Re: MPS: Crash while completing symbol with corfu

[Eli Zaretskii <eliz@gnu.org>]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: emacs-devel@gnu.org,  Eli Zaretskii <eliz@gnu.org>,  eller.helmut@gmail.com
> Date: Mon, 01 Jul 2024 16:48:21 +0200
> 
> 
> Not the slightest idea what's happening there. Aoparently Gtk gets
> involved somehow and then everything is optimized out.
> 
> Maybe you could buld with CFLAGS="-g -O0" or something? Otherwise one
> can't see much.

The problem is that GTK calls our callback:

> > Thread 1 "emacs" hit Breakpoint 1, terminate_due_to_signal (sig=sig@entry=11, backtrace_limit=backtrace_limit@entry=40) at emacs.c:443
> > 443	{
> > (gdb) bt
> > #0  terminate_due_to_signal (sig=sig@entry=11, backtrace_limit=backtrace_limit@entry=40) at emacs.c:443
> > #1  0x00005555556e446b in handle_fatal_signal (sig=sig@entry=11) at sysdep.c:1800
> > #2  0x00005555556e44d0 in deliver_thread_signal (sig=11, handler=0x5555556e4457 <handle_fatal_signal>) at sysdep.c:1792
> > #3  deliver_fatal_thread_signal (sig=sig@entry=11) at sysdep.c:1812
> > #4  0x00005555556e44fd in handle_sigsegv (sig=11, siginfo=<optimized out>, arg=<optimized out>) at sysdep.c:1950
> > #5  0x00007ffff3048050 in <signal handler called> () at /lib64/libc.so.6
> > #6  0x00007ffff304822b in kill () at /lib64/libc.so.6
> > #7  0x0000555555880af9 in sigHandle (sig=<optimized out>, info=<optimized out>, uap=<optimized out>) at /home/yantar92/Dist/mps/code/protsgix.c:114
> > #8  0x00007ffff3048050 in <signal handler called> () at /lib64/libc.so.6
> > #9  qttip_cb (widget=0x5555913b54b0, xpos=222, ypos=80, keyboard_mode=0, tooltip=0x555556741b10, user_data=0x7ffee6e6b3c8) at gtkutil.c:855
> > #10 0x00007ffff7486d63 in ??? () at /usr/lib64/libgtk-3.so.0
> > #11 0x00007ffff6e08d30 in g_closure_invoke () at /usr/lib64/libgobject-2.0.so.0

See that qttip_cb from gtkutil.c?  That callback (from a tool-tip?)
probably accesses some data that MPS owns or something.