git a/src/sysdir.c b/src/sysdir.c
index 29e53e239..ed11221a3 100644
--- a/src/sysdir.c
+++ b/src/sysdir.c
@@ -150,7 +150,7 @@ int git_sysdir_get_str(
 	GITERR_CHECK_ERROR(git_sysdir_get(&path, which));
 
 	if (!out || path->size >= outlen) {
-		giterr_set(GITERR_NOMEMORY, "Buffer is too short for the path");
+		giterr_set(GITERR_NOMEMORY, "buffer is too short for the path");
 		return GIT_EBUFS;
 	}
 
@@ -171,7 +171,7 @@ int git_sysdir_set(git_sysdir_t which, const char *search_path)
 		expand_path = strstr(search_path, PATH_MAGIC);
 
 	/* reset the default if this path has been cleared */
-	if (!search_path || expand_path)
+	if (!search_path)
 		git_sysdir__dirs[which].guess(&git_sysdir__dirs[which].buf);
 
 	/* if $PATH is not referenced, then just set the path */
@@ -241,7 +241,7 @@ static int git_sysdir_find_in_dirlist(
 
 done:
 	git_buf_free(path);
-	giterr_set(GITERR_OS, "The %s file '%s' doesn't exist", label, name);
+	giterr_set(GITERR_OS, "the %s file '%s' doesn't exist", label, name);
 	return GIT_ENOTFOUND;
 }
 
diff --git a/src/tag.c b/src/tag.c
index fe840fe82..2bf23fc3c 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -61,7 +61,7 @@ const char *git_tag_message(const git_tag *t)
 
 static int tag_error(const char *str)
 {
-	giterr_set(GITERR_TAG, "Failed to parse tag. %s", str);
+	giterr_set(GITERR_TAG, "failed to parse tag: %s", str);
 	return -1;
 }
 
@@ -76,13 +76,13 @@ static int tag_parse(git_tag *tag, const char *buffer, const char *buffer_end)
 	char *search;
 
 	if (git_oid__parse(&tag->target, &buffer, buffer_end, "object ") < 0)
-		return tag_error("Object field invalid");
+		return tag_error("object field invalid");
 
 	if (buffer + 5 >= buffer_end)
-		return tag_error("Object too short");
+		return tag_error("object too short");
 
 	if (memcmp(buffer, "type ", 5) != 0)
-		return tag_error("Type field not found");
+		return tag_error("type field not found");
 	buffer += 5;
 
 	tag->type = GIT_OBJ_BAD;
@@ -91,7 +91,7 @@ static int tag_parse(git_tag *tag, const char *buffer, const char *buffer_end)
 		size_t type_length = strlen(tag_types[i]);
 
 		if (buffer + type_length >= buffer_end)
-			return tag_error("Object too short");
+			return tag_error("object too short");
 
 		if (memcmp(buffer, tag_types[i], type_length) == 0) {
 			tag->type = i;
@@ -101,19 +101,19 @@ static int tag_parse(git_tag *tag, const char *buffer, const char *buffer_end)
 	}
 
 	if (tag->type == GIT_OBJ_BAD)
-		return tag_error("Invalid object type");
+		return tag_error("invalid object type");
 
 	if (buffer + 4 >= buffer_end)
-		return tag_error("Object too short");
+		return tag_error("object too short");
 
 	if (memcmp(buffer, "tag ", 4) != 0)
-		return tag_error("Tag field not found");
+		return tag_error("tag field not found");
 
 	buffer += 4;
 
 	search = memchr(buffer, '\n', buffer_end - buffer);
 	if (search == NULL)
-		return tag_error("Object too short");
+		return tag_error("object too short");
 
 	text_len = search - buffer;
 
@@ -234,7 +234,7 @@ static int write_tag_annotation(
 
 on_error:
 	git_buf_free(&tag);
-	giterr_set(GITERR_OBJECT, "Failed to create tag annotation.");
+	giterr_set(GITERR_OBJECT, "failed to create tag annotation");
 	return -1;
 }
 
@@ -257,7 +257,7 @@ static int git_tag_create__internal(
 	assert(!create_tag_annotation || (tagger && message));
 
 	if (git_object_owner(target) != repo) {
-		giterr_set(GITERR_INVALID, "The given target does not belong to this repository");
+		giterr_set(GITERR_INVALID, "the given target does not belong to this repository");
 		return -1;
 	}
 
@@ -269,7 +269,7 @@ static int git_tag_create__internal(
 	 *	reference unless overwriting has explicitly been requested **/
 	if (error == 0 && !allow_ref_overwrite) {
 		git_buf_free(&ref_name);
-		giterr_set(GITERR_TAG, "Tag already exists");
+		giterr_set(GITERR_TAG, "tag already exists");
 		return GIT_EEXISTS;
 	}
 
@@ -349,7 +349,7 @@ int git_tag_create_frombuffer(git_oid *oid, git_repository *repo, const char *bu
 		goto on_error;
 
 	if (tag.type != target_obj->cached.type) {
-		giterr_set(GITERR_TAG, "The type for the given target is invalid");
+		giterr_set(GITERR_TAG, "the type for the given target is invalid");
 		goto on_error;
 	}
 
@@ -366,7 +366,7 @@ int git_tag_create_frombuffer(git_oid *oid, git_repository *repo, const char *bu
 	/** Ensure the tag name doesn't conflict with an already existing
 	 *	reference unless overwriting has explicitly been requested **/
 	if (error == 0 && !allow_ref_overwrite) {
-		giterr_set(GITERR_TAG, "Tag already exists");
+		giterr_set(GITERR_TAG, "tag already exists");
 		return GIT_EEXISTS;
 	}
 
diff --git a/src/trace.c b/src/trace.c
index ee5039f56..0f2142861 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -32,7 +32,7 @@ int git_trace_set(git_trace_level_t level, git_trace_callback callback)
 	GIT_UNUSED(callback);
 
 	giterr_set(GITERR_INVALID,
-		"This version of libgit2 was not built with tracing.");
+		"this version of libgit2 was not built with tracing.");
 	return -1;
 #endif
 }
diff --git a/src/transport.c b/src/transport.c
index f08d2dc68..b66165332 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -121,7 +121,7 @@ int git_transport_new(git_transport **out, git_remote *owner, const char *url)
 	int error;
 
 	if ((error = transport_find_fn(&fn, url, &param)) == GIT_ENOTFOUND) {
-		giterr_set(GITERR_NET, "Unsupported URL protocol");
+		giterr_set(GITERR_NET, "unsupported URL protocol");
 		return -1;
 	} else if (error < 0)
 		return error;
diff --git a/src/transports/auth_negotiate.c b/src/transports/auth_negotiate.c
index 8b99fc735..7c868c9fd 100644
--- a/src/transports/auth_negotiate.c
+++ b/src/transports/auth_negotiate.c
@@ -107,13 +107,13 @@ static int negotiate_next_token(
 	challenge_len = ctx->challenge ? strlen(ctx->challenge) : 0;
 
 	if (challenge_len < 9) {
-		giterr_set(GITERR_NET, "No negotiate challenge sent from server");
+		giterr_set(GITERR_NET, "no negotiate challenge sent from server");
 		error = -1;
 		goto done;
 	} else if (challenge_len > 9) {
 		if (git_buf_decode_base64(&input_buf,
 				ctx->challenge + 10, challenge_len - 10) < 0) {
-			giterr_set(GITERR_NET, "Invalid negotiate challenge from server");
+			giterr_set(GITERR_NET, "invalid negotiate challenge from server");
 			error = -1;
 			goto done;
 		}
@@ -122,7 +122,7 @@ static int negotiate_next_token(
 		input_token.length = input_buf.size;
 		input_token_ptr = &input_token;
 	} else if (ctx->gss_context != GSS_C_NO_CONTEXT) {
-		giterr_set(GITERR_NET, "Could not restart authentication");
+		giterr_set(GITERR_NET, "could not restart authentication");
 		error = -1;
 		goto done;
 	}
@@ -228,7 +228,7 @@ static int negotiate_init_context(
 	gss_release_oid_set(&status_minor, &mechanism_list);
 
 	if (!ctx->oid) {
-		giterr_set(GITERR_NET, "Negotiate authentication is not supported");
+		giterr_set(GITERR_NET, "negotiate authentication is not supported");
 		return -1;
 	}
 
diff --git a/src/transports/cred.c b/src/transports/cred.c
index 49ede48bf..8e3f64435 100644
--- a/src/transports/cred.c
+++ b/src/transports/cred.c
@@ -216,7 +216,7 @@ int git_cred_ssh_key_memory_new(
 	GIT_UNUSED(passphrase);
 
 	giterr_set(GITERR_INVALID,
-		"This version of libgit2 was not built with ssh memory credentials.");
+		"this version of libgit2 was not built with ssh memory credentials.");
 	return -1;
 #endif
 }
diff --git a/src/transports/git.c b/src/transports/git.c
index 6c6acf9c5..01edfdc49 100644
--- a/src/transports/git.c
+++ b/src/transports/git.c
@@ -45,7 +45,7 @@ static int gen_proto(git_buf *request, const char *cmd, const char *url)
 
 	delim = strchr(url, '/');
 	if (delim == NULL) {
-		giterr_set(GITERR_NET, "Malformed URL");
+		giterr_set(GITERR_NET, "malformed URL");
 		return -1;
 	}
 
@@ -240,7 +240,7 @@ static int _git_uploadpack(
 		return 0;
 	}
 
-	giterr_set(GITERR_NET, "Must call UPLOADPACK_LS before UPLOADPACK");
+	giterr_set(GITERR_NET, "must call UPLOADPACK_LS before UPLOADPACK");
 	return -1;
 }
 
@@ -296,7 +296,7 @@ static int _git_receivepack(
 		return 0;
 	}
 
-	giterr_set(GITERR_NET, "Must call RECEIVEPACK_LS before RECEIVEPACK");
+	giterr_set(GITERR_NET, "must call RECEIVEPACK_LS before RECEIVEPACK");
 	return -1;
 }
 
diff --git a/src/transports/http.c b/src/transports/http.c
index ca1f5042f..949e857b0 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -208,7 +208,7 @@ static int gen_request(
 
 	git_buf_printf(buf, "%s %s%s HTTP/1.1\r\n", s->verb, path, s->service_url);
 
-	git_buf_printf(buf, "User-Agent: git/1.0 (%s)\r\n", user_agent());
+	git_buf_printf(buf, "User-Agent: git/2.0 (%s)\r\n", user_agent());
 	git_buf_printf(buf, "Host: %s\r\n", t->connection_data.host);
 
 	if (s->chunked || content_length > 0) {
@@ -403,7 +403,7 @@ static int on_headers_complete(http_parser *parser)
 	    t->location) {
 
 		if (s->redirect_count >= 7) {
-			giterr_set(GITERR_NET, "Too many redirects");
+			giterr_set(GITERR_NET, "too many redirects");
 			return t->parse_error = PARSE_ERROR_GENERIC;
 		}
 
@@ -428,14 +428,14 @@ static int on_headers_complete(http_parser *parser)
 	/* Check for a 200 HTTP status code. */
 	if (parser->status_code != 200) {
 		giterr_set(GITERR_NET,
-			"Unexpected HTTP status code: %d",
+			"unexpected HTTP status code: %d",
 			parser->status_code);
 		return t->parse_error = PARSE_ERROR_GENERIC;
 	}
 
 	/* The response must contain a Content-Type header. */
 	if (!t->content_type) {
-		giterr_set(GITERR_NET, "No Content-Type header in response");
+		giterr_set(GITERR_NET, "no Content-Type header in response");
 		return t->parse_error = PARSE_ERROR_GENERIC;
 	}
 
@@ -455,7 +455,7 @@ static int on_headers_complete(http_parser *parser)
 	if (strcmp(t->content_type, git_buf_cstr(&buf))) {
 		git_buf_free(&buf);
 		giterr_set(GITERR_NET,
-			"Invalid Content-Type: %s",
+			"invalid Content-Type: %s",
 			t->content_type);
 		return t->parse_error = PARSE_ERROR_GENERIC;
 	}
@@ -488,7 +488,7 @@ static int on_body_fill_buffer(http_parser *parser, const char *str, size_t len)
 		return 0;
 
 	if (ctx->buf_size < len) {
-		giterr_set(GITERR_NET, "Can't fit data in the buffer");
+		giterr_set(GITERR_NET, "can't fit data in the buffer");
 		return t->parse_error = PARSE_ERROR_GENERIC;
 	}
 
@@ -624,13 +624,12 @@ static int http_connect(http_subtransport *t)
 	if ((!error || error == GIT_ECERTIFICATE) && t->owner->certificate_check_cb != NULL &&
 	    git_stream_is_encrypted(t->io)) {
 		git_cert *cert;
-		int is_valid;
+		int is_valid = (error == GIT_OK);
 
 		if ((error = git_stream_certificate(&cert, t->io)) < 0)
 			return error;
 
 		giterr_clear();
-		is_valid = error != GIT_ECERTIFICATE;
 		error = t->owner->certificate_check_cb(cert, is_valid, t->connection_data.host, t->owner->message_cb_payload);
 
 		if (error < 0) {
@@ -857,7 +856,7 @@ static int http_stream_write_single(
 	assert(t->connected);
 
 	if (s->sent_request) {
-		giterr_set(GITERR_NET, "Subtransport configured for only one write");
+		giterr_set(GITERR_NET, "subtransport configured for only one write");
 		return -1;
 	}
 
diff --git a/src/transports/local.c b/src/transports/local.c
index 4eae9dead..87745add5 100644
--- a/src/transports/local.c
+++ b/src/transports/local.c
@@ -252,7 +252,7 @@ static int local_ls(const git_remote_head ***out, size_t *size, git_transport *t
 	transport_local *t = (transport_local *)transport;
 
 	if (!t->have_refs) {
-		giterr_set(GITERR_NET, "The transport has not yet loaded the refs");
+		giterr_set(GITERR_NET, "the transport has not yet loaded the refs");
 		return -1;
 	}
 
@@ -371,7 +371,7 @@ static int local_push(
 	   but we forbid all pushes just in case */
 	if (!remote_repo->is_bare) {
 		error = GIT_EBAREREPO;
-		giterr_set(GITERR_INVALID, "Local push doesn't (yet) support pushing to non-bare repos.");
+		giterr_set(GITERR_INVALID, "local push doesn't (yet) support pushing to non-bare repos.");
 		goto on_error;
 	}
 
diff --git a/src/transports/smart.c b/src/transports/smart.c
index 7a35c39d8..e4aa26d86 100644
--- a/src/transports/smart.c
+++ b/src/transports/smart.c
@@ -231,7 +231,7 @@ static int git_smart__connect(
 	else if (GIT_DIRECTION_PUSH == t->direction)
 		service = GIT_SERVICE_RECEIVEPACK_LS;
 	else {
-		giterr_set(GITERR_NET, "Invalid direction");
+		giterr_set(GITERR_NET, "invalid direction");
 		return -1;
 	}
 
@@ -252,7 +252,7 @@ static int git_smart__connect(
 		pkt = (git_pkt *)git_vector_get(&t->refs, 0);
 
 		if (!pkt || GIT_PKT_COMMENT != pkt->type) {
-			giterr_set(GITERR_NET, "Invalid response");
+			giterr_set(GITERR_NET, "invalid response");
 			return -1;
 		} else {
 			/* Remove the comment pkt from the list */
@@ -299,7 +299,7 @@ static int git_smart__ls(const git_remote_head ***out, size_t *size, git_transpo
 	transport_smart *t = (transport_smart *)transport;
 
 	if (!t->have_refs) {
-		giterr_set(GITERR_NET, "The transport has not yet loaded the refs");
+		giterr_set(GITERR_NET, "the transport has not yet loaded the refs");
 		return -1;
 	}
 
@@ -319,7 +319,7 @@ int git_smart__negotiation_step(git_transport *transport, void *data, size_t len
 		return -1;
 
 	if (GIT_DIRECTION_FETCH != t->direction) {
-		giterr_set(GITERR_NET, "This operation is only valid for fetch");
+		giterr_set(GITERR_NET, "this operation is only valid for fetch");
 		return -1;
 	}
 
@@ -348,7 +348,7 @@ int git_smart__get_push_stream(transport_smart *t, git_smart_subtransport_stream
 		return -1;
 
 	if (GIT_DIRECTION_PUSH != t->direction) {
-		giterr_set(GITERR_NET, "This operation is only valid for push");
+		giterr_set(GITERR_NET, "this operation is only valid for push");
 		return -1;
 	}
 
diff --git a/src/transports/smart_pkt.c b/src/transports/smart_pkt.c
index 2297cc94f..a661dfe13 100644
--- a/src/transports/smart_pkt.c
+++ b/src/transports/smart_pkt.c
@@ -226,7 +226,7 @@ static int ref_pkt(git_pkt **out, const char *line, size_t len)
 
 	/* Check for a bit of consistency */
 	if (line[GIT_OID_HEXSZ] != ' ') {
-		giterr_set(GITERR_NET, "Error parsing pkt-line");
+		giterr_set(GITERR_NET, "error parsing pkt-line");
 		error = -1;
 		goto error_out;
 	}
@@ -270,7 +270,7 @@ static int ok_pkt(git_pkt **out, const char *line, size_t len)
 
 	line += 3; /* skip "ok " */
 	if (!(ptr = strchr(line, '\n'))) {
-		giterr_set(GITERR_NET, "Invalid packet line");
+		giterr_set(GITERR_NET, "invalid packet line");
 		git__free(pkt);
 		return -1;
 	}
@@ -327,7 +327,7 @@ static int ng_pkt(git_pkt **out, const char *line, size_t len)
 	return 0;
 
 out_err:
-	giterr_set(GITERR_NET, "Invalid packet line");
+	giterr_set(GITERR_NET, "invalid packet line");
 	git__free(pkt->ref);
 	git__free(pkt);
 	return -1;
@@ -427,15 +427,23 @@ int git_pkt_parse_line(
 	if (bufflen > 0 && bufflen < (size_t)len)
 		return GIT_EBUFS;
 
+	/*
+	 * The length has to be exactly 0 in case of a flush
+	 * packet or greater than PKT_LEN_SIZE, as the decoded
+	 * length includes its own encoded length of four bytes.
+	 */
+	if (len != 0 && len < PKT_LEN_SIZE)
+		return GIT_ERROR;
+
 	line += PKT_LEN_SIZE;
 	/*
-	 * TODO: How do we deal with empty lines? Try again? with the next
-	 * line?
+	 * The Git protocol does not specify empty lines as part
+	 * of the protocol. Not knowing what to do with an empty
+	 * line, we should return an error upon hitting one.
 	 */
 	if (len == PKT_LEN_SIZE) {
-		*head = NULL;
-		*out = line;
-		return 0;
+		giterr_set_str(GITERR_NET, "Invalid empty packet");
+		return GIT_ERROR;
 	}
 
 	if (len == 0) { /* Flush pkt */
@@ -535,7 +543,7 @@ static int buffer_want_with_caps(const git_remote_head *head, transport_smart_ca
 
 	if (len > 0xffff) {
 		giterr_set(GITERR_NET,
-			"Tried to produce packet with invalid length %" PRIuZ, len);
+			"tried to produce packet with invalid length %" PRIuZ, len);
 		return -1;
 	}
 
diff --git a/src/transports/smart_protocol.c b/src/transports/smart_protocol.c
index 3448fa7fb..7a1d4dc14 100644
--- a/src/transports/smart_protocol.c
+++ b/src/transports/smart_protocol.c
@@ -50,7 +50,7 @@ int git_smart__store_refs(transport_smart *t, int flushes)
 			if ((recvd = gitno_recv(buf)) < 0)
 				return recvd;
 
-			if (recvd == 0 && !flush) {
+			if (recvd == 0) {
 				giterr_set(GITERR_NET, "early EOF");
 				return GIT_EEOF;
 			}
@@ -60,7 +60,7 @@ int git_smart__store_refs(transport_smart *t, int flushes)
 
 		gitno_consume(buf, line_end);
 		if (pkt->type == GIT_PKT_ERR) {
-			giterr_set(GITERR_NET, "Remote error: %s", ((git_pkt_err *)pkt)->error);
+			giterr_set(GITERR_NET, "remote error: %s", ((git_pkt_err *)pkt)->error);
 			git__free(pkt);
 			return -1;
 		}
@@ -222,8 +222,12 @@ static int recv_pkt(git_pkt **out, gitno_buffer *buf)
 		if (error < 0 && error != GIT_EBUFS)
 			return error;
 
-		if ((ret = gitno_recv(buf)) < 0)
+		if ((ret = gitno_recv(buf)) < 0) {
 			return ret;
+		} else if (ret == 0) {
+			giterr_set(GITERR_NET, "early EOF");
+			return GIT_EEOF;
+		}
 	} while (error);
 
 	gitno_consume(buf, line_end);
@@ -408,12 +412,12 @@ int git_smart__negotiate_fetch(git_transport *transport, git_repository *repo, c
 
 		if (i % 20 == 0 && t->rpc) {
 			git_pkt_ack *pkt;
-			unsigned int i;
+			unsigned int j;
 
 			if ((error = git_pkt_buffer_wants(wants, count, &t->caps, &data)) < 0)
 				goto on_error;
 
-			git_vector_foreach(&t->common, i, pkt) {
+			git_vector_foreach(&t->common, j, pkt) {
 				if ((error = git_pkt_buffer_have(&pkt->oid, &data)) < 0)
 					goto on_error;
 			}
@@ -428,12 +432,12 @@ int git_smart__negotiate_fetch(git_transport *transport, git_repository *repo, c
 	/* Tell the other end that we're done negotiating */
 	if (t->rpc && t->common.length > 0) {
 		git_pkt_ack *pkt;
-		unsigned int i;
+		unsigned int j;
 
 		if ((error = git_pkt_buffer_wants(wants, count, &t->caps, &data)) < 0)
 			goto on_error;
 
-		git_vector_foreach(&t->common, i, pkt) {
+		git_vector_foreach(&t->common, j, pkt) {
 			if ((error = git_pkt_buffer_have(&pkt->oid, &data)) < 0)
 				goto on_error;
 		}
@@ -724,7 +728,7 @@ static int add_push_report_pkt(git_push *push, git_pkt *pkt)
 static int add_push_report_sideband_pkt(git_push *push, git_pkt_data *data_pkt, git_buf *data_pkt_buf)
 {
 	git_pkt *pkt;
-	const char *line, *line_end;
+	const char *line, *line_end = NULL;
 	size_t line_len;
 	int error;
 	int reading_from_buf = data_pkt_buf->size > 0;
@@ -759,14 +763,6 @@ static int add_push_report_sideband_pkt(git_push *push, git_pkt_data *data_pkt,
 		line_len -= (line_end - line);
 		line = line_end;
 
-		/* When a valid packet with no content has been
-		 * read, git_pkt_parse_line does not report an
-		 * error, but the pkt pointer has not been set.
-		 * Handle this by skipping over empty packets.
-		 */
-		if (pkt == NULL)
-			continue;
-
 		error = add_push_report_pkt(push, pkt);
 
 		git_pkt_free(pkt);
@@ -821,9 +817,6 @@ static int parse_report(transport_smart *transport, git_push *push)
 
 		error = 0;
 
-		if (pkt == NULL)
-			continue;
-
 		switch (pkt->type) {
 			case GIT_PKT_DATA:
 				/* This is a sideband packet which contains other packets */
diff --git a/src/transports/ssh.c b/src/transports/ssh.c
index cfd573665..44d02e522 100644
--- a/src/transports/ssh.c
+++ b/src/transports/ssh.c
@@ -83,7 +83,7 @@ static int gen_proto(git_buf *request, const char *cmd, const char *url)
 
 done:
 	if (!repo) {
-		giterr_set(GITERR_NET, "Malformed git protocol URL");
+		giterr_set(GITERR_NET, "malformed git protocol URL");
 		return -1;
 	}
 
@@ -274,7 +274,7 @@ static int git_ssh_extract_url_parts(
 	}
 
 	if (colon == NULL || (colon < start)) {
-		giterr_set(GITERR_NET, "Malformed URL");
+		giterr_set(GITERR_NET, "malformed URL");
 		return -1;
 	}
 
@@ -445,7 +445,7 @@ static int request_creds(git_cred **out, ssh_subtransport *t, const char *user,
 		else if (error < 0)
 			return error;
 		else if (!cred) {
-			giterr_set(GITERR_SSH, "Callback failed to initialize SSH credentials");
+			giterr_set(GITERR_SSH, "callback failed to initialize SSH credentials");
 			return -1;
 		}
 	}
@@ -478,7 +478,7 @@ static int _git_ssh_session_create(
 
 	s = libssh2_session_init();
 	if (!s) {
-		giterr_set(GITERR_NET, "Failed to initialize SSH session");
+		giterr_set(GITERR_NET, "failed to initialize SSH session");
 		return -1;
 	}
 
@@ -487,7 +487,7 @@ static int _git_ssh_session_create(
 	} while (LIBSSH2_ERROR_EAGAIN == rc || LIBSSH2_ERROR_TIMEOUT == rc);
 
 	if (rc != LIBSSH2_ERROR_NONE) {
-		ssh_error(s, "Failed to start SSH session");
+		ssh_error(s, "failed to start SSH session");
 		libssh2_session_free(s);
 		return -1;
 	}
@@ -685,7 +685,7 @@ static int ssh_uploadpack(
 		return 0;
 	}
 
-	giterr_set(GITERR_NET, "Must call UPLOADPACK_LS before UPLOADPACK");
+	giterr_set(GITERR_NET, "must call UPLOADPACK_LS before UPLOADPACK");
 	return -1;
 }
 
@@ -712,7 +712,7 @@ static int ssh_receivepack(
 		return 0;
 	}
 
-	giterr_set(GITERR_NET, "Must call RECEIVEPACK_LS before RECEIVEPACK");
+	giterr_set(GITERR_NET, "must call RECEIVEPACK_LS before RECEIVEPACK");
 	return -1;
 }
 
@@ -844,7 +844,7 @@ int git_smart_subtransport_ssh(
 	assert(out);
 	*out = NULL;
 
-	giterr_set(GITERR_INVALID, "Cannot create SSH transport. Library was built without SSH support");
+	giterr_set(GITERR_INVALID, "cannot create SSH transport. Library was built without SSH support");
 	return -1;
 #endif
 }
@@ -888,7 +888,7 @@ int git_transport_ssh_with_paths(git_transport **out, git_remote *owner, void *p
 	assert(out);
 	*out = NULL;
 
-	giterr_set(GITERR_INVALID, "Cannot create SSH transport. Library was built without SSH support");
+	giterr_set(GITERR_INVALID, "cannot create SSH transport. Library was built without SSH support");
 	return -1;
 #endif
 }
diff --git a/src/transports/winhttp.c b/src/transports/winhttp.c
index 78e42cf3b..79b3ac6b4 100644
--- a/src/transports/winhttp.c
+++ b/src/transports/winhttp.c
@@ -68,7 +68,8 @@ static const IID IID_IInternetSecurityManager_mingw =
 
 typedef enum {
 	GIT_WINHTTP_AUTH_BASIC = 1,
-	GIT_WINHTTP_AUTH_NEGOTIATE = 2,
+	GIT_WINHTTP_AUTH_NTLM = 2,
+	GIT_WINHTTP_AUTH_NEGOTIATE = 4,
 } winhttp_authmechanism_t;
 
 typedef struct {
@@ -95,79 +96,66 @@ typedef struct {
 	git_cred *cred;
 	git_cred *url_cred;
 	git_cred *proxy_cred;
-	int auth_mechanism;
+	int auth_mechanisms;
 	HINTERNET session;
 	HINTERNET connection;
 } winhttp_subtransport;
 
-static int apply_basic_credential_proxy(HINTERNET request, git_cred *cred)
+static int _apply_userpass_credential(HINTERNET request, DWORD target, DWORD scheme, git_cred *cred)
 {
 	git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
 	wchar_t *user, *pass;
-	int error;
+	int user_len = 0, pass_len = 0, error = 0;
 
-	if ((error = git__utf8_to_16_alloc(&user, c->username)) < 0)
-		return error;
+	if ((error = user_len = git__utf8_to_16_alloc(&user, c->username)) < 0)
+		goto done;
 
-	if ((error = git__utf8_to_16_alloc(&pass, c->password)) < 0)
-		return error;
+	if ((error = pass_len = git__utf8_to_16_alloc(&pass, c->password)) < 0)
+		goto done;
 
-	if (!WinHttpSetCredentials(request, WINHTTP_AUTH_TARGET_PROXY, WINHTTP_AUTH_SCHEME_BASIC,
-	                           user, pass, NULL)) {
-		giterr_set(GITERR_OS, "failed to set proxy auth");
+	if (!WinHttpSetCredentials(request, target, scheme, user, pass, NULL)) {
+		giterr_set(GITERR_OS, "failed to set credentials");
 		error = -1;
 	}
 
+done:
+	if (user_len > 0)
+		git__memzero(user, user_len * sizeof(wchar_t));
+
+	if (pass_len > 0)
+		git__memzero(pass, pass_len * sizeof(wchar_t));
+
 	git__free(user);
 	git__free(pass);
 
 	return error;
 }
 
-static int apply_basic_credential(HINTERNET request, git_cred *cred)
+static int apply_userpass_credential_proxy(HINTERNET request, git_cred *cred)
 {
-	git_cred_userpass_plaintext *c = (git_cred_userpass_plaintext *)cred;
-	git_buf buf = GIT_BUF_INIT, raw = GIT_BUF_INIT;
-	wchar_t *wide = NULL;
-	int error = -1, wide_len;
-
-	git_buf_printf(&raw, "%s:%s", c->username, c->password);
-
-	if (git_buf_oom(&raw) ||
-		git_buf_puts(&buf, "Authorization: Basic ") < 0 ||
-		git_buf_encode_base64(&buf, git_buf_cstr(&raw), raw.size) < 0)
-		goto on_error;
+	return _apply_userpass_credential(request, WINHTTP_AUTH_TARGET_PROXY,
+		WINHTTP_AUTH_SCHEME_BASIC, cred);
+}
 
-	if ((wide_len = git__utf8_to_16_alloc(&wide, git_buf_cstr(&buf))) < 0) {
-		giterr_set(GITERR_OS, "Failed to convert string to wide form");
-		goto on_error;
-	}
+static int apply_userpass_credential(HINTERNET request, int mechanisms, git_cred *cred)
+{
+	DWORD native_scheme;
 
-	if (!WinHttpAddRequestHeaders(request, wide, (ULONG) -1L, WINHTTP_ADDREQ_FLAG_ADD)) {
-		giterr_set(GITERR_OS, "Failed to add a header to the request");
-		goto on_error;
+	if ((mechanisms & GIT_WINHTTP_AUTH_NTLM) ||
+		(mechanisms & GIT_WINHTTP_AUTH_NEGOTIATE)) {
+		native_scheme = WINHTTP_AUTH_SCHEME_NTLM;
+	} else if (mechanisms & GIT_WINHTTP_AUTH_BASIC) {
+		native_scheme = WINHTTP_AUTH_SCHEME_BASIC;
+	} else {
+		giterr_set(GITERR_NET, "invalid authentication scheme");
+		return -1;
 	}
 
-	error = 0;
-
-on_error:
-	/* We were dealing with plaintext passwords, so clean up after ourselves a bit. */
-	if (wide)
-		memset(wide, 0x0, wide_len * sizeof(wchar_t));
-
-	if (buf.size)
-		memset(buf.ptr, 0x0, buf.size);
-
-	if (raw.size)
-		memset(raw.ptr, 0x0, raw.size);
-
-	git__free(wide);
-	git_buf_free(&buf);
-	git_buf_free(&raw);
-	return error;
+	return _apply_userpass_credential(request, WINHTTP_AUTH_TARGET_SERVER,
+		native_scheme, cred);
 }
 
-static int apply_default_credentials(HINTERNET request)
+static int apply_default_credentials(HINTERNET request, int mechanisms)
 {
 	/* Either the caller explicitly requested that default credentials be passed,
 	 * or our fallback credential callback was invoked and checked that the target
@@ -177,6 +165,12 @@ static int apply_default_credentials(HINTERNET request)
 	 * to Internet Explorer security zones, but in fact does not. */
 	DWORD data = WINHTTP_AUTOLOGON_SECURITY_LEVEL_LOW;
 
+	if ((mechanisms & GIT_WINHTTP_AUTH_NTLM) == 0 &&
+		(mechanisms & GIT_WINHTTP_AUTH_NEGOTIATE) == 0) {
+		giterr_set(GITERR_NET, "invalid authentication scheme");
+		return -1;
+	}
+
 	if (!WinHttpSetOption(request, WINHTTP_OPTION_AUTOLOGON_POLICY, &data, sizeof(DWORD)))
 		return -1;
 
@@ -202,7 +196,7 @@ static int fallback_cred_acquire_cb(
 
 		/* Convert URL to wide characters */
 		if (git__utf8_to_16_alloc(&wide_url, url) < 0) {
-			giterr_set(GITERR_OS, "Failed to convert string to wide form");
+			giterr_set(GITERR_OS, "failed to convert string to wide form");
 			return -1;
 		}
 
@@ -351,7 +345,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 
 	/* Convert URL to wide characters */
 	if (git__utf8_to_16_alloc(&s->request_uri, git_buf_cstr(&buf)) < 0) {
-		giterr_set(GITERR_OS, "Failed to convert string to wide form");
+		giterr_set(GITERR_OS, "failed to convert string to wide form");
 		goto on_error;
 	}
 
@@ -366,12 +360,12 @@ static int winhttp_stream_connect(winhttp_stream *s)
 			t->connection_data.use_ssl ? WINHTTP_FLAG_SECURE : 0);
 
 	if (!s->request) {
-		giterr_set(GITERR_OS, "Failed to open request");
+		giterr_set(GITERR_OS, "failed to open request");
 		goto on_error;
 	}
 
 	if (!WinHttpSetTimeouts(s->request, default_timeout, default_connect_timeout, default_timeout, default_timeout)) {
-		giterr_set(GITERR_OS, "Failed to set timeouts for WinHTTP");
+		giterr_set(GITERR_OS, "failed to set timeouts for WinHTTP");
 		goto on_error;
 	}
 
@@ -444,7 +438,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 			WINHTTP_OPTION_PROXY,
 			&proxy_info,
 			sizeof(WINHTTP_PROXY_INFO))) {
-			giterr_set(GITERR_OS, "Failed to set proxy");
+			giterr_set(GITERR_OS, "failed to set proxy");
 			git__free(proxy_wide);
 			goto on_error;
 		}
@@ -453,7 +447,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 
 		if (t->proxy_cred) {
 			if (t->proxy_cred->credtype == GIT_CREDTYPE_USERPASS_PLAINTEXT) {
-				if ((error = apply_basic_credential_proxy(s->request, t->proxy_cred)) < 0)
+				if ((error = apply_userpass_credential_proxy(s->request, t->proxy_cred)) < 0)
 					goto on_error;
 			}
 		}
@@ -467,7 +461,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 		WINHTTP_OPTION_DISABLE_FEATURE,
 		&disable_redirects,
 		sizeof(disable_redirects))) {
-			giterr_set(GITERR_OS, "Failed to disable redirects");
+			giterr_set(GITERR_OS, "failed to disable redirects");
 			goto on_error;
 	}
 
@@ -481,7 +475,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 
 	/* Send Pragma: no-cache header */
 	if (!WinHttpAddRequestHeaders(s->request, pragma_nocache, (ULONG) -1L, WINHTTP_ADDREQ_FLAG_ADD)) {
-		giterr_set(GITERR_OS, "Failed to add a header to the request");
+		giterr_set(GITERR_OS, "failed to add a header to the request");
 		goto on_error;
 	}
 
@@ -494,13 +488,13 @@ static int winhttp_stream_connect(winhttp_stream *s)
 			goto on_error;
 
 		if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
-			giterr_set(GITERR_OS, "Failed to convert content-type to wide characters");
+			giterr_set(GITERR_OS, "failed to convert content-type to wide characters");
 			goto on_error;
 		}
 
 		if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
 			WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
-			giterr_set(GITERR_OS, "Failed to add a header to the request");
+			giterr_set(GITERR_OS, "failed to add a header to the request");
 			goto on_error;
 		}
 
@@ -511,13 +505,13 @@ static int winhttp_stream_connect(winhttp_stream *s)
 			goto on_error;
 
 		if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
-			giterr_set(GITERR_OS, "Failed to convert accept header to wide characters");
+			giterr_set(GITERR_OS, "failed to convert accept header to wide characters");
 			goto on_error;
 		}
 
 		if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
 			WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
-			giterr_set(GITERR_OS, "Failed to add a header to the request");
+			giterr_set(GITERR_OS, "failed to add a header to the request");
 			goto on_error;
 		}
 	}
@@ -527,13 +521,13 @@ static int winhttp_stream_connect(winhttp_stream *s)
 			git_buf_clear(&buf);
 			git_buf_puts(&buf, t->owner->custom_headers.strings[i]);
 			if (git__utf8_to_16(ct, MAX_CONTENT_TYPE_LEN, git_buf_cstr(&buf)) < 0) {
-				giterr_set(GITERR_OS, "Failed to convert custom header to wide characters");
+				giterr_set(GITERR_OS, "failed to convert custom header to wide characters");
 				goto on_error;
 			}
 
 			if (!WinHttpAddRequestHeaders(s->request, ct, (ULONG)-1L,
 				WINHTTP_ADDREQ_FLAG_ADD | WINHTTP_ADDREQ_FLAG_REPLACE)) {
-				giterr_set(GITERR_OS, "Failed to add a header to the request");
+				giterr_set(GITERR_OS, "failed to add a header to the request");
 				goto on_error;
 			}
 		}
@@ -550,13 +544,11 @@ static int winhttp_stream_connect(winhttp_stream *s)
 	/* If we have a credential on the subtransport, apply it to the request */
 	if (t->cred &&
 		t->cred->credtype == GIT_CREDTYPE_USERPASS_PLAINTEXT &&
-		t->auth_mechanism == GIT_WINHTTP_AUTH_BASIC &&
-		apply_basic_credential(s->request, t->cred) < 0)
+		apply_userpass_credential(s->request, t->auth_mechanisms, t->cred) < 0)
 		goto on_error;
 	else if (t->cred &&
 		t->cred->credtype == GIT_CREDTYPE_DEFAULT &&
-		t->auth_mechanism == GIT_WINHTTP_AUTH_NEGOTIATE &&
-		apply_default_credentials(s->request) < 0)
+		apply_default_credentials(s->request, t->auth_mechanisms) < 0)
 		goto on_error;
 
 	/* If no other credentials have been applied and the URL has username and
@@ -565,7 +557,7 @@ static int winhttp_stream_connect(winhttp_stream *s)
 		if (!t->url_cred &&
 			git_cred_userpass_plaintext_new(&t->url_cred, t->connection_data.user, t->connection_data.pass) < 0)
 			goto on_error;
-		if (apply_basic_credential(s->request, t->url_cred) < 0)
+		if (apply_userpass_credential(s->request, GIT_WINHTTP_AUTH_BASIC, t->url_cred) < 0)
 			goto on_error;
 	}
 
@@ -585,30 +577,35 @@ on_error:
 static int parse_unauthorized_response(
 	HINTERNET request,
 	int *allowed_types,
-	int *auth_mechanism)
+	int *allowed_mechanisms)
 {
 	DWORD supported, first, target;
 
 	*allowed_types = 0;
-	*auth_mechanism = 0;
+	*allowed_mechanisms = 0;
 
 	/* WinHttpQueryHeaders() must be called before WinHttpQueryAuthSchemes(). 
 	 * We can assume this was already done, since we know we are unauthorized. 
 	 */
 	if (!WinHttpQueryAuthSchemes(request, &supported, &first, &target)) {
-		giterr_set(GITERR_OS, "Failed to parse supported auth schemes"); 
+		giterr_set(GITERR_OS, "failed to parse supported auth schemes"); 
 		return -1;
 	}
 
-	if (WINHTTP_AUTH_SCHEME_BASIC & supported) {
+	if (WINHTTP_AUTH_SCHEME_NTLM & supported) {
 		*allowed_types |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
-		*auth_mechanism = GIT_WINHTTP_AUTH_BASIC;
+		*allowed_types |= GIT_CREDTYPE_DEFAULT;
+		*allowed_mechanisms = GIT_WINHTTP_AUTH_NEGOTIATE;
 	}
 
-	if ((WINHTTP_AUTH_SCHEME_NTLM & supported) ||
-		(WINHTTP_AUTH_SCHEME_NEGOTIATE & supported)) {
+	if (WINHTTP_AUTH_SCHEME_NEGOTIATE & supported) {
 		*allowed_types |= GIT_CREDTYPE_DEFAULT;
-		*auth_mechanism = GIT_WINHTTP_AUTH_NEGOTIATE;
+		*allowed_mechanisms = GIT_WINHTTP_AUTH_NEGOTIATE;
+	}
+
+	if (WINHTTP_AUTH_SCHEME_BASIC & supported) {
+		*allowed_types |= GIT_CREDTYPE_USERPASS_PLAINTEXT;
+		*allowed_mechanisms |= GIT_WINHTTP_AUTH_BASIC;
 	}
 
 	return 0;
@@ -629,7 +626,7 @@ static int write_chunk(HINTERNET request, const char *buffer, size_t len)
 		git_buf_cstr(&buf),	(DWORD)git_buf_len(&buf),
 		&bytes_written)) {
 		git_buf_free(&buf);
-		giterr_set(GITERR_OS, "Failed to write chunk header");
+		giterr_set(GITERR_OS, "failed to write chunk header");
 		return -1;
 	}
 
@@ -639,7 +636,7 @@ static int write_chunk(HINTERNET request, const char *buffer, size_t len)
 	if (!WinHttpWriteData(request,
 		buffer, (DWORD)len,
 		&bytes_written)) {
-		giterr_set(GITERR_OS, "Failed to write chunk");
+		giterr_set(GITERR_OS, "failed to write chunk");
 		return -1;
 	}
 
@@ -647,7 +644,7 @@ static int write_chunk(HINTERNET request, const char *buffer, size_t len)
 	if (!WinHttpWriteData(request,
 		"\r\n", 2,
 		&bytes_written)) {
-		giterr_set(GITERR_OS, "Failed to write chunk footer");
+		giterr_set(GITERR_OS, "failed to write chunk footer");
 		return -1;
 	}
 
@@ -660,7 +657,7 @@ static int winhttp_close_connection(winhttp_subtransport *t)
 
 	if (t->connection) {
 		if (!WinHttpCloseHandle(t->connection)) {
-			giterr_set(GITERR_OS, "Unable to close connection");
+			giterr_set(GITERR_OS, "unable to close connection");
 			ret = -1;
 		}
 
@@ -669,7 +666,7 @@ static int winhttp_close_connection(winhttp_subtransport *t)
 
 	if (t->session) {
 		if (!WinHttpCloseHandle(t->session)) {
-			giterr_set(GITERR_OS, "Unable to close session");
+			giterr_set(GITERR_OS, "unable to close session");
 			ret = -1;
 		}
 
@@ -714,7 +711,7 @@ static int winhttp_connect(
 
 	/* Prepare host */
 	if (git__utf8_to_16_alloc(&wide_host, t->connection_data.host) < 0) {
-		giterr_set(GITERR_OS, "Unable to convert host to wide characters");
+		giterr_set(GITERR_OS, "unable to convert host to wide characters");
 		return -1;
 	}
 
@@ -724,7 +721,7 @@ static int winhttp_connect(
 	}
 
 	if (git__utf8_to_16_alloc(&wide_ua, git_buf_cstr(&ua)) < 0) {
-		giterr_set(GITERR_OS, "Unable to convert host to wide characters");
+		giterr_set(GITERR_OS, "unable to convert host to wide characters");
 		git__free(wide_host);
 		git_buf_free(&ua);
 		return -1;
@@ -741,12 +738,12 @@ static int winhttp_connect(
 		0);
 
 	if (!t->session) {
-		giterr_set(GITERR_OS, "Failed to init WinHTTP");
+		giterr_set(GITERR_OS, "failed to init WinHTTP");
 		goto on_error;
 	}
 
 	if (!WinHttpSetTimeouts(t->session, default_timeout, default_connect_timeout, default_timeout, default_timeout)) {
-		giterr_set(GITERR_OS, "Failed to set timeouts for WinHTTP");
+		giterr_set(GITERR_OS, "failed to set timeouts for WinHTTP");
 		goto on_error;
 	}
 
@@ -759,7 +756,7 @@ static int winhttp_connect(
 		0);
 
 	if (!t->connection) {
-		giterr_set(GITERR_OS, "Failed to connect to host");
+		giterr_set(GITERR_OS, "failed to connect to host");
 		goto on_error;
 	}
 
@@ -853,7 +850,7 @@ static int winhttp_stream_read(
 replay:
 	/* Enforce a reasonable cap on the number of replays */
 	if (++replay_count >= 7) {
-		giterr_set(GITERR_NET, "Too many redirects or authentication replays");
+		giterr_set(GITERR_NET, "too many redirects or authentication replays");
 		return -1;
 	}
 
@@ -888,7 +885,7 @@ replay:
 			if (!WinHttpWriteData(s->request,
 				"0\r\n\r\n", 5,
 				&bytes_written)) {
-				giterr_set(GITERR_OS, "Failed to write final chunk");
+				giterr_set(GITERR_OS, "failed to write final chunk");
 				return -1;
 			}
 		}
@@ -899,7 +896,7 @@ replay:
 			if (INVALID_SET_FILE_POINTER == SetFilePointer(s->post_body,
 					0, 0, FILE_BEGIN) &&
 				NO_ERROR != GetLastError()) {
-				giterr_set(GITERR_OS, "Failed to reset file pointer");
+				giterr_set(GITERR_OS, "failed to reset file pointer");
 				return -1;
 			}
 
@@ -913,14 +910,14 @@ replay:
 					&bytes_read, NULL) ||
 					!bytes_read) {
 					git__free(buffer);
-					giterr_set(GITERR_OS, "Failed to read from temp file");
+					giterr_set(GITERR_OS, "failed to read from temp file");
 					return -1;
 				}
 
 				if (!WinHttpWriteData(s->request, buffer,
 					bytes_read, &bytes_written)) {
 					git__free(buffer);
-					giterr_set(GITERR_OS, "Failed to write data");
+					giterr_set(GITERR_OS, "failed to write data");
 					return -1;
 				}
 
@@ -936,7 +933,7 @@ replay:
 		}
 
 		if (!WinHttpReceiveResponse(s->request, 0)) {
-			giterr_set(GITERR_OS, "Failed to receive response");
+			giterr_set(GITERR_OS, "failed to receive response");
 			return -1;
 		}
 
@@ -948,7 +945,7 @@ replay:
 			WINHTTP_HEADER_NAME_BY_INDEX,
 			&status_code, &status_code_length,
 			WINHTTP_NO_HEADER_INDEX)) {
-				giterr_set(GITERR_OS, "Failed to retrieve status code");
+				giterr_set(GITERR_OS, "failed to retrieve status code");
 				return -1;
 		}
 
@@ -978,7 +975,7 @@ replay:
 				&location_length,
 				WINHTTP_NO_HEADER_INDEX) ||
 				GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
-				giterr_set(GITERR_OS, "Failed to read Location header");
+				giterr_set(GITERR_OS, "failed to read Location header");
 				return -1;
 			}
 
@@ -991,14 +988,14 @@ replay:
 				location,
 				&location_length,
 				WINHTTP_NO_HEADER_INDEX)) {
-				giterr_set(GITERR_OS, "Failed to read Location header");
+				giterr_set(GITERR_OS, "failed to read Location header");
 				git__free(location);
 				return -1;
 			}
 
 			/* Convert the Location header to UTF-8 */
 			if (git__utf16_to_8_alloc(&location8, location) < 0) {
-				giterr_set(GITERR_OS, "Failed to convert Location header to UTF-8");
+				giterr_set(GITERR_OS, "failed to convert Location header to UTF-8");
 				git__free(location);
 				return -1;
 			}
@@ -1029,7 +1026,7 @@ replay:
 		if (status_code == HTTP_STATUS_PROXY_AUTH_REQ) {
 			int allowed_types;
 
-			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanism) < 0)
+			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanisms) < 0)
 				return -1;
 
 			/* TODO: extract the username from the url, no payload? */
@@ -1049,7 +1046,7 @@ replay:
 		if (HTTP_STATUS_DENIED == status_code && get_verb == s->verb) {
 			int allowed_types;
 
-			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanism) < 0)
+			if (parse_unauthorized_response(s->request, &allowed_types, &t->auth_mechanisms) < 0)
 				return -1;
 
 			if (allowed_types) {
@@ -1090,7 +1087,7 @@ replay:
 		}
 
 		if (HTTP_STATUS_OK != status_code) {
-			giterr_set(GITERR_NET, "Request failed with status code: %d", status_code);
+			giterr_set(GITERR_NET, "request failed with status code: %d", status_code);
 			return -1;
 		}
 
@@ -1101,7 +1098,7 @@ replay:
 			p_snprintf(expected_content_type_8, MAX_CONTENT_TYPE_LEN, "application/x-git-%s-advertisement", s->service);
 
 		if (git__utf8_to_16(expected_content_type, MAX_CONTENT_TYPE_LEN, expected_content_type_8) < 0) {
-			giterr_set(GITERR_OS, "Failed to convert expected content-type to wide characters");
+			giterr_set(GITERR_OS, "failed to convert expected content-type to wide characters");
 			return -1;
 		}
 
@@ -1112,12 +1109,12 @@ replay:
 			WINHTTP_HEADER_NAME_BY_INDEX,
 			&content_type, &content_type_length,
 			WINHTTP_NO_HEADER_INDEX)) {
-				giterr_set(GITERR_OS, "Failed to retrieve response content-type");
+				giterr_set(GITERR_OS, "failed to retrieve response content-type");
 				return -1;
 		}
 
 		if (wcscmp(expected_content_type, content_type)) {
-			giterr_set(GITERR_NET, "Received unexpected content-type");
+			giterr_set(GITERR_NET, "received unexpected content-type");
 			return -1;
 		}
 
@@ -1129,7 +1126,7 @@ replay:
 		(DWORD)buf_size,
 		&dw_bytes_read))
 	{
-		giterr_set(GITERR_OS, "Failed to read data");
+		giterr_set(GITERR_OS, "failed to read data");
 		return -1;
 	}
 
@@ -1152,7 +1149,7 @@ static int winhttp_stream_write_single(
 
 	/* This implementation of write permits only a single call. */
 	if (s->sent_request) {
-		giterr_set(GITERR_NET, "Subtransport configured for only one write");
+		giterr_set(GITERR_NET, "subtransport configured for only one write");
 		return -1;
 	}
 
@@ -1165,7 +1162,7 @@ static int winhttp_stream_write_single(
 			(LPCVOID)buffer,
 			(DWORD)len,
 			&bytes_written)) {
-		giterr_set(GITERR_OS, "Failed to write data");
+		giterr_set(GITERR_OS, "failed to write data");
 		return -1;
 	}
 
@@ -1183,12 +1180,12 @@ static int put_uuid_string(LPWSTR buffer, size_t buffer_len_cch)
 	if (RPC_S_OK != status &&
 		RPC_S_UUID_LOCAL_ONLY != status &&
 		RPC_S_UUID_NO_ADDRESS != status) {
-		giterr_set(GITERR_NET, "Unable to generate name for temp file");
+		giterr_set(GITERR_NET, "unable to generate name for temp file");
 		return -1;
 	}
 
 	if (buffer_len_cch < UUID_LENGTH_CCH + 1) {
-		giterr_set(GITERR_NET, "Buffer too small for name of temp file");
+		giterr_set(GITERR_NET, "buffer too small for name of temp file");
 		return -1;
 	}
 
@@ -1203,7 +1200,7 @@ static int put_uuid_string(LPWSTR buffer, size_t buffer_len_cch)
 		uuid.Data4[4], uuid.Data4[5], uuid.Data4[6], uuid.Data4[7]);
 
 	if (result < UUID_LENGTH_CCH) {
-		giterr_set(GITERR_OS, "Unable to generate name for temp file");
+		giterr_set(GITERR_OS, "unable to generate name for temp file");
 		return -1;
 	}
 
@@ -1215,7 +1212,7 @@ static int get_temp_file(LPWSTR buffer, DWORD buffer_len_cch)
 	size_t len;
 
 	if (!GetTempPathW(buffer_len_cch, buffer)) {
-		giterr_set(GITERR_OS, "Failed to get temp path");
+		giterr_set(GITERR_OS, "failed to get temp path");
 		return -1;
 	}
 
@@ -1258,13 +1255,13 @@ static int winhttp_stream_write_buffered(
 
 		if (INVALID_HANDLE_VALUE == s->post_body) {
 			s->post_body = NULL;
-			giterr_set(GITERR_OS, "Failed to create temporary file");
+			giterr_set(GITERR_OS, "failed to create temporary file");
 			return -1;
 		}
 	}
 
 	if (!WriteFile(s->post_body, buffer, (DWORD)len, &bytes_written, NULL)) {
-		giterr_set(GITERR_OS, "Failed to write to temporary file");
+		giterr_set(GITERR_OS, "failed to write to temporary file");
 		return -1;
 	}
 
@@ -1291,7 +1288,7 @@ static int winhttp_stream_write_chunked(
 		if (!WinHttpAddRequestHeaders(s->request,
 			transfer_encoding, (ULONG) -1L,
 			WINHTTP_ADDREQ_FLAG_ADD)) {
-			giterr_set(GITERR_OS, "Failed to add a header to the request");
+			giterr_set(GITERR_OS, "failed to add a header to the request");
 			return -1;
 		}
 
diff --git a/src/tree-cache.c b/src/tree-cache.c
index b37be0f0d..548054136 100644
--- a/src/tree-cache.c
+++ b/src/tree-cache.c
@@ -137,7 +137,7 @@ static int read_tree_internal(git_tree_cache **out,
 	return 0;
 
  corrupted:
-	giterr_set(GITERR_INDEX, "Corrupted TREE extension in index");
+	giterr_set(GITERR_INDEX, "corrupted TREE extension in index");
 	return -1;
 }
 
@@ -149,7 +149,7 @@ int git_tree_cache_read(git_tree_cache **tree, const char *buffer, size_t buffer
 		return -1;
 
 	if (buffer < buffer_end) {
-		giterr_set(GITERR_INDEX, "Corrupted TREE extension in index (unexpected trailing data)");
+		giterr_set(GITERR_INDEX, "corrupted TREE extension in index (unexpected trailing data)");
 		return -1;
 	}
 
diff --git a/src/tree.c b/src/tree.c
index 6008a9544..783dca41f 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -627,7 +627,7 @@ int git_tree__write_index(
 
 	if (git_index_has_conflicts(index)) {
 		giterr_set(GITERR_INDEX,
-			"Cannot create a tree from a not fully merged index.");
+			"cannot create a tree from a not fully merged index.");
 		return GIT_EUNMERGED;
 	}
 
@@ -909,7 +909,7 @@ int git_tree_entry_bypath(
 	filename_len = subpath_len(path);
 
 	if (filename_len == 0) {
-		giterr_set(GITERR_TREE, "Invalid tree path given");
+		giterr_set(GITERR_TREE, "invalid tree path given");
 		return GIT_ENOTFOUND;
 	}
 
@@ -917,7 +917,7 @@ int git_tree_entry_bypath(
 
 	if (entry == NULL) {
 		giterr_set(GITERR_TREE,
-			   "the path '%.*s' does not exist in the given tree", filename_len, path);
+			   "the path '%.*s' does not exist in the given tree", (int) filename_len, path);
 		return GIT_ENOTFOUND;
 	}
 
@@ -927,7 +927,7 @@ int git_tree_entry_bypath(
 		 * then this entry *must* be a tree */
 		if (!git_tree_entry__is_tree(entry)) {
 			giterr_set(GITERR_TREE,
-				   "the path '%.*s' exists but is not a tree", filename_len, path);
+				   "the path '%.*s' exists but is not a tree", (int) filename_len, path);
 			return GIT_ENOTFOUND;
 		}
 
@@ -1027,7 +1027,7 @@ int git_tree_walk(
 	git_buf root_path = GIT_BUF_INIT;
 
 	if (mode != GIT_TREEWALK_POST && mode != GIT_TREEWALK_PRE) {
-		giterr_set(GITERR_INVALID, "Invalid walking mode for tree walk");
+		giterr_set(GITERR_INVALID, "invalid walking mode for tree walk");
 		return -1;
 	}
 
@@ -1164,8 +1164,8 @@ int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseli
 		goto cleanup;
 
 	for (i = 0; i < nupdates; i++) {
-		const git_tree_update *last_update = i == 0 ? NULL : &updates[i-1];
-		const git_tree_update *update = &updates[i];
+		const git_tree_update *last_update = i == 0 ? NULL : git_vector_get(&entries, i-1);
+		const git_tree_update *update = git_vector_get(&entries, i);
 		size_t common_prefix = 0, steps_up, j;
 		const char *path;
 
@@ -1200,6 +1200,9 @@ int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseli
 
 			last = git_array_last(stack);
 			entry = last->tree ? git_tree_entry_byname(last->tree, component.ptr) : NULL;
+			if (!entry)
+				entry = treebuilder_get(last->bld, component.ptr);
+
 			if (entry && git_tree_entry_type(entry) != GIT_OBJ_TREE) {
 				giterr_set(GITERR_TREE, "D/F conflict when updating tree");
 				error = -1;
@@ -1234,7 +1237,7 @@ int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseli
 				const git_tree_entry *e = git_treebuilder_get(last->bld, basename);
 				if (e && git_tree_entry_type(e) != git_object__type_from_filemode(update->filemode)) {
 					git__free(basename);
-					giterr_set(GITERR_TREE, "Cannot replace '%s' with '%s' at '%s'",
+					giterr_set(GITERR_TREE, "cannot replace '%s' with '%s' at '%s'",
 						   git_object_type2string(git_tree_entry_type(e)),
 						   git_object_type2string(git_object__type_from_filemode(update->filemode)),
 						   update->path);
@@ -1254,7 +1257,7 @@ int git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseli
 				break;
 			}
 			default:
-				giterr_set(GITERR_TREE, "unkown action for update");
+				giterr_set(GITERR_TREE, "unknown action for update");
 				error = -1;
 				goto cleanup;
 		}
diff --git a/src/unix/map.c b/src/unix/map.c
index c55ad1aa7..9d9b1fe38 100644
--- a/src/unix/map.c
+++ b/src/unix/map.c
@@ -52,7 +52,7 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offs
 	out->data = mmap(NULL, len, mprot, mflag, fd, offset);
 
 	if (!out->data || out->data == MAP_FAILED) {
-		giterr_set(GITERR_OS, "Failed to mmap. Could not write data");
+		giterr_set(GITERR_OS, "failed to mmap. Could not write data");
 		return -1;
 	}
 
diff --git a/src/unix/pthread.h b/src/unix/pthread.h
index 0f3f17927..3f23d10d5 100644
--- a/src/unix/pthread.h
+++ b/src/unix/pthread.h
@@ -17,6 +17,8 @@ typedef struct {
 	pthread_create(&(git_thread_ptr)->thread, NULL, start_routine, arg)
 #define git_thread_join(git_thread_ptr, status) \
 	pthread_join((git_thread_ptr)->thread, status)
+#define git_thread_currentid() ((size_t)(pthread_self()))
+#define git_thread_exit(retval) pthread_exit(retval)
 
 /* Git Mutex */
 #define git_mutex pthread_mutex_t
diff --git a/src/util.c b/src/util.c
index 76ca711b2..a44f4c9ac 100644
--- a/src/util.c
+++ b/src/util.c
@@ -136,7 +136,7 @@ int git__strntol64(int64_t *result, const char *nptr, size_t nptr_len, const cha
 
 Return:
 	if (ndig == 0) {
-		giterr_set(GITERR_INVALID, "Failed to convert string to long. Not a number");
+		giterr_set(GITERR_INVALID, "failed to convert string to long: not a number");
 		return -1;
 	}
 
@@ -144,7 +144,7 @@ Return:
 		*endptr = p;
 
 	if (ovfl) {
-		giterr_set(GITERR_INVALID, "Failed to convert string to long. Overflow error");
+		giterr_set(GITERR_INVALID, "failed to convert string to long: overflow error");
 		return -1;
 	}
 
@@ -169,7 +169,7 @@ int git__strntol32(int32_t *result, const char *nptr, size_t nptr_len, const cha
 
 	tmp_int = tmp_long & 0xFFFFFFFF;
 	if (tmp_int != tmp_long) {
-		giterr_set(GITERR_INVALID, "Failed to convert. '%s' is too large", nptr);
+		giterr_set(GITERR_INVALID, "failed to convert: '%s' is too large", nptr);
 		return -1;
 	}
 
diff --git a/src/win32/dir.c b/src/win32/dir.c
index c15757085..8a724a4e9 100644
--- a/src/win32/dir.c
+++ b/src/win32/dir.c
@@ -28,7 +28,7 @@ git__DIR *git__opendir(const char *dir)
 	new->h = FindFirstFileW(filter_w, &new->f);
 
 	if (new->h == INVALID_HANDLE_VALUE) {
-		giterr_set(GITERR_OS, "Could not open directory '%s'", dir);
+		giterr_set(GITERR_OS, "could not open directory '%s'", dir);
 		git__free(new);
 		return NULL;
 	}
@@ -53,7 +53,7 @@ int git__readdir_ext(
 	else if (!FindNextFileW(d->h, &d->f)) {
 		if (GetLastError() == ERROR_NO_MORE_FILES)
 			return 0;
-		giterr_set(GITERR_OS, "Could not read from directory '%s'", d->dir);
+		giterr_set(GITERR_OS, "could not read from directory '%s'", d->dir);
 		return -1;
 	}
 
@@ -98,7 +98,7 @@ void git__rewinddir(git__DIR *d)
 	d->h = FindFirstFileW(filter_w, &d->f);
 
 	if (d->h == INVALID_HANDLE_VALUE)
-		giterr_set(GITERR_OS, "Could not open directory '%s'", d->dir);
+		giterr_set(GITERR_OS, "could not open directory '%s'", d->dir);
 	else
 		d->first = 1;
 }
diff --git a/src/win32/findfile.c b/src/win32/findfile.c
index 58c22279e..1c768f7f4 100644
--- a/src/win32/findfile.c
+++ b/src/win32/findfile.c
@@ -38,7 +38,7 @@ static int win32_path_to_8(git_buf *dest, const wchar_t *src)
 	git_win32_utf8_path utf8_path;
 
 	if (git_win32_path_to_utf8(utf8_path, src) < 0) {
-		giterr_set(GITERR_OS, "Unable to convert path to UTF-8");
+		giterr_set(GITERR_OS, "unable to convert path to UTF-8");
 		return -1;
 	}
 
diff --git a/src/win32/map.c b/src/win32/map.c
index 03a3646a6..5fcc1085b 100644
--- a/src/win32/map.c
+++ b/src/win32/map.c
@@ -67,7 +67,7 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offs
 
 	if (fh == INVALID_HANDLE_VALUE) {
 		errno = EBADF;
-		giterr_set(GITERR_OS, "Failed to mmap. Invalid handle value");
+		giterr_set(GITERR_OS, "failed to mmap. Invalid handle value");
 		return -1;
 	}
 
@@ -86,13 +86,13 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offs
 
 	if (page_offset != 0) { /* offset must be multiple of the allocation granularity */
 		errno = EINVAL;
-		giterr_set(GITERR_OS, "Failed to mmap. Offset must be multiple of allocation granularity");
+		giterr_set(GITERR_OS, "failed to mmap. Offset must be multiple of allocation granularity");
 		return -1;
 	}
 
 	out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL);
 	if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) {
-		giterr_set(GITERR_OS, "Failed to mmap. Invalid handle value");
+		giterr_set(GITERR_OS, "failed to mmap. Invalid handle value");
 		out->fmh = NULL;
 		return -1;
 	}
@@ -103,7 +103,7 @@ int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offs
 	off_hi = (DWORD)(page_start >> 32);
 	out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len);
 	if (!out->data) {
-		giterr_set(GITERR_OS, "Failed to mmap. No data written");
+		giterr_set(GITERR_OS, "failed to mmap. No data written");
 		CloseHandle(out->fmh);
 		out->fmh = NULL;
 		return -1;
@@ -121,7 +121,7 @@ int p_munmap(git_map *map)
 
 	if (map->data) {
 		if (!UnmapViewOfFile(map->data)) {
-			giterr_set(GITERR_OS, "Failed to munmap. Could not unmap view of file");
+			giterr_set(GITERR_OS, "failed to munmap. Could not unmap view of file");
 			error = -1;
 		}
 		map->data = NULL;
@@ -129,7 +129,7 @@ int p_munmap(git_map *map)
 
 	if (map->fmh) {
 		if (!CloseHandle(map->fmh)) {
-			giterr_set(GITERR_OS, "Failed to munmap. Could not close handle");
+			giterr_set(GITERR_OS, "failed to munmap. Could not close handle");
 			error = -1;
 		}
 		map->fmh = NULL;
diff --git a/src/win32/thread.c b/src/win32/thread.c
index 80d56ce5d..87318c9d3 100644
--- a/src/win32/thread.c
+++ b/src/win32/thread.c
@@ -26,6 +26,9 @@ static DWORD WINAPI git_win32__threadproc(LPVOID lpParameter)
 {
 	git_thread *thread = lpParameter;
 
+	/* Set the current thread for `git_thread_exit` */
+	GIT_GLOBAL->current_thread = thread;
+
 	thread->result = thread->proc(thread->param);
 
 	git__free_tls_data();
@@ -95,6 +98,21 @@ int git_thread_join(
 	return 0;
 }
 
+void git_thread_exit(void *value)
+{
+	assert(GIT_GLOBAL->current_thread);
+	GIT_GLOBAL->current_thread->result = value;
+
+	git__free_tls_data();
+
+	ExitThread(CLEAN_THREAD_EXIT);
+}
+
+size_t git_thread_currentid(void)
+{
+	return GetCurrentThreadId();
+}
+
 int git_mutex_init(git_mutex *GIT_RESTRICT mutex)
 {
 	InitializeCriticalSection(mutex);
diff --git a/src/win32/thread.h b/src/win32/thread.h
index 0d01822a6..7f4a2170f 100644
--- a/src/win32/thread.h
+++ b/src/win32/thread.h
@@ -41,6 +41,8 @@ int git_thread_create(git_thread *GIT_RESTRICT,
 	void *(*) (void *),
 	void *GIT_RESTRICT);
 int git_thread_join(git_thread *, void **);
+size_t git_thread_currentid(void);
+void git_thread_exit(void *);
 
 int git_mutex_init(git_mutex *GIT_RESTRICT mutex);
 int git_mutex_free(git_mutex *);
diff --git a/src/win32/w32_crtdbg_stacktrace.c b/src/win32/w32_crtdbg_stacktrace.c
index a778f4164..2dbdaf45b 100644
--- a/src/win32/w32_crtdbg_stacktrace.c
+++ b/src/win32/w32_crtdbg_stacktrace.c
@@ -253,11 +253,11 @@ int git_win32__crtdbg_stacktrace__dump(
 	bool b_quiet            = IS_BIT_SET(opt, GIT_WIN32__CRTDBG_STACKTRACE__QUIET);
 
 	if (b_leaks_since_mark && b_leaks_total) {
-		giterr_set(GITERR_INVALID, "Cannot combine LEAKS_SINCE_MARK and LEAKS_TOTAL.");
+		giterr_set(GITERR_INVALID, "cannot combine LEAKS_SINCE_MARK and LEAKS_TOTAL.");
 		return GIT_ERROR;
 	}
 	if (!b_set_mark && !b_leaks_since_mark && !b_leaks_total) {
-		giterr_set(GITERR_INVALID, "Nothing to do.");
+		giterr_set(GITERR_INVALID, "nothing to do.");
 		return GIT_ERROR;
 	}
 
diff --git a/src/win32/w32_util.c b/src/win32/w32_util.c
index 60311bb50..b7b1ffa10 100644
--- a/src/win32/w32_util.c
+++ b/src/win32/w32_util.c
@@ -68,7 +68,7 @@ int git_win32__set_hidden(const char *path, bool hidden)
 		newattrs = attrs & ~FILE_ATTRIBUTE_HIDDEN;
 
 	if (attrs != newattrs && !SetFileAttributesW(buf, newattrs)) {
-		giterr_set(GITERR_OS, "Failed to %s hidden bit for '%s'",
+		giterr_set(GITERR_OS, "failed to %s hidden bit for '%s'",
 			hidden ? "set" : "unset", path);
 		return -1;
 	}
diff --git a/src/win32/w32_util.h b/src/win32/w32_util.h
index 2e475e5e9..77973b502 100644
--- a/src/win32/w32_util.h
+++ b/src/win32/w32_util.h
@@ -174,7 +174,7 @@ GIT_INLINE(int) git_win32__file_attribute_to_stat(
 			/* st_size gets the UTF-8 length of the target name, in bytes,
 			 * not counting the NULL terminator */
 			if ((st->st_size = git__utf16_to_8(NULL, 0, target)) < 0) {
-				giterr_set(GITERR_OS, "Could not convert reparse point name for '%s'", path);
+				giterr_set(GITERR_OS, "could not convert reparse point name for '%ls'", path);
 				return -1;
 			}
 		}
diff --git a/src/zstream.c b/src/zstream.c
index d9ad4ca89..141b49b27 100644
--- a/src/zstream.c
+++ b/src/zstream.c
@@ -21,9 +21,9 @@ static int zstream_seterr(git_zstream *zs)
 	if (zs->zerr == Z_MEM_ERROR)
 		giterr_set_oom();
 	else if (zs->z.msg)
-		giterr_set(GITERR_ZLIB, zs->z.msg);
+		giterr_set_str(GITERR_ZLIB, zs->z.msg);
 	else
-		giterr_set(GITERR_ZLIB, "Unknown compression error");
+		giterr_set(GITERR_ZLIB, "unknown compression error");
 
 	return -1;
 }
diff --git a/tests/checkout/tree.c b/tests/checkout/tree.c
index 4a0314a9e..c9581fdc5 100644
--- a/tests/checkout/tree.c
+++ b/tests/checkout/tree.c
@@ -422,6 +422,44 @@ void test_checkout_tree__can_checkout_with_pattern(void)
 	cl_assert(git_path_exists("testrepo/new.txt"));
 }
 
+void test_checkout_tree__pathlist_checkout_ignores_non_matches(void)
+{
+	char *entries[] = { "branch_file.txt", "link_to_new.txt" };
+
+	/* reset to beginning of history (i.e. just a README file) */
+
+	g_opts.checkout_strategy =
+		GIT_CHECKOUT_FORCE | GIT_CHECKOUT_REMOVE_UNTRACKED;
+
+	cl_git_pass(git_revparse_single(&g_object, g_repo, "refs/heads/master"));
+
+	cl_git_pass(git_checkout_tree(g_repo, g_object, &g_opts));
+	cl_git_pass(git_repository_set_head(g_repo, "refs/heads/master"));
+
+	cl_assert(git_path_exists("testrepo/README"));
+	cl_assert(git_path_exists("testrepo/branch_file.txt"));
+	cl_assert(git_path_exists("testrepo/link_to_new.txt"));
+	cl_assert(git_path_exists("testrepo/new.txt"));
+
+	cl_git_pass(git_revparse_single(&g_object, g_repo, "8496071c1b46c854b31185ea97743be6a8774479"));
+
+	g_opts.checkout_strategy =
+		GIT_CHECKOUT_FORCE | GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH;
+	g_opts.paths.strings = entries;
+	g_opts.paths.count = 2;
+
+	cl_git_pass(git_checkout_tree(g_repo, g_object, &g_opts));
+
+	cl_assert(git_path_exists("testrepo/README"));
+	cl_assert(!git_path_exists("testrepo/branch_file.txt"));
+	cl_assert(!git_path_exists("testrepo/link_to_new.txt"));
+	cl_assert(git_path_exists("testrepo/new.txt"));
+
+	git_object_free(g_object);
+	g_object = NULL;
+
+}
+
 void test_checkout_tree__can_disable_pattern_match(void)
 {
 	char *entries[] = { "b*.txt" };
diff --git a/tests/clar_libgit2.h b/tests/clar_libgit2.h
index d7e635302..fc08bbf1f 100644
--- a/tests/clar_libgit2.h
+++ b/tests/clar_libgit2.h
@@ -41,6 +41,51 @@
 	} \
 	} while(0)
 
+/**
+ * Thread safe assertions; you cannot use `cl_git_report_failure` from a
+ * child thread since it will try to `longjmp` to abort and "the effect of
+ * a call to longjmp() where initialization of the jmp_buf structure was
+ * not performed in the calling thread is undefined."
+ *
+ * Instead, callers can provide a clar thread error context to a thread,
+ * which will populate and return it on failure.  Callers can check the
+ * status with `cl_git_thread_check`.
+ */
+typedef struct {
+	int error;
+	const char *file;
+	int line;
+	const char *expr;
+	char error_msg[4096];
+} cl_git_thread_err;
+
+#ifdef GIT_THREADS
+# define cl_git_thread_pass(threaderr, expr) cl_git_thread_pass_(threaderr, (expr), __FILE__, __LINE__)
+#else
+# define cl_git_thread_pass(threaderr, expr) cl_git_pass(expr)
+#endif
+
+#define cl_git_thread_pass_(__threaderr, __expr, __file, __line) do { \
+	giterr_clear(); \
+	if ((((cl_git_thread_err *)__threaderr)->error = (__expr)) != 0) { \
+		const git_error *_last = giterr_last(); \
+		((cl_git_thread_err *)__threaderr)->file = __file; \
+		((cl_git_thread_err *)__threaderr)->line = __line; \
+		((cl_git_thread_err *)__threaderr)->expr = "Function call failed: " #__expr; \
+		p_snprintf(((cl_git_thread_err *)__threaderr)->error_msg, 4096, "thread 0x%" PRIxZ " - error %d - %s", \
+			git_thread_currentid(), ((cl_git_thread_err *)__threaderr)->error, \
+			_last ? _last->message : "<no message>"); \
+		git_thread_exit(__threaderr); \
+	} \
+	} while (0)
+
+GIT_INLINE(void) cl_git_thread_check(void *data)
+{
+	cl_git_thread_err *threaderr = (cl_git_thread_err *)data;
+	if (threaderr->error != 0)
+		clar__assert(0, threaderr->file, threaderr->line, threaderr->expr, threaderr->error_msg, 1);
+}
+
 void cl_git_report_failure(int, const char *, int, const char *);
 
 #define cl_assert_at_line(expr,file,line) \
diff --git a/tests/core/env.c b/tests/core/env.c
index ee08258a6..1af0e6e5d 100644
--- a/tests/core/env.c
+++ b/tests/core/env.c
@@ -298,3 +298,24 @@ void test_core_env__2(void)
 	git_buf_free(&path);
 	git_buf_free(&found);
 }
+
+void test_core_env__substitution(void)
+{
+  git_buf buf = GIT_BUF_INIT, expected = GIT_BUF_INIT;
+
+  /* Set it to something non-default so we have controllable values */
+  cl_git_pass(git_libgit2_opts(GIT_OPT_SET_SEARCH_PATH, GIT_CONFIG_LEVEL_GLOBAL, "/tmp/a"));
+  cl_git_pass(git_libgit2_opts(GIT_OPT_GET_SEARCH_PATH, GIT_CONFIG_LEVEL_GLOBAL, &buf));
+  cl_assert_equal_s("/tmp/a", buf.ptr);
+
+  git_buf_clear(&buf);
+  cl_git_pass(git_buf_join(&buf, GIT_PATH_LIST_SEPARATOR, "$PATH", "/tmp/b"));
+  cl_git_pass(git_libgit2_opts(GIT_OPT_SET_SEARCH_PATH, GIT_CONFIG_LEVEL_GLOBAL, buf.ptr));
+  cl_git_pass(git_libgit2_opts(GIT_OPT_GET_SEARCH_PATH, GIT_CONFIG_LEVEL_GLOBAL, &buf));
+
+  cl_git_pass(git_buf_join(&expected, GIT_PATH_LIST_SEPARATOR, "/tmp/a", "/tmp/b"));
+  cl_assert_equal_s(expected.ptr, buf.ptr);
+
+  git_buf_free(&expected);
+  git_buf_free(&buf);
+}
diff --git a/tests/core/init.c b/tests/core/init.c
index e17b7845f..a8cbd930b 100644
--- a/tests/core/init.c
+++ b/tests/core/init.c
@@ -12,3 +12,43 @@ void test_core_init__returns_count(void)
 	cl_assert_equal_i(1, git_libgit2_shutdown());
 }
 
+void test_core_init__reinit_succeeds(void)
+{
+	cl_assert_equal_i(0, git_libgit2_shutdown());
+	cl_assert_equal_i(1, git_libgit2_init());
+	cl_sandbox_set_search_path_defaults();
+}
+
+#ifdef GIT_THREADS
+static void *reinit(void *unused)
+{
+	unsigned i;
+
+	for (i = 0; i < 20; i++) {
+		cl_assert(git_libgit2_init() > 0);
+		cl_assert(git_libgit2_shutdown() >= 0);
+	}
+
+	return unused;
+}
+#endif
+
+void test_core_init__concurrent_init_succeeds(void)
+{
+#ifdef GIT_THREADS
+	git_thread threads[10];
+	unsigned i;
+
+	cl_assert_equal_i(2, git_libgit2_init());
+
+	for (i = 0; i < ARRAY_SIZE(threads); i++)
+		git_thread_create(&threads[i], reinit, NULL);
+	for (i = 0; i < ARRAY_SIZE(threads); i++)
+		git_thread_join(&threads[i], NULL);
+
+	cl_assert_equal_i(1, git_libgit2_shutdown());
+	cl_sandbox_set_search_path_defaults();
+#else
+	cl_skip();
+#endif
+}
diff --git a/tests/core/pqueue.c b/tests/core/pqueue.c
index bcd4eea9f..2b90f4172 100644
--- a/tests/core/pqueue.c
+++ b/tests/core/pqueue.c
@@ -93,7 +93,29 @@ void test_core_pqueue__max_heap_size(void)
 	cl_assert_equal_i(0, git_pqueue_size(&pq));
 
 	git_pqueue_free(&pq);
+}
+
+void test_core_pqueue__max_heap_size_without_comparison(void)
+{
+	git_pqueue pq;
+	int i, vals[100] = { 0 };
+
+	cl_git_pass(git_pqueue_init(&pq, GIT_PQUEUE_FIXED_SIZE, 50, NULL));
+
+	for (i = 0; i < 100; ++i)
+		cl_git_pass(git_pqueue_insert(&pq, &vals[i]));
 
+	cl_assert_equal_i(50, git_pqueue_size(&pq));
+
+	/* As we have no comparison function, we cannot make any
+	 * actual assumptions about which entries are part of the
+	 * pqueue */
+	for (i = 0; i < 50; ++i)
+		cl_assert(git_pqueue_pop(&pq));
+
+	cl_assert_equal_i(0, git_pqueue_size(&pq));
+
+	git_pqueue_free(&pq);
 }
 
 static int cmp_ints_like_commit_time(const void *a, const void *b)
diff --git a/tests/core/vector.c b/tests/core/vector.c
index 336254cce..c2e5d3f34 100644
--- a/tests/core/vector.c
+++ b/tests/core/vector.c
@@ -404,4 +404,6 @@ void test_core_vector__reverse(void)
 
 	for (i = 0; i < 5; i++)
 		cl_assert_equal_p(out2[i], git_vector_get(&v, i));
+
+	git_vector_free(&v);
 }
diff --git a/tests/fetchhead/nonetwork.c b/tests/fetchhead/nonetwork.c
index 3b750af5e..ea4b70e4a 100644
--- a/tests/fetchhead/nonetwork.c
+++ b/tests/fetchhead/nonetwork.c
@@ -293,7 +293,7 @@ void test_fetchhead_nonetwork__invalid_for_merge(void)
 	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tinvalid-merge\t\n");
 	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
 
-	cl_assert(git__prefixcmp(giterr_last()->message, "Invalid for-merge") == 0);
+	cl_assert(git__prefixcmp(giterr_last()->message, "invalid for-merge") == 0);
 }
 
 void test_fetchhead_nonetwork__invalid_description(void)
@@ -304,7 +304,7 @@ void test_fetchhead_nonetwork__invalid_description(void)
 	cl_git_rewritefile("./test1/.git/FETCH_HEAD", "49322bb17d3acc9146f98c97d078513228bbf3c0\tnot-for-merge\n");
 	cl_git_fail(git_repository_fetchhead_foreach(g_repo, read_noop, NULL));
 
-	cl_assert(git__prefixcmp(giterr_last()->message, "Invalid description") == 0);
+	cl_assert(git__prefixcmp(giterr_last()->message, "invalid description") == 0);
 }
 
 static int assert_master_for_merge(const char *ref, const char *url, const git_oid *id, unsigned int is_merge, void *data)
diff --git a/tests/merge/trees/renames.c b/tests/merge/trees/renames.c
index d7721c894..6f5c36b0a 100644
--- a/tests/merge/trees/renames.c
+++ b/tests/merge/trees/renames.c
@@ -242,6 +242,8 @@ void test_merge_trees_renames__no_rename_index(void)
 		{ 0100644, "b69fe837e4cecfd4c9a40cdca7c138468687df07", 3, "7-both-renamed.txt" },
 	};
 
+	opts.flags &= ~GIT_MERGE_FIND_RENAMES;
+
 	cl_git_pass(merge_trees_from_branches(&index, repo,
 		BRANCH_RENAME_OURS, BRANCH_RENAME_THEIRS,
 		&opts));
diff --git a/tests/object/tree/update.c b/tests/object/tree/update.c
index 54c4335f5..b76e8612a 100644
--- a/tests/object/tree/update.c
+++ b/tests/object/tree/update.c
@@ -196,6 +196,63 @@ void test_object_tree_update__add_blobs(void)
 	git_tree_free(base_tree);
 }
 
+void test_object_tree_update__add_blobs_unsorted(void)
+{
+	git_oid tree_index_id, tree_updater_id, base_id;
+	git_tree *base_tree;
+	git_index *idx;
+	git_index_entry entry = { {0} };
+	int i;
+	const char *paths[] = {
+		"some/deep/path",
+		"a/path/elsewhere",
+		"some/other/path",
+	};
+
+	git_tree_update updates[] = {
+		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[0]},
+		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[1]},
+		{ GIT_TREE_UPDATE_UPSERT, {{0}}, GIT_FILEMODE_BLOB, paths[2]},
+	};
+
+	cl_git_pass(git_oid_fromstr(&base_id, "c4dc1555e4d4fa0e0c9c3fc46734c7c35b3ce90b"));
+
+	entry.mode = GIT_FILEMODE_BLOB;
+	cl_git_pass(git_oid_fromstr(&entry.id, "fa49b077972391ad58037050f2a75f74e3671e92"));
+
+	for (i = 0; i < 3; i++) {
+		cl_git_pass(git_oid_fromstr(&updates[i].id, "fa49b077972391ad58037050f2a75f74e3671e92"));
+	}
+
+	for (i = 0; i < 2; i++) {
+		int j;
+
+		/* Create it with an index */
+		cl_git_pass(git_index_new(&idx));
+
+		base_tree = NULL;
+		if (i == 1) {
+			cl_git_pass(git_tree_lookup(&base_tree, g_repo, &base_id));
+			cl_git_pass(git_index_read_tree(idx, base_tree));
+		}
+
+		for (j = 0; j < 3; j++) {
+			entry.path = paths[j];
+			cl_git_pass(git_index_add(idx, &entry));
+		}
+
+		cl_git_pass(git_index_write_tree_to(&tree_index_id, idx, g_repo));
+		git_index_free(idx);
+
+		/* Perform the same operations via the tree updater */
+		cl_git_pass(git_tree_create_updated(&tree_updater_id, g_repo, base_tree, 3, updates));
+
+		cl_assert_equal_oid(&tree_index_id, &tree_updater_id);
+	}
+
+	git_tree_free(base_tree);
+}
+
 void test_object_tree_update__add_conflict(void)
 {
 	int i;
diff --git a/tests/odb/backend/nobackend.c b/tests/odb/backend/nobackend.c
index 783641e8f..3c4f344b1 100644
--- a/tests/odb/backend/nobackend.c
+++ b/tests/odb/backend/nobackend.c
@@ -40,7 +40,7 @@ void test_odb_backend_nobackend__write_fails_gracefully(void)
 	cl_git_fail(git_odb_write(&id, odb, "Hello world!\n", 13, GIT_OBJ_BLOB));
 
 	err = giterr_last();
-	cl_assert_equal_s(err->message, "Cannot write object - unsupported in the loaded odb backends");
+	cl_assert_equal_s(err->message, "cannot write object - unsupported in the loaded odb backends");
 
 	git_odb_free(odb);
 }
diff --git a/tests/online/badssl.c b/tests/online/badssl.c
index 66b090df4..aa4c24d9c 100644
--- a/tests/online/badssl.c
+++ b/tests/online/badssl.c
@@ -10,37 +10,71 @@ static bool g_has_ssl = true;
 static bool g_has_ssl = false;
 #endif
 
+static int cert_check_assert_invalid(git_cert *cert, int valid, const char* host, void *payload)
+{
+	GIT_UNUSED(cert); GIT_UNUSED(host); GIT_UNUSED(payload);
+
+	cl_assert_equal_i(0, valid);
+
+	return GIT_ECERTIFICATE;
+}
+
 void test_online_badssl__expired(void)
 {
+	git_clone_options opts = GIT_CLONE_OPTIONS_INIT;
+	opts.fetch_opts.callbacks.certificate_check = cert_check_assert_invalid;
+
 	if (!g_has_ssl)
 		cl_skip();
 
 	cl_git_fail_with(GIT_ECERTIFICATE,
 			 git_clone(&g_repo, "https://expired.badssl.com/fake.git", "./fake", NULL));
+
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://expired.badssl.com/fake.git", "./fake", &opts));
 }
 
 void test_online_badssl__wrong_host(void)
 {
+	git_clone_options opts = GIT_CLONE_OPTIONS_INIT;
+	opts.fetch_opts.callbacks.certificate_check = cert_check_assert_invalid;
+
 	if (!g_has_ssl)
 		cl_skip();
 
 	cl_git_fail_with(GIT_ECERTIFICATE,
 			 git_clone(&g_repo, "https://wrong.host.badssl.com/fake.git", "./fake", NULL));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://wrong.host.badssl.com/fake.git", "./fake", &opts));
 }
 
 void test_online_badssl__self_signed(void)
 {
+	git_clone_options opts = GIT_CLONE_OPTIONS_INIT;
+	opts.fetch_opts.callbacks.certificate_check = cert_check_assert_invalid;
+
 	if (!g_has_ssl)
 		cl_skip();
 
 	cl_git_fail_with(GIT_ECERTIFICATE,
 			 git_clone(&g_repo, "https://self-signed.badssl.com/fake.git", "./fake", NULL));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://self-signed.badssl.com/fake.git", "./fake", &opts));
 }
 
 void test_online_badssl__old_cipher(void)
 {
+	git_clone_options opts = GIT_CLONE_OPTIONS_INIT;
+	opts.fetch_opts.callbacks.certificate_check = cert_check_assert_invalid;
+
+	/* FIXME: we don't actually reject RC4 anywhere, figure out what to tweak */
+	cl_skip();
+
 	if (!g_has_ssl)
 		cl_skip();
 
-	cl_git_fail(git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", NULL));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", NULL));
+	cl_git_fail_with(GIT_ECERTIFICATE,
+			 git_clone(&g_repo, "https://rc4.badssl.com/fake.git", "./fake", &opts));
 }
diff --git a/tests/online/fetchhead.c b/tests/online/fetchhead.c
index 9aaad253c..c1ac06dbe 100644
--- a/tests/online/fetchhead.c
+++ b/tests/online/fetchhead.c
@@ -126,6 +126,8 @@ void test_online_fetchhead__explicit_dst_refspec_creates_branch(void)
 
 	cl_git_pass(git_branch_lookup(&ref, g_repo, "explicit-refspec", GIT_BRANCH_ALL));
 	cl_assert_equal_i(refs + 1, count_references());
+
+	git_reference_free(ref);
 }
 
 void test_online_fetchhead__empty_dst_refspec_creates_no_branch(void)
diff --git a/tests/pack/indexer.c b/tests/pack/indexer.c
index 49a106d98..1e514b2d6 100644
--- a/tests/pack/indexer.c
+++ b/tests/pack/indexer.c
@@ -125,3 +125,44 @@ void test_pack_indexer__fix_thin(void)
 		git_indexer_free(idx);
 	}
 }
+
+static int find_tmp_file_recurs(void *opaque, git_buf *path)
+{
+	int error = 0;
+	git_buf *first_tmp_file = opaque;
+	struct stat st;
+
+	if ((error = p_lstat_posixly(path->ptr, &st)) < 0)
+		return error;
+
+	if (S_ISDIR(st.st_mode))
+		return git_path_direach(path, 0, find_tmp_file_recurs, opaque);
+
+	/* This is the template that's used in git_futils_mktmp. */
+	if (strstr(git_buf_cstr(path), "_git2_") != NULL)
+		return git_buf_sets(first_tmp_file, git_buf_cstr(path));
+
+	return 0;
+}
+
+void test_pack_indexer__no_tmp_files(void)
+{
+	git_indexer *idx = NULL;
+	git_buf path = GIT_BUF_INIT;
+	git_buf first_tmp_file = GIT_BUF_INIT;
+
+	/* Precondition: there are no temporary files. */
+	cl_git_pass(git_buf_sets(&path, clar_sandbox_path()));
+	cl_git_pass(find_tmp_file_recurs(&first_tmp_file, &path));
+	git_buf_free(&path);
+	cl_assert(git_buf_len(&first_tmp_file) == 0);
+
+	cl_git_pass(git_indexer_new(&idx, ".", 0, NULL, NULL, NULL));
+	git_indexer_free(idx);
+
+	cl_git_pass(git_buf_sets(&path, clar_sandbox_path()));
+	cl_git_pass(find_tmp_file_recurs(&first_tmp_file, &path));
+	git_buf_free(&path);
+	cl_assert(git_buf_len(&first_tmp_file) == 0);
+	git_buf_free(&first_tmp_file);
+}
diff --git a/tests/rebase/merge.c b/tests/rebase/merge.c
index 0f06ed153..7b2d6876c 100644
--- a/tests/rebase/merge.c
+++ b/tests/rebase/merge.c
@@ -1,4 +1,5 @@
 #include "clar_libgit2.h"
+#include "git2/checkout.h"
 #include "git2/rebase.h"
 #include "posix.h"
 #include "signature.h"
@@ -475,6 +476,59 @@ void test_rebase_merge__finish(void)
 	git_rebase_free(rebase);
 }
 
+void test_rebase_merge__detached_finish(void)
+{
+	git_rebase *rebase;
+	git_reference *branch_ref, *upstream_ref, *head_ref;
+	git_annotated_commit *branch_head, *upstream_head;
+	git_rebase_operation *rebase_operation;
+	git_oid commit_id;
+	git_reflog *reflog;
+	const git_reflog_entry *reflog_entry;
+	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
+	int error;
+
+	cl_git_pass(git_reference_lookup(&branch_ref, repo, "refs/heads/gravy"));
+	cl_git_pass(git_reference_lookup(&upstream_ref, repo, "refs/heads/veal"));
+
+	cl_git_pass(git_annotated_commit_from_ref(&branch_head, repo, branch_ref));
+	cl_git_pass(git_annotated_commit_from_ref(&upstream_head, repo, upstream_ref));
+
+	cl_git_pass(git_repository_set_head_detached_from_annotated(repo, branch_head));
+	opts.checkout_strategy = GIT_CHECKOUT_FORCE;
+	git_checkout_head(repo, &opts);
+
+	cl_git_pass(git_rebase_init(&rebase, repo, NULL, upstream_head, NULL, NULL));
+
+	cl_git_pass(git_rebase_next(&rebase_operation, rebase));
+	cl_git_pass(git_rebase_commit(&commit_id, rebase, NULL, signature,
+		NULL, NULL));
+
+	cl_git_fail(error = git_rebase_next(&rebase_operation, rebase));
+	cl_assert_equal_i(GIT_ITEROVER, error);
+
+	cl_git_pass(git_rebase_finish(rebase, signature));
+
+	cl_assert_equal_i(GIT_REPOSITORY_STATE_NONE, git_repository_state(repo));
+
+	cl_git_pass(git_reference_lookup(&head_ref, repo, "HEAD"));
+	cl_assert_equal_i(GIT_REF_OID, git_reference_type(head_ref));
+
+	/* Make sure the reflogs are updated appropriately */
+	cl_git_pass(git_reflog_read(&reflog, repo, "HEAD"));
+	cl_assert(reflog_entry = git_reflog_entry_byindex(reflog, 0));
+	cl_assert_equal_oid(git_annotated_commit_id(upstream_head), git_reflog_entry_id_old(reflog_entry));
+	cl_assert_equal_oid(&commit_id, git_reflog_entry_id_new(reflog_entry));
+
+	git_reflog_free(reflog);
+	git_annotated_commit_free(branch_head);
+	git_annotated_commit_free(upstream_head);
+	git_reference_free(head_ref);
+	git_reference_free(branch_ref);
+	git_reference_free(upstream_ref);
+	git_rebase_free(rebase);
+}
+
 void test_rebase_merge__finish_with_ids(void)
 {
 	git_rebase *rebase;
diff --git a/tests/refs/branches/create.c b/tests/refs/branches/create.c
index 31dec0678..69488e6c7 100644
--- a/tests/refs/branches/create.c
+++ b/tests/refs/branches/create.c
@@ -65,10 +65,14 @@ void test_refs_branches_create__can_force_create_over_an_existing_branch(void)
 	cl_assert_equal_s("refs/heads/br2", git_reference_name(branch));
 }
 
-void test_refs_branches_create__cannot_force_create_over_current_branch(void)
+void test_refs_branches_create__cannot_force_create_over_current_branch_in_nonbare_repo(void)
 {
 	const git_oid *oid;
 	git_reference *branch2;
+
+	/* Default repo for these tests is a bare repo, but this test requires a non-bare one */
+	cl_git_sandbox_cleanup();
+	repo = cl_git_sandbox_init("testrepo");
 	retrieve_known_commit(&target, repo);
 
 	cl_git_pass(git_branch_lookup(&branch2, repo, "master", GIT_BRANCH_LOCAL));
@@ -84,6 +88,26 @@ void test_refs_branches_create__cannot_force_create_over_current_branch(void)
 	git_reference_free(branch2);
 }
 
+void test_refs_branches_create__can_force_create_over_current_branch_in_bare_repo(void)
+{
+	const git_oid *oid;
+	git_reference *branch2;
+	retrieve_known_commit(&target, repo);
+
+	cl_git_pass(git_branch_lookup(&branch2, repo, "master", GIT_BRANCH_LOCAL));
+	cl_assert_equal_s("refs/heads/master", git_reference_name(branch2));
+	cl_assert_equal_i(true, git_branch_is_head(branch2));
+	oid = git_commit_id(target);
+
+	cl_git_pass(git_branch_create(&branch, repo, "master", target, 1));
+	git_reference_free(branch);
+	branch = NULL;
+	cl_git_pass(git_branch_lookup(&branch, repo, "master", GIT_BRANCH_LOCAL));
+	cl_assert_equal_s("refs/heads/master", git_reference_name(branch));
+	cl_git_pass(git_oid_cmp(git_reference_target(branch), oid));
+	git_reference_free(branch2);
+}
+
 void test_refs_branches_create__creating_a_branch_with_an_invalid_name_returns_EINVALIDSPEC(void)
 {
 	retrieve_known_commit(&target, repo);
diff --git a/tests/refs/branches/upstream.c b/tests/refs/branches/upstream.c
index 8f2e7a2ca..82f5665d8 100644
--- a/tests/refs/branches/upstream.c
+++ b/tests/refs/branches/upstream.c
@@ -175,7 +175,7 @@ void test_refs_branches_upstream__no_fetch_refspec(void)
 	cl_git_pass(git_reference_lookup(&branch, repo, "refs/heads/test"));
 	cl_git_pass(git_reference_create(&ref, repo, "refs/remotes/matching/master", git_reference_target(branch), 1, "fetch"));
 	cl_git_fail(git_branch_set_upstream(branch, "matching/master"));
-	cl_assert_equal_s("Could not determine remote for 'refs/remotes/matching/master'",
+	cl_assert_equal_s("could not determine remote for 'refs/remotes/matching/master'",
 			  giterr_last()->message);
 
 	/* we can't set it automatically, so let's test the user setting it by hand */
diff --git a/tests/refs/reflog/reflog.c b/tests/refs/reflog/reflog.c
index fdb15502c..9e46c8ae9 100644
--- a/tests/refs/reflog/reflog.c
+++ b/tests/refs/reflog/reflog.c
@@ -261,7 +261,7 @@ void test_refs_reflog_reflog__reading_a_reflog_with_invalid_format_returns_error
 	error = giterr_last();
 
 	cl_assert(error != NULL);
-	cl_assert_equal_s("Unable to parse OID - contains invalid characters", error->message);
+	cl_assert_equal_s("unable to parse OID - contains invalid characters", error->message);
 
 	git_reference_free(ref);
 	git_buf_free(&logpath);
diff --git a/tests/repo/discover.c b/tests/repo/discover.c
index 358daee9f..48aa27581 100644
--- a/tests/repo/discover.c
+++ b/tests/repo/discover.c
@@ -9,6 +9,7 @@
 
 #define SUB_REPOSITORY_FOLDER_NAME "sub_repo"
 #define SUB_REPOSITORY_FOLDER DISCOVER_FOLDER "/" SUB_REPOSITORY_FOLDER_NAME
+#define SUB_REPOSITORY_GITDIR SUB_REPOSITORY_FOLDER "/.git"
 #define SUB_REPOSITORY_FOLDER_SUB SUB_REPOSITORY_FOLDER "/sub"
 #define SUB_REPOSITORY_FOLDER_SUB_SUB SUB_REPOSITORY_FOLDER_SUB "/subsub"
 #define SUB_REPOSITORY_FOLDER_SUB_SUB_SUB SUB_REPOSITORY_FOLDER_SUB_SUB "/subsubsub"
@@ -24,20 +25,26 @@
 #define ALTERNATE_NOT_FOUND_FOLDER DISCOVER_FOLDER "/alternate_not_found_repo"
 
 static void ensure_repository_discover(const char *start_path,
-                                       const char *ceiling_dirs,
-				       git_buf *expected_path)
+				       const char *ceiling_dirs,
+				       const char *expected_path)
 {
-	git_buf found_path = GIT_BUF_INIT;
+	git_buf found_path = GIT_BUF_INIT, resolved = GIT_BUF_INIT;
+
+	git_buf_attach(&resolved, p_realpath(expected_path, NULL), 0);
+	cl_assert(resolved.size > 0);
+	cl_git_pass(git_path_to_dir(&resolved));
 	cl_git_pass(git_repository_discover(&found_path, start_path, 0, ceiling_dirs));
-	//across_fs is always 0 as we can't automate the filesystem change tests
-	cl_assert_equal_s(found_path.ptr, expected_path->ptr);
+
+	cl_assert_equal_s(found_path.ptr, resolved.ptr);
+
+	git_buf_free(&resolved);
 	git_buf_free(&found_path);
 }
 
 static void write_file(const char *path, const char *content)
 {
 	git_file file;
-   int error;
+	int error;
 
 	if (git_path_exists(path)) {
 		cl_git_pass(p_unlink(path));
@@ -68,42 +75,30 @@ static void append_ceiling_dir(git_buf *ceiling_dirs, const char *path)
 	cl_assert(git_buf_oom(ceiling_dirs) == 0);
 }
 
-void test_repo_discover__0(void)
+static git_buf discovered;
+static git_buf ceiling_dirs;
+
+void test_repo_discover__initialize(void)
 {
-	// test discover
 	git_repository *repo;
-	git_buf ceiling_dirs_buf = GIT_BUF_INIT, repository_path = GIT_BUF_INIT,
-		sub_repository_path = GIT_BUF_INIT, found_path = GIT_BUF_INIT;
-	const char *ceiling_dirs;
 	const mode_t mode = 0777;
-
 	git_futils_mkdir_r(DISCOVER_FOLDER, mode);
-	append_ceiling_dir(&ceiling_dirs_buf, TEMP_REPO_FOLDER);
-	ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
 
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&repository_path, DISCOVER_FOLDER, 0, ceiling_dirs));
+	git_buf_init(&discovered, 0);
+	git_buf_init(&ceiling_dirs, 0);
+	append_ceiling_dir(&ceiling_dirs, TEMP_REPO_FOLDER);
 
 	cl_git_pass(git_repository_init(&repo, DISCOVER_FOLDER, 1));
-	cl_git_pass(git_repository_discover(&repository_path, DISCOVER_FOLDER, 0, ceiling_dirs));
 	git_repository_free(repo);
 
 	cl_git_pass(git_repository_init(&repo, SUB_REPOSITORY_FOLDER, 0));
 	cl_git_pass(git_futils_mkdir_r(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, mode));
-	cl_git_pass(git_repository_discover(&sub_repository_path, SUB_REPOSITORY_FOLDER, 0, ceiling_dirs));
-
 	cl_git_pass(git_futils_mkdir_r(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, mode));
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, ceiling_dirs, &sub_repository_path);
 
 	cl_git_pass(git_futils_mkdir_r(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, mode));
 	write_file(REPOSITORY_ALTERNATE_FOLDER "/" DOT_GIT, "gitdir: ../" SUB_REPOSITORY_FOLDER_NAME "/" DOT_GIT);
 	write_file(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB "/" DOT_GIT, "gitdir: ../../../" SUB_REPOSITORY_FOLDER_NAME "/" DOT_GIT);
 	write_file(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB "/" DOT_GIT, "gitdir: ../../../../");
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs, &repository_path);
 
 	cl_git_pass(git_futils_mkdir_r(ALTERNATE_MALFORMED_FOLDER1, mode));
 	write_file(ALTERNATE_MALFORMED_FOLDER1 "/" DOT_GIT, "Anything but not gitdir:");
@@ -113,41 +108,94 @@ void test_repo_discover__0(void)
 	write_file(ALTERNATE_MALFORMED_FOLDER3 "/" DOT_GIT, "gitdir: \n\n\n");
 	cl_git_pass(git_futils_mkdir_r(ALTERNATE_NOT_FOUND_FOLDER, mode));
 	write_file(ALTERNATE_NOT_FOUND_FOLDER "/" DOT_GIT, "gitdir: a_repository_that_surely_does_not_exist");
-	cl_git_fail(git_repository_discover(&found_path, ALTERNATE_MALFORMED_FOLDER1, 0, ceiling_dirs));
-	cl_git_fail(git_repository_discover(&found_path, ALTERNATE_MALFORMED_FOLDER2, 0, ceiling_dirs));
-	cl_git_fail(git_repository_discover(&found_path, ALTERNATE_MALFORMED_FOLDER3, 0, ceiling_dirs));
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, ALTERNATE_NOT_FOUND_FOLDER, 0, ceiling_dirs));
 
-	append_ceiling_dir(&ceiling_dirs_buf, SUB_REPOSITORY_FOLDER_SUB);
-	ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
+	git_repository_free(repo);
+}
+
+void test_repo_discover__cleanup(void)
+{
+	git_buf_free(&discovered);
+	git_buf_free(&ceiling_dirs);
+	cl_git_pass(git_futils_rmdir_r(TEMP_REPO_FOLDER, NULL, GIT_RMDIR_REMOVE_FILES));
+}
+
+void test_repo_discover__discovering_repo_with_exact_path_succeeds(void)
+{
+	cl_git_pass(git_repository_discover(&discovered, DISCOVER_FOLDER, 0, ceiling_dirs.ptr));
+	cl_git_pass(git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER, 0, ceiling_dirs.ptr));
+}
+
+void test_repo_discover__discovering_nonexistent_dir_fails(void)
+{
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, DISCOVER_FOLDER "-nonexistent", 0, NULL));
+}
+
+void test_repo_discover__discovering_repo_with_subdirectory_succeeds(void)
+{
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+}
+
+void test_repo_discover__discovering_repository_with_alternative_gitdir_succeeds(void)
+{
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs.ptr, DISCOVER_FOLDER);
+}
+
+void test_repo_discover__discovering_repository_with_malformed_alternative_gitdir_fails(void)
+{
+	cl_git_fail(git_repository_discover(&discovered, ALTERNATE_MALFORMED_FOLDER1, 0, ceiling_dirs.ptr));
+	cl_git_fail(git_repository_discover(&discovered, ALTERNATE_MALFORMED_FOLDER2, 0, ceiling_dirs.ptr));
+	cl_git_fail(git_repository_discover(&discovered, ALTERNATE_MALFORMED_FOLDER3, 0, ceiling_dirs.ptr));
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, ALTERNATE_NOT_FOUND_FOLDER, 0, ceiling_dirs.ptr));
+}
+
+void test_repo_discover__discovering_repository_with_ceiling(void)
+{
+	append_ceiling_dir(&ceiling_dirs, SUB_REPOSITORY_FOLDER_SUB);
 
 	/* this must pass as ceiling_directories cannot prevent the current
 	 * working directory to be checked */
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB, ceiling_dirs, &sub_repository_path);
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, SUB_REPOSITORY_FOLDER_SUB_SUB, 0, ceiling_dirs));
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, 0, ceiling_dirs));
-
-	append_ceiling_dir(&ceiling_dirs_buf, SUB_REPOSITORY_FOLDER);
-	ceiling_dirs = git_buf_cstr(&ceiling_dirs_buf);
-
-	//this must pass as ceiling_directories cannot predent the current
-	//working directory to be checked
-	ensure_repository_discover(SUB_REPOSITORY_FOLDER, ceiling_dirs, &sub_repository_path);
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, SUB_REPOSITORY_FOLDER_SUB, 0, ceiling_dirs));
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, SUB_REPOSITORY_FOLDER_SUB_SUB, 0, ceiling_dirs));
-	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&found_path, SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, 0, ceiling_dirs));
-
-	//.gitfile redirection should not be affected by ceiling directories
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs, &sub_repository_path);
-	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs, &repository_path);
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
 
-	cl_git_pass(git_futils_rmdir_r(TEMP_REPO_FOLDER, NULL, GIT_RMDIR_REMOVE_FILES));
-	git_repository_free(repo);
-	git_buf_free(&ceiling_dirs_buf);
-	git_buf_free(&repository_path);
-	git_buf_free(&sub_repository_path);
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER_SUB_SUB, 0, ceiling_dirs.ptr));
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, 0, ceiling_dirs.ptr));
+}
+
+void test_repo_discover__other_ceiling(void)
+{
+	append_ceiling_dir(&ceiling_dirs, SUB_REPOSITORY_FOLDER);
+
+	/* this must pass as ceiling_directories cannot predent the current
+	 * working directory to be checked */
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER_SUB, 0, ceiling_dirs.ptr));
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER_SUB_SUB, 0, ceiling_dirs.ptr));
+	cl_assert_equal_i(GIT_ENOTFOUND, git_repository_discover(&discovered, SUB_REPOSITORY_FOLDER_SUB_SUB_SUB, 0, ceiling_dirs.ptr));
 }
 
+void test_repo_discover__ceiling_should_not_affect_gitdir_redirection(void)
+{
+	append_ceiling_dir(&ceiling_dirs, SUB_REPOSITORY_FOLDER);
+
+	/* gitfile redirection should not be affected by ceiling directories */
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB, ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+	ensure_repository_discover(REPOSITORY_ALTERNATE_FOLDER_SUB_SUB_SUB, ceiling_dirs.ptr, DISCOVER_FOLDER);
+}
+
+void test_repo_discover__discovery_starting_at_file_succeeds(void)
+{
+	int fd;
+
+	cl_assert((fd = p_creat(SUB_REPOSITORY_FOLDER "/file", 0600)) >= 0);
+	cl_assert(p_close(fd) == 0);
+
+	ensure_repository_discover(SUB_REPOSITORY_FOLDER "/file", ceiling_dirs.ptr, SUB_REPOSITORY_GITDIR);
+}
diff --git a/tests/submodule/lookup.c b/tests/submodule/lookup.c
index 148f9273e..e36fc44e0 100644
--- a/tests/submodule/lookup.c
+++ b/tests/submodule/lookup.c
@@ -388,3 +388,28 @@ void test_submodule_lookup__renamed(void)
 	cl_git_pass(git_submodule_foreach(g_repo, sm_lookup_cb, &data));
 	cl_assert_equal_i(8, data.count);
 }
+
+void test_submodule_lookup_cached(void) {
+	git_submodule *sm;
+	git_submodule *sm2;
+	/* See that the simple tests still pass. */
+
+	git_repository_submodule_cache_all(g_repo);
+	test_submodule_lookup__simple_lookup();
+	git_repository_submodule_cache_clear(g_repo);
+	test_submodule_lookup__simple_lookup();
+
+	/* Check that subsequent calls return different objects when cached. */
+	git_repository_submodule_cache_all(g_repo);
+	cl_git_pass(git_submodule_lookup(&sm, g_repo, "sm_unchanged"));
+	cl_git_pass(git_submodule_lookup(&sm2, g_repo, "sm_unchanged"));
+	cl_assert_equal_p(sm, sm2);
+	git_submodule_free(sm2);
+
+	/* and that we get new objects again after clearing the cache. */
+	git_repository_submodule_cache_clear(g_repo);
+	cl_git_pass(git_submodule_lookup(&sm2, g_repo, "sm_unchanged"));
+	cl_assert(sm != sm2);
+	git_submodule_free(sm);
+	git_submodule_free(sm2);
+}
diff --git a/tests/threads/basic.c b/tests/threads/basic.c
index 9c342bc42..a9310bbd4 100644
--- a/tests/threads/basic.c
+++ b/tests/threads/basic.c
@@ -48,3 +48,36 @@ void test_threads_basic__set_error(void)
 {
 	run_in_parallel(1, 4, set_error, NULL, NULL);
 }
+
+#ifdef GIT_THREADS
+static void *return_normally(void *param)
+{
+	return param;
+}
+
+static void *exit_abruptly(void *param)
+{
+	git_thread_exit(param);
+	return NULL;
+}
+#endif
+
+void test_threads_basic__exit(void)
+{
+#ifndef GIT_THREADS
+	clar__skip();
+#else
+	git_thread thread;
+	void *result;
+
+	/* Ensure that the return value of the threadproc is returned. */
+	cl_git_pass(git_thread_create(&thread, return_normally, (void *)424242));
+	cl_git_pass(git_thread_join(&thread, &result));
+	cl_assert_equal_sz(424242, (size_t)result);
+
+	/* Ensure that the return value of `git_thread_exit` is returned. */
+	cl_git_pass(git_thread_create(&thread, return_normally, (void *)232323));
+	cl_git_pass(git_thread_join(&thread, &result));
+	cl_assert_equal_sz(232323, (size_t)result);
+#endif
+}
diff --git a/tests/threads/refdb.c b/tests/threads/refdb.c
index f869bcb44..94c5f5057 100644
--- a/tests/threads/refdb.c
+++ b/tests/threads/refdb.c
@@ -5,6 +5,12 @@
 static git_repository *g_repo;
 static int g_expected = 0;
 
+#ifdef GIT_WIN32
+static bool concurrent_compress = false;
+#else
+static bool concurrent_compress = true;
+#endif
+
 void test_threads_refdb__initialize(void)
 {
 	g_repo = NULL;
@@ -18,14 +24,28 @@ void test_threads_refdb__cleanup(void)
 
 #define REPEAT 20
 #define THREADS 20
+/* Number of references to create or delete in each thread */
+#define NREFS 10
+
+struct th_data {
+	cl_git_thread_err error;
+	int id;
+	const char *path;
+};
 
 static void *iterate_refs(void *arg)
 {
+	struct th_data *data = (struct th_data *) arg;
 	git_reference_iterator *i;
 	git_reference *ref;
-	int count = 0;
+	int count = 0, error;
+	git_repository *repo;
 
-	cl_git_pass(git_reference_iterator_new(&i, g_repo));
+	cl_git_thread_pass(data, git_repository_open(&repo, data->path));
+	do {
+		error = git_reference_iterator_new(&i, repo);
+	} while (error == GIT_ELOCKED);
+	cl_git_thread_pass(data, error);
 
 	for (count = 0; !git_reference_next(&ref, i); ++count) {
 		cl_assert(ref != NULL);
@@ -37,112 +57,92 @@ static void *iterate_refs(void *arg)
 
 	git_reference_iterator_free(i);
 
+	git_repository_free(repo);
 	giterr_clear();
 	return arg;
 }
 
-void test_threads_refdb__iterator(void)
-{
-	int r, t;
-	git_thread th[THREADS];
-	int id[THREADS];
-	git_oid head;
-	git_reference *ref;
-	char name[128];
-	git_refdb *refdb;
-
-	g_repo = cl_git_sandbox_init("testrepo2");
-
-	cl_git_pass(git_reference_name_to_id(&head, g_repo, "HEAD"));
-
-	/* make a bunch of references */
-
-	for (r = 0; r < 200; ++r) {
-		p_snprintf(name, sizeof(name), "refs/heads/direct-%03d", r);
-		cl_git_pass(git_reference_create(&ref, g_repo, name, &head, 0, NULL));
-		git_reference_free(ref);
-	}
-
-	cl_git_pass(git_repository_refdb(&refdb, g_repo));
-	cl_git_pass(git_refdb_compress(refdb));
-	git_refdb_free(refdb);
-
-	g_expected = 206;
-
-	for (r = 0; r < REPEAT; ++r) {
-		g_repo = cl_git_sandbox_reopen(); /* reopen to flush caches */
-
-		for (t = 0; t < THREADS; ++t) {
-			id[t] = t;
-#ifdef GIT_THREADS
-			cl_git_pass(git_thread_create(&th[t], iterate_refs, &id[t]));
-#else
-			th[t] = t;
-			iterate_refs(&id[t]);
-#endif
-		}
-
-#ifdef GIT_THREADS
-		for (t = 0; t < THREADS; ++t) {
-			cl_git_pass(git_thread_join(&th[t], NULL));
-		}
-#endif
-
-		memset(th, 0, sizeof(th));
-	}
-}
-
 static void *create_refs(void *arg)
 {
-	int *id = arg, i;
+	int i, error;
+	struct th_data *data = (struct th_data *) arg;
 	git_oid head;
 	char name[128];
-	git_reference *ref[10];
+	git_reference *ref[NREFS];
+	git_repository *repo;
 
-	cl_git_pass(git_reference_name_to_id(&head, g_repo, "HEAD"));
+	cl_git_thread_pass(data, git_repository_open(&repo, data->path));
 
-	for (i = 0; i < 10; ++i) {
-		p_snprintf(name, sizeof(name), "refs/heads/thread-%03d-%02d", *id, i);
-		cl_git_pass(git_reference_create(&ref[i], g_repo, name, &head, 0, NULL));
+	do {
+		error = git_reference_name_to_id(&head, repo, "HEAD");
+	} while (error == GIT_ELOCKED);
+	cl_git_thread_pass(data, error);
 
-		if (i == 5) {
+	for (i = 0; i < NREFS; ++i) {
+		p_snprintf(name, sizeof(name), "refs/heads/thread-%03d-%02d", data->id, i);
+		do {
+			error = git_reference_create(&ref[i], repo, name, &head, 0, NULL);
+		} while (error == GIT_ELOCKED);
+		cl_git_thread_pass(data, error);
+
+		if (concurrent_compress && i == NREFS/2) {
 			git_refdb *refdb;
-			cl_git_pass(git_repository_refdb(&refdb, g_repo));
-			cl_git_pass(git_refdb_compress(refdb));
+			cl_git_thread_pass(data, git_repository_refdb(&refdb, repo));
+			do {
+				error = git_refdb_compress(refdb);
+			} while (error == GIT_ELOCKED);
+			cl_git_thread_pass(data, error);
 			git_refdb_free(refdb);
 		}
 	}
 
-	for (i = 0; i < 10; ++i)
+	for (i = 0; i < NREFS; ++i)
 		git_reference_free(ref[i]);
 
+	git_repository_free(repo);
+
 	giterr_clear();
 	return arg;
 }
 
 static void *delete_refs(void *arg)
 {
-	int *id = arg, i;
+	int i, error;
+	struct th_data *data = (struct th_data *) arg;
 	git_reference *ref;
 	char name[128];
+	git_repository *repo;
 
-	for (i = 0; i < 10; ++i) {
+	cl_git_thread_pass(data, git_repository_open(&repo, data->path));
+
+	for (i = 0; i < NREFS; ++i) {
 		p_snprintf(
-			name, sizeof(name), "refs/heads/thread-%03d-%02d", (*id) & ~0x3, i);
+			name, sizeof(name), "refs/heads/thread-%03d-%02d", (data->id) & ~0x3, i);
+
+		if (!git_reference_lookup(&ref, repo, name)) {
+			do {
+				error = git_reference_delete(ref);
+			} while (error == GIT_ELOCKED);
+			/* Sometimes we race with other deleter threads */
+			if (error == GIT_ENOTFOUND)
+				error = 0;
 
-		if (!git_reference_lookup(&ref, g_repo, name)) {
-			cl_git_pass(git_reference_delete(ref));
+			cl_git_thread_pass(data, error);
 			git_reference_free(ref);
 		}
 
-		if (i == 5) {
+		if (concurrent_compress && i == NREFS/2) {
 			git_refdb *refdb;
-			cl_git_pass(git_repository_refdb(&refdb, g_repo));
-			cl_git_pass(git_refdb_compress(refdb));
+			cl_git_thread_pass(data, git_repository_refdb(&refdb, repo));
+			do {
+				error = git_refdb_compress(refdb);
+			} while (error == GIT_ELOCKED);
+			cl_git_thread_pass(data, error);
 			git_refdb_free(refdb);
 		}
 	}
 
+	git_repository_free(repo);
 	giterr_clear();
 	return arg;
 }
@@ -150,7 +150,7 @@ static void *delete_refs(void *arg)
 void test_threads_refdb__edit_while_iterate(void)
 {
 	int r, t;
-	int id[THREADS];
+	struct th_data th_data[THREADS];
 	git_oid head;
 	git_reference *ref;
 	char name[128];
@@ -189,33 +189,32 @@ void test_threads_refdb__edit_while_iterate(void)
 		default: fn = iterate_refs; break;
 		}
 
-		id[t] = t;
-
-		/* It appears with all reflog writing changes, etc., that this
-		 * test has started to fail quite frequently, so let's disable it
-		 * for now by just running on a single thread...
-		 */
-/* #ifdef GIT_THREADS */
-/*		cl_git_pass(git_thread_create(&th[t], fn, &id[t])); */
-/* #else */
-		fn(&id[t]);
-/* #endif */
+		th_data[t].id = t;
+		th_data[t].path = git_repository_path(g_repo);
+
+#ifdef GIT_THREADS
+		cl_git_pass(git_thread_create(&th[t], fn, &th_data[t]));
+#else
+		fn(&th_data[t]);
+#endif
 	}
 
 #ifdef GIT_THREADS
-/*	for (t = 0; t < THREADS; ++t) { */
-/*		cl_git_pass(git_thread_join(th[t], NULL)); */
-/*	} */
+	for (t = 0; t < THREADS; ++t) {
+		cl_git_pass(git_thread_join(&th[t], NULL));
+		cl_git_thread_check(&th_data[t]);
+	}
 
 	memset(th, 0, sizeof(th));
 
 	for (t = 0; t < THREADS; ++t) {
-		id[t] = t;
-		cl_git_pass(git_thread_create(&th[t], iterate_refs, &id[t]));
+		th_data[t].id = t;
+		cl_git_pass(git_thread_create(&th[t], iterate_refs, &th_data[t]));
 	}
 
 	for (t = 0; t < THREADS; ++t) {
 		cl_git_pass(git_thread_join(&th[t], NULL));
+		cl_git_thread_check(&th_data[t]);
 	}
 #endif
 }