Re: `git status -u no` suppresses modified files too.

[Rusty Russell <rusty@rustcorp.com.au>]

Jeff King <peff@peff.net> writes:
> On Fri, Feb 08, 2019 at 12:18:57PM +1030, Rusty Russell wrote:
>
>> This broke my "is this clean?" sanity check and very much violates
>> the man page description.
>
> Wow, this one had me scratching my head for a minute. What you're
> describing here:
>
>>         $ git status -u no
>>         On branch guilt/repro
>
> ...seems horribly broken, and the behavior goes back to the beginnings
> of "-u". So I wondered how we would not have noticed for so long.
>
> But what is going on is quite subtle. The "-u" option takes an optional
> argument, and so must be used in its "stuck" form. I.e.,
>
>   git status -uno

Urgh, manual page even *says* this, and I missed it:

        It is optional: it
        defaults to all, and if specified, it must be stuck to the option (e.g.  -uno, but not -u
        no).

Note that optional arguments are fundamentally broken like this: you
should *never* add them to your programs.  If -u suddently wanted an
argument, a new option should have been added.

But despite that "well, I wouldn't start from here!" advice, I think
your patch seems really helpful.

Thanks for clue contribution! 
Rusty.

> does do what you expect. We cannot allow the separated form here,
> because that would conflict with another actual option, like:
>
>   git status -u --porcelain
>
> So why does it behave as it does? We accept "no" as its own pathspec
> argument, and thus we limit the status to that path. And that's why
> there's "nothing to commit"; there's nothing in that pathspec.
>
> This is a pretty horrible UI trap. Most of the time with pathspecs we
> require them to be on the right-hand side of a "--" unless the paths
> actually exist in the filesystem. But then, in most of those cases we're
> making sure they're not ambiguous between revisions and paths. So maybe
> it's overkill here. I dunno. But the patch below certainly makes what's
> going on in your case less subtle:
>
>   $ git status -u no
>   fatal: no: no such path in the working tree.
>   Use 'git <command> -- <path>...' to specify paths that do not exist locally.
>
> You do still have to figure out why it wasn't stuck to "-u", though.
>
> ---
> diff --git a/builtin/commit.c b/builtin/commit.c
> index 2986553d5f..7177d7d82f 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -1300,6 +1300,16 @@ static int git_status_config(const char *k, const char *v, void *cb)
>  	return git_diff_ui_config(k, v, NULL);
>  }
>  
> +static void verify_pathspec(const char *prefix, const char **argv)
> +{
> +	while (*argv) {
> +		const char *arg = *argv++;
> +		if (!strcmp(arg, "--"))
> +			return;
> +		verify_filename(prefix, arg, 0);
> +	}
> +}
> +
>  int cmd_status(int argc, const char **argv, const char *prefix)
>  {
>  	static int no_renames = -1;
> @@ -1351,7 +1361,7 @@ int cmd_status(int argc, const char **argv, const char *prefix)
>  	status_init_config(&s, git_status_config);
>  	argc = parse_options(argc, argv, prefix,
>  			     builtin_status_options,
> -			     builtin_status_usage, 0);
> +			     builtin_status_usage, PARSE_OPT_KEEP_DASHDASH);
>  	finalize_colopts(&s.colopts, -1);
>  	finalize_deferred_config(&s);
>  
> @@ -1362,6 +1372,7 @@ int cmd_status(int argc, const char **argv, const char *prefix)
>  	    s.show_untracked_files == SHOW_NO_UNTRACKED_FILES)
>  		die(_("Unsupported combination of ignored and untracked-files arguments"));
>  
> +	verify_pathspec(prefix, argv);
>  	parse_pathspec(&s.pathspec, 0,
>  		       PATHSPEC_PREFER_FULL,
>  		       prefix, argv);