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, 7 insertions, 7 deletions

diff --git a/tests/path/core.c b/tests/path/core.c
index c875a862c..1d6066933 100644
--- a/tests/path/core.c
+++ b/tests/path/core.c
@@ -12,11 +12,11 @@ static void test_make_relative(
 	const char *parent,
 	int expected_status)
 {
-	git_buf buf = GIT_BUF_INIT;
-	git_buf_puts(&buf, path);
+	git_str buf = GIT_STR_INIT;
+	git_str_puts(&buf, path);
 	cl_assert_equal_i(expected_status, git_path_make_relative(&buf, parent));
 	cl_assert_equal_s(expected_path, buf.ptr);
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 }
 
 void test_path_core__make_relative(void)
@@ -373,19 +373,19 @@ static void test_join_unrooted(
 	const char *path,
 	const char *base)
 {
-	git_buf result = GIT_BUF_INIT;
+	git_str result = GIT_STR_INIT;
 	ssize_t root_at;
 
 	cl_git_pass(git_path_join_unrooted(&result, path, base, &root_at));
 	cl_assert_equal_s(expected_result, result.ptr);
 	cl_assert_equal_i(expected_rootlen, root_at);
 
-	git_buf_dispose(&result);
+	git_str_dispose(&result);
 }
 
 void test_path_core__join_unrooted(void)
 {
-	git_buf out = GIT_BUF_INIT;
+	git_str out = GIT_STR_INIT;
 
 	test_join_unrooted("foo", 0, "foo", NULL);
 	test_join_unrooted("foo/bar", 0, "foo/bar", NULL);
@@ -421,7 +421,7 @@ void test_path_core__join_unrooted(void)
 	/* Trailing slash in the base is ignored */
 	test_join_unrooted("c:/foo/bar/foobar", 6, "c:/foo/bar/foobar", "c:/foo/");
 
-	git_buf_dispose(&out);
+	git_str_dispose(&out);
 }
 
 void test_path_core__join_unrooted_respects_funny_windows_roots(void)