bug#65198: 29.1; Emacs29.1 crash in function face_for_font

[Eli Zaretskii]

> From: 张云峰 <zhangyunfeng0101@gmail.com>
> Date: Fri, 11 Aug 2023 22:21:11 +0800
> Cc: 65198@debbugs.gnu.org
> 
> Thread 1 "emacs" received signal SIGSEGV, Segmentation fault.
> 0x0000555555616206 in produce_glyphless_glyph (it=0x7fffffff6cc0,
> for_no_font=for_no_font@entry=false, acronym=acronym@entry=0x0) at
> xdisp.c:31791
> 31791 font = face->font ? face->font : FRAME_FONT (it->f);
> (gdb) p it->face_id
> $1 = 0
> (gdb) p it->c
> $2 = 9888
> (gdb) p FRAME_FONT(it->f)
> No symbol "FRAME_FONT" in current context.
> (gdb) p (it->f)->output_data.x->font

Since it turns out this is a PGTK build, please show this instead:

  (gdb) p (it->f)->output_data.pgtk->font