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, 13 insertions, 13 deletions

diff --git a/tests/attr/repo.c b/tests/attr/repo.c
index eabc033eb..e7b975290 100644
--- a/tests/attr/repo.c
+++ b/tests/attr/repo.c
@@ -230,12 +230,12 @@ void test_attr_repo__manpage_example(void)
 
 static void add_to_workdir(const char *filename, const char *content)
 {
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 
-	cl_git_pass(git_buf_joinpath(&buf, "attr", filename));
-	cl_git_rewritefile(git_buf_cstr(&buf), content);
+	cl_git_pass(git_str_joinpath(&buf, "attr", filename));
+	cl_git_rewritefile(git_str_cstr(&buf), content);
 
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 }
 
 static void assert_proper_normalization(git_index *index, const char *filename, const char *expected_sha)
@@ -311,12 +311,12 @@ void test_attr_repo__bare_repo_with_index(void)
 
 void test_attr_repo__sysdir(void)
 {
-	git_buf sysdir = GIT_BUF_INIT;
+	git_str sysdir = GIT_STR_INIT;
 	const char *value;
 
 	cl_git_pass(p_mkdir("system", 0777));
 	cl_git_rewritefile("system/gitattributes", "file merge=foo");
-	cl_git_pass(git_buf_joinpath(&sysdir, clar_sandbox_path(), "system"));
+	cl_git_pass(git_str_joinpath(&sysdir, clar_sandbox_path(), "system"));
 	cl_git_pass(git_sysdir_set(GIT_SYSDIR_SYSTEM, sysdir.ptr));
 	g_repo = cl_git_sandbox_reopen();
 
@@ -325,18 +325,18 @@ void test_attr_repo__sysdir(void)
 
 	cl_git_pass(p_unlink("system/gitattributes"));
 	cl_git_pass(p_rmdir("system"));
-	git_buf_dispose(&sysdir);
+	git_str_dispose(&sysdir);
 }
 
 void test_attr_repo__sysdir_with_session(void)
 {
 	const char *values[2], *attrs[2] = { "foo", "bar" };
-	git_buf sysdir = GIT_BUF_INIT;
+	git_str sysdir = GIT_STR_INIT;
 	git_attr_session session;
 
 	cl_git_pass(p_mkdir("system", 0777));
 	cl_git_rewritefile("system/gitattributes", "file foo=1 bar=2");
-	cl_git_pass(git_buf_joinpath(&sysdir, clar_sandbox_path(), "system"));
+	cl_git_pass(git_str_joinpath(&sysdir, clar_sandbox_path(), "system"));
 	cl_git_pass(git_sysdir_set(GIT_SYSDIR_SYSTEM, sysdir.ptr));
 	g_repo = cl_git_sandbox_reopen();
 
@@ -348,7 +348,7 @@ void test_attr_repo__sysdir_with_session(void)
 
 	cl_git_pass(p_unlink("system/gitattributes"));
 	cl_git_pass(p_rmdir("system"));
-	git_buf_dispose(&sysdir);
+	git_str_dispose(&sysdir);
 	git_attr_session__free(&session);
 }
 
@@ -371,11 +371,11 @@ void test_attr_repo__rewrite(void)
 
 void test_attr_repo__rewrite_sysdir(void)
 {
-	git_buf sysdir = GIT_BUF_INIT;
+	git_str sysdir = GIT_STR_INIT;
 	const char *value;
 
 	cl_git_pass(p_mkdir("system", 0777));
-	cl_git_pass(git_buf_joinpath(&sysdir, clar_sandbox_path(), "system"));
+	cl_git_pass(git_str_joinpath(&sysdir, clar_sandbox_path(), "system"));
 	cl_git_pass(git_sysdir_set(GIT_SYSDIR_SYSTEM, sysdir.ptr));
 	g_repo = cl_git_sandbox_reopen();
 
@@ -387,7 +387,7 @@ void test_attr_repo__rewrite_sysdir(void)
 	cl_git_pass(git_attr_get(&value, g_repo, 0, "file", "foo"));
 	cl_assert_equal_s(value, "second");
 
-	git_buf_dispose(&sysdir);
+	git_str_dispose(&sysdir);
 }
 
 void test_attr_repo__unlink(void)