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, 11 deletions

diff --git a/tests/refs/rename.c b/tests/refs/rename.c
index b1b75cd64..fa732234a 100644
--- a/tests/refs/rename.c
+++ b/tests/refs/rename.c
@@ -36,11 +36,11 @@ void test_refs_rename__loose(void)
 {
 	/* rename a loose reference */
 	git_reference *looked_up_ref, *new_ref, *another_looked_up_ref;
-	git_buf temp_path = GIT_BUF_INIT;
+	git_str temp_path = GIT_STR_INIT;
 	const char *new_name = "refs/tags/Nemo/knows/refs.kung-fu";
 
 	/* Ensure the ref doesn't exist on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), new_name));
+	cl_git_pass(git_str_joinpath(&temp_path, git_repository_path(g_repo), new_name));
 	cl_assert(!git_path_exists(temp_path.ptr));
 
 	/* Retrieval of the reference to rename */
@@ -66,23 +66,23 @@ void test_refs_rename__loose(void)
 	cl_assert(reference_is_packed(new_ref) == 0);
 
 	/* ...and the ref can be found in the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), new_name));
+	cl_git_pass(git_str_joinpath(&temp_path, git_repository_path(g_repo), new_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	git_reference_free(new_ref);
 	git_reference_free(another_looked_up_ref);
-	git_buf_dispose(&temp_path);
+	git_str_dispose(&temp_path);
 }
 
 void test_refs_rename__packed(void)
 {
 	/* rename a packed reference (should make it loose) */
 	git_reference *looked_up_ref, *new_ref, *another_looked_up_ref;
-	git_buf temp_path = GIT_BUF_INIT;
+	git_str temp_path = GIT_STR_INIT;
 	const char *brand_new_name = "refs/heads/brand_new_name";
 
 	/* Ensure the ref doesn't exist on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), packed_head_name));
+	cl_git_pass(git_str_joinpath(&temp_path, git_repository_path(g_repo), packed_head_name));
 	cl_assert(!git_path_exists(temp_path.ptr));
 
 	/* The reference can however be looked-up... */
@@ -108,23 +108,23 @@ void test_refs_rename__packed(void)
 	cl_assert(reference_is_packed(new_ref) == 0);
 
 	/* ...and the ref now happily lives in the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), brand_new_name));
+	cl_git_pass(git_str_joinpath(&temp_path, git_repository_path(g_repo), brand_new_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	git_reference_free(new_ref);
 	git_reference_free(another_looked_up_ref);
-	git_buf_dispose(&temp_path);
+	git_str_dispose(&temp_path);
 }
 
 void test_refs_rename__packed_doesnt_pack_others(void)
 {
 	/* renaming a packed reference does not pack another reference which happens to be in both loose and pack state */
 	git_reference *looked_up_ref, *another_looked_up_ref, *renamed_ref;
-	git_buf temp_path = GIT_BUF_INIT;
+	git_str temp_path = GIT_STR_INIT;
 	const char *brand_new_name = "refs/heads/brand_new_name";
 
 	/* Ensure the other reference exists on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), packed_test_head_name));
+	cl_git_pass(git_str_joinpath(&temp_path, git_repository_path(g_repo), packed_test_head_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	/* Lookup the other reference */
@@ -155,7 +155,7 @@ void test_refs_rename__packed_doesnt_pack_others(void)
 
 	git_reference_free(renamed_ref);
 	git_reference_free(another_looked_up_ref);
-	git_buf_dispose(&temp_path);
+	git_str_dispose(&temp_path);
 }
 
 void test_refs_rename__name_collision(void)