Re: [PATCH/RFC 3/3] stash: pass the pathspec argument to git reset

[Thomas Gummerer <t.gummerer@gmail.com>]

On 03/20, Jeff King wrote:
> On Sun, Mar 19, 2017 at 08:23:51PM +0000, Thomas Gummerer wrote:
> 
> > For "git stash -p --no-keep-index", the pathspec argument is currently
> > not passed to "git reset".  This means that changed that are staged but
> > that are excluded from the pathspec still get unstaged by git stash -p.
> 
> Yeah, I noticed this while playing around with patch 2. This seems
> like an improvement to me. Unlike the other patches (which are just
> tweaking quietness), I think this one really needs a test.
>
> Also, s/changed/changes/ above.

Thanks.  Will add a test in the re-roll.

> > ---
> > So this make things a bit inconsistent in for example the following
> > situation:
> > 
> >     $ git status -s
> >      M git-stash.sh
> >     M  read-cache.c
> > 
> > where using git stash -p --no-keep-index, when only changes in
> > git-stash.sh are added to the stash would reset read-cache.c, but with
> > git stash -p --no-keep-index -- git-stash.sh, read-cache.c would not
> > be reset.
> 
> I think it's OK. You can't select (or not select) changes from the index
> anyway. TBH, I kind of wonder if "git stash -p --no-keep-index" makes
> any sense at all.

Yeah I don't have any use case for it, but maybe someone does, so I
think fixing it this way now is the best way forward.

> > However it does bring things more in line with git stash --
> > <pathspec>, so I think this is an improvement.
> 
> I did notice one other case while looking at this that I think is much
> more serious. The "read-tree" call in the non-patch-mode case doesn't
> use a pathspec either. So if we have our same setup where "one" and
> "two" have unstaged changes and we do:
> 
>   git stash push -k one
> 
> Then we stash "one", but the change in "two" is wiped out completely!

Good catch, that's definitely another bug :/ 

> I don't think read-tree takes pathspecs, so it would have to drop the
> "-u" and replace it with checkout-index. I'm confused about why we would
> need it in the first place, though. We should have already dealt with
> the working tree files in the earlier block, so there should be nothing
> to checkout.
> 
> The "-u" goes all the way back to 7bedebcaa (stash: introduce 'stash
> save --keep-index' option, 2008-06-27). I wonder if it has always been
> unnecessary, but we never noticed because it's just a noop.

I do think the "-u" is necessary.  Say we have a repository with
changes in 'foo' and 'bar', where the changes in bar are added to the
index.

Then 'git stash -k' would wipe out the changes in both 'foo' and 'bar'
through 'git reset --hard', but we do want the changes in 'bar' to
still exist on disk, which they wouldn't without the "-u".

But I'll replace the "-u" with checkout-index, so we can respect the
pathspec.

Thanks!

> -Peff