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

From: Jeff King <peff@peff.net>
Date: Mar 14, 2017, 22:09 UTC
Message-ID: <20170314220937.xg6isonertnykx4y@sigill.intra.peff.net>
In-Reply-To: <xmqqd1djh5xl.fsf@gitster.mtv.corp.google.com>

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

Show 18 quoted lines

> 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).

Show 7 quoted lines

> >      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