Re: [PATCH v4 04/10] setup_git_directory_1(): avoid changing global state

> +	switch (setup_git_directory_gently_1(&dir, &gitdir)) {
> +	case GIT_DIR_NONE:
> +		prefix = NULL;
> +		break;
> +	case GIT_DIR_EXPLICIT:
> +		prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
> +		break;
> +	case GIT_DIR_DISCOVERED:
> +		if (dir.len < cwd.len && chdir(dir.buf))
> +			die(_("Cannot change to '%s'"), dir.buf);
> +		prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
> +						  nongit_ok);
> +		break;
> +	case GIT_DIR_BARE:
> +		if (dir.len < cwd.len && chdir(dir.buf))
> +			die(_("Cannot change to '%s'"), dir.buf);
> +		prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
> +		break;
> +	case GIT_DIR_HIT_CEILING:
> +		prefix = setup_nongit(cwd.buf, nongit_ok);
> +		break;
> +	case GIT_DIR_HIT_MOUNT_POINT:
> +		if (nongit_ok) {
> +			*nongit_ok = 1;
> +			return NULL;
> +		}
> +		die(_("Not a git repository (or any parent up to mount point %s)\n"
> +		      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
> +		    dir.buf);
> +	default:
> +		die("BUG: unhandled setup_git_directory_1() result");
> +	}