Add BARE option to git_repository_open_ext

This adds a BARE option to git_repository_open_ext which allows
a fast open path that still knows how to read gitlinks and to
search for the actual .git directory from a subdirectory.

`git_repository_open_bare` is still simpler and faster, but having
a gitlink aware fast open is very useful for submodules where we
want to quickly be able to peek at the HEAD and index data without
doing any other meaningful repo operations.

1 files changed, 9 insertions, 6 deletions

diff --git a/src/repository.c b/src/repository.c
index ed9469c59..bd7ef5476 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -266,7 +266,7 @@ static int find_ceiling_dir_offset(
 			buf[--len] = '\0';
 
 		if (!strncmp(path, buf2, len) &&
-			path[len] == '/' &&
+			(path[len] == '/' || !path[len]) &&
 			len > max_len)
 		{
 			max_len = len;
@@ -322,17 +322,18 @@ static int find_repo(
 	git_buf path = GIT_BUF_INIT;
 	struct stat st;
 	dev_t initial_device = 0;
-	bool try_with_dot_git = false;
+	bool try_with_dot_git = ((flags & GIT_REPOSITORY_OPEN_BARE) != 0);
 	int ceiling_offset;
 
 	git_buf_free(repo_path);
 
-	if ((error = git_path_prettify_dir(&path, start_path, NULL)) < 0)
+	if ((error = git_path_prettify(&path, start_path, NULL)) < 0)
 		return error;
 
 	ceiling_offset = find_ceiling_dir_offset(path.ptr, ceiling_dirs);
 
-	if ((error = git_buf_joinpath(&path, path.ptr, DOT_GIT)) < 0)
+	if (!try_with_dot_git &&
+		(error = git_buf_joinpath(&path, path.ptr, DOT_GIT)) < 0)
 		return error;
 
 	while (!error && !git_buf_len(repo_path)) {
@@ -384,7 +385,7 @@ static int find_repo(
 		try_with_dot_git = !try_with_dot_git;
 	}
 
-	if (!error && parent_path != NULL) {
+	if (!error && parent_path && !(flags & GIT_REPOSITORY_OPEN_BARE)) {
 		if (!git_buf_len(repo_path))
 			git_buf_clear(parent_path);
 		else {
@@ -460,7 +461,9 @@ int git_repository_open_ext(
 	repo->path_repository = git_buf_detach(&path);
 	GITERR_CHECK_ALLOC(repo->path_repository);
 
-	if ((error = load_config_data(repo)) < 0 ||
+	if ((flags & GIT_REPOSITORY_OPEN_BARE) != 0)
+		repo->is_bare = 1;
+	else if ((error = load_config_data(repo)) < 0 ||
 		(error = load_workdir(repo, &parent)) < 0)
 	{
 		git_repository_free(repo);