Re: [scratch/igc] 985247b6bee crash on Linux, KDE, Wayland

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: Eval EXEC <execvy@gmail.com>,  pipcet@protonmail.com,  emacs-devel@gnu.org
> Date: Thu, 05 Sep 2024 15:20:40 +0200
> 
> >> #23 <signal handler called>
> >> No symbol table info available.
> >> #24 0x0000000000692cd8 in fix_frame (f=0x7f5f87885498, ss=0x7ffe0290f6a8) at /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/igc.c:2068
> >
> > This segfault is here:
> >
> >     if (!FRAME_INITIAL_P (f))
> >       {
> > 	/* This is typically stored in the display_info, e.g.
> > 	   ns_display_info.  Check for being NULL anyway.  */
> > 	Mouse_HLInfo *hlinfo = MOUSE_HL_INFO (f);  <<<<<<<<<<<<<<<<<<<<<<<
> > 	if (hlinfo)
> > 	  {
> > 	    IGC_FIX12_OBJ (ss, &hlinfo->mouse_face_window);
> > 	    IGC_FIX12_OBJ (ss, &hlinfo->mouse_face_overlay);
> > 	    IGC_FIX12_RAW (ss, &hlinfo->mouse_face_mouse_frame);
> > 	  }
> >       }
> >
> > This code was added just a few days ago.  MOUSE_HL_INFO expands to:
> >
> >   # define MOUSE_HL_INFO(F)					\
> >     (FRAME_WINDOW_P (F)						\
> >      ? &FRAME_DISPLAY_INFO(F)->mouse_highlight			\
> >      : &(F)->output_data.tty->display_info->mouse_highlight)
> >
> > So this looks like FRAME_DISPLAY_INFO(F) is not traced or something?
> 
> Hm, sesms we have to check for FRAME_OUTPUT_DATA being null for window
> frames.

Why do you think so?  Are we sure FRAME_OUTPUT_DATA is NULL in this
case (as opposed to a pointer that cannot be dereferenced because it
was moved)?