bug#71289: 30.0.50; cmcheckmagic aborts when tty_write_glyphs writes "Garbage collecting..." in some cases

[Daniel Clemente]

> I see a different abort, for which I've now installed a fix.  To try
> to fix the above one, I need some additional data:

In an Emacs build with this patch, I can't see the minibuffer anymore,
also not while I type. Happens with -Q, with and without daemon.
I didn't have time to test this thoroughly or to find where it came from.

On Thu, 6 Jun 2024 at 14:53, Eli Zaretskii <eliz@gnu.org> wrote:
>
> > From: Daniel Clemente <n142857@gmail.com>
> > Date: Thu, 6 Jun 2024 12:34:34 +0000
> > Cc: 71289@debbugs.gnu.org
> >
> > The key to reproduce it to have 2 Emacs windows inside the frame:
> > 1. Open emacs (no need for emacsclient) with -Q. No need to set
> > garbage-collection-messages to t
> > 2. Do C-x 2 to have 2 windows, one above one below
> > 3. Resize the X window to make it very small, (1 line or so)
> > 4. It should immediately crash.
> >
> > (gdb) bt full
> > #0  terminate_due_to_signal (sig=6, backtrace_limit=40) at emacs.c:443
> > No locals.
> > #1  0x00005555556bd41b in emacs_abort () at sysdep.c:2391
> > No locals.
> > #2  0x000055555558cb33 in check_matrix_pointers 
> > (window_matrix=0x5555588efa10,
> >     frame_matrix=0x5555595855c0) at dispnew.c:3129
> >         i = 0
> >         j = 0
> > #3  0x000055555558ca52 in check_window_matrix_pointers (w=0x5555591f66b8)
> >     at dispnew.c:3098
> >         f = 0x555558008768
> > #4  0x000055555558c9df in check_window_matrix_pointers (w=0x555559452b90)
> >     at dispnew.c:3094
> > No locals.
> > #5  0x000055555558c9df in check_window_matrix_pointers (w=0x55555960d2d8)
> >     at dispnew.c:3094
> > No locals.
> > #6  0x000055555558d10e in update_frame (f=0x555558008768, force_p=true,
> >     inhibit_hairy_id_p=false) at dispnew.c:3359
> >         paused_p = false
> >         root_window = 0x55555960d2d8
>
> I see a different abort, for which I've now installed a fix.  To try
> to fix the above one, I need some additional data:
>
>   (gdb) frame 2
>   (gdb) p window_matrix->rows->glyphs[0]
>   (gdb) p frame_matrix->rows->glyphs[0]
>   (gdb) p frame_matrix->rows->glyphs[2]
>   (gdb) p window_matrix->nrows
>   (gdb) p frame_matrix->nrows