Function setup_explicit_git_dir

setup.c:1107–1205

}

static const char *setup_explicit_git_dir(struct repository *repo,
					  const char *gitdirenv,
					  struct strbuf *cwd,
					  struct repository_format *repo_fmt,
					  int *nongit_ok)
{
	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
	const char *worktree;
	char *gitfile;
	int offset;

	if (PATH_MAX - 40 < strlen(gitdirenv))
		die(_("'$%s' too big"), GIT_DIR_ENVIRONMENT);

	gitfile = (char*)read_gitfile(gitdirenv);
	if (gitfile) {
		gitfile = xstrdup(gitfile);
		gitdirenv = gitfile;
	}

	if (!is_git_directory(gitdirenv)) {
		if (nongit_ok) {
			*nongit_ok = 1;
			free(gitfile);
			return NULL;
		}
		die(_("not a git repository: '%s'"), gitdirenv);
	}

	if (check_repository_format_gently(gitdirenv, repo_fmt, nongit_ok)) {
		free(gitfile);
		return NULL;
	}

	/* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
	if (work_tree_env)
		set_git_work_tree(repo, work_tree_env);
	else if (is_bare_repository_cfg > 0) {
		if (git_work_tree_cfg) {
			/* #22.2, #30 */
			warning("core.bare and core.worktree do not make sense");
			repo->worktree_config_is_bogus = true;
		}

		/* #18, #26 */
		set_git_dir(repo, gitdirenv, 0);
		free(gitfile);
		return NULL;
	}
	else if (git_work_tree_cfg) { /* #6, #14 */
		if (is_absolute_path(git_work_tree_cfg))
			set_git_work_tree(repo, git_work_tree_cfg);
		else {
			char *core_worktree;
			if (chdir(gitdirenv))
				die_errno(_("cannot chdir to '%s'"), gitdirenv);
			if (chdir(git_work_tree_cfg))
				die_errno(_("cannot chdir to '%s'"), git_work_tree_cfg);