bug#55672: 29.0.50; Emacs crashes when calling start-process-shell-command xdg-open with process-connection-type set to nil

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Ihor Radchenko <yantar92@gmail.com> writes:

> Starting program: /home/yantar92/Git/emacs/src/emacs -Q -l /home/yantar92/bug.el
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib64/libthread_db.so.1".
> [New Thread 0x7ffff049d640 (LWP 17839)]
> [Detaching after vfork from child process 17907] <- flickering
> [Detaching after vfork from child process 18197] <- flickering
> [Detaching after vfork from child process 18326] <- flickering
> [Detaching after vfork from child process 18419] <- flickering
> [Detaching after vfork from child process 18542] <- flickering
> [Detaching after vfork from child process 18654]
>
> Thread 1 "emacs" hit Breakpoint 2, x_error_quitter (display=0x555559323390, event=0x7fffffffa210) at xterm.c:21573
> 21573	{
> (gdb) 
> (gdb) 
> quit
> A debugging session is active.
>
> 	Inferior 1 [process 17832] will be killed.
>
> Quit anyway? (y or n) y
>
> Best,
> Ihor

Please follow the instructions in the file etc/DEBUG on debugging X
errors, and show a complete backtrace (type "bt" at the gdb prompt).

Unless the error happens at a very early stage of display setup, you
should run Emacs with "-q -xrm Emacs.synchronous: true", to ensure that
X errors are reported immediately after the call that caused them,
instead of at the next synchronization point.