bug#15686: 24.3.50; Face related crash in current trunk

[Eli Zaretskii]

> Date: Tue, 22 Oct 2013 20:20:19 +0200
> From: martin rudalics <rudalics@gmx.at>
> 
> #0  terminate_due_to_signal (sig=22, backtrace_limit=2147483647) at 
> emacs.c:350
> #1  0x01151496 in die (msg=0x146e018 "((((struct vectorlike_header *) ((void 
> *) ((font_object) - (Lisp_Vectorlike)))) ->size) & (PSEUDOVECTOR_FLAG | 
> PVEC_TYPE_MASK)) == (PSEUDOVECTOR_FLAG | (PVEC_FONT << 
> PSEUDOVECTOR_AREA_BITS))", file=0x146d0b0 "xfaces.c", line=5261) at 
> alloc.c:6670
> #2  0x010d7ab0 in realize_default_face (f=0x3c2f770) at xfaces.c:5261

What kind of object is font_object in frame #2?