help needed for getting a backtrace ( multi-head emacs_abort on lucid-frame)

[Andrés Ramírez]

Hi.

The first time I used the --daemon command line option I got:
,---- [  ]
| Warning: due to a long standing Gtk+ bug
| https://gitlab.gnome.org/GNOME/gtk/issues/221
| Emacs might crash when run in daemon mode and the X11 connection is 
unexpectedly lost.
| Using an Emacs configured with --with-x-toolkit=lucid does not have this 
problem.
| Starting Emacs daemon.
`----

The output of that message lead me to the lucid toolkit.

Also the first time I did M-x report-emacs-bug I got:
,---- [  ]
| Please describe exactly what actions triggered the bug
| and the precise symptoms of the bug.  If you can, give
| a recipe starting from `emacs -Q':
`----

That's the reason for trying to get a proper backtrace for this case.

Having said that this is the recipe for the missing backtrace:
source code: emacs-28.1.tar.xz
compiled emacs with: "--enable-checking=yes,glyphs 
--enable-check-lisp-object-type 'CFLAGS=-O0 -g3' --with-cairo --with-harfbuzz 
--with-modules --with-wide-int --with-x-toolkit=lucid --with-json=yes 
--with-xft"
 
--8<---------------cut here---------------start------------->8---
1. @host ./emacs  -Q -f toggle-debug-on-error --daemon
2. @host emacsclient -c -n --eval '(eshell)'
3. on eshell-buffer emacs-version Return 
4. @remoteMachine emacsclient -c -n ~/.bashrc {inside xterm} {JIC: be4 do 'ssh 
-Y user@host'} {.bashrc could have just a comment character}
5. M-x dired-jump
6. M-x eval-expression "(x-synchronize t)" {without the quotes}{when doing this 
step do not do #8}
7. M-x close-display-connection {both opened frames close, and emacs aborts. 
check trying to open a new-frame}
8. type exit and press Return on xterm.  {this step depends on step#6}
--8<---------------cut here---------------end--------------->8---

Expected Output:
emacs crash {it's an emacs_abort}
Both opened frames close. #2 and #4

NOTE: when starting emacs without calling 'toggle-debug-on-error' after step#7 
when You open a new
frame. You could get the message:
'X protocol error: RenderBadGlyph (invalid Glyph parameter) on protocol request 
139'

For Trying to get backtrace I have appended those lines to the file
/tmp/emacs/src/emacs-28.1/src/.gdbinit

,---- [  ]
| #@theEndOf close-display-connection x-close-connection is called
| # b  xfns.c:x-close-connection # does not work
| b xterm.c:x_delete_terminal
| b xterm.c:x_delete_display
| b terminal.c:delete_terminal
| b frame.c:delete_frame #very long function
| b sysdep.c:emacs_abort
| b emacs.c:terminate_due_to_signal
`----

Those breakpoints never get hitted.

Please. Let me know the right way of getting a backtrace on this
situation.

Best Regards