Re: Building the igc branch on MS-Windows

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> Cc: eller.helmut@gmail.com,  emacs-devel@gnu.org
>> Date: Fri, 26 Apr 2024 12:56:29 +0200
>> 
>> I've meanwhile pushed something that handles the use of PVEC_OTHER in
>> modules. Nothing done for the scroll_bar struct in w32. Caution: I
>> remved the assert.
>
> This still crashes while scrolling through xdisp.c, but with a
> different backtrace.  I've noticed that it crashes after GC kicks in
> and releases a large amount of memory (about 100MB).  Here's the
> backtrace:
>
>   Thread 1 received signal SIGSEGV, Segmentation fault.
>   XCAR (c=0xab5ca1b) at lisp.h:751
>   751       return lisp_h_XLP (o);
>   (gdb) bt
>   #0  XCAR (c=0xab5ca1b) at lisp.h:751
>   #1  assoc_no_quit (key=<optimized out>, alist=0xab5ca1b) at fns.c:2032
>   #2  0x00cbc12d in font_list_entities (f=0xaa1c478, spec=0xa84227d)
>       at font.c:2795
>   #3  0x00cbce93 in font_find_for_lface (f=<optimized out>, f@entry=0xaa1c478,
>       attrs=<optimized out>, attrs@entry=0x743a2b0, spec=<optimized out>,
>       spec@entry=0xa8421dd, c=<optimized out>, c@entry=-1) at font.c:3316

Looks to be like something "in the font department", something related
to fonts, contains references that are not yet traced. When a GC moves a
lot of stuff, these references are therefore updated because they are
not traces, therefore point to old locations, and ...