bug#30800: 26.0.91; unknown crash on macos

[Eli Zaretskii]

> From: Aaron Jensen <aaronjensen@gmail.com>
> Date: Wed, 21 Mar 2018 22:35:23 -0700
> Cc: Alan Third <alan@idiocy.org>, 30800@debbugs.gnu.org
> 
> >>     if (represented_frame == f)
> >>       represented_frame = NULL;
> >>
> >> to x_destroy_frame as you say.
> >
> > If that fixes the problem, it's the safest change I can think of, so
> > perhaps Aaron could try running Emacs 26.0.91 with it.
> 
> It seems to fix it. I'm unable to reproduce the crash with this patch
> applied.

Thanks.  Let's see if you encounter the crash while running with the
change a little longer.