Subject: bug#76517: 31.0.50; feature/igc 6ff509af3d31 crash on Wayland KDE, (with -g3

From: Eli Zaretskii <[email-masked]>
Date: Mon, 24 Feb 2025 14:46:49 +0200

> From: Eval Exec <[email-masked]>
> Date: Mon, 24 Feb 2025 10:26:46 +0800
> 
> Hello,
> I'm helping to test feature/igc branch
> 
> I got crash:
> (gdb) source /home/exec/Projects/git.savannah.gnu.org/git/emacs
> emacs/       emacs-build/ emacs-criu/  emacs-flake/
> (gdb) source /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/.gdbinit
> warning: /home/exec/../lwlib: No such file or directory
> SIGINT is used by the debugger.
> Are you sure you want to change it? (y or n) [answered Y; input not
> from terminal]
> DISPLAY = :0
> WAYLAND_DISPLAY = wayland-0
> TERM = tmux-256color
> Breakpoint 1 at 0x423d97: file
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/emacs.c, line
> 425.
> (gdb) bt full
> #0  0x00007f1f3ed30a9c in __pthread_kill_implementation () from
> /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6
> No symbol table info available.
> #1  0x00007f1f3ecde576 in raise () from
> /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6
> No symbol table info available.
> #2  0x0000000000423e51 in terminate_due_to_signal (sig=11,
> backtrace_limit=<optimized out>) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/emacs.c:463
> No locals.
> #3  0x000000000042443c in handle_fatal_signal (sig=11) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/sysdep.c:1793
> No locals.
> #4  deliver_thread_signal (handler=<optimized out>, sig=11) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/sysdep.c:1785
>         old_errno = <optimized out>
>         old_errno = <optimized out>
> #5  deliver_fatal_thread_signal (sig=11) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/sysdep.c:1805
> No locals.
> #6  handle_sigsegv (sig=11, siginfo=0x9054f0 <sigsegv_stack+62640>,
> arg=<optimized out>) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/sysdep.c:1943
>         fatal = <optimized out>
> #7  <signal handler called>
> No symbol table info available.
> #8  0x00007f1f3ecde86b in kill () from
> /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6
> No symbol table info available.
> #9  0x00000000007b6d19 in sigHandle ()
> No symbol table info available.
> #10 <signal handler called>
> No symbol table info available.
> #11 0x0000000000508a1a in PSEUDOVECTORP (code=35, a=XIL(0x3aa8ff70d))
> at /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/lisp.h:1098
> No locals.
> #12 SUB_CHAR_TABLE_P (a=XIL(0x3aa8ff70d)) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/lisp.h:2186
> No locals.
> #13 char_table_ref (table=<optimized out>, c=<optimized out>) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/chartab.c:239
>         tbl = 0x7f1ebd459420
>         val = XIL(0x3aa8ff70d)

Sounds like the buffer display table is corrupted/garbled?

> #14 0x00000000004773b9 in disp_char_vector (dp=0x7f1ebd459420,
> c=<optimized out>) at
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/xdisp.c:18040
>         table = XIL(0x7f1ebd459425)
>         val = <optimized out>
> #15 0x0000000000508de0 in char_width (c=-1003068911,
> dp=0x7f1ebd459420) at

The value of 'c' looks bogus.

> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/character.c:238
>         disp = <optimized out>
>         ch = <optimized out>
>         i = <optimized out>
>         width = <optimized out>
> #16 0x00000000004933d8 in c_string_width (nbytes=<synthetic pointer>,
> nchars=<synthetic pointer>, precision=<optimized out>, len=69,
>     str=0x7f1ec16860fa "\274\214我中间使用 充电宝给电脑冲了一次电。还行。。。") at

Does this string ring any bells?  It should be shown somewhere on the
mode line.  What is it?