bug#12007: 24.1.50; Crash in auto-revert-handler

[Eli Zaretskii]

> Date: Wed, 15 Aug 2012 20:50:15 +0400
> From: Dmitry Antipov <dmantipov@yandex.ru>
> CC: cschol2112@googlemail.com, 12007@debbugs.gnu.org
> 
> > Today's trunk still crashes on startup.  Can this be fixed, please?
> 
> I don't know whether you have received my previous e-mail, but it was:
> 
> Eli, please review a fix.

Sorry, I wrote that before I saw you mail.

> This looks simple: it's wrong to look at with f->output_data.XXX without
> checking f->output_method first, so, FRAME_X_OUTPUT (f) may be non-zero
> for TTY frames, and segfault comes when xg_mark_data looks at initial
> ("F1") frame with non-zero f->output_data.tty member.

The patch works for me, and it seems to be the right one.  Jan, could
you take a look?  (I don't feel I know enough about the GTK build.)

> P.S. BTW, this is X/GTK bug rather that GC bug.

Right again, sorry for jumping the gun too soon.