Re: [PATCH] add--interactive: do not expand pathspecs with ls-files

[Jeff King <peff@peff.net>]

On Tue, Mar 14, 2017 at 03:03:34PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > We can improve this by skipping "ls-files" completely, and
> > just feeding the original pathspecs to the diff commands.
> > This solution was discussed in 2010:
> >
> >   http://public-inbox.org/git/20100105041438.GB12574@coredump.intra.peff.net/
> >
> > but at the time the diff code's pathspecs were more
> > primitive than those used by ls-files (e.g., they did not
> > support globs). Making the change would have caused a
> > user-visible regression, so we didn't.
> 
> Heh.  The change and the reasoning are both obviously correct, but
> how did you find this?  Do you have a pile of "old patches that
> should be resurrected when time is right" and this was picked out of
> it, or did you see somebody else hit the same thing recently and
> then went back to the archive?

The latter.  Mislav reported it to me off-list earlier today, and I
generated the patch. But after scratching my head at the familiarity and
especially wondering if there was some reason to use "ls-files" here, I
dug up the linked thread. The fact that the patches are identical is
just coincidence (though it's such a simple change that it seems highly
likely).

> >      So this takes us one step closer to working correctly
> >      with files whose names contain wildcard characters, but
> >      it's likely that others remain (e.g., if "git add -i"
> >      feeds the selected paths to "git add").
> 
> We didn't run with --literal-pathspecs which was a bug, but I
> suspect that it didn't exist back then ;-).

Yep. I think judiciously inserting "--literal-pathspecs" is probably the
correct fix. In an earlier thread (that I linked elsewhere from the
discussion here) I suggested just setting $GIT_LITERAL_PATHSPECS to 1.
But that is probably a bad idea. As this patch shows, we do still
sometimes feed the original non-expanded pathspec to some commands.

I left that as potential low-hanging fruit for somebody who cares more
(the trickiest part is probably not the fix, but coming up with a test
case).

-Peff