Re: [FR] Allow `git stash create` to include untracked changes

Hi Junio,

On Mon, 28 Oct 2019, Junio C Hamano wrote:

Careful, this is a false friend. It _is_ work horse of `git stash create`, but not _quite_ in the way you think:

-- snap --
create)
	shift
	create_stash -m "$*" && echo "$w_commit"
	;;
-- snap --

So what is the reason for the existence of this command-line parsing:

Why, `push_stash` calls `create_stash` ;-)

-- snip --
push_stash () {
	[...]
        untracked=
	[...]
                -u|--include-untracked)
			untracked=untracked
			;;
	[...]
        create_stash -m "$stash_msg" -u "$untracked" -- "$@"
	[...]
-- snap --

So the reason that `git stash create -u ...` does not work is that it never was designed to work ;-)

Well, given this code in `builtin/stash.c`, I would imagine that `git stash push -u ...` works both in the legacy and the built-in version of `git stash`:

-- snip --
static int push_stash(int argc, const char **argv, const char *prefix)
{
	int keep_index = -1;
	int patch_mode = 0;
	int include_untracked = 0;
	int quiet = 0;
	const char *stash_msg = NULL;
	struct pathspec ps;
	struct option options[] = {
		OPT_BOOL('k', "keep-index", &keep_index,
			 N_("keep index")),
		OPT_BOOL('p', "patch", &patch_mode,
			 N_("stash in patch mode")),
		OPT__QUIET(&quiet, N_("quiet mode")),
		OPT_BOOL('u', "include-untracked", &include_untracked,
			 N_("include untracked files in stash")),
		OPT_SET_INT('a', "all", &include_untracked,
			    N_("include ignore files"), 2),
		OPT_STRING('m', "message", &stash_msg, N_("message"),
			   N_("stash message")),
		OPT_END()
	};

	if (argc)
		argc = parse_options(argc, argv, prefix, options,
				     git_stash_push_usage,
				     0);

	parse_pathspec(&ps, 0, PATHSPEC_PREFER_FULL | PATHSPEC_PREFIX_ORIGIN,
		       prefix, argv);
	return do_push_stash(&ps, stash_msg, quiet, keep_index, patch_mode,
			     include_untracked);
}
-- snap --

So why does `git stash create -u ...` not work? Because the original design of `git stash create` never intended to take any command-line arguments other than the stash message. And that design can obviously not be fixed without breaking backwards compatibility.

What we _could_ do is to add a new command-line option to `git stash push` that would make it behave like the `create` subsubcommand: _not_ update the `refs/stash` ref but instead print the commit hash.

I am not quite sure how to call this option (`--ephemeral` came to my mind, as the created commit is not reachable from anywhere and is hence subject to garbage collection).

A completely different approach would be to allow overriding the ref to store the stash in, with an empty value triggering the mode where the ref is not updated but the commit hash would be printed instead. I am thinking of something like `git stash -r '' push ...`, starting with this patch:

-- snip --