Re: Emacs exited with message “X protocol error: BadPixmap”

[Eli Zaretskii]

> From: storm@cua.dk (Kim F. Storm)
> Date: Tue, 14 Aug 2007 10:27:23 +0200
> Cc: bug-gnu-emacs@gnu.org, Joe Wells <jbw@macs.hw.ac.uk>
> 
> I mostly run emacs under a debugger - but not every time, as
> it is not always practical to do so.
> 
> E.g. when emacs is started through a desktop shortcut or launced by
> some other program (like through the emacs.bash script distributed
> with Emacs), there's no debugger involved ... and sometimes I just
> continue working in such an Emacs instance ... without the debugger
> in place.

You can always attach the debugger to a running instance of Emacs.

> Anyways, I've seen on Windoze that if Emacs crashes, Visual Studio
> kicks in and offers you to debug the crashed process.

That's Windows JIT debugging in action.  (Since I use the MinGW
compiled Emacs, Visual Studio is useless for me, so I set up DrMinGW
as the JIT debugger instead.  It's a pity GDB itself doesn't support
the JIT API on Windows, and it's a pity I don't have time to write
it myself.)

> Can't Emacs be taught to do something similar by hooking various
> signal handlers (SIGSEGV, SIGILL, etc) to a function that launches GDB
> with command line parameters that attaches it to the (crashed) Emacs
> runtime?  That way, GDB is only started _if_ Emacs crashes.

It's doable, we did something like this on my daytime job (not for
Emacs).

(Btw, we already catch all fatal signals, so we just need to modify
fatal_error_signal, which handles them all.)