Re: "git stash pop" is doing an unwanted "git add" when there are conflicts.

[Jeff King <peff@peff.net>]

On Tue, Dec 22, 2015 at 09:17:38AM +0100, Dennis Kaarsemaker wrote:

> On ma, 2015-12-21 at 14:29 +0000, Alan Mackenzie wrote:
> > Hello, git project.
> > 
> > Last night, whilst clearing out a stale "stash stack", I did "git stash
> > pop".  There were conflicts in two files.
> > 
> > However, all the popped files became staged.  This doesn't normally happen.
> > It was intensely irritating, and required me to do "git reset HEAD" on
> > each of the files, none of which I wanted to commit.
> > 
> > I searched the git-stash man page for this scenario, but found nothing
> > about it.
> > 
> > Surely staging all the files is a bug?
> 
> That depends. A stash is two commits: one for all changes that were in
> the index when you ran 'git stash save' and one for all changes not yet
> in the index. When you pop the stash, these then get restored as staged
> resp. unstaged changes. So if your changes are now all staged, I'd
> wager that they were staged when you ran git stash save.

No, I think there's something else going on. Try this:
  
    git init repo &&
    cd repo &&
    
    echo base >one &&
    echo base >two &&
    git add . &&
    git commit -m base &&
    
    echo stash >one &&
    echo stash >two &&
    git stash &&
    
    echo "==> No conflicts, nothing staged"
    git stash apply &&
    
    git reset --hard &&
    echo changes >two &&
    git commit -am changes &&
    
    echo "==> Conflict stages non-conflicting file 'one'"
    ! git stash apply &&
    git status

It seems to be a side effect of merge-recursive to stage the results,
and in the no-conflict path we explicitly reset the index. For the
conflicting case, it's trickier, because we would want to retain the
unmerged entries.

So I agree it's kind of weird, but the conflicting case is inherently
going to touch the index, and you'd generally have to `git add` to mark
the resolutions (but if you really want to just touch the working tree,
you'd need to `git reset`).

-Peff