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

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Eval EXEC <execvy@gmail.com>
>> Cc: emacs-devel <emacs-devel@gnu.org>
>> Date: Thu, 05 Sep 2024 19:49:56 +0800
>> 
>> 
>> It crash again:
>> [...]
>> #19 0x00000000006d7a10 in deliver_thread_signal.constprop.0 (sig=11, handler=<optimized out>) at /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/sysdep.c:1792
>>         old_errno = <optimized out>
>> #20 <signal handler called>
>> No symbol table info available.
>> #21 0x00007f5fde45316b in kill () from /nix/store/dbcw19dshdwnxdv5q2g6wldj6syyvq7l-glibc-2.39-52/lib/libc.so.6
>> No symbol table info available.
>> #22 0x0000000000767b69 in sigHandle ()
>> No symbol table info available.
>> #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. Sorry for that. I'll push a fix tomorrow unless someone beats me
to it. Something like

   if (!FRAME_INITIAL_P (f) && (!FRAME_WINDOW_P (f) || FRAME_OUTPUT_DATA (f)))

or something. Or maybe even nicer would be to let MOUES_HL_INFO return
NULL if !FRAME_OUTPUT_DATA, but whatever.