bug#21457: 25.0.50; vc-test-git03-working-revision test fails

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Glenn Morris <rgm@gnu.org>,  21457@debbugs.gnu.org
> Date: Sat, 12 Sep 2015 11:42:59 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > The patches below make this work for me.  The first one should
> > probably be applied regardless, as without it vc-git--rev-parse is not
> > safe to call in some borderline cases.
> >
> > diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
> > index 8a0f554..af2b39f 100644
> > --- a/lisp/vc/vc-git.el
> > +++ b/lisp/vc/vc-git.el
> > @@ -1137,7 +1137,9 @@ (defun vc-git--rev-parse (rev)
> >    (with-temp-buffer
> >      (and
> >       (vc-git--out-ok "rev-parse" rev)
> > -     (buffer-substring-no-properties (point-min) (+ (point-min) 40)))))
> > +     (buffer-substring-no-properties (point-min)
> > +                                     (min (1- (point-max))
> > +                                          (+ (point-min) 40))))))
> 
> Why does vc-git--out-ok return true when git rev-parse failed?

Good question, I will look into it soon.

Do you know whether "HEAD" is indeed what the latest Git should return
in this case, though?  The original test expected "master".  Was this
some change in Git?  I cannot find anything about this in Google, but
that's a small wonder as including "HEAD" in the query brings in a lot
of useless clutter.