str: introduce `git_str` for internal, `git_buf` is externalethomson/gitstr

libgit2 has two distinct requirements that were previously solved by
`git_buf`.  We require:

1. A general purpose string class that provides a number of utility APIs
   for manipulating data (eg, concatenating, truncating, etc).
2. A structure that we can use to return strings to callers that they
   can take ownership of.

By using a single class (`git_buf`) for both of these purposes, we have
confused the API to the point that refactorings are difficult and
reasoning about correctness is also difficult.

Move the utility class `git_buf` to be called `git_str`: this represents
its general purpose, as an internal string buffer class.  The name also
is an homage to Junio Hamano ("gitstr").

The public API remains `git_buf`, and has a much smaller footprint.  It
is generally only used as an "out" param with strict requirements that
follow the documentation.  (Exceptions exist for some legacy APIs to
avoid breaking callers unnecessarily.)

Utility functions exist to convert a user-specified `git_buf` to a
`git_str` so that we can call internal functions, then converting it
back again.

1 files changed, 11 insertions, 12 deletions

diff --git a/tests/checkout/tree.c b/tests/checkout/tree.c
index 3241a3eb7..cdfb456b7 100644
--- a/tests/checkout/tree.c
+++ b/tests/checkout/tree.c
@@ -3,7 +3,6 @@
 
 #include "git2/checkout.h"
 #include "repository.h"
-#include "buffer.h"
 #include "futils.h"
 
 static git_repository *g_repo;
@@ -519,7 +518,7 @@ void assert_conflict(
 	git_index *index;
 	git_object *hack_tree;
 	git_reference *branch, *head;
-	git_buf file_path = GIT_BUF_INIT;
+	git_str file_path = GIT_STR_INIT;
 
 	cl_git_pass(git_repository_index(&index, g_repo));
 
@@ -549,9 +548,9 @@ void assert_conflict(
 	g_object = NULL;
 
 	/* Create a conflicting file */
-	cl_git_pass(git_buf_joinpath(&file_path, "./testrepo", entry_path));
-	cl_git_mkfile(git_buf_cstr(&file_path), new_content);
-	git_buf_dispose(&file_path);
+	cl_git_pass(git_str_joinpath(&file_path, "./testrepo", entry_path));
+	cl_git_mkfile(git_str_cstr(&file_path), new_content);
+	git_str_dispose(&file_path);
 
 	/* Trying to checkout the original commit */
 	cl_git_pass(git_revparse_single(&g_object, g_repo, commit_sha));
@@ -1037,17 +1036,17 @@ void test_checkout_tree__filemode_preserved_in_index(void)
 
 mode_t read_filemode(const char *path)
 {
-	git_buf fullpath = GIT_BUF_INIT;
+	git_str fullpath = GIT_STR_INIT;
 	struct stat st;
 	mode_t result;
 
-	git_buf_joinpath(&fullpath, "testrepo", path);
+	git_str_joinpath(&fullpath, "testrepo", path);
 	cl_must_pass(p_stat(fullpath.ptr, &st));
 
 	result = GIT_PERMS_IS_EXEC(st.st_mode) ?
 		GIT_FILEMODE_BLOB_EXECUTABLE : GIT_FILEMODE_BLOB;
 
-	git_buf_dispose(&fullpath);
+	git_str_dispose(&fullpath);
 
 	return result;
 }
@@ -1317,7 +1316,7 @@ void test_checkout_tree__caches_attributes_during_checkout(void)
 	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
 	git_oid oid;
 	git_object *obj = NULL;
-	git_buf ident1 = GIT_BUF_INIT, ident2 = GIT_BUF_INIT;
+	git_str ident1 = GIT_STR_INIT, ident2 = GIT_STR_INIT;
 	char *ident_paths[] = { "ident1.txt", "ident2.txt" };
 
 	opts.progress_cb = update_attr_callback;
@@ -1346,8 +1345,8 @@ void test_checkout_tree__caches_attributes_during_checkout(void)
 	cl_assert_equal_strn(ident1.ptr, "# $Id: ", 7);
 	cl_assert_equal_strn(ident2.ptr, "# $Id: ", 7);
 
-	git_buf_dispose(&ident1);
-	git_buf_dispose(&ident2);
+	git_str_dispose(&ident1);
+	git_str_dispose(&ident2);
 	git_object_free(obj);
 }
 
@@ -1679,6 +1678,6 @@ void test_checkout_tree__dry_run(void)
 
 	/* check that notify callback was invoked */
 	cl_assert_equal_i(ct.n_updates, 2);
-	
+
 	git_object_free(obj);
 }