Merge branch 'main' into pr/pks-t/5254

45 files changed, 1771 insertions, 461 deletions

diff --git a/include/git2/annotated_commit.h b/include/git2/annotated_commit.h
index fa795bfc4..3b7103f20 100644
--- a/include/git2/annotated_commit.h
+++ b/include/git2/annotated_commit.h
@@ -78,7 +78,7 @@ GIT_EXTERN(int) git_annotated_commit_lookup(
 	const git_oid *id);
 
 /**
- * Creates a `git_annotated_comit` from a revision string.
+ * Creates a `git_annotated_commit` from a revision string.
  *
  * See `man gitrevisions`, or
  * http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
diff --git a/include/git2/apply.h b/include/git2/apply.h
index b248eaafe..bc637df1c 100644
--- a/include/git2/apply.h
+++ b/include/git2/apply.h
@@ -100,6 +100,7 @@ GIT_EXTERN(int) git_apply_options_init(git_apply_options *opts, unsigned int ver
  * @param preimage the tree to apply the diff to
  * @param diff the diff to apply
  * @param options the options for the apply (or null for defaults)
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_apply_to_tree(
 	git_index **out,
@@ -137,6 +138,7 @@ typedef enum {
  * @param diff the diff to apply
  * @param location the location to apply (workdir, index or both)
  * @param options the options for the apply (or null for defaults)
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_apply(
 	git_repository *repo,
diff --git a/include/git2/attr.h b/include/git2/attr.h
index a3ab5a7a2..3891a0c97 100644
--- a/include/git2/attr.h
+++ b/include/git2/attr.h
@@ -130,9 +130,38 @@ GIT_EXTERN(git_attr_value_t) git_attr_value(const char *attr);
  *
  * Passing the `GIT_ATTR_CHECK_INCLUDE_HEAD` flag will use attributes
  * from a `.gitattributes` file in the repository at the HEAD revision.
+ *
+ * Passing the `GIT_ATTR_CHECK_INCLUDE_COMMIT` flag will use attributes
+ * from a `.gitattributes` file in a specific commit.
  */
 #define GIT_ATTR_CHECK_NO_SYSTEM        (1 << 2)
 #define GIT_ATTR_CHECK_INCLUDE_HEAD     (1 << 3)
+#define GIT_ATTR_CHECK_INCLUDE_COMMIT   (1 << 4)
+
+/**
+* An options structure for querying attributes.
+*/
+typedef struct {
+	unsigned int version;
+
+	/** A combination of GIT_ATTR_CHECK flags */
+	unsigned int flags;
+
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
+	git_oid *commit_id;
+#endif
+
+	/**
+	 * The commit to load attributes from, when
+	 * `GIT_ATTR_CHECK_INCLUDE_COMMIT` is specified.
+	 */
+	git_oid attr_commit_id;
+} git_attr_options;
+
+#define GIT_ATTR_OPTIONS_VERSION 1
+#define GIT_ATTR_OPTIONS_INIT {GIT_ATTR_OPTIONS_VERSION}
 
 /**
  * Look up the value of one git attribute for path.
@@ -157,6 +186,28 @@ GIT_EXTERN(int) git_attr_get(
 	const char *name);
 
 /**
+ * Look up the value of one git attribute for path with extended options.
+ *
+ * @param value_out Output of the value of the attribute.  Use the GIT_ATTR_...
+ *             macros to test for TRUE, FALSE, UNSPECIFIED, etc. or just
+ *             use the string value for attributes set to a value.  You
+ *             should NOT modify or free this value.
+ * @param repo The repository containing the path.
+ * @param opts The `git_attr_options` to use when querying these attributes.
+ * @param path The path to check for attributes.  Relative paths are
+ *             interpreted relative to the repo root.  The file does
+ *             not have to exist, but if it does not, then it will be
+ *             treated as a plain file (not a directory).
+ * @param name The name of the attribute to look up.
+ */
+GIT_EXTERN(int) git_attr_get_ext(
+	const char **value_out,
+	git_repository *repo,
+	git_attr_options *opts,
+	const char *path,
+	const char *name);
+
+/**
  * Look up a list of git attributes for path.
  *
  * Use this if you have a known list of attributes that you want to
@@ -194,6 +245,30 @@ GIT_EXTERN(int) git_attr_get_many(
 	const char **names);
 
 /**
+ * Look up a list of git attributes for path with extended options.
+ *
+ * @param values_out An array of num_attr entries that will have string
+ *             pointers written into it for the values of the attributes.
+ *             You should not modify or free the values that are written
+ *             into this array (although of course, you should free the
+ *             array itself if you allocated it).
+ * @param repo The repository containing the path.
+ * @param opts The `git_attr_options` to use when querying these attributes.
+ * @param path The path inside the repo to check attributes.  This
+ *             does not have to exist, but if it does not, then
+ *             it will be treated as a plain file (i.e. not a directory).
+ * @param num_attr The number of attributes being looked up
+ * @param names An array of num_attr strings containing attribute names.
+ */
+GIT_EXTERN(int) git_attr_get_many_ext(
+	const char **values_out,
+	git_repository *repo,
+	git_attr_options *opts,
+	const char *path,
+	size_t num_attr,
+	const char **names);
+
+/**
  * The callback used with git_attr_foreach.
  *
  * This callback will be invoked only once per attribute name, even if there
@@ -232,6 +307,26 @@ GIT_EXTERN(int) git_attr_foreach(
 	void *payload);
 
 /**
+ * Loop over all the git attributes for a path with extended options.
+ *
+ * @param repo The repository containing the path.
+ * @param opts The `git_attr_options` to use when querying these attributes.
+ * @param path Path inside the repo to check attributes.  This does not have
+ *             to exist, but if it does not, then it will be treated as a
+ *             plain file (i.e. not a directory).
+ * @param callback Function to invoke on each attribute name and value.
+ *                 See git_attr_foreach_cb.
+ * @param payload Passed on as extra parameter to callback function.
+ * @return 0 on success, non-zero callback return value, or error code
+ */
+GIT_EXTERN(int) git_attr_foreach_ext(
+	git_repository *repo,
+	git_attr_options *opts,
+	const char *path,
+	git_attr_foreach_cb callback,
+	void *payload);
+
+/**
  * Flush the gitattributes cache.
  *
  * Call this if you have reason to believe that the attributes files on
diff --git a/include/git2/blame.h b/include/git2/blame.h
index f42c81552..d193ce14e 100644
--- a/include/git2/blame.h
+++ b/include/git2/blame.h
@@ -26,27 +26,52 @@ GIT_BEGIN_DECL
 typedef enum {
 	/** Normal blame, the default */
 	GIT_BLAME_NORMAL = 0,
-	/** Track lines that have moved within a file (like `git blame -M`).
-	 * NOT IMPLEMENTED. */
+
+	/**
+	 * Track lines that have moved within a file (like `git blame -M`).
+	 *
+	 * This is not yet implemented and reserved for future use.
+	 */
 	GIT_BLAME_TRACK_COPIES_SAME_FILE = (1<<0),
-	/** Track lines that have moved across files in the same commit (like `git blame -C`).
-	 * NOT IMPLEMENTED. */
+
+	/**
+	 * Track lines that have moved across files in the same commit
+	 * (like `git blame -C`).
+	 *
+	 * This is not yet implemented and reserved for future use.
+	 */
 	GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES = (1<<1),
-	/** Track lines that have been copied from another file that exists in the
-	 * same commit (like `git blame -CC`). Implies SAME_FILE.
-	 * NOT IMPLEMENTED. */
+
+	/**
+	 * Track lines that have been copied from another file that exists
+	 * in the same commit (like `git blame -CC`).  Implies SAME_FILE.
+	 *
+	 * This is not yet implemented and reserved for future use.
+	 */
 	GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES = (1<<2),
-	/** Track lines that have been copied from another file that exists in *any*
-	 * commit (like `git blame -CCC`). Implies SAME_COMMIT_COPIES.
-	 * NOT IMPLEMENTED. */
+
+	/**
+	 * Track lines that have been copied from another file that exists in
+	 * *any* commit (like `git blame -CCC`).  Implies SAME_COMMIT_COPIES.
+	 *
+	 * This is not yet implemented and reserved for future use.
+	 */
 	GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES = (1<<3),
-	/** Restrict the search of commits to those reachable following only the
-	 * first parents. */
+
+	/**
+	 * Restrict the search of commits to those reachable following only
+	 * the first parents.
+	 */
 	GIT_BLAME_FIRST_PARENT = (1<<4),
-	/** Use mailmap file to map author and committer names and email addresses
-	 * to canonical real names and email addresses. The mailmap will be read
-	 * from the working directory, or HEAD in a bare repository. */
+
+	/**
+	 * Use mailmap file to map author and committer names and email
+	 * addresses to canonical real names and email addresses. The
+	 * mailmap will be read from the working directory, or HEAD in a
+	 * bare repository.
+	 */
 	GIT_BLAME_USE_MAILMAP = (1<<5),
+
 	/** Ignore whitespace differences */
 	GIT_BLAME_IGNORE_WHITESPACE = (1<<6),
 } git_blame_flag_t;
@@ -63,25 +88,33 @@ typedef struct git_blame_options {
 
 	/** A combination of `git_blame_flag_t` */
 	uint32_t flags;
-	/** The lower bound on the number of alphanumeric
-	 *   characters that must be detected as moving/copying within a file for it to
-	 *   associate those lines with the parent commit. The default value is 20.
-	 *   This value only takes effect if any of the `GIT_BLAME_TRACK_COPIES_*`
-	 *   flags are specified.
+
+	/**
+	 * The lower bound on the number of alphanumeric characters that
+	 * must be detected as moving/copying within a file for it to
+	 * associate those lines with the parent commit. The default value
+	 * is 20.
+	 *
+	 * This value only takes effect if any of the `GIT_BLAME_TRACK_COPIES_*`
+	 * flags are specified.
 	 */
 	uint16_t min_match_characters;
+
 	/** The id of the newest commit to consider. The default is HEAD. */
 	git_oid newest_commit;
+
 	/**
 	 * The id of the oldest commit to consider.
 	 * The default is the first commit encountered with a NULL parent.
 	 */
 	git_oid oldest_commit;
+
 	/**
 	 * The first line in the file to blame.
 	 * The default is 1 (line numbers start with 1).
 	 */
 	size_t min_line;
+
 	/**
 	 * The last line in the file to blame.
 	 * The default is the last line of the file.
@@ -108,41 +141,59 @@ GIT_EXTERN(int) git_blame_options_init(
 
 /**
  * Structure that represents a blame hunk.
- *
- * - `lines_in_hunk` is the number of lines in this hunk
- * - `final_commit_id` is the OID of the commit where this line was last
- *   changed.
- * - `final_start_line_number` is the 1-based line number where this hunk
- *   begins, in the final version of the file
- * - `final_signature` is the author of `final_commit_id`. If
- *   `GIT_BLAME_USE_MAILMAP` has been specified, it will contain the canonical
- *    real name and email address.
- * - `orig_commit_id` is the OID of the commit where this hunk was found.  This
- *   will usually be the same as `final_commit_id`, except when
- *   `GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES` has been specified.
- * - `orig_path` is the path to the file where this hunk originated, as of the
- *   commit specified by `orig_commit_id`.
- * - `orig_start_line_number` is the 1-based line number where this hunk begins
- *   in the file named by `orig_path` in the commit specified by
- *   `orig_commit_id`.
- * - `orig_signature` is the author of `orig_commit_id`. If
- *   `GIT_BLAME_USE_MAILMAP` has been specified, it will contain the canonical
- *    real name and email address.
- * - `boundary` is 1 iff the hunk has been tracked to a boundary commit (the
- *   root, or the commit specified in git_blame_options.oldest_commit)
  */
 typedef struct git_blame_hunk {
+	/**
+	 * The number of lines in this hunk.
+	 */
 	size_t lines_in_hunk;
 
+	/**
+	 * The OID of the commit where this line was last changed.
+	 */
 	git_oid final_commit_id;
+
+	/**
+	 * The 1-based line number where this hunk begins, in the final version
+	 * of the file.
+	 */
 	size_t final_start_line_number;
+
+	/**
+	 * The author of `final_commit_id`. If `GIT_BLAME_USE_MAILMAP` has been
+	 * specified, it will contain the canonical real name and email address.
+	 */
 	git_signature *final_signature;
 
+	/**
+	 * The OID of the commit where this hunk was found.
+	 * This will usually be the same as `final_commit_id`, except when
+	 * `GIT_BLAME_TRACK_COPIES_ANY_COMMIT_COPIES` has been specified.
+	 */
 	git_oid orig_commit_id;
+
+	/**
+	 * The path to the file where this hunk originated, as of the commit
+	 * specified by `orig_commit_id`.
+	 */
 	const char *orig_path;
+
+	/**
+	 * The 1-based line number where this hunk begins in the file named by
+	 * `orig_path` in the commit specified by `orig_commit_id`.
+	 */
 	size_t orig_start_line_number;
+
+	/**
+	 * The author of `orig_commit_id`. If `GIT_BLAME_USE_MAILMAP` has been
+	 * specified, it will contain the canonical real name and email address.
+	 */
 	git_signature *orig_signature;
 
+	/**
+	 * The 1 iff the hunk has been tracked to a boundary commit (the root,
+	 * or the commit specified in git_blame_options.oldest_commit)
+	 */
 	char boundary;
 } git_blame_hunk;
 
diff --git a/include/git2/blob.h b/include/git2/blob.h
index 7e2a745d1..8fc73919d 100644
--- a/include/git2/blob.h
+++ b/include/git2/blob.h
@@ -84,7 +84,7 @@ GIT_EXTERN(git_repository *) git_blob_owner(const git_blob *blob);
  * time.
  *
  * @param blob pointer to the blob
- * @return the pointer
+ * @return the pointer, or NULL on error
  */
 GIT_EXTERN(const void *) git_blob_rawcontent(const git_blob *blob);
 
@@ -113,23 +113,57 @@ typedef enum {
 	 * When set, filters will be loaded from a `.gitattributes` file
 	 * in the HEAD commit.
 	 */
-	GIT_BLOB_FILTER_ATTTRIBUTES_FROM_HEAD = (1 << 2),
+	GIT_BLOB_FILTER_ATTRIBUTES_FROM_HEAD = (1 << 2),
+
+	/**
+	 * When set, filters will be loaded from a `.gitattributes` file
+	 * in the specified commit.
+	 */
+	GIT_BLOB_FILTER_ATTRIBUTES_FROM_COMMIT = (1 << 3),
 } git_blob_filter_flag_t;
 
 /**
  * The options used when applying filter options to a file.
+ *
+ * Initialize with `GIT_BLOB_FILTER_OPTIONS_INIT`. Alternatively, you can
+ * use `git_blob_filter_options_init`.
+ *
  */
 typedef struct {
 	int version;
 
 	/** Flags to control the filtering process, see `git_blob_filter_flag_t` above */
 	uint32_t flags;
+
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
+	git_oid *commit_id;
+#endif
+
+	/**
+	 * The commit to load attributes from, when
+	 * `GIT_BLOB_FILTER_ATTRIBUTES_FROM_COMMIT` is specified.
+	 */
+	git_oid attr_commit_id;
 } git_blob_filter_options;
 
 #define GIT_BLOB_FILTER_OPTIONS_VERSION 1
 #define GIT_BLOB_FILTER_OPTIONS_INIT {GIT_BLOB_FILTER_OPTIONS_VERSION, GIT_BLOB_FILTER_CHECK_FOR_BINARY}
 
 /**
+ * Initialize git_blob_filter_options structure
+ *
+ * Initializes a `git_blob_filter_options` with default values. Equivalent
+ * to creating an instance with `GIT_BLOB_FILTER_OPTIONS_INIT`.
+ *
+ * @param opts The `git_blob_filter_options` struct to initialize.
+ * @param version The struct version; pass `GIT_BLOB_FILTER_OPTIONS_VERSION`.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_blob_filter_options_init(git_blob_filter_options *opts, unsigned int version);
+
+/**
  * Get a buffer with the filtered content of a blob.
  *
  * This applies filters as if the blob was being checked out to the
@@ -229,7 +263,7 @@ GIT_EXTERN(int) git_blob_create_from_stream_commit(
  * Write an in-memory buffer to the ODB as a blob
  *
  * @param id return the id of the written blob
- * @param repo repository where to blob will be written
+ * @param repo repository where the blob will be written
  * @param buffer data to be written into the blob
  * @param len length of the data
  * @return 0 or an error code
diff --git a/include/git2/branch.h b/include/git2/branch.h
index ba6235900..24ea7f7d0 100644
--- a/include/git2/branch.h
+++ b/include/git2/branch.h
@@ -304,6 +304,31 @@ GIT_EXTERN(int) git_branch_remote_name(
  */
  GIT_EXTERN(int) git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname);
 
+/**
+ * Retrieve the upstream merge of a local branch
+ *
+ * This will return the currently configured "branch.*.merge" for a given
+ * branch. This branch must be local.
+ *
+ * @param buf the buffer into which to write the name
+ * @param repo the repository in which to look
+ * @param refname the full name of the branch
+ * @return 0 or an error code
+ */
+ GIT_EXTERN(int) git_branch_upstream_merge(git_buf *buf, git_repository *repo, const char *refname);
+
+/**
+ * Determine whether a branch name is valid, meaning that (when prefixed
+ * with `refs/heads/`) that it is a valid reference name, and that any
+ * additional branch name restrictions are imposed (eg, it cannot start
+ * with a `-`).
+ *
+ * @param valid output pointer to set with validity of given branch name
+ * @param name a branch name to test
+ * @return 0 on success or an error code
+ */
+GIT_EXTERN(int) git_branch_name_is_valid(int *valid, const char *name);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/cert.h b/include/git2/cert.h
index e8cd2d180..0ed38ffcd 100644
--- a/include/git2/cert.h
+++ b/include/git2/cert.h
@@ -8,6 +8,7 @@
 #define INCLUDE_git_cert_h__
 
 #include "common.h"
+#include "types.h"
 
 /**
  * @file git2/cert.h
@@ -80,8 +81,27 @@ typedef enum {
 	GIT_CERT_SSH_SHA1 = (1 << 1),
 	/** SHA-256 is available */
 	GIT_CERT_SSH_SHA256 = (1 << 2),
+	/** Raw hostkey is available */
+	GIT_CERT_SSH_RAW = (1 << 3),
 } git_cert_ssh_t;
 
+typedef enum {
+	/** The raw key is of an unknown type. */
+	GIT_CERT_SSH_RAW_TYPE_UNKNOWN = 0,
+	/** The raw key is an RSA key. */
+	GIT_CERT_SSH_RAW_TYPE_RSA = 1,
+	/** The raw key is a DSS key. */
+	GIT_CERT_SSH_RAW_TYPE_DSS = 2,
+	/** The raw key is a ECDSA 256 key. */
+	GIT_CERT_SSH_RAW_TYPE_KEY_ECDSA_256 = 3,
+	/** The raw key is a ECDSA 384 key. */
+	GIT_CERT_SSH_RAW_TYPE_KEY_ECDSA_384 = 4,
+	/** The raw key is a ECDSA 521 key. */
+	GIT_CERT_SSH_RAW_TYPE_KEY_ECDSA_521 = 5,
+	/** The raw key is a ED25519 key. */
+	GIT_CERT_SSH_RAW_TYPE_KEY_ED25519 = 6
+} git_cert_ssh_raw_type_t;
+
 /**
  * Hostkey information taken from libssh2
  */
@@ -89,28 +109,45 @@ typedef struct {
 	git_cert parent; /**< The parent cert */
 
 	/**
-	 * A hostkey type from libssh2, either
-	 * `GIT_CERT_SSH_MD5` or `GIT_CERT_SSH_SHA1`
+	 * A bitmask containing the available fields.
 	 */
 	git_cert_ssh_t type;
 
 	/**
-	 * Hostkey hash. If type has `GIT_CERT_SSH_MD5` set, this will
+	 * Hostkey hash. If `type` has `GIT_CERT_SSH_MD5` set, this will
 	 * have the MD5 hash of the hostkey.
 	 */
 	unsigned char hash_md5[16];
 
 	/**
-	 * Hostkey hash. If type has `GIT_CERT_SSH_SHA1` set, this will
+	 * Hostkey hash. If `type` has `GIT_CERT_SSH_SHA1` set, this will
 	 * have the SHA-1 hash of the hostkey.
 	 */
 	unsigned char hash_sha1[20];
 
 	/**
-	 * Hostkey hash. If type has `GIT_CERT_SSH_SHA256` set, this will
+	 * Hostkey hash. If `type` has `GIT_CERT_SSH_SHA256` set, this will
 	 * have the SHA-256 hash of the hostkey.
 	 */
 	unsigned char hash_sha256[32];
+
+	/**
+	 * Raw hostkey type. If `type` has `GIT_CERT_SSH_RAW` set, this will
+	 * have the type of the raw hostkey.
+	 */
+	git_cert_ssh_raw_type_t raw_type;
+
+	/**
+	 * Pointer to the raw hostkey. If `type` has `GIT_CERT_SSH_RAW` set,
+	 * this will have the raw contents of the hostkey.
+	 */
+	const char *hostkey;
+
+	/**
+	 * Raw hostkey length. If `type` has `GIT_CERT_SSH_RAW` set, this will
+	 * have the length of the raw contents of the hostkey.
+	 */
+	size_t hostkey_len;
 } git_cert_hostkey;
 
 /**
diff --git a/include/git2/checkout.h b/include/git2/checkout.h
index 3c87001bf..c7aeee431 100644
--- a/include/git2/checkout.h
+++ b/include/git2/checkout.h
@@ -178,6 +178,12 @@ typedef enum {
 	GIT_CHECKOUT_DONT_WRITE_INDEX = (1u << 23),
 
 	/**
+	 * Show what would be done by a checkout.  Stop after sending
+	 * notifications; don't update the working directory or index.
+	 */
+	GIT_CHECKOUT_DRY_RUN = (1u << 24),
+	
+	/**
 	 * THE FOLLOWING OPTIONS ARE NOT YET IMPLEMENTED
 	 */
 
@@ -194,18 +200,6 @@ typedef enum {
  * Checkout will invoke an options notification callback (`notify_cb`) for
  * certain cases - you pick which ones via `notify_flags`:
  *
- * - GIT_CHECKOUT_NOTIFY_CONFLICT invokes checkout on conflicting paths.
- *
- * - GIT_CHECKOUT_NOTIFY_DIRTY notifies about "dirty" files, i.e. those that
- *   do not need an update but no longer match the baseline.  Core git
- *   displays these files when checkout runs, but won't stop the checkout.
- *
- * - GIT_CHECKOUT_NOTIFY_UPDATED sends notification for any file changed.
- *
- * - GIT_CHECKOUT_NOTIFY_UNTRACKED notifies about untracked files.
- *
- * - GIT_CHECKOUT_NOTIFY_IGNORED notifies about ignored files.
- *
  * Returning a non-zero value from this callback will cancel the checkout.
  * The non-zero return value will be propagated back and returned by the
  * git_checkout_... call.
@@ -216,10 +210,32 @@ typedef enum {
  */
 typedef enum {
 	GIT_CHECKOUT_NOTIFY_NONE      = 0,
+
+	/**
+	 * Invokes checkout on conflicting paths.
+	 */
 	GIT_CHECKOUT_NOTIFY_CONFLICT  = (1u << 0),
+
+	/**
+	 * Notifies about "dirty" files, i.e. those that do not need an update
+	 * but no longer match the baseline.  Core git displays these files when
+	 * checkout runs, but won't stop the checkout.
+	 */
 	GIT_CHECKOUT_NOTIFY_DIRTY     = (1u << 1),
+
+	/**
+	 * Sends notification for any file changed.
+	 */
 	GIT_CHECKOUT_NOTIFY_UPDATED   = (1u << 2),
+
+	/**
+	 * Notifies about untracked files.
+	 */
 	GIT_CHECKOUT_NOTIFY_UNTRACKED = (1u << 3),
+
+	/**
+	 * Notifies about ignored files.
+	 */
 	GIT_CHECKOUT_NOTIFY_IGNORED   = (1u << 4),
 
 	GIT_CHECKOUT_NOTIFY_ALL       = 0x0FFFFu
diff --git a/include/git2/clone.h b/include/git2/clone.h
index 2d6f68705..3c3ea260e 100644
--- a/include/git2/clone.h
+++ b/include/git2/clone.h
@@ -133,7 +133,7 @@ typedef struct git_clone_options {
 	 * The name of the branch to checkout. NULL means use the
 	 * remote's default branch.
 	 */
-	const char* checkout_branch;
+	const char *checkout_branch;
 
 	/**
 	 * A callback used to create the new repository into which to
diff --git a/include/git2/commit.h b/include/git2/commit.h
index e6c4656a9..4d74b8994 100644
--- a/include/git2/commit.h
+++ b/include/git2/commit.h
@@ -503,25 +503,41 @@ GIT_EXTERN(int) git_commit_create_with_signature(
 GIT_EXTERN(int) git_commit_dup(git_commit **out, git_commit *source);
 
 /**
- * Commit signing callback.
- *
- * The callback will be called with the commit content, giving a user an
- * opportunity to sign the commit content. The signature_field
- * buf may be left empty to specify the default field "gpgsig".
- *
- * Signatures can take the form of any string, and can be created on an arbitrary
- * header field. Signatures are most commonly used for verifying authorship of a
- * commit using GPG or a similar cryptographically secure signing algorithm.
- * See https://git-scm.com/book/en/v2/Git-Tools-Signing-Your-Work for more
- * details.
- *
- * When the callback:
- * - returns GIT_PASSTHROUGH, no signature will be added to the commit.
- * - returns < 0, commit creation will be aborted.
- * - returns GIT_OK, the signature parameter is expected to be filled.
- */
-typedef int (*git_commit_signing_cb)(
-	git_buf *signature, git_buf *signature_field, const char *commit_content, void *payload);
+ * Commit creation callback: used when a function is going to create
+ * commits (for example, in `git_rebase_commit`) to allow callers to
+ * override the commit creation behavior.  For example, users may
+ * wish to sign commits by providing this information to
+ * `git_commit_create_buffer`, signing that buffer, then calling
+ * `git_commit_create_with_signature`.  The resultant commit id
+ * should be set in the `out` object id parameter.
+ *
+ * @param out pointer that this callback will populate with the object
+ *            id of the commit that is created
+ * @param author the author name and time of the commit
+ * @param committer the committer name and time of the commit
+ * @param message_encoding the encoding of the given message, or NULL
+ *                         to assume UTF8
+ * @param message the commit message
+ * @param tree the tree to be committed
+ * @param parent_count the number of parents for this commit
+ * @param parents the commit parents
+ * @param payload the payload pointer in the rebase options
+ * @return 0 if this callback has created the commit and populated the out
+ *         parameter, GIT_PASSTHROUGH if the callback has not created a
+ *         commit and wants the calling function to create the commit as
+ *         if no callback had been specified, any other value to stop
+ *         and return a failure
+ */
+typedef int (*git_commit_create_cb)(
+	git_oid *out,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_tree *tree,
+	size_t parent_count,
+	const git_commit *parents[],
+	void *payload);
 
 /** @} */
 GIT_END_DECL
diff --git a/include/git2/common.h b/include/git2/common.h
index d6696061d..2ee829025 100644
--- a/include/git2/common.h
+++ b/include/git2/common.h
@@ -91,10 +91,10 @@ GIT_BEGIN_DECL
 
 /**
  * The separator used in path list strings (ie like in the PATH
- * environment variable). A semi-colon ";" is used on Windows, and
- * a colon ":" for all other systems.
+ * environment variable). A semi-colon ";" is used on Windows and
+ * AmigaOS, and a colon ":" for all other systems.
  */
-#ifdef GIT_WIN32
+#if defined(GIT_WIN32) || defined(AMIGA)
 #define GIT_PATH_LIST_SEPARATOR ';'
 #else
 #define GIT_PATH_LIST_SEPARATOR ':'
@@ -205,7 +205,13 @@ typedef enum {
 	GIT_OPT_GET_PACK_MAX_OBJECTS,
 	GIT_OPT_SET_PACK_MAX_OBJECTS,
 	GIT_OPT_DISABLE_PACK_KEEP_FILE_CHECKS,
-	GIT_OPT_ENABLE_HTTP_EXPECT_CONTINUE
+	GIT_OPT_ENABLE_HTTP_EXPECT_CONTINUE,
+	GIT_OPT_GET_MWINDOW_FILE_LIMIT,
+	GIT_OPT_SET_MWINDOW_FILE_LIMIT,
+	GIT_OPT_SET_ODB_PACKED_PRIORITY,
+	GIT_OPT_SET_ODB_LOOSE_PRIORITY,
+	GIT_OPT_GET_EXTENSIONS,
+	GIT_OPT_SET_EXTENSIONS
 } git_libgit2_opt_t;
 
 /**
@@ -227,8 +233,18 @@ typedef enum {
  *
  *	* opts(GIT_OPT_SET_MWINDOW_MAPPED_LIMIT, size_t):
  *
- *		>Set the maximum amount of memory that can be mapped at any time
- *		by the library
+ *		> Set the maximum amount of memory that can be mapped at any time
+ *		> by the library
+ *
+ *	* opts(GIT_OPT_GET_MWINDOW_FILE_LIMIT, size_t *):
+ *
+ *		> Get the maximum number of files that will be mapped at any time by the
+ *		> library
+ *
+ *	* opts(GIT_OPT_SET_MWINDOW_FILE_LIMIT, size_t):
+ *
+ *		> Set the maximum number of files that can be mapped at any time
+ *		> by the library. The default (0) is unlimited.
  *
  *	* opts(GIT_OPT_GET_SEARCH_PATH, int level, git_buf *buf)
  *
@@ -344,6 +360,11 @@ typedef enum {
  *		>
  *		> - `ciphers` is the list of ciphers that are eanbled.
  *
+ *	* opts(GIT_OPT_GET_USER_AGENT, git_buf *out)
+ *
+ *		> Get the value of the User-Agent header.
+ *		> The User-Agent is written to the `out` buffer.
+ *
  *	* opts(GIT_OPT_ENABLE_OFS_DELTA, int enabled)
  *
  *		> Enable or disable the use of "offset deltas" when creating packfiles,
@@ -404,6 +425,30 @@ typedef enum {
  *		> authentication, use expect/continue when POSTing data.
  *		> This option is not available on Windows.
  *
+ *   opts(GIT_OPT_SET_ODB_PACKED_PRIORITY, int priority)
+ *      > Override the default priority of the packed ODB backend which
+ *      > is added when default backends are assigned to a repository
+ *
+ *   opts(GIT_OPT_SET_ODB_LOOSE_PRIORITY, int priority)
+ *      > Override the default priority of the loose ODB backend which
+ *      > is added when default backends are assigned to a repository
+ *
+ *   opts(GIT_OPT_GET_EXTENSIONS, git_strarray *out)
+ *      > Returns the list of git extensions that are supported.  This
+ *      > is the list of built-in extensions supported by libgit2 and
+ *      > custom extensions that have been added with
+ *      > `GIT_OPT_SET_EXTENSIONS`.  Extensions that have been negated
+ *      > will not be returned.  The returned list should be released
+ *      > with `git_strarray_dispose`.
+ *
+ *   opts(GIT_OPT_SET_EXTENSIONS, const char **extensions, size_t len)
+ *      > Set that the given git extensions are supported by the caller.
+ *      > Extensions supported by libgit2 may be negated by prefixing
+ *      > them with a `!`.  For example: setting extensions to
+ *      > { "!noop", "newext" } indicates that the caller does not want
+ *      > to support repositories with the `noop` extension but does want
+ *      > to support repositories with the `newext` extension.
+ *
  * @param option Option key
  * @param ... value to set the option
  * @return 0 on success, <0 on failure
diff --git a/include/git2/config.h b/include/git2/config.h
index abf5bbbd0..7c8e388b2 100644
--- a/include/git2/config.h
+++ b/include/git2/config.h
@@ -263,7 +263,7 @@ GIT_EXTERN(int) git_config_open_level(
  *
  * Git allows you to store your global configuration at
  * `$HOME/.gitconfig` or `$XDG_CONFIG_HOME/git/config`. For backwards
- * compatability, the XDG file shouldn't be used unless the use has
+ * compatibility, the XDG file shouldn't be used unless the use has
  * created it explicitly. With this function you'll open the correct
  * one to write to.
  *
diff --git a/include/git2/deprecated.h b/include/git2/deprecated.h
index ffef14597..37b9fa0e2 100644
--- a/include/git2/deprecated.h
+++ b/include/git2/deprecated.h
@@ -18,6 +18,7 @@
 #include "describe.h"
 #include "diff.h"
 #include "errors.h"
+#include "filter.h"
 #include "index.h"
 #include "indexer.h"
 #include "merge.h"
@@ -29,6 +30,7 @@
 #include "trace.h"
 #include "repository.h"
 #include "revert.h"
+#include "revparse.h"
 #include "stash.h"
 #include "status.h"
 #include "submodule.h"
@@ -80,16 +82,19 @@ typedef git_attr_value_t git_attr_t;
 
 /**@}*/
 
-/** @name Deprecated Blob Functions
+/** @name Deprecated Blob Functions and Constants
  *
- * These functions are retained for backward compatibility.  The newer
- * versions of these functions should be preferred in all new code.
+ * These functions and enumeration values are retained for backward
+ * compatibility.  The newer versions of these functions and values
+ * should be preferred in all new code.
  *
  * There is no plan to remove these backward compatibility values at
  * this time.
  */
 /**@{*/
 
+#define GIT_BLOB_FILTER_ATTTRIBUTES_FROM_HEAD GIT_BLOB_FILTER_ATTRIBUTES_FROM_HEAD
+
 GIT_EXTERN(int) git_blob_create_fromworkdir(git_oid *id, git_repository *repo, const char *relative_path);
 GIT_EXTERN(int) git_blob_create_fromdisk(git_oid *id, git_repository *repo, const char *path);
 GIT_EXTERN(int) git_blob_create_fromstream(
@@ -102,7 +107,11 @@ GIT_EXTERN(int) git_blob_create_fromstream_commit(
 GIT_EXTERN(int) git_blob_create_frombuffer(
 	git_oid *id, git_repository *repo, const void *buffer, size_t len);
 
-/** Deprecated in favor of @see git_blob_filter */
+/** Deprecated in favor of `git_blob_filter`.
+ *
+ * @deprecated Use git_blob_filter
+ * @see git_blob_filter
+ */
 GIT_EXTERN(int) git_blob_filtered_content(
 	git_buf *out,
 	git_blob *blob,
@@ -111,6 +120,66 @@ GIT_EXTERN(int) git_blob_filtered_content(
 
 /**@}*/
 
+/** @name Deprecated Filter Functions
+ *
+ * These functions are retained for backward compatibility.  The
+ * newer versions of these functions should be preferred in all
+ * new code.
+ *
+ * There is no plan to remove these backward compatibility values at
+ * this time.
+ */
+/**@{*/
+
+/** Deprecated in favor of `git_filter_list_stream_buffer`.
+ *
+ * @deprecated Use git_filter_list_stream_buffer
+ * @see Use git_filter_list_stream_buffer
+ */
+GIT_EXTERN(int) git_filter_list_stream_data(
+	git_filter_list *filters,
+	git_buf *data,
+	git_writestream *target);
+
+/** Deprecated in favor of `git_filter_list_apply_to_buffer`.
+ *
+ * @deprecated Use git_filter_list_apply_to_buffer
+ * @see Use git_filter_list_apply_to_buffer
+ */
+GIT_EXTERN(int) git_filter_list_apply_to_data(
+	git_buf *out,
+	git_filter_list *filters,
+	git_buf *in);
+
+/**@}*/
+
+/** @name Deprecated Tree Functions
+ *
+ * These functions are retained for backward compatibility.  The
+ * newer versions of these functions and values should be preferred
+ * in all new code.
+ *
+ * There is no plan to remove these backward compatibility values at
+ * this time.
+ */
+/**@{*/
+
+/**
+ * Write the contents of the tree builder as a tree object.
+ * This is an alias of `git_treebuilder_write` and is preserved
+ * for backward compatibility.
+ *
+ * This function is deprecated, but there is no plan to remove this
+ * function at this time.
+ *
+ * @deprecated Use git_treebuilder_write
+ * @see git_treebuilder_write
+ */
+GIT_EXTERN(int) git_treebuilder_write_with_buffer(
+	git_oid *oid, git_treebuilder *bld, git_buf *tree);
+
+/**@}*/
+
 /** @name Deprecated Buffer Functions
  *
  * These functions and enumeration values are retained for backward
@@ -123,6 +192,61 @@ GIT_EXTERN(int) git_blob_filtered_content(
 /**@{*/
 
 /**
+ * Static initializer for git_buf from static buffer
+ */
+#define GIT_BUF_INIT_CONST(STR,LEN) { (char *)(STR), 0, (size_t)(LEN) }
+
+/**
+ * Resize the buffer allocation to make more space.
+ *
+ * This will attempt to grow the buffer to accommodate the target size.
+ *
+ * If the buffer refers to memory that was not allocated by libgit2 (i.e.
+ * the `asize` field is zero), then `ptr` will be replaced with a newly
+ * allocated block of data.  Be careful so that memory allocated by the
+ * caller is not lost.  As a special variant, if you pass `target_size` as
+ * 0 and the memory is not allocated by libgit2, this will allocate a new
+ * buffer of size `size` and copy the external data into it.
+ *
+ * Currently, this will never shrink a buffer, only expand it.
+ *
+ * If the allocation fails, this will return an error and the buffer will be
+ * marked as invalid for future operations, invaliding the contents.
+ *
+ * @param buffer The buffer to be resized; may or may not be allocated yet
+ * @param target_size The desired available size
+ * @return 0 on success, -1 on allocation failure
+ */
+GIT_EXTERN(int) git_buf_grow(git_buf *buffer, size_t target_size);
+
+/**
+ * Set buffer to a copy of some raw data.
+ *
+ * @param buffer The buffer to set
+ * @param data The data to copy into the buffer
+ * @param datalen The length of the data to copy into the buffer
+ * @return 0 on success, -1 on allocation failure
+ */
+GIT_EXTERN(int) git_buf_set(
+	git_buf *buffer, const void *data, size_t datalen);
+
+/**
+* Check quickly if buffer looks like it contains binary data
+*
+* @param buf Buffer to check
+* @return 1 if buffer looks like non-text data
+*/
+GIT_EXTERN(int) git_buf_is_binary(const git_buf *buf);
+
+/**
+* Check quickly if buffer contains a NUL byte
+*
+* @param buf Buffer to check
+* @return 1 if buffer contains a NUL byte
+*/
+GIT_EXTERN(int) git_buf_contains_nul(const git_buf *buf);
+
+/**
  * Free the memory referred to by the git_buf.  This is an alias of
  * `git_buf_dispose` and is preserved for backward compatibility.
  *
@@ -136,6 +260,27 @@ GIT_EXTERN(void) git_buf_free(git_buf *buffer);
 
 /**@}*/
 
+/** @name Deprecated Commit Definitions
+ */
+/**@{*/
+
+/**
+ * Provide a commit signature during commit creation.
+ *
+ * Callers should instead define a `git_commit_create_cb` that
+ * generates a commit buffer using `git_commit_create_buffer`, sign
+ * that buffer and call `git_commit_create_with_signature`.
+ *
+ * @deprecated use a `git_commit_create_cb` instead
+ */
+typedef int (*git_commit_signing_cb)(
+	git_buf *signature,
+	git_buf *signature_field,
+	const char *commit_content,
+	void *payload);
+
+/**@}*/
+
 /** @name Deprecated Config Functions and Constants
  */
 /**@{*/
@@ -149,6 +294,102 @@ typedef git_configmap git_cvar_map;
 
 /**@}*/
 
+/** @name Deprecated Diff Functions and Constants
+ *
+ * These functions and enumeration values are retained for backward
+ * compatibility.  The newer versions of these functions and values
+ * should be preferred in all new code.
+ *
+ * There is no plan to remove these backward compatibility values at
+ * this time.
+ */
+/**@{*/
+
+/**
+ * Formatting options for diff e-mail generation
+ */
+typedef enum {
+	/** Normal patch, the default */
+	GIT_DIFF_FORMAT_EMAIL_NONE = 0,
+
+	/** Don't insert "[PATCH]" in the subject header*/
+	GIT_DIFF_FORMAT_EMAIL_EXCLUDE_SUBJECT_PATCH_MARKER = (1 << 0),
+
+} git_diff_format_email_flags_t;
+
+/**
+ * Options for controlling the formatting of the generated e-mail.
+ */
+typedef struct {
+	unsigned int version;
+
+	/** see `git_diff_format_email_flags_t` above */
+	uint32_t flags;
+
+	/** This patch number */
+	size_t patch_no;
+
+	/** Total number of patches in this series */
+	size_t total_patches;
+
+	/** id to use for the commit */
+	const git_oid *id;
+
+	/** Summary of the change */
+	const char *summary;
+
+	/** Commit message's body */
+	const char *body;
+
+	/** Author of the change */
+	const git_signature *author;
+} git_diff_format_email_options;
+
+#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION 1
+#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT {GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION, 0, 1, 1, NULL, NULL, NULL, NULL}
+
+/**
+ * Create an e-mail ready patch from a diff.
+ *
+ * @deprecated git_email_create_from_diff
+ * @see git_email_create_from_diff
+ */
+GIT_EXTERN(int) git_diff_format_email(
+	git_buf *out,
+	git_diff *diff,
+	const git_diff_format_email_options *opts);
+
+/**
+ * Create an e-mail ready patch for a commit.
+ *
+ * @deprecated git_email_create_from_commit
+ * @see git_email_create_from_commit
+ */
+GIT_EXTERN(int) git_diff_commit_as_email(
+	git_buf *out,
+	git_repository *repo,
+	git_commit *commit,
+	size_t patch_no,
+	size_t total_patches,
+	uint32_t flags,
+	const git_diff_options *diff_opts);
+
+/**
+ * Initialize git_diff_format_email_options structure
+ *
+ * Initializes a `git_diff_format_email_options` with default values. Equivalent
+ * to creating an instance with GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT.
+ *
+ * @param opts The `git_blame_options` struct to initialize.
+ * @param version The struct version; pass `GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION`.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_diff_format_email_options_init(
+	git_diff_format_email_options *opts,
+	unsigned int version);
+
+/**@}*/
+
 /** @name Deprecated Error Functions and Constants
  *
  * These functions and enumeration values are retained for backward
@@ -233,7 +474,7 @@ GIT_EXTERN(void) giterr_clear(void);
 GIT_EXTERN(void) giterr_set_str(int error_class, const char *string);
 
 /**
- * Indicates that an out-of-memory situation occured.  This is an alias
+ * Indicates that an out-of-memory situation occurred.  This is an alias
  * of `git_error_set_oom` and is preserved for backward compatibility.
  *
  * This function is deprecated, but there is no plan to remove this
@@ -336,10 +577,32 @@ GIT_EXTERN(size_t) git_object__size(git_object_t type);
 
 /**@}*/
 
-/** @name Deprecated Reference Constants
+/** @name Deprecated Remote Functions
  *
- * These enumeration values are retained for backward compatibility.  The
- * newer versions of these values should be preferred in all new code.
+ * These functions are retained for backward compatibility.  The newer
+ * versions of these functions should be preferred in all new code.
+ *
+ * There is no plan to remove these backward compatibility functions at
+ * this time.
+ */
+/**@{*/
+
+/**
+ * Ensure the remote name is well-formed.
+ *
+ * @deprecated Use git_remote_name_is_valid
+ * @param remote_name name to be checked.
+ * @return 1 if the reference name is acceptable; 0 if it isn't
+ */
+GIT_EXTERN(int) git_remote_is_valid_name(const char *remote_name);
+
+/**@}*/
+
+/** @name Deprecated Reference Functions and Constants
+ *
+ * These functions and enumeration values are retained for backward
+ * compatibility.  The newer versions of these values should be
+ * preferred in all new code.
  *
  * There is no plan to remove these backward compatibility values at
  * this time.
@@ -360,6 +623,23 @@ GIT_EXTERN(size_t) git_object__size(git_object_t type);
 #define GIT_REF_FORMAT_REFSPEC_PATTERN GIT_REFERENCE_FORMAT_REFSPEC_PATTERN
 #define GIT_REF_FORMAT_REFSPEC_SHORTHAND GIT_REFERENCE_FORMAT_REFSPEC_SHORTHAND
 
+/**
+ * Ensure the reference name is well-formed.
+ *
+ * Valid reference names must follow one of two patterns:
+ *
+ * 1. Top-level names must contain only capital letters and underscores,
+ *    and must begin and end with a letter. (e.g. "HEAD", "ORIG_HEAD").
+ * 2. Names prefixed with "refs/" can be almost anything.  You must avoid
+ *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
+ *    sequences ".." and "@{" which have special meaning to revparse.
+ *
+ * @deprecated Use git_reference_name_is_valid
+ * @param refname name to be checked.
+ * @return 1 if the reference name is acceptable; 0 if it isn't
+ */
+GIT_EXTERN(int) git_reference_is_valid_name(const char *refname);
+
 GIT_EXTERN(int) git_tag_create_frombuffer(
 	git_oid *oid,
 	git_repository *repo,
@@ -368,6 +648,25 @@ GIT_EXTERN(int) git_tag_create_frombuffer(
 
 /**@}*/
 
+/** @name Deprecated Revspec Constants
+ *
+ * These enumeration values are retained for backward compatibility.
+ * The newer versions of these values should be preferred in all new
+ * code.
+ *
+ * There is no plan to remove these backward compatibility values at
+ * this time.
+ */
+/**@{*/
+
+typedef git_revspec_t git_revparse_mode_t;
+
+#define GIT_REVPARSE_SINGLE GIT_REVSPEC_SINGLE
+#define GIT_REVPARSE_RANGE GIT_REVSPEC_RANGE
+#define GIT_REVPARSE_MERGE_BASE GIT_REVSPEC_MERGE_BASE
+
+/**@}*/
+
 /** @name Deprecated Credential Types
  *
  * These types are retained for backward compatibility.  The newer
@@ -376,6 +675,7 @@ GIT_EXTERN(int) git_tag_create_frombuffer(
  * There is no plan to remove these backward compatibility values at
  * this time.
  */
+/**@{*/
 
 typedef git_credential git_cred;
 typedef git_credential_userpass_plaintext git_cred_userpass_plaintext;
@@ -479,6 +779,30 @@ GIT_EXTERN(int) git_oid_iszero(const git_oid *id);
 
 /**@}*/
 
+/** @name Deprecated OID Array Functions
+ *
+ * These types are retained for backward compatibility.  The newer
+ * versions of these values should be preferred in all new code.
+ *
+ * There is no plan to remove these backward compatibility values at
+ * this time.
+ */
+/**@{*/
+
+/**
+ * Free the memory referred to by the git_oidarray.  This is an alias of
+ * `git_oidarray_dispose` and is preserved for backward compatibility.
+ *
+ * This function is deprecated, but there is no plan to remove this
+ * function at this time.
+ *
+ * @deprecated Use git_oidarray_dispose
+ * @see git_oidarray_dispose
+ */
+GIT_EXTERN(void) git_oidarray_free(git_oidarray *array);
+
+/**@}*/
+
 /** @name Deprecated Transfer Progress Types
  *
  * These types are retained for backward compatibility.  The newer
diff --git a/include/git2/diff.h b/include/git2/diff.h
index 3976ab1b9..a14c01993 100644
--- a/include/git2/diff.h
+++ b/include/git2/diff.h
@@ -133,6 +133,9 @@ typedef enum {
 	 */
 	GIT_DIFF_INDENT_HEURISTIC = (1u << 18),
 
+	/** Ignore blank lines */
+	GIT_DIFF_IGNORE_BLANK_LINES = (1u << 19),
+
 	/** Treat all files as text, disabling binary attributes & detection */
 	GIT_DIFF_FORCE_TEXT = (1u << 20),
 	/** Treat all files as binary, disabling text diffs */
@@ -237,32 +240,43 @@ typedef enum {
  * Although this is called a "file", it could represent a file, a symbolic
  * link, a submodule commit id, or even a tree (although that only if you
  * are tracking type changes or ignored/untracked directories).
- *
- * The `id` is the `git_oid` of the item.  If the entry represents an
- * absent side of a diff (e.g. the `old_file` of a `GIT_DELTA_ADDED` delta),
- * then the oid will be zeroes.
- *
- * `path` is the NUL-terminated path to the entry relative to the working
- * directory of the repository.
- *
- * `size` is the size of the entry in bytes.
- *
- * `flags` is a combination of the `git_diff_flag_t` types
- *
- * `mode` is, roughly, the stat() `st_mode` value for the item.  This will
- * be restricted to one of the `git_filemode_t` values.
- *
- * The `id_abbrev` represents the known length of the `id` field, when
- * converted to a hex string.  It is generally `GIT_OID_HEXSZ`, unless this
- * delta was created from reading a patch file, in which case it may be
- * abbreviated to something reasonable, like 7 characters.
  */
 typedef struct {
+	/**
+	 * The `git_oid` of the item.  If the entry represents an
+	 * absent side of a diff (e.g. the `old_file` of a `GIT_DELTA_ADDED` delta),
+	 * then the oid will be zeroes.
+	 */
 	git_oid            id;
+
+	/**
+	 * The NUL-terminated path to the entry relative to the working
+	 * directory of the repository.
+	 */
 	const char        *path;
+
+	/**
+	 * The size of the entry in bytes.
+	 */
 	git_object_size_t  size;
+
+	/**
+	 * A combination of the `git_diff_flag_t` types
+	 */
 	uint32_t           flags;
+
+	/**
+	 * Roughly, the stat() `st_mode` value for the item.  This will
+	 * be restricted to one of the `git_filemode_t` values.
+	 */
 	uint16_t           mode;
+
+	/**
+	 * Represents the known length of the `id` field, when
+	 * converted to a hex string.  It is generally `GIT_OID_HEXSZ`, unless this
+	 * delta was created from reading a patch file, in which case it may be
+	 * abbreviated to something reasonable, like 7 characters.
+	 */
 	uint16_t           id_abbrev;
 } git_diff_file;
 
@@ -998,7 +1012,7 @@ GIT_EXTERN(size_t) git_diff_num_deltas(const git_diff *diff);
 /**
  * Query how many diff deltas are there in a diff filtered by type.
  *
- * This works just like `git_diff_entrycount()` with an extra parameter
+ * This works just like `git_diff_num_deltas()` with an extra parameter
  * that is a `git_delta_t` and returns just the count of how many deltas
  * match that particular type.
  *
@@ -1362,99 +1376,6 @@ GIT_EXTERN(int) git_diff_stats_to_buf(
 GIT_EXTERN(void) git_diff_stats_free(git_diff_stats *stats);
 
 /**
- * Formatting options for diff e-mail generation
- */
-typedef enum {
-	/** Normal patch, the default */
-	GIT_DIFF_FORMAT_EMAIL_NONE = 0,
-
-	/** Don't insert "[PATCH]" in the subject header*/
-	GIT_DIFF_FORMAT_EMAIL_EXCLUDE_SUBJECT_PATCH_MARKER = (1 << 0),
-
-} git_diff_format_email_flags_t;
-
-/**
- * Options for controlling the formatting of the generated e-mail.
- */
-typedef struct {
-	unsigned int version;
-
-	/** see `git_diff_format_email_flags_t` above */
-	uint32_t flags;
-
-	/** This patch number */
-	size_t patch_no;
-
-	/** Total number of patches in this series */
-	size_t total_patches;
-
-	/** id to use for the commit */
-	const git_oid *id;
-
-	/** Summary of the change */
-	const char *summary;
-
-	/** Commit message's body */
-	const char *body;
-
-	/** Author of the change */
-	const git_signature *author;
-} git_diff_format_email_options;
-
-#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION 1
-#define GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT {GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION, 0, 1, 1, NULL, NULL, NULL, NULL}
-
-/**
- * Create an e-mail ready patch from a diff.
- *
- * @param out buffer to store the e-mail patch in
- * @param diff containing the commit
- * @param opts structure with options to influence content and formatting.
- * @return 0 or an error code
- */
-GIT_EXTERN(int) git_diff_format_email(
-	git_buf *out,
-	git_diff *diff,
-	const git_diff_format_email_options *opts);
-
-/**
- * Create an e-mail ready patch for a commit.
- *
- * Does not support creating patches for merge commits (yet).
- *
- * @param out buffer to store the e-mail patch in
- * @param repo containing the commit
- * @param commit pointer to up commit
- * @param patch_no patch number of the commit
- * @param total_patches total number of patches in the patch set
- * @param flags determines the formatting of the e-mail
- * @param diff_opts structure with options to influence diff or NULL for defaults.
- * @return 0 or an error code
- */
-GIT_EXTERN(int) git_diff_commit_as_email(
-	git_buf *out,
-	git_repository *repo,
-	git_commit *commit,
-	size_t patch_no,
-	size_t total_patches,
-	uint32_t flags,
-	const git_diff_options *diff_opts);
-
-/**
- * Initialize git_diff_format_email_options structure
- *
- * Initializes a `git_diff_format_email_options` with default values. Equivalent
- * to creating an instance with GIT_DIFF_FORMAT_EMAIL_OPTIONS_INIT.
- *
- * @param opts The `git_blame_options` struct to initialize.
- * @param version The struct version; pass `GIT_DIFF_FORMAT_EMAIL_OPTIONS_VERSION`.
- * @return Zero on success; -1 on failure.
- */
-GIT_EXTERN(int) git_diff_format_email_options_init(
-	git_diff_format_email_options *opts,
-	unsigned int version);
-
-/**
  * Patch ID options structure
  *
  * Initialize with `GIT_PATCHID_OPTIONS_INIT`. Alternatively, you can
diff --git a/include/git2/email.h b/include/git2/email.h
new file mode 100644
index 000000000..b56be5d0e
--- /dev/null
+++ b/include/git2/email.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_email_h__
+#define INCLUDE_git_email_h__
+
+#include "common.h"
+
+/**
+ * @file git2/email.h
+ * @brief Git email formatting and application routines.
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Formatting options for diff e-mail generation
+ */
+typedef enum {
+	/** Normal patch, the default */
+	GIT_EMAIL_CREATE_DEFAULT = 0,
+
+	/** Do not include patch numbers in the subject prefix. */
+	GIT_EMAIL_CREATE_OMIT_NUMBERS = (1u << 0),
+
+	/**
+	 * Include numbers in the subject prefix even when the
+	 * patch is for a single commit (1/1).
+	 */
+	GIT_EMAIL_CREATE_ALWAYS_NUMBER = (1u << 1),
+
+	/** Do not perform rename or similarity detection. */
+	GIT_EMAIL_CREATE_NO_RENAMES = (1u << 2),
+} git_email_create_flags_t;
+
+/**
+ * Options for controlling the formatting of the generated e-mail.
+ */
+typedef struct {
+	unsigned int version;
+
+	/** see `git_email_create_flags_t` above */
+	uint32_t flags;
+
+	/** Options to use when creating diffs */
+	git_diff_options diff_opts;
+
+	/** Options for finding similarities within diffs */
+	git_diff_find_options diff_find_opts;
+
+	/**
+	 * The subject prefix, by default "PATCH".  If set to an empty
+	 * string ("") then only the patch numbers will be shown in the
+	 * prefix.  If the subject_prefix is empty and patch numbers
+	 * are not being shown, the prefix will be omitted entirely.
+	 */
+	const char *subject_prefix;
+
+	/**
+	 * The starting patch number; this cannot be 0.  By default,
+	 * this is 1.
+	 */
+	size_t start_number;
+
+	/** The "re-roll" number.  By default, there is no re-roll. */
+	size_t reroll_number;
+} git_email_create_options;
+
+/*
+ * By default, our options include rename detection and binary
+ * diffs to match `git format-patch`.
+ */
+#define GIT_EMAIL_CREATE_OPTIONS_VERSION 1
+#define GIT_EMAIL_CREATE_OPTIONS_INIT \
+{ \
+	GIT_EMAIL_CREATE_OPTIONS_VERSION, \
+	GIT_EMAIL_CREATE_DEFAULT, \
+	{ GIT_DIFF_OPTIONS_VERSION, GIT_DIFF_SHOW_BINARY, GIT_SUBMODULE_IGNORE_UNSPECIFIED, {NULL,0}, NULL, NULL, NULL, 3 }, \
+	GIT_DIFF_FIND_OPTIONS_INIT \
+}
+
+/**
+ * Create a diff for a commit in mbox format for sending via email.
+ *
+ * @param out buffer to store the e-mail patch in
+ * @param diff the changes to include in the email
+ * @param patch_idx the patch index
+ * @param patch_count the total number of patches that will be included
+ * @param commit_id the commit id for this change
+ * @param summary the commit message for this change
+ * @param body optional text to include above the diffstat
+ * @param author the person who authored this commit
+ * @param opts email creation options
+ */
+GIT_EXTERN(int) git_email_create_from_diff(
+	git_buf *out,
+	git_diff *diff,
+	size_t patch_idx,
+	size_t patch_count,
+	const git_oid *commit_id,
+	const char *summary,
+	const char *body,
+	const git_signature *author,
+	const git_email_create_options *opts);
+
+/**
+ * Create a diff for a commit in mbox format for sending via email.
+ * The commit must not be a merge commit.
+ *
+ * @param out buffer to store the e-mail patch in
+ * @param commit commit to create a patch for
+ * @param opts email creation options
+ */
+GIT_EXTERN(int) git_email_create_from_commit(
+	git_buf *out,
+	git_commit *commit,
+	const git_email_create_options *opts);
+
+GIT_END_DECL
+
+/** @} */
+
+#endif
diff --git a/include/git2/errors.h b/include/git2/errors.h
index 47a79b76c..9bb9f25e6 100644
--- a/include/git2/errors.h
+++ b/include/git2/errors.h
@@ -42,14 +42,14 @@ typedef enum {
 	GIT_ECONFLICT       = -13,	/**< Checkout conflicts prevented operation */
 	GIT_ELOCKED         = -14,	/**< Lock file prevented operation */
 	GIT_EMODIFIED       = -15,	/**< Reference value does not match expected */
-	GIT_EAUTH           = -16,      /**< Authentication error */
-	GIT_ECERTIFICATE    = -17,      /**< Server certificate is invalid */
+	GIT_EAUTH           = -16,	/**< Authentication error */
+	GIT_ECERTIFICATE    = -17,	/**< Server certificate is invalid */
 	GIT_EAPPLIED        = -18,	/**< Patch/merge has already been applied */
-	GIT_EPEEL           = -19,      /**< The requested peel operation is not possible */
-	GIT_EEOF            = -20,      /**< Unexpected EOF */
-	GIT_EINVALID        = -21,      /**< Invalid operation or input */
+	GIT_EPEEL           = -19,	/**< The requested peel operation is not possible */
+	GIT_EEOF            = -20,	/**< Unexpected EOF */
+	GIT_EINVALID        = -21,	/**< Invalid operation or input */
 	GIT_EUNCOMMITTED    = -22,	/**< Uncommitted changes in index prevented operation */
-	GIT_EDIRECTORY      = -23,      /**< The operation is not valid for a directory */
+	GIT_EDIRECTORY      = -23,	/**< The operation is not valid for a directory */
 	GIT_EMERGECONFLICT  = -24,	/**< A merge conflict exists and cannot continue */
 
 	GIT_PASSTHROUGH     = -30,	/**< A user-configured callback refused to act */
diff --git a/include/git2/filter.h b/include/git2/filter.h
index 886059051..0465e5b14 100644
--- a/include/git2/filter.h
+++ b/include/git2/filter.h
@@ -49,9 +49,40 @@ typedef enum {
 
 	/** Load attributes from `.gitattributes` in the root of HEAD */
 	GIT_FILTER_ATTRIBUTES_FROM_HEAD = (1u << 2),
+
+	/**
+	 * Load attributes from `.gitattributes` in a given commit.
+	 * This can only be specified in a `git_filter_options`.
+	 */
+	GIT_FILTER_ATTRIBUTES_FROM_COMMIT = (1u << 3),
 } git_filter_flag_t;
 
 /**
+ * Filtering options
+ */
+typedef struct {
+	unsigned int version;
+
+	/** See `git_filter_flag_t` above */
+	uint32_t flags;
+
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
+	git_oid *commit_id;
+#endif
+
+	/**
+	 * The commit to load attributes from, when
+	 * `GIT_FILTER_ATTRIBUTES_FROM_COMMIT` is specified.
+	 */
+	git_oid attr_commit_id;
+} git_filter_options;
+
+ #define GIT_FILTER_OPTIONS_VERSION 1
+ #define GIT_FILTER_OPTIONS_INIT {GIT_FILTER_OPTIONS_VERSION}
+
+/**
  * A filter that can transform file data
  *
  * This represents a filter that can be used to transform or even replace
@@ -104,6 +135,29 @@ GIT_EXTERN(int) git_filter_list_load(
 	uint32_t flags);
 
 /**
+ * Load the filter list for a given path.
+ *
+ * This will return 0 (success) but set the output git_filter_list to NULL
+ * if no filters are requested for the given file.
+ *
+ * @param filters Output newly created git_filter_list (or NULL)
+ * @param repo Repository object that contains `path`
+ * @param blob The blob to which the filter will be applied (if known)
+ * @param path Relative path of the file to be filtered
+ * @param mode Filtering direction (WT->ODB or ODB->WT)
+ * @param opts The `git_filter_options` to use when loading filters
+ * @return 0 on success (which could still return NULL if no filters are
+ *         needed for the requested file), <0 on error
+ */
+GIT_EXTERN(int) git_filter_list_load_ext(
+	git_filter_list **filters,
+	git_repository *repo,
+	git_blob *blob,
+	const char *path,
+	git_filter_mode_t mode,
+	git_filter_options *opts);
+
+/**
  * Query the filter list to see if a given filter (by name) will run.
  * The built-in filters "crlf" and "ident" can be queried, otherwise this
  * is the name of the filter specified by the filter attribute.
@@ -122,27 +176,17 @@ GIT_EXTERN(int) git_filter_list_contains(
 /**
  * Apply filter list to a data buffer.
  *
- * See `git2/buffer.h` for background on `git_buf` objects.
- *
- * If the `in` buffer holds data allocated by libgit2 (i.e. `in->asize` is
- * not zero), then it will be overwritten when applying the filters.  If
- * not, then it will be left untouched.
- *
- * If there are no filters to apply (or `filters` is NULL), then the `out`
- * buffer will reference the `in` buffer data (with `asize` set to zero)
- * instead of allocating data.  This keeps allocations to a minimum, but
- * it means you have to be careful about freeing the `in` data since `out`
- * may be pointing to it!
- *
  * @param out Buffer to store the result of the filtering
  * @param filters A loaded git_filter_list (or NULL)
  * @param in Buffer containing the data to filter
+ * @param in_len The length of the input buffer
  * @return 0 on success, an error code otherwise
  */
-GIT_EXTERN(int) git_filter_list_apply_to_data(
+GIT_EXTERN(int) git_filter_list_apply_to_buffer(
 	git_buf *out,
 	git_filter_list *filters,
-	git_buf *in);
+	const char *in,
+	size_t in_len);
 
 /**
  * Apply a filter list to the contents of a file on disk
@@ -175,12 +219,14 @@ GIT_EXTERN(int) git_filter_list_apply_to_blob(
  * Apply a filter list to an arbitrary buffer as a stream
  *
  * @param filters the list of filters to apply
- * @param data the buffer to filter
+ * @param buffer the buffer to filter
+ * @param len the size of the buffer
  * @param target the stream into which the data will be written
  */
-GIT_EXTERN(int) git_filter_list_stream_data(
+GIT_EXTERN(int) git_filter_list_stream_buffer(
 	git_filter_list *filters,
-	git_buf *data,
+	const char *buffer,
+	size_t len,
 	git_writestream *target);
 
 /**
diff --git a/include/git2/graph.h b/include/git2/graph.h
index 213ae9777..712ae474a 100644
--- a/include/git2/graph.h
+++ b/include/git2/graph.h
@@ -43,8 +43,9 @@ GIT_EXTERN(int) git_graph_ahead_behind(size_t *ahead, size_t *behind, git_reposi
  * Note that a commit is not considered a descendant of itself, in contrast
  * to `git merge-base --is-ancestor`.
  *
- * @param commit a previously loaded commit.
- * @param ancestor a potential ancestor commit.
+ * @param repo the repository where the commits exist
+ * @param commit a previously loaded commit
+ * @param ancestor a potential ancestor commit
  * @return 1 if the given commit is a descendant of the potential ancestor,
  * 0 if not, error code otherwise.
  */
@@ -53,6 +54,23 @@ GIT_EXTERN(int) git_graph_descendant_of(
 	const git_oid *commit,
 	const git_oid *ancestor);
 
+/**
+ * Determine if a commit is reachable from any of a list of commits by
+ * following parent edges.
+ *
+ * @param repo the repository where the commits exist
+ * @param commit a previously loaded commit
+ * @param length the number of commits in the provided `descendant_array`
+ * @param descendant_array oids of the commits
+ * @return 1 if the given commit is an ancestor of any of the given potential
+ * descendants, 0 if not, error code otherwise.
+ */
+GIT_EXTERN(int) git_graph_reachable_from_any(
+	git_repository *repo,
+	const git_oid *commit,
+	const git_oid descendant_array[],
+	size_t length);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/index.h b/include/git2/index.h
index 314135109..532a52091 100644
--- a/include/git2/index.h
+++ b/include/git2/index.h
@@ -349,7 +349,7 @@ GIT_EXTERN(int) git_index_write_tree(git_oid *out, git_index *index);
  *
  * The index must not contain any file in conflict.
  *
- * @param out Pointer where to store OID of the the written tree
+ * @param out Pointer where to store OID of the written tree
  * @param index Index to write
  * @param repo Repository where to write the tree
  * @return 0 on success, GIT_EUNMERGED when the index is not clean
@@ -702,7 +702,7 @@ GIT_EXTERN(int) git_index_update_all(
  * @param at_pos the address to which the position of the index entry is written (optional)
  * @param index an existing index object
  * @param path path to search
- * @return a zero-based position in the index if found; GIT_ENOTFOUND otherwise
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_index_find(size_t *at_pos, git_index *index, const char *path);
 
@@ -713,7 +713,7 @@ GIT_EXTERN(int) git_index_find(size_t *at_pos, git_index *index, const char *pat
  * @param at_pos the address to which the position of the index entry is written (optional)
  * @param index an existing index object
  * @param prefix the prefix to search for
- * @return 0 with valid value in at_pos; an error code otherwise
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_index_find_prefix(size_t *at_pos, git_index *index, const char *prefix);
 
diff --git a/include/git2/indexer.h b/include/git2/indexer.h
index 8059e4db3..a434d243f 100644
--- a/include/git2/indexer.h
+++ b/include/git2/indexer.h
@@ -51,7 +51,7 @@ typedef struct git_indexer_progress {
  * Type for progress callbacks during indexing.  Return a value less
  * than zero to cancel the indexing or download.
  *
- * @param stats Structure containing information about the state of the tran    sfer
+ * @param stats Structure containing information about the state of the transfer
  * @param payload Payload provided by caller
  */
 typedef int GIT_CALLBACK(git_indexer_progress_cb)(const git_indexer_progress *stats, void *payload);
@@ -64,6 +64,7 @@ typedef struct git_indexer_options {
 
 	/** progress_cb function to call with progress information */
 	git_indexer_progress_cb progress_cb;
+
 	/** progress_cb_payload payload for the progress callback */
 	void *progress_cb_payload;
 
diff --git a/include/git2/notes.h b/include/git2/notes.h
index c36149e5b..c135881a7 100644
--- a/include/git2/notes.h
+++ b/include/git2/notes.h
@@ -84,8 +84,8 @@ GIT_EXTERN(void) git_note_iterator_free(git_note_iterator *it);
  *         (negative value)
  */
 GIT_EXTERN(int) git_note_next(
-	git_oid* note_id,
-	git_oid* annotated_id,
+	git_oid *note_id,
+	git_oid *annotated_id,
 	git_note_iterator *it);
 
 
diff --git a/include/git2/odb.h b/include/git2/odb.h
index c4bfa5290..dd484553f 100644
--- a/include/git2/odb.h
+++ b/include/git2/odb.h
@@ -70,7 +70,7 @@ GIT_EXTERN(int) git_odb_open(git_odb **out, const char *objects_dir);
  *
  * @param odb database to add the backend to
  * @param path path to the objects folder for the alternate
- * @return 0 on success; error code otherwise
+ * @return 0 on success, error code otherwise
  */
 GIT_EXTERN(int) git_odb_add_disk_alternate(git_odb *odb, const char *path);
 
@@ -94,9 +94,8 @@ GIT_EXTERN(void) git_odb_free(git_odb *db);
  * @param out pointer where to store the read object
  * @param db database to search for the object in.
  * @param id identity of the object to read.
- * @return
- * - 0 if the object was read;
- * - GIT_ENOTFOUND if the object is not in the database.
+ * @return 0 if the object was read, GIT_ENOTFOUND if the object is
+ *         not in the database.
  */
 GIT_EXTERN(int) git_odb_read(git_odb_object **out, git_odb *db, const git_oid *id);
 
@@ -122,10 +121,9 @@ GIT_EXTERN(int) git_odb_read(git_odb_object **out, git_odb *db, const git_oid *i
  * @param db database to search for the object in.
  * @param short_id a prefix of the id of the object to read.
  * @param len the length of the prefix
- * @return
- * - 0 if the object was read;
- * - GIT_ENOTFOUND if the object is not in the database.
- * - GIT_EAMBIGUOUS if the prefix is ambiguous (several objects match the prefix)
+ * @return 0 if the object was read, GIT_ENOTFOUND if the object is not in the
+ *         database. GIT_EAMBIGUOUS if the prefix is ambiguous
+ *         (several objects match the prefix)
  */
 GIT_EXTERN(int) git_odb_read_prefix(git_odb_object **out, git_odb *db, const git_oid *short_id, size_t len);
 
@@ -143,9 +141,8 @@ GIT_EXTERN(int) git_odb_read_prefix(git_odb_object **out, git_odb *db, const git
  * @param type_out pointer where to store the type
  * @param db database to search for the object in.
  * @param id identity of the object to read.
- * @return
- * - 0 if the object was read;
- * - GIT_ENOTFOUND if the object is not in the database.
+ * @return 0 if the object was read, GIT_ENOTFOUND if the object is not
+ *         in the database.
  */
 GIT_EXTERN(int) git_odb_read_header(size_t *len_out, git_object_t *type_out, git_odb *db, const git_oid *id);
 
@@ -154,9 +151,7 @@ GIT_EXTERN(int) git_odb_read_header(size_t *len_out, git_object_t *type_out, git
  *
  * @param db database to be searched for the given object.
  * @param id the object to search for.
- * @return
- * - 1, if the object was found
- * - 0, otherwise
+ * @return 1 if the object was found, 0 otherwise
  */
 GIT_EXTERN(int) git_odb_exists(git_odb *db, const git_oid *id);
 
@@ -305,7 +300,7 @@ GIT_EXTERN(int) git_odb_open_wstream(git_odb_stream **out, git_odb *db, git_obje
  * @param stream the stream
  * @param buffer the data to write
  * @param len the buffer's length
- * @return 0 if the write succeeded; error code otherwise
+ * @return 0 if the write succeeded, error code otherwise
  */
 GIT_EXTERN(int) git_odb_stream_write(git_odb_stream *stream, const char *buffer, size_t len);
 
@@ -320,7 +315,7 @@ GIT_EXTERN(int) git_odb_stream_write(git_odb_stream *stream, const char *buffer,
  *
  * @param out pointer to store the resulting object's id
  * @param stream the stream
- * @return 0 on success; an error code otherwise
+ * @return 0 on success, an error code otherwise
  */
 GIT_EXTERN(int) git_odb_stream_finalize_write(git_oid *out, git_odb_stream *stream);
 
@@ -362,7 +357,7 @@ GIT_EXTERN(void) git_odb_stream_free(git_odb_stream *stream);
  * @param type pointer where to store the type of the object
  * @param db object database where the stream will read from
  * @param oid oid of the object the stream will read from
- * @return 0 if the stream was created; error code otherwise
+ * @return 0 if the stream was created, error code otherwise
  */
 GIT_EXTERN(int) git_odb_open_rstream(
 	git_odb_stream **out,
@@ -396,6 +391,20 @@ GIT_EXTERN(int) git_odb_write_pack(
 	void *progress_payload);
 
 /**
+ * Write a `multi-pack-index` file from all the `.pack` files in the ODB.
+ *
+ * If the ODB layer understands pack files, then this will create a file called
+ * `multi-pack-index` next to the `.pack` and `.idx` files, which will contain
+ * an index of all objects stored in `.pack` files. This will allow for
+ * O(log n) lookup for n objects (regardless of how many packfiles there
+ * exist).
+ *
+ * @param db object database where the `multi-pack-index` file will be written.
+ */
+GIT_EXTERN(int) git_odb_write_multi_pack_index(
+	git_odb *db);
+
+/**
  * Determine the object-ID (sha1 hash) of a data buffer
  *
  * The resulting SHA-1 OID will be the identifier for the data
@@ -501,7 +510,7 @@ GIT_EXTERN(git_object_t) git_odb_object_type(git_odb_object *object);
  * @param odb database to add the backend to
  * @param backend pointer to a git_odb_backend instance
  * @param priority Value for ordering the backends queue
- * @return 0 on success; error code otherwise
+ * @return 0 on success, error code otherwise
  */
 GIT_EXTERN(int) git_odb_add_backend(git_odb *odb, git_odb_backend *backend, int priority);
 
@@ -522,7 +531,7 @@ GIT_EXTERN(int) git_odb_add_backend(git_odb *odb, git_odb_backend *backend, int
  * @param odb database to add the backend to
  * @param backend pointer to a git_odb_backend instance
  * @param priority Value for ordering the backends queue
- * @return 0 on success; error code otherwise
+ * @return 0 on success, error code otherwise
  */
 GIT_EXTERN(int) git_odb_add_alternate(git_odb *odb, git_odb_backend *backend, int priority);
 
@@ -540,10 +549,25 @@ GIT_EXTERN(size_t) git_odb_num_backends(git_odb *odb);
  * @param out output pointer to ODB backend at pos
  * @param odb object database
  * @param pos index into object database backend list
- * @return 0 on success; GIT_ENOTFOUND if pos is invalid; other errors < 0
+ * @return 0 on success, GIT_ENOTFOUND if pos is invalid, other errors < 0
  */
 GIT_EXTERN(int) git_odb_get_backend(git_odb_backend **out, git_odb *odb, size_t pos);
 
+/**
+ * Set the git commit-graph for the ODB.
+ *
+ * After a successfull call, the ownership of the cgraph parameter will be
+ * transferred to libgit2, and the caller should not free it.
+ *
+ * The commit-graph can also be unset by explicitly passing NULL as the cgraph
+ * parameter.
+ *
+ * @param odb object database
+ * @param cgraph the git commit-graph
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_odb_set_commit_graph(git_odb *odb, git_commit_graph *cgraph);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/oidarray.h b/include/git2/oidarray.h
index 0b3204597..94fc58dab 100644
--- a/include/git2/oidarray.h
+++ b/include/git2/oidarray.h
@@ -19,19 +19,16 @@ typedef struct git_oidarray {
 } git_oidarray;
 
 /**
- * Free the OID array
- *
- * This method must (and must only) be called on `git_oidarray`
- * objects where the array is allocated by the library. Not doing so,
- * will result in a memory leak.
+ * Free the object IDs contained in an oid_array.  This method should
+ * be called on `git_oidarray` objects that were provided by the
+ * library.  Not doing so will result in a memory leak.
  *
  * This does not free the `git_oidarray` itself, since the library will
- * never allocate that object directly itself (it is more commonly embedded
- * inside another struct or created on the stack).
+ * never allocate that object directly itself.
  *
  * @param array git_oidarray from which to free oid data
  */
-GIT_EXTERN(void) git_oidarray_free(git_oidarray *array);
+GIT_EXTERN(void) git_oidarray_dispose(git_oidarray *array);
 
 /** @} */
 GIT_END_DECL
diff --git a/include/git2/patch.h b/include/git2/patch.h
index b177798e6..fde9659e7 100644
--- a/include/git2/patch.h
+++ b/include/git2/patch.h
@@ -29,6 +29,14 @@ GIT_BEGIN_DECL
 typedef struct git_patch git_patch;
 
 /**
+ * Get the repository associated with this patch. May be NULL.
+ *
+ * @param patch the patch
+ * @return a pointer to the repository
+ */
+GIT_EXTERN(git_repository *) git_patch_owner(const git_patch *patch);
+
+/**
  * Return a patch for an entry in the diff list.
  *
  * The `git_patch` is a newly created object contains the text diffs
diff --git a/include/git2/rebase.h b/include/git2/rebase.h
index 99a02fef9..11e452cbf 100644
--- a/include/git2/rebase.h
+++ b/include/git2/rebase.h
@@ -75,13 +75,37 @@ typedef struct {
 	git_checkout_options checkout_options;
 
 	/**
+	 * Optional callback that allows users to override commit
+	 * creation in `git_rebase_commit`.  If specified, users can
+	 * create their own commit and provide the commit ID, which
+	 * may be useful for signing commits or otherwise customizing
+	 * the commit creation.
+	 *
+	 * If this callback returns `GIT_PASSTHROUGH`, then
+	 * `git_rebase_commit` will continue to create the commit.
+	 */
+	git_commit_create_cb commit_create_cb;
+
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
+	/**
 	 * If provided, this will be called with the commit content, allowing
 	 * a signature to be added to the rebase commit. Can be skipped with
 	 * GIT_PASSTHROUGH. If GIT_PASSTHROUGH is returned, a commit will be made
 	 * without a signature.
+	 *
 	 * This field is only used when performing git_rebase_commit.
+	 *
+	 * This callback is not invoked if a `git_commit_create_cb` is
+	 * specified.
+	 *
+	 * This callback is deprecated; users should provide a
+	 * creation callback as `commit_create_cb` that produces a
+	 * commit buffer, signs it, and commits it.
 	 */
-	git_commit_signing_cb signing_cb;
+	int (*signing_cb)(git_buf *, git_buf *, const char *, void *);
+#endif
 
 	/**
 	 * This will be passed to each of the callbacks in this struct
diff --git a/include/git2/refs.h b/include/git2/refs.h
index c9cce2212..7ebb209b2 100644
--- a/include/git2/refs.h
+++ b/include/git2/refs.h
@@ -97,6 +97,9 @@ GIT_EXTERN(int) git_reference_dwim(git_reference **out, git_repository *repo, co
  * of updating does not match the one passed through `current_value`
  * (i.e. if the ref has changed since the user read it).
  *
+ * If `current_value` is all zeros, this function will return GIT_EMODIFIED
+ * if the ref already exists.
+ *
  * @param out Pointer to the newly created reference
  * @param repo Repository where that reference will live
  * @param name The name of the reference
@@ -169,7 +172,7 @@ GIT_EXTERN(int) git_reference_symbolic_create(git_reference **out, git_repositor
  *
  * The message for the reflog will be ignored if the reference does
  * not belong in the standard set (HEAD, branches and remote-tracking
- * branches) and and it does not have a reflog.
+ * branches) and it does not have a reflog.
  *
  * @param out Pointer to the newly created reference
  * @param repo Repository where that reference will live
@@ -206,7 +209,7 @@ GIT_EXTERN(int) git_reference_create(git_reference **out, git_repository *repo,
  *
  * The message for the reflog will be ignored if the reference does
  * not belong in the standard set (HEAD, branches and remote-tracking
- * branches) and and it does not have a reflog.
+ * branches) and it does not have a reflog.
  *
  * It will return GIT_EMODIFIED if the reference's value at the time
  * of updating does not match the one passed through `current_id`
@@ -318,7 +321,7 @@ GIT_EXTERN(git_repository *) git_reference_owner(const git_reference *ref);
  *
  * The message for the reflog will be ignored if the reference does
  * not belong in the standard set (HEAD, branches and remote-tracking
- * branches) and and it does not have a reflog.
+ * branches) and it does not have a reflog.
  *
  * @param out Pointer to the newly created reference
  * @param ref The reference
@@ -743,10 +746,11 @@ GIT_EXTERN(int) git_reference_peel(
  *    the characters '~', '^', ':', '\\', '?', '[', and '*', and the
  *    sequences ".." and "@{" which have special meaning to revparse.
  *
+ * @param valid output pointer to set with validity of given reference name
  * @param refname name to be checked.
- * @return 1 if the reference name is acceptable; 0 if it isn't
+ * @return 0 on success or an error code
  */
-GIT_EXTERN(int) git_reference_is_valid_name(const char *refname);
+GIT_EXTERN(int) git_reference_name_is_valid(int *valid, const char *refname);
 
 /**
  * Get the reference's short name
diff --git a/include/git2/remote.h b/include/git2/remote.h
index 51d9c7235..4d57eaaf7 100644
--- a/include/git2/remote.h
+++ b/include/git2/remote.h
@@ -212,7 +212,8 @@ GIT_EXTERN(const char *) git_remote_name(const git_remote *remote);
  * Get the remote's url
  *
  * If url.*.insteadOf has been configured for this URL, it will
- * return the modified URL.
+ * return the modified URL.  If `git_remote_set_instance_pushurl`
+ * has been called for this remote, then that URL will be returned.
  *
  * @param remote the remote
  * @return a pointer to the url
@@ -220,10 +221,11 @@ GIT_EXTERN(const char *) git_remote_name(const git_remote *remote);
 GIT_EXTERN(const char *) git_remote_url(const git_remote *remote);
 
 /**
- * Get the remote's url for pushing
+ * Get the remote's url for pushing.
  *
  * If url.*.pushInsteadOf has been configured for this URL, it
- * will return the modified URL.
+ * will return the modified URL.  If `git_remote_set_instance_pushurl`
+ * has been called for this remote, then that URL will be returned.
  *
  * @param remote the remote
  * @return a pointer to the url or NULL if no special url for pushing is set
@@ -241,7 +243,7 @@ GIT_EXTERN(const char *) git_remote_pushurl(const git_remote *remote);
  * @param url the url to set
  * @return 0 or an error value
  */
-GIT_EXTERN(int) git_remote_set_url(git_repository *repo, const char *remote, const char* url);
+GIT_EXTERN(int) git_remote_set_url(git_repository *repo, const char *remote, const char *url);
 
 /**
  * Set the remote's url for pushing in the configuration.
@@ -253,8 +255,29 @@ GIT_EXTERN(int) git_remote_set_url(git_repository *repo, const char *remote, con
  * @param repo the repository in which to perform the change
  * @param remote the remote's name
  * @param url the url to set
+ * @return 0, or an error code
  */
-GIT_EXTERN(int) git_remote_set_pushurl(git_repository *repo, const char *remote, const char* url);
+GIT_EXTERN(int) git_remote_set_pushurl(git_repository *repo, const char *remote, const char *url);
+
+/**
+ * Set the url for this particular url instance.  The URL in the
+ * configuration will be ignored, and will not be changed.
+ *
+ * @param remote the remote's name
+ * @param url the url to set
+ * @return 0 or an error value
+ */
+GIT_EXTERN(int) git_remote_set_instance_url(git_remote *remote, const char *url);
+
+/**
+ * Set the push url for this particular url instance.  The URL in the
+ * configuration will be ignored, and will not be changed.
+ *
+ * @param remote the remote's name
+ * @param url the url to set
+ * @return 0 or an error value
+ */
+GIT_EXTERN(int) git_remote_set_instance_pushurl(git_remote *remote, const char *url);
 
 /**
  * Add a fetch refspec to the remote's configuration
@@ -428,7 +451,7 @@ typedef int GIT_CALLBACK(git_push_transfer_progress_cb)(
 	unsigned int current,
 	unsigned int total,
 	size_t bytes,
-	void* payload);
+	void *payload);
 
 /**
  * Represents an update which will be performed on the remote during push
@@ -476,6 +499,7 @@ typedef int GIT_CALLBACK(git_push_negotiation)(const git_push_update **updates,
  */
 typedef int GIT_CALLBACK(git_push_update_reference_cb)(const char *refname, const char *status, void *data);
 
+#ifndef GIT_DEPRECATE_HARD
 /**
  * Callback to resolve URLs before connecting to remote
  *
@@ -487,8 +511,22 @@ typedef int GIT_CALLBACK(git_push_update_reference_cb)(const char *refname, cons
  * @param direction GIT_DIRECTION_FETCH or GIT_DIRECTION_PUSH
  * @param payload Payload provided by the caller
  * @return 0 on success, GIT_PASSTHROUGH or an error
+ * @deprecated Use `git_remote_set_instance_url`
  */
 typedef int GIT_CALLBACK(git_url_resolve_cb)(git_buf *url_resolved, const char *url, int direction, void *payload);
+#endif
+
+/**
+ * Callback invoked immediately before we attempt to connect to the
+ * given url.  Callers may change the URL before the connection by
+ * calling `git_remote_set_instance_url` in the callback.
+ *
+ * @param remote The remote to be connected
+ * @param direction GIT_DIRECTION_FETCH or GIT_DIRECTION_PUSH
+ * @param payload Payload provided by the caller
+ * @return 0 on success, or an error
+ */
+typedef int GIT_CALLBACK(git_remote_ready_cb)(git_remote *remote, int direction, void *payload);
 
 /**
  * The callback settings structure
@@ -575,16 +613,28 @@ struct git_remote_callbacks {
 	git_transport_cb transport;
 
 	/**
+	 * Callback when the remote is ready to connect.
+	 */
+	git_remote_ready_cb remote_ready;
+
+	/**
 	 * This will be passed to each of the callbacks in this struct
 	 * as the last parameter.
 	 */
 	void *payload;
 
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
 	/**
 	 * Resolve URL before connecting to remote.
 	 * The returned URL will be used to connect to the remote instead.
+	 *
+	 * This callback is deprecated; users should use
+	 * git_remote_ready_cb and configure the instance URL instead.
 	 */
 	git_url_resolve_cb resolve_url;
+#endif
 };
 
 #define GIT_REMOTE_CALLBACKS_VERSION 1
@@ -876,8 +926,10 @@ GIT_EXTERN(git_remote_autotag_option_t) git_remote_autotag(const git_remote *rem
  * @param repo the repository in which to make the change
  * @param remote the name of the remote
  * @param value the new value to take.
+ * @return 0, or an error code.
  */
 GIT_EXTERN(int) git_remote_set_autotag(git_repository *repo, const char *remote, git_remote_autotag_option_t value);
+
 /**
  * Retrieve the ref-prune setting
  *
@@ -915,10 +967,11 @@ GIT_EXTERN(int) git_remote_rename(
 /**
  * Ensure the remote name is well-formed.
  *
+ * @param valid output pointer to set with validity of given remote name
  * @param remote_name name to be checked.
- * @return 1 if the reference name is acceptable; 0 if it isn't
+ * @return 0 on success or an error code
  */
-GIT_EXTERN(int) git_remote_is_valid_name(const char *remote_name);
+GIT_EXTERN(int) git_remote_name_is_valid(int *valid, const char *remote_name);
 
 /**
 * Delete an existing persisted remote.
@@ -943,7 +996,7 @@ GIT_EXTERN(int) git_remote_delete(git_repository *repo, const char *name);
  *
  * This function must only be called after connecting.
  *
- * @param out the buffern in which to store the reference name
+ * @param out the buffer in which to store the reference name
  * @param remote the remote
  * @return 0, GIT_ENOTFOUND if the remote does not have any references
  * or none of them point to HEAD's commit, or an error message.
diff --git a/include/git2/repository.h b/include/git2/repository.h
index aa81e3843..ec8adfb29 100644
--- a/include/git2/repository.h
+++ b/include/git2/repository.h
@@ -220,36 +220,54 @@ GIT_EXTERN(int) git_repository_init(
  *
  * These flags configure extra behaviors to `git_repository_init_ext`.
  * In every case, the default behavior is the zero value (i.e. flag is
- * not set).  Just OR the flag values together for the `flags` parameter
- * when initializing a new repo.  Details of individual values are:
- *
- * * BARE   - Create a bare repository with no working directory.
- * * NO_REINIT - Return an GIT_EEXISTS error if the repo_path appears to
- *        already be an git repository.
- * * NO_DOTGIT_DIR - Normally a "/.git/" will be appended to the repo
- *        path for non-bare repos (if it is not already there), but
- *        passing this flag prevents that behavior.
- * * MKDIR  - Make the repo_path (and workdir_path) as needed.  Init is
- *        always willing to create the ".git" directory even without this
- *        flag.  This flag tells init to create the trailing component of
- *        the repo and workdir paths as needed.
- * * MKPATH - Recursively make all components of the repo and workdir
- *        paths as necessary.
- * * EXTERNAL_TEMPLATE - libgit2 normally uses internal templates to
- *        initialize a new repo.  This flags enables external templates,
- *        looking the "template_path" from the options if set, or the
- *        `init.templatedir` global config if not, or falling back on
- *        "/usr/share/git-core/templates" if it exists.
- * * GIT_REPOSITORY_INIT_RELATIVE_GITLINK - If an alternate workdir is
- *        specified, use relative paths for the gitdir and core.worktree.
+ * not set). Just OR the flag values together for the `flags` parameter
+ * when initializing a new repo.
  */
 typedef enum {
+	/**
+	 * Create a bare repository with no working directory.
+	 */
 	GIT_REPOSITORY_INIT_BARE              = (1u << 0),
+
+	/**
+	 * Return an GIT_EEXISTS error if the repo_path appears to already be
+	 * an git repository.
+	 */
 	GIT_REPOSITORY_INIT_NO_REINIT         = (1u << 1),
+
+	/**
+	 * Normally a "/.git/" will be appended to the repo path for
+	 * non-bare repos (if it is not already there), but passing this flag
+	 * prevents that behavior.
+	 */
 	GIT_REPOSITORY_INIT_NO_DOTGIT_DIR     = (1u << 2),
+
+	/**
+	 * Make the repo_path (and workdir_path) as needed. Init is always willing
+	 * to create the ".git" directory even without this flag. This flag tells
+	 * init to create the trailing component of the repo and workdir paths
+	 * as needed.
+	 */
 	GIT_REPOSITORY_INIT_MKDIR             = (1u << 3),
+
+	/**
+	 * Recursively make all components of the repo and workdir paths as
+	 * necessary.
+	 */
 	GIT_REPOSITORY_INIT_MKPATH            = (1u << 4),
+
+	/**
+	 * libgit2 normally uses internal templates to initialize a new repo.
+	 * This flags enables external templates, looking the "template_path" from
+	 * the options if set, or the `init.templatedir` global config if not,
+	 * or falling back on "/usr/share/git-core/templates" if it exists.
+	 */
 	GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE = (1u << 5),
+
+	/**
+	 * If an alternate workdir is specified, use relative paths for the gitdir
+	 * and core.worktree.
+	 */
 	GIT_REPOSITORY_INIT_RELATIVE_GITLINK  = (1u << 6),
 } git_repository_init_flag_t;
 
@@ -258,17 +276,23 @@ typedef enum {
  *
  * Set the mode field of the `git_repository_init_options` structure
  * either to the custom mode that you would like, or to one of the
- * following modes:
- *
- * * SHARED_UMASK - Use permissions configured by umask - the default.
- * * SHARED_GROUP - Use "--shared=group" behavior, chmod'ing the new repo
- *        to be group writable and "g+sx" for sticky group assignment.
- * * SHARED_ALL - Use "--shared=all" behavior, adding world readability.
- * * Anything else - Set to custom value.
+ * defined modes.
  */
 typedef enum {
+	/**
+	 * Use permissions configured by umask - the default.
+	 */
 	GIT_REPOSITORY_INIT_SHARED_UMASK = 0,
+
+	/**
+	 * Use "--shared=group" behavior, chmod'ing the new repo to be group
+	 * writable and "g+sx" for sticky group assignment.
+	 */
 	GIT_REPOSITORY_INIT_SHARED_GROUP = 0002775,
+
+	/**
+	 * Use "--shared=all" behavior, adding world readability.
+	 */
 	GIT_REPOSITORY_INIT_SHARED_ALL   = 0002777,
 } git_repository_init_mode_t;
 
@@ -276,38 +300,57 @@ typedef enum {
  * Extended options structure for `git_repository_init_ext`.
  *
  * This contains extra options for `git_repository_init_ext` that enable
- * additional initialization features.  The fields are:
- *
- * * flags - Combination of GIT_REPOSITORY_INIT flags above.
- * * mode  - Set to one of the standard GIT_REPOSITORY_INIT_SHARED_...
- *        constants above, or to a custom value that you would like.
- * * workdir_path - The path to the working dir or NULL for default (i.e.
- *        repo_path parent on non-bare repos).  IF THIS IS RELATIVE PATH,
- *        IT WILL BE EVALUATED RELATIVE TO THE REPO_PATH.  If this is not
- *        the "natural" working directory, a .git gitlink file will be
- *        created here linking to the repo_path.
- * * description - If set, this will be used to initialize the "description"
- *        file in the repository, instead of using the template content.
- * * template_path - When GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE is set,
- *        this contains the path to use for the template directory.  If
- *        this is NULL, the config or default directory options will be
- *        used instead.
- * * initial_head - The name of the head to point HEAD at.  If NULL, then
- *        this will be treated as "master" and the HEAD ref will be set
- *        to "refs/heads/master".  If this begins with "refs/" it will be
- *        used verbatim; otherwise "refs/heads/" will be prefixed.
- * * origin_url - If this is non-NULL, then after the rest of the
- *        repository initialization is completed, an "origin" remote
- *        will be added pointing to this URL.
+ * additional initialization features.
  */
 typedef struct {
 	unsigned int version;
+
+	/**
+	 * Combination of GIT_REPOSITORY_INIT flags above.
+	 */
 	uint32_t    flags;
+
+	/**
+	 * Set to one of the standard GIT_REPOSITORY_INIT_SHARED_... constants
+	 * above, or to a custom value that you would like.
+	 */
 	uint32_t    mode;
+
+	/**
+	 * The path to the working dir or NULL for default (i.e. repo_path parent
+	 * on non-bare repos). IF THIS IS RELATIVE PATH, IT WILL BE EVALUATED
+	 * RELATIVE TO THE REPO_PATH. If this is not the "natural" working
+	 * directory, a .git gitlink file will be created here linking to the
+	 * repo_path.
+	 */
 	const char *workdir_path;
+
+	/**
+	 * If set, this will be used to initialize the "description" file in the
+	 * repository, instead of using the template content.
+	 */
 	const char *description;
+
+	/**
+	 * When GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE is set, this contains
+	 * the path to use for the template directory. If this is NULL, the config
+	 * or default directory options will be used instead.
+	 */
 	const char *template_path;
+
+	/**
+	 * The name of the head to point HEAD at. If NULL, then this will be
+	 * treated as "master" and the HEAD ref will be set to "refs/heads/master".
+	 * If this begins with "refs/" it will be used verbatim;
+	 * otherwise "refs/heads/" will be prefixed.
+	 */
 	const char *initial_head;
+
+	/**
+	 * If this is non-NULL, then after the rest of the repository
+	 * initialization is completed, an "origin" remote will be added
+	 * pointing to this URL.
+	 */
 	const char *origin_url;
 } git_repository_init_options;
 
@@ -720,13 +763,15 @@ GIT_EXTERN(int) git_repository_mergehead_foreach(
  *
  * @param out Output value of calculated SHA
  * @param repo Repository pointer
- * @param path Path to file on disk whose contents should be hashed. If the
- *             repository is not NULL, this can be a relative path.
+ * @param path Path to file on disk whose contents should be hashed.  This
+ *             may be an absolute path or a relative path, in which case it
+ *             will be treated as a path within the working directory.
  * @param type The object type to hash as (e.g. GIT_OBJECT_BLOB)
  * @param as_path The path to use to look up filtering rules. If this is
- *             NULL, then the `path` parameter will be used instead. If
- *             this is passed as the empty string, then no filters will be
- *             applied when calculating the hash.
+ *             an empty string then no filters will be applied when
+ *             calculating the hash. If this is `NULL` and the `path`
+ *             parameter is a file within the repository's working
+ *             directory, then the `path` will be used.
  * @return 0 on success, or an error code
  */
 GIT_EXTERN(int) git_repository_hashfile(
@@ -755,8 +800,8 @@ GIT_EXTERN(int) git_repository_hashfile(
  * @return 0 on success, or an error code
  */
 GIT_EXTERN(int) git_repository_set_head(
-	git_repository* repo,
-	const char* refname);
+	git_repository *repo,
+	const char *refname);
 
 /**
  * Make the repository HEAD directly point to the Commit.
@@ -775,8 +820,8 @@ GIT_EXTERN(int) git_repository_set_head(
  * @return 0 on success, or an error code
  */
 GIT_EXTERN(int) git_repository_set_head_detached(
-	git_repository* repo,
-	const git_oid* commitish);
+	git_repository *repo,
+	const git_oid *commitish);
 
 /**
  * Make the repository HEAD directly point to the Commit.
@@ -812,7 +857,7 @@ GIT_EXTERN(int) git_repository_set_head_detached_from_annotated(
  * branch or an error code
  */
 GIT_EXTERN(int) git_repository_detach_head(
-	git_repository* repo);
+	git_repository *repo);
 
 /**
  * Repository state
diff --git a/include/git2/revparse.h b/include/git2/revparse.h
index d170e1621..e14ddee96 100644
--- a/include/git2/revparse.h
+++ b/include/git2/revparse.h
@@ -70,12 +70,12 @@ GIT_EXTERN(int) git_revparse_ext(
  */
 typedef enum {
 	/** The spec targeted a single object. */
-	GIT_REVPARSE_SINGLE         = 1 << 0,
+	GIT_REVSPEC_SINGLE         = 1 << 0,
 	/** The spec targeted a range of commits. */
-	GIT_REVPARSE_RANGE          = 1 << 1,
+	GIT_REVSPEC_RANGE          = 1 << 1,
 	/** The spec used the '...' operator, which invokes special semantics. */
-	GIT_REVPARSE_MERGE_BASE     = 1 << 2,
-} git_revparse_mode_t;
+	GIT_REVSPEC_MERGE_BASE     = 1 << 2,
+} git_revspec_t;
 
 /**
  * Git Revision Spec: output of a `git_revparse` operation
@@ -85,7 +85,7 @@ typedef struct {
 	git_object *from;
 	/** The right element of the revspec; must be freed by the user */
 	git_object *to;
-	/** The intent of the revspec (i.e. `git_revparse_mode_t` flags) */
+	/** The intent of the revspec (i.e. `git_revspec_mode_t` flags) */
 	unsigned int flags;
 } git_revspec;
 
diff --git a/include/git2/stash.h b/include/git2/stash.h
index 625e51b4b..795920ebc 100644
--- a/include/git2/stash.h
+++ b/include/git2/stash.h
@@ -200,7 +200,7 @@ GIT_EXTERN(int) git_stash_apply(
  */
 typedef int GIT_CALLBACK(git_stash_cb)(
 	size_t index,
-	const char* message,
+	const char *message,
 	const git_oid *stash_id,
 	void *payload);
 
diff --git a/include/git2/status.h b/include/git2/status.h
index 9693cc478..543e3faa8 100644
--- a/include/git2/status.h
+++ b/include/git2/status.h
@@ -69,89 +69,141 @@ typedef int GIT_CALLBACK(git_status_cb)(
  * With `git_status_foreach_ext`, this will control which changes get
  * callbacks.  With `git_status_list_new`, these will control which
  * changes are included in the list.
- *
- * - GIT_STATUS_SHOW_INDEX_AND_WORKDIR is the default.  This roughly
- *   matches `git status --porcelain` regarding which files are
- *   included and in what order.
- * - GIT_STATUS_SHOW_INDEX_ONLY only gives status based on HEAD to index
- *   comparison, not looking at working directory changes.
- * - GIT_STATUS_SHOW_WORKDIR_ONLY only gives status based on index to
- *   working directory comparison, not comparing the index to the HEAD.
  */
 typedef enum {
+	/**
+	 * The default. This roughly matches `git status --porcelain` regarding
+	 * which files are included and in what order.
+	 */
 	GIT_STATUS_SHOW_INDEX_AND_WORKDIR = 0,
+
+	/**
+	 * Only gives status based on HEAD to index comparison, not looking at
+	 * working directory changes.
+	 */
 	GIT_STATUS_SHOW_INDEX_ONLY = 1,
+
+	/**
+	 * Only gives status based on index to working directory comparison,
+	 * not comparing the index to the HEAD.
+	 */
 	GIT_STATUS_SHOW_WORKDIR_ONLY = 2,
 } git_status_show_t;
 
 /**
  * Flags to control status callbacks
  *
- * - GIT_STATUS_OPT_INCLUDE_UNTRACKED says that callbacks should be made
- *   on untracked files.  These will only be made if the workdir files are
- *   included in the status "show" option.
- * - GIT_STATUS_OPT_INCLUDE_IGNORED says that ignored files get callbacks.
- *   Again, these callbacks will only be made if the workdir files are
- *   included in the status "show" option.
- * - GIT_STATUS_OPT_INCLUDE_UNMODIFIED indicates that callback should be
- *   made even on unmodified files.
- * - GIT_STATUS_OPT_EXCLUDE_SUBMODULES indicates that submodules should be
- *   skipped.  This only applies if there are no pending typechanges to
- *   the submodule (either from or to another type).
- * - GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS indicates that all files in
- *   untracked directories should be included.  Normally if an entire
- *   directory is new, then just the top-level directory is included (with
- *   a trailing slash on the entry name).  This flag says to include all
- *   of the individual files in the directory instead.
- * - GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH indicates that the given path
- *   should be treated as a literal path, and not as a pathspec pattern.
- * - GIT_STATUS_OPT_RECURSE_IGNORED_DIRS indicates that the contents of
- *   ignored directories should be included in the status.  This is like
- *   doing `git ls-files -o -i --exclude-standard` with core git.
- * - GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX indicates that rename detection
- *   should be processed between the head and the index and enables
- *   the GIT_STATUS_INDEX_RENAMED as a possible status flag.
- * - GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR indicates that rename
- *   detection should be run between the index and the working directory
- *   and enabled GIT_STATUS_WT_RENAMED as a possible status flag.
- * - GIT_STATUS_OPT_SORT_CASE_SENSITIVELY overrides the native case
- *   sensitivity for the file system and forces the output to be in
- *   case-sensitive order
- * - GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY overrides the native case
- *   sensitivity for the file system and forces the output to be in
- *   case-insensitive order
- * - GIT_STATUS_OPT_RENAMES_FROM_REWRITES indicates that rename detection
- *   should include rewritten files
- * - GIT_STATUS_OPT_NO_REFRESH bypasses the default status behavior of
- *   doing a "soft" index reload (i.e. reloading the index data if the
- *   file on disk has been modified outside libgit2).
- * - GIT_STATUS_OPT_UPDATE_INDEX tells libgit2 to refresh the stat cache
- *   in the index for files that are unchanged but have out of date stat
- *   information in the index.  It will result in less work being done on
- *   subsequent calls to get status.  This is mutually exclusive with the
- *   NO_REFRESH option.
- *
  * Calling `git_status_foreach()` is like calling the extended version
  * with: GIT_STATUS_OPT_INCLUDE_IGNORED, GIT_STATUS_OPT_INCLUDE_UNTRACKED,
  * and GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS.  Those options are bundled
  * together as `GIT_STATUS_OPT_DEFAULTS` if you want them as a baseline.
  */
 typedef enum {
+	/**
+	 * Says that callbacks should be made on untracked files.
+	 * These will only be made if the workdir files are included in the status
+	 * "show" option.
+	 */
 	GIT_STATUS_OPT_INCLUDE_UNTRACKED                = (1u << 0),
+
+	/**
+	 * Says that ignored files get callbacks.
+	 * Again, these callbacks will only be made if the workdir files are
+	 * included in the status "show" option.
+	 */
 	GIT_STATUS_OPT_INCLUDE_IGNORED                  = (1u << 1),
+
+	/**
+	 * Indicates that callback should be made even on unmodified files.
+	 */
 	GIT_STATUS_OPT_INCLUDE_UNMODIFIED               = (1u << 2),
+
+	/**
+	 * Indicates that submodules should be skipped.
+	 * This only applies if there are no pending typechanges to the submodule
+	 * (either from or to another type).
+	 */
 	GIT_STATUS_OPT_EXCLUDE_SUBMODULES               = (1u << 3),
+
+	/**
+	 * Indicates that all files in untracked directories should be included.
+	 * Normally if an entire directory is new, then just the top-level
+	 * directory is included (with a trailing slash on the entry name).
+	 * This flag says to include all of the individual files in the directory
+	 * instead.
+	 */
 	GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS           = (1u << 4),
+
+	/**
+	 * Indicates that the given path should be treated as a literal path,
+	 * and not as a pathspec pattern.
+	 */
 	GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH           = (1u << 5),
+
+	/**
+	 * Indicates that the contents of ignored directories should be included
+	 * in the status. This is like doing `git ls-files -o -i --exclude-standard`
+	 * with core git.
+	 */
 	GIT_STATUS_OPT_RECURSE_IGNORED_DIRS             = (1u << 6),
+
+	/**
+	 * Indicates that rename detection should be processed between the head and
+	 * the index and enables the GIT_STATUS_INDEX_RENAMED as a possible status
+	 * flag.
+	 */
 	GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX            = (1u << 7),
+
+	/**
+	 * Indicates that rename detection should be run between the index and the
+	 * working directory and enabled GIT_STATUS_WT_RENAMED as a possible status
+	 * flag.
+	 */
 	GIT_STATUS_OPT_RENAMES_INDEX_TO_WORKDIR         = (1u << 8),
+
+	/**
+	 * Overrides the native case sensitivity for the file system and forces
+	 * the output to be in case-sensitive order.
+	 */
 	GIT_STATUS_OPT_SORT_CASE_SENSITIVELY            = (1u << 9),
+
+	/**
+	 * Overrides the native case sensitivity for the file system and forces
+	 * the output to be in case-insensitive order.
+	 */
 	GIT_STATUS_OPT_SORT_CASE_INSENSITIVELY          = (1u << 10),
+
+	/**
+	 * Iindicates that rename detection should include rewritten files.
+	 */
 	GIT_STATUS_OPT_RENAMES_FROM_REWRITES            = (1u << 11),
+
+	/**
+	 * Bypasses the default status behavior of doing a "soft" index reload
+	 * (i.e. reloading the index data if the file on disk has been modified
+	 * outside libgit2).
+	 */
 	GIT_STATUS_OPT_NO_REFRESH                       = (1u << 12),
+
+	/**
+	 * Tells libgit2 to refresh the stat cache in the index for files that are
+	 * unchanged but have out of date stat einformation in the index.
+	 * It will result in less work being done on subsequent calls to get status.
+	 * This is mutually exclusive with the NO_REFRESH option.
+	 */
 	GIT_STATUS_OPT_UPDATE_INDEX                     = (1u << 13),
+
+	/**
+	 * Normally files that cannot be opened or read are ignored as
+	 * these are often transient files; this option will return
+	 * unreadable files as `GIT_STATUS_WT_UNREADABLE`.
+	 */
 	GIT_STATUS_OPT_INCLUDE_UNREADABLE               = (1u << 14),
+
+	/**
+	 * Unreadable files will be detected and given the status
+	 * untracked instead of unreadable.
+	 */
 	GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED  = (1u << 15),
 } git_status_opt_t;
 
@@ -168,7 +220,10 @@ typedef enum {
  *
  */
 typedef struct {
-	unsigned int      version; /**< The version */
+	/**
+	 * The struct version; pass `GIT_STATUS_OPTIONS_VERSION`.
+	 */
+	unsigned int version;
 
 	/**
 	 * The `show` value is one of the `git_status_show_t` constants that
@@ -177,21 +232,22 @@ typedef struct {
 	git_status_show_t show;
 
 	/**
-	 * The `flags` value is an OR'ed combination of the `git_status_opt_t`
-	 * values above.
+	 * The `flags` value is an OR'ed combination of the
+	 * `git_status_opt_t` values above.
 	 */
 	unsigned int      flags;
 
 	/**
 	 * The `pathspec` is an array of path patterns to match (using
-	 * fnmatch-style matching), or just an array of paths to match exactly if
-	 * `GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH` is specified in the flags.
+	 * fnmatch-style matching), or just an array of paths to match
+	 * exactly if `GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH` is specified
+	 * in the flags.
 	 */
 	git_strarray      pathspec;
 
 	/**
-	 * The `baseline` is the tree to be used for comparison to the working directory
-	 * and index; defaults to HEAD.
+	 * The `baseline` is the tree to be used for comparison to the
+	 * working directory and index; defaults to HEAD.
 	 */
 	git_tree          *baseline;
 } git_status_options;
diff --git a/include/git2/stdint.h b/include/git2/stdint.h
index c66fbb817..6950427d2 100644
--- a/include/git2/stdint.h
+++ b/include/git2/stdint.h
@@ -29,9 +29,7 @@
 //
 ///////////////////////////////////////////////////////////////////////////////
 
-#ifndef _MSC_VER // [
-#error "Use this header only with Microsoft Visual C++ compilers!"
-#endif // _MSC_VER ]
+#ifdef _MSC_VER // [
 
 #ifndef _MSC_STDINT_H_ // [
 #define _MSC_STDINT_H_
@@ -245,3 +243,5 @@ typedef uint64_t  uintmax_t;
 
 
 #endif // _MSC_STDINT_H_ ]
+
+#endif // _MSC_VER ]
\ No newline at end of file
diff --git a/include/git2/submodule.h b/include/git2/submodule.h
index bedd76d6a..29d8bc1ce 100644
--- a/include/git2/submodule.h
+++ b/include/git2/submodule.h
@@ -224,6 +224,15 @@ GIT_EXTERN(int) git_submodule_lookup(
 	const char *name);
 
 /**
+ * Create an in-memory copy of a submodule. The copy must be explicitly
+ * free'd or it will leak.
+ *
+ * @param out Pointer to store the copy of the submodule.
+ * @param source Original submodule to copy.
+ */
+GIT_EXTERN(int) git_submodule_dup(git_submodule **out, git_submodule *source);
+
+/**
  * Release a submodule
  *
  * @param submodule Submodule object
diff --git a/include/git2/sys/commit_graph.h b/include/git2/sys/commit_graph.h
new file mode 100644
index 000000000..f6c0fc4b5
--- /dev/null
+++ b/include/git2/sys/commit_graph.h
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_commit_graph_h__
+#define INCLUDE_sys_git_commit_graph_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+
+/**
+ * @file git2/sys/commit_graph.h
+ * @brief Git commit-graph
+ * @defgroup git_commit_graph Git commit-graph APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Opens a `git_commit_graph` from a path to an objects directory.
+ *
+ * This finds, opens, and validates the `commit-graph` file.
+ *
+ * @param cgraph_out the `git_commit_graph` struct to initialize.
+ * @param objects_dir the path to a git objects directory.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_commit_graph_open(git_commit_graph **cgraph_out, const char *objects_dir);
+
+/**
+ * Frees commit-graph data. This should only be called when memory allocated
+ * using `git_commit_graph_open` is not returned to libgit2 because it was not
+ * associated with the ODB through a successful call to
+ * `git_odb_set_commit_graph`.
+ *
+ * @param cgraph the commit-graph object to free. If NULL, no action is taken.
+ */
+GIT_EXTERN(void) git_commit_graph_free(git_commit_graph *cgraph);
+
+/**
+ * Create a new writer for `commit-graph` files.
+ *
+ * @param out Location to store the writer pointer.
+ * @param objects_info_dir The `objects/info` directory.
+ * The `commit-graph` file will be written in this directory.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_graph_writer_new(
+		git_commit_graph_writer **out,
+		const char *objects_info_dir);
+
+/**
+ * Free the commit-graph writer and its resources.
+ *
+ * @param w The writer to free. If NULL no action is taken.
+ */
+GIT_EXTERN(void) git_commit_graph_writer_free(git_commit_graph_writer *w);
+
+/**
+ * Add an `.idx` file (associated to a packfile) to the writer.
+ *
+ * @param w The writer.
+ * @param repo The repository that owns the `.idx` file.
+ * @param idx_path The path of an `.idx` file.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_graph_writer_add_index_file(
+		git_commit_graph_writer *w,
+		git_repository *repo,
+		const char *idx_path);
+
+/**
+ * Add a revwalk to the writer. This will add all the commits from the revwalk
+ * to the commit-graph.
+ *
+ * @param w The writer.
+ * @param walk The git_revwalk.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_graph_writer_add_revwalk(
+		git_commit_graph_writer *w,
+		git_revwalk *walk);
+
+
+/**
+ * The strategy to use when adding a new set of commits to a pre-existing
+ * commit-graph chain.
+ */
+typedef enum {
+	/**
+	 * Do not split commit-graph files. The other split strategy-related option
+	 * fields are ignored.
+	 */
+	GIT_COMMIT_GRAPH_SPLIT_STRATEGY_SINGLE_FILE = 0,
+} git_commit_graph_split_strategy_t;
+
+/**
+ * Options structure for
+ * `git_commit_graph_writer_commit`/`git_commit_graph_writer_dump`.
+ *
+ * Initialize with `GIT_COMMIT_GRAPH_WRITER_OPTIONS_INIT`. Alternatively, you
+ * can use `git_commit_graph_writer_options_init`.
+ */
+typedef struct {
+	unsigned int version;
+
+	/**
+	 * The strategy to use when adding new commits to a pre-existing commit-graph
+	 * chain.
+	 */
+	git_commit_graph_split_strategy_t split_strategy;
+
+	/**
+	 * The number of commits in level N is less than X times the number of
+	 * commits in level N + 1. Default is 2.
+	 */
+	float size_multiple;
+
+	/**
+	 * The number of commits in level N + 1 is more than C commits.
+	 * Default is 64000.
+	 */
+	size_t max_commits;
+} git_commit_graph_writer_options;
+
+#define GIT_COMMIT_GRAPH_WRITER_OPTIONS_VERSION 1
+#define GIT_COMMIT_GRAPH_WRITER_OPTIONS_INIT { \
+		GIT_COMMIT_GRAPH_WRITER_OPTIONS_VERSION \
+	}
+
+/**
+ * Initialize git_commit_graph_writer_options structure
+ *
+ * Initializes a `git_commit_graph_writer_options` with default values. Equivalent to
+ * creating an instance with `GIT_COMMIT_GRAPH_WRITER_OPTIONS_INIT`.
+ *
+ * @param opts The `git_commit_graph_writer_options` struct to initialize.
+ * @param version The struct version; pass `GIT_COMMIT_GRAPH_WRITER_OPTIONS_VERSION`.
+ * @return Zero on success; -1 on failure.
+ */
+GIT_EXTERN(int) git_commit_graph_writer_options_init(
+	git_commit_graph_writer_options *opts,
+	unsigned int version);
+
+/**
+ * Write a `commit-graph` file to a file.
+ *
+ * @param w The writer
+ * @param opts Pointer to git_commit_graph_writer_options struct.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_graph_writer_commit(
+		git_commit_graph_writer *w,
+		git_commit_graph_writer_options *opts);
+
+/**
+ * Dump the contents of the `commit-graph` to an in-memory buffer.
+ *
+ * @param buffer Buffer where to store the contents of the `commit-graph`.
+ * @param w The writer.
+ * @param opts Pointer to git_commit_graph_writer_options struct.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_commit_graph_writer_dump(
+		git_buf *buffer,
+		git_commit_graph_writer *w,
+		git_commit_graph_writer_options *opts);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/sys/email.h b/include/git2/sys/email.h
new file mode 100644
index 000000000..6f4a28662
--- /dev/null
+++ b/include/git2/sys/email.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_email_h__
+#define INCLUDE_sys_git_email_h__
+
+/**
+ * @file git2/sys/email.h
+ * @brief Advanced git email creation routines
+ * @defgroup git_email Advanced git email creation routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a diff for a commit in mbox format for sending via email.
+ *
+ * @param out buffer to store the e-mail patch in
+ * @param diff the changes to include in the email
+ * @param patch_idx the patch index
+ * @param patch_count the total number of patches that will be included
+ * @param commit_id the commit id for this change
+ * @param summary the commit message for this change
+ * @param body optional text to include above the diffstat
+ * @param author the person who authored this commit
+ * @param opts email creation options
+ */
+GIT_EXTERN(int) git_email_create_from_diff(
+	git_buf *out,
+	git_diff *diff,
+	size_t patch_idx,
+	size_t patch_count,
+	const git_oid *commit_id,
+	const char *summary,
+	const char *body,
+	const git_signature *author,
+	const git_email_create_options *opts);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/sys/filter.h b/include/git2/sys/filter.h
index e43fde55c..b3759416a 100644
--- a/include/git2/sys/filter.h
+++ b/include/git2/sys/filter.h
@@ -167,17 +167,18 @@ typedef void GIT_CALLBACK(git_filter_shutdown_fn)(git_filter *self);
  *
  * The `payload` will be a pointer to a reference payload for the filter.
  * This will start as NULL, but `check` can assign to this pointer for
- * later use by the `apply` callback.  Note that the value should be heap
- * allocated (not stack), so that it doesn't go away before the `apply`
+ * later use by the `stream` callback.  Note that the value should be heap
+ * allocated (not stack), so that it doesn't go away before the `stream`
  * callback can use it.  If a filter allocates and assigns a value to the
  * `payload`, it will need a `cleanup` callback to free the payload.
  */
 typedef int GIT_CALLBACK(git_filter_check_fn)(
-	git_filter  *self,
-	void       **payload, /* points to NULL ptr on entry, may be set */
+	git_filter              *self,
+	void                   **payload, /* NULL on entry, may be set */
 	const git_filter_source *src,
-	const char **attr_values);
+	const char             **attr_values);
 
+#ifndef GIT_DEPRECATE_HARD
 /**
  * Callback to actually perform the data filtering
  *
@@ -189,32 +190,45 @@ typedef int GIT_CALLBACK(git_filter_check_fn)(
  *
  * The `payload` value will refer to any payload that was set by the
  * `check` callback.  It may be read from or written to as needed.
+ *
+ * @deprecated use git_filter_stream_fn
  */
 typedef int GIT_CALLBACK(git_filter_apply_fn)(
-	git_filter    *self,
-	void         **payload, /* may be read and/or set */
-	git_buf       *to,
-	const git_buf *from,
+	git_filter              *self,
+	void                   **payload, /* may be read and/or set */
+	git_buf                 *to,
+	const git_buf           *from,
 	const git_filter_source *src);
+#endif
 
+/**
+ * Callback to perform the data filtering.
+ *
+ * Specified as `filter.stream`, this is a callback that filters data
+ * in a streaming manner.  This function will provide a
+ * `git_writestream` that will the original data will be written to;
+ * with that data, the `git_writestream` will then perform the filter
+ * translation and stream the filtered data out to the `next` location.
+ */
 typedef int GIT_CALLBACK(git_filter_stream_fn)(
-	git_writestream **out,
-	git_filter *self,
-	void **payload,
+	git_writestream        **out,
+	git_filter              *self,
+	void                   **payload,
 	const git_filter_source *src,
-	git_writestream *next);
+	git_writestream         *next);
 
 /**
  * Callback to clean up after filtering has been applied
  *
  * Specified as `filter.cleanup`, this is an optional callback invoked
- * after the filter has been applied.  If the `check` or `apply` callbacks
- * allocated a `payload` to keep per-source filter state, use this
- * callback to free that payload and release resources as required.
+ * after the filter has been applied.  If the `check`, `apply`, or
+ * `stream` callbacks allocated a `payload` to keep per-source filter
+ * state, use this callback to free that payload and release resources
+ * as required.
  */
 typedef void GIT_CALLBACK(git_filter_cleanup_fn)(
-	git_filter *self,
-	void       *payload);
+	git_filter              *self,
+	void                    *payload);
 
 /**
  * Filter structure used to register custom filters.
@@ -248,21 +262,28 @@ struct git_filter {
 	/**
 	 * Called to determine whether the filter should be invoked for a
 	 * given file.  If this function returns `GIT_PASSTHROUGH` then the
-	 * `apply` function will not be invoked and the contents will be passed
-	 * through unmodified.
+	 * `stream` or `apply` functions will not be invoked and the
+	 * contents will be passed through unmodified.
 	 */
 	git_filter_check_fn    check;
 
+#ifdef GIT_DEPRECATE_HARD
+	void *reserved;
+#else
 	/**
-	 * Called to actually apply the filter to file contents.  If this
-	 * function returns `GIT_PASSTHROUGH` then the contents will be passed
-	 * through unmodified.
+	 * Provided for backward compatibility; this will apply the
+	 * filter to the given contents in a `git_buf`.  Callers should
+	 * provide a `stream` function instead.
 	 */
 	git_filter_apply_fn    apply;
+#endif
 
 	/**
-	 * Called to apply the filter in a streaming manner.  If this is not
-	 * specified then the system will call `apply` with the whole buffer.
+	 * Called to apply the filter, this function will provide a
+	 * `git_writestream` that will the original data will be
+	 * written to; with that data, the `git_writestream` will then
+	 * perform the filter translation and stream the filtered data
+	 * out to the `next` location.
 	 */
 	git_filter_stream_fn   stream;
 
@@ -289,9 +310,9 @@ GIT_EXTERN(int) git_filter_init(git_filter *filter, unsigned int version);
  * As mentioned elsewhere, the initialize callback will not be invoked
  * immediately.  It is deferred until the filter is used in some way.
  *
- * A filter's attribute checks and `check` and `apply` callbacks will be
- * issued in order of `priority` on smudge (to workdir), and in reverse
- * order of `priority` on clean (to odb).
+ * A filter's attribute checks and `check` and `stream` (or `apply`)
+ * callbacks will be issued in order of `priority` on smudge (to
+ * workdir), and in reverse order of `priority` on clean (to odb).
  *
  * Two filters are preregistered with libgit2:
  * - GIT_FILTER_CRLF with priority 0
diff --git a/include/git2/sys/midx.h b/include/git2/sys/midx.h
new file mode 100644
index 000000000..e3d749829
--- /dev/null
+++ b/include/git2/sys/midx.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_sys_git_midx_h__
+#define INCLUDE_sys_git_midx_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+
+/**
+ * @file git2/midx.h
+ * @brief Git multi-pack-index routines
+ * @defgroup git_midx Git multi-pack-index routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new writer for `multi-pack-index` files.
+ *
+ * @param out location to store the writer pointer.
+ * @param pack_dir the directory where the `.pack` and `.idx` files are. The
+ * `multi-pack-index` file will be written in this directory, too.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_midx_writer_new(
+		git_midx_writer **out,
+		const char *pack_dir);
+
+/**
+ * Free the multi-pack-index writer and its resources.
+ *
+ * @param w the writer to free. If NULL no action is taken.
+ */
+GIT_EXTERN(void) git_midx_writer_free(git_midx_writer *w);
+
+/**
+ * Add an `.idx` file to the writer.
+ *
+ * @param w the writer
+ * @param idx_path the path of an `.idx` file.
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_midx_writer_add(
+		git_midx_writer *w,
+		const char *idx_path);
+
+/**
+ * Write a `multi-pack-index` file to a file.
+ *
+ * @param w the writer
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_midx_writer_commit(
+		git_midx_writer *w);
+
+/**
+ * Dump the contents of the `multi-pack-index` to an in-memory buffer.
+ *
+ * @param midx Buffer where to store the contents of the `multi-pack-index`.
+ * @param w the writer
+ * @return 0 or an error code
+ */
+GIT_EXTERN(int) git_midx_writer_dump(
+		git_buf *midx,
+		git_midx_writer *w);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/sys/odb_backend.h b/include/git2/sys/odb_backend.h
index 4dba460af..9ae0ed9b3 100644
--- a/include/git2/sys/odb_backend.h
+++ b/include/git2/sys/odb_backend.h
@@ -85,6 +85,13 @@ struct git_odb_backend {
 		git_indexer_progress_cb progress_cb, void *progress_payload);
 
 	/**
+	 * If the backend supports pack files, this will create a
+	 * `multi-pack-index` file which will contain an index of all objects
+	 * across all the `.pack` files.
+	 */
+	int GIT_CALLBACK(writemidx)(git_odb_backend *);
+
+	/**
 	 * "Freshens" an already existing object, updating its last-used
 	 * time.  This occurs when `git_odb_write` was called, but the
 	 * object already existed (and will not be re-written).  The
diff --git a/include/git2/sys/transport.h b/include/git2/sys/transport.h
index 6cee42f54..fee34544f 100644
--- a/include/git2/sys/transport.h
+++ b/include/git2/sys/transport.h
@@ -9,6 +9,7 @@
 #define INCLUDE_sys_git_transport_h
 
 #include "git2/net.h"
+#include "git2/transport.h"
 #include "git2/types.h"
 #include "git2/strarray.h"
 #include "git2/proxy.h"
diff --git a/include/git2/tag.h b/include/git2/tag.h
index 4e5fe1db1..a3921369d 100644
--- a/include/git2/tag.h
+++ b/include/git2/tag.h
@@ -365,6 +365,18 @@ GIT_EXTERN(int) git_tag_peel(
  */
 GIT_EXTERN(int) git_tag_dup(git_tag **out, git_tag *source);
 
+/**
+ * Determine whether a tag name is valid, meaning that (when prefixed
+ * with `refs/tags/`) that it is a valid reference name, and that any
+ * additional tag name restrictions are imposed (eg, it cannot start
+ * with a `-`).
+ *
+ * @param valid output pointer to set with validity of given tag name
+ * @param name a tag name to test
+ * @return 0 on success or an error code
+ */
+GIT_EXTERN(int) git_tag_name_is_valid(int *valid, const char *name);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/transport.h b/include/git2/transport.h
index fc99ce8f3..5a27de9a8 100644
--- a/include/git2/transport.h
+++ b/include/git2/transport.h
@@ -23,7 +23,7 @@
 GIT_BEGIN_DECL
 
 /**
- * Callback for messages recieved by the transport.
+ * Callback for messages received by the transport.
  *
  * Return a negative value to cancel the network operation.
  *
diff --git a/include/git2/tree.h b/include/git2/tree.h
index 1a8e155fc..f2289fc7e 100644
--- a/include/git2/tree.h
+++ b/include/git2/tree.h
@@ -334,6 +334,7 @@ GIT_EXTERN(int) git_treebuilder_insert(
  *
  * @param bld Tree builder
  * @param filename Filename of the entry to remove
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_treebuilder_remove(
 	git_treebuilder *bld, const char *filename);
@@ -378,20 +379,6 @@ GIT_EXTERN(int) git_treebuilder_filter(
 GIT_EXTERN(int) git_treebuilder_write(
 	git_oid *id, git_treebuilder *bld);
 
-/**
- * Write the contents of the tree builder as a tree object
- * using a shared git_buf.
- *
- * @see git_treebuilder_write
- *
- * @param oid Pointer to store the OID of the newly written tree
- * @param bld Tree builder to write
- * @param tree Shared buffer for writing the tree. Will be grown as necessary.
- * @return 0 or an error code
- */
-GIT_EXTERN(int) git_treebuilder_write_with_buffer(
-	git_oid *oid, git_treebuilder *bld, git_buf *tree);
-
 /** Callback for the tree traversal method */
 typedef int GIT_CALLBACK(git_treewalk_cb)(
 	const char *root, const git_tree_entry *entry, void *payload);
@@ -477,6 +464,7 @@ typedef struct {
  * @param baseline the tree to base these changes on
  * @param nupdates the number of elements in the update list
  * @param updates the list of updates to perform
+ * @return 0 or an error code
  */
 GIT_EXTERN(int) git_tree_create_updated(git_oid *out, git_repository *repo, git_tree *baseline, size_t nupdates, const git_tree_update *updates);
 
diff --git a/include/git2/types.h b/include/git2/types.h
index ade0c7d32..aac8e42e2 100644
--- a/include/git2/types.h
+++ b/include/git2/types.h
@@ -96,12 +96,21 @@ typedef struct git_odb_stream git_odb_stream;
 /** A stream to write a packfile to the ODB */
 typedef struct git_odb_writepack git_odb_writepack;
 
+/** a writer for multi-pack-index files. */
+typedef struct git_midx_writer git_midx_writer;
+
 /** An open refs database handle. */
 typedef struct git_refdb git_refdb;
 
 /** A custom backend for refs */
 typedef struct git_refdb_backend git_refdb_backend;
 
+/** A git commit-graph */
+typedef struct git_commit_graph git_commit_graph;
+
+/** a writer for commit-graph files. */
+typedef struct git_commit_graph_writer git_commit_graph_writer;
+
 /**
  * Representation of an existing git repository,
  * including all its object contents
diff --git a/include/git2/version.h b/include/git2/version.h
index b078e1ea2..3503a6278 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 "1.0.0"
+#define LIBGIT2_VERSION "1.3.0"
 #define LIBGIT2_VER_MAJOR 1
-#define LIBGIT2_VER_MINOR 0
+#define LIBGIT2_VER_MINOR 3
 #define LIBGIT2_VER_REVISION 0
 #define LIBGIT2_VER_PATCH 0
 
-#define LIBGIT2_SOVERSION "1.0"
+#define LIBGIT2_SOVERSION "1.3"
 
 #endif
diff --git a/include/git2/worktree.h b/include/git2/worktree.h
index 049511da1..23084d8cd 100644
--- a/include/git2/worktree.h
+++ b/include/git2/worktree.h
@@ -198,6 +198,7 @@ typedef enum {
 typedef struct git_worktree_prune_options {
 	unsigned int version;
 
+	/** A combination of `git_worktree_prune_t` */
 	uint32_t flags;
 } git_worktree_prune_options;