Subject: Re: bug#63589: 29.0.91; crash after creating graphical frames via emacsclient when compiled with cairo-xcb

From: Po Lu <[email-masked]>
Date: Sat, 20 May 2023 09:46:45 +0800

Thiago Melo <[email-masked]> writes:

> emacs: ../../../../src/cairo-xcb-screen.c:219: _get_screen_index:
> Assertion `!"reached"' failed.
>
> Fatal error 6: Aborted
> ```
>
> Affects starting emacs with `emacs -Q --daemon`.
>
> Issue happens since commit de614ec9 ("Use Cairo XCB surfaces when XCB
> is available").

This is one bug.  Thanks for bringing it to our attention.  However,
this crash happens when a display connection is closed, which is not
common in normal use.  As the backtraces you attached show, an unrelated
X error is what caused a connection to be closed.

To really fix this bug, we need to know the details of the X error.
Once you reach the breakpoint on `x_error_quitter', would you please
run:

  (gdb) p *event

and send us the resulting print out?