Function is_git_directory

setup.c:415–453

* Test if it looks like we're at a git directory. * We want to see: * * - either an objects/ directory _or_ the proper * GIT_OBJECT_DIRECTORY environment variable * - a refs/ directory * - either a HEAD symlink or a HEAD file that is formatted as * a proper "ref:", or a regular file HEAD that has a properly * formatted sha1 object name. */

 *    formatted sha1 object name.
 */
int is_git_directory(const char *suspect)
{
	struct strbuf path = STRBUF_INIT;
	int ret = 0;
	size_t len;

	/* Check worktree-related signatures */
	strbuf_addstr(&path, suspect);
	strbuf_complete(&path, '/');
	strbuf_addstr(&path, "HEAD");
	if (validate_headref(path.buf))
		goto done;

	strbuf_reset(&path);
	get_common_dir(&path, suspect);
	len = path.len;

	/* Check non-worktree-related signatures */
	if (getenv(DB_ENVIRONMENT)) {
		if (access(getenv(DB_ENVIRONMENT), X_OK))
			goto done;
	}
	else {
		strbuf_setlen(&path, len);
		strbuf_addstr(&path, "/objects");
		if (access(path.buf, X_OK))
			goto done;
	}

	strbuf_setlen(&path, len);
	strbuf_addstr(&path, "/refs");
	if (access(path.buf, X_OK))
		goto done;

	ret = 1;
done:
	strbuf_release(&path);
	return ret;
}

int is_nonbare_repository_dir(struct strbuf *path)
{