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, 21 insertions, 22 deletions

diff --git a/tests/online/push.c b/tests/online/push.c
index c82b606cb..51adc3930 100644
--- a/tests/online/push.c
+++ b/tests/online/push.c
@@ -1,5 +1,4 @@
 #include "clar_libgit2.h"
-#include "buffer.h"
 #include "posix.h"
 #include "vector.h"
 #include "../submodule/submodule_helpers.h"
@@ -129,28 +128,28 @@ static void do_verify_push_status(record_callbacks_data *data, const push_status
 			}
 
 	if (failed) {
-		git_buf msg = GIT_BUF_INIT;
+		git_str msg = GIT_STR_INIT;
 
-		git_buf_puts(&msg, "Expected and actual push statuses differ:\nEXPECTED:\n");
+		git_str_puts(&msg, "Expected and actual push statuses differ:\nEXPECTED:\n");
 
 		for(i = 0; i < expected_len; i++) {
-			git_buf_printf(&msg, "%s: %s\n",
+			git_str_printf(&msg, "%s: %s\n",
 				expected[i].ref,
 				expected[i].success ? "success" : "failed");
 		}
 
-		git_buf_puts(&msg, "\nACTUAL:\n");
+		git_str_puts(&msg, "\nACTUAL:\n");
 
 		git_vector_foreach(actual, i, iter) {
 			if (iter->success)
-				git_buf_printf(&msg, "%s: success\n", iter->ref);
+				git_str_printf(&msg, "%s: success\n", iter->ref);
 			else
-				git_buf_printf(&msg, "%s: failed with message: %s", iter->ref, iter->msg);
+				git_str_printf(&msg, "%s: failed with message: %s", iter->ref, iter->msg);
 		}
 
-		cl_fail(git_buf_cstr(&msg));
+		cl_fail(git_str_cstr(&msg));
 
-		git_buf_dispose(&msg);
+		git_str_dispose(&msg);
 	}
 
 	git_vector_foreach(actual, i, iter) {
@@ -192,7 +191,7 @@ static void verify_tracking_branches(git_remote *remote, expected_ref expected_r
 {
 	git_refspec *fetch_spec;
 	size_t i, j;
-	git_buf msg = GIT_BUF_INIT;
+	git_str msg = GIT_STR_INIT;
 	git_buf ref_name = GIT_BUF_INIT;
 	git_vector actual_refs = GIT_VECTOR_INIT;
 	git_branch_iterator *iter;
@@ -230,12 +229,12 @@ static void verify_tracking_branches(git_remote *remote, expected_ref expected_r
 
 		/* Find matching remote branch */
 		git_vector_foreach(&actual_refs, j, actual_ref) {
-			if (!strcmp(git_buf_cstr(&ref_name), actual_ref))
+			if (!strcmp(ref_name.ptr, actual_ref))
 				break;
 		}
 
 		if (j == actual_refs.length) {
-			git_buf_printf(&msg, "Did not find expected tracking branch '%s'.", git_buf_cstr(&ref_name));
+			git_str_printf(&msg, "Did not find expected tracking branch '%s'.", ref_name.ptr);
 			failed = 1;
 			goto failed;
 		}
@@ -244,7 +243,7 @@ static void verify_tracking_branches(git_remote *remote, expected_ref expected_r
 		cl_git_pass(git_reference_name_to_id(&oid, remote->repo, actual_ref));
 
 		if (git_oid_cmp(expected_refs[i].oid, &oid) != 0) {
-			git_buf_puts(&msg, "Tracking branch commit does not match expected ID.");
+			git_str_puts(&msg, "Tracking branch commit does not match expected ID.");
 			failed = 1;
 			goto failed;
 		}
@@ -255,27 +254,27 @@ static void verify_tracking_branches(git_remote *remote, expected_ref expected_r
 
 	/* Make sure there are no extra branches */
 	if (actual_refs.length > 0) {
-		git_buf_puts(&msg, "Unexpected remote tracking branches exist.");
+		git_str_puts(&msg, "Unexpected remote tracking branches exist.");
 		failed = 1;
 		goto failed;
 	}
 
 failed:
 	if (failed)
-		cl_fail(git_buf_cstr(&msg));
+		cl_fail(git_str_cstr(&msg));
 
 	git_vector_foreach(&actual_refs, i, actual_ref)
 		git__free(actual_ref);
 
 	git_vector_free(&actual_refs);
-	git_buf_dispose(&msg);
+	git_str_dispose(&msg);
 	git_buf_dispose(&ref_name);
 }
 
 static void verify_update_tips_callback(git_remote *remote, expected_ref expected_refs[], size_t expected_refs_len)
 {
 	git_refspec *fetch_spec;
-	git_buf msg = GIT_BUF_INIT;
+	git_str msg = GIT_STR_INIT;
 	git_buf ref_name = GIT_BUF_INIT;
 	updated_tip *tip = NULL;
 	size_t i, j;
@@ -293,18 +292,18 @@ static void verify_update_tips_callback(git_remote *remote, expected_ref expecte
 
 		/* Find matching update_tip entry */
 		git_vector_foreach(&_record_cbs_data.updated_tips, j, tip) {
-			if (!strcmp(git_buf_cstr(&ref_name), tip->name))
+			if (!strcmp(ref_name.ptr, tip->name))
 				break;
 		}
 
 		if (j == _record_cbs_data.updated_tips.length) {
-			git_buf_printf(&msg, "Did not find expected updated tip entry for branch '%s'.", git_buf_cstr(&ref_name));
+			git_str_printf(&msg, "Did not find expected updated tip entry for branch '%s'.", ref_name.ptr);
 			failed = 1;
 			goto failed;
 		}
 
 		if (git_oid_cmp(expected_refs[i].oid, &tip->new_oid) != 0) {
-			git_buf_printf(&msg, "Updated tip ID does not match expected ID");
+			git_str_printf(&msg, "Updated tip ID does not match expected ID");
 			failed = 1;
 			goto failed;
 		}
@@ -312,10 +311,10 @@ static void verify_update_tips_callback(git_remote *remote, expected_ref expecte
 
 failed:
 	if (failed)
-		cl_fail(git_buf_cstr(&msg));
+		cl_fail(git_str_cstr(&msg));
 
 	git_buf_dispose(&ref_name);
-	git_buf_dispose(&msg);
+	git_str_dispose(&msg);
 }
 
 void test_online_push__initialize(void)