bug#8705: 23.3; Emacs occasionally crashes (segfault) just after starting it

[Eli Zaretskii <eliz@gnu.org>]

> From: Vincent Lefevre <vincent@vinc17.net>
> Date: Fri, 20 May 2011 10:54:28 +0200
> Cc: vincent@vinc17.net
> 
> Emacs23 occasionally crashes (segmentation fault) just after starting
> it. Here this was the first time with Emacs 23.3 (Debian's package).
> 
> All crashes of Emacs 22 and 23 I got occurred immediately after
> starting it, and most of them (if not all) occurred either on an
> XML file or when Emacs was started via svn to write a log message.
> 
> Here's a backtrace:
> 
> (gdb) bt
> #0  0x00007fa7df0056b7 in kill () at ../sysdeps/unix/syscall-template.S:82
> #1  0x00000000004e4a5f in ?? ()
> #2  <signal handler called>
> #3  getenv (name=0x7fa7df118177 "NGUAGE") at getenv.c:84
> #4  0x00007fa7df00034e in guess_category_value (
>     domainname=0x7fa7e4afea1a "gtk20-properties", 
>     msgid1=<value optimized out>, msgid2=<value optimized out>, 
>     plural=<value optimized out>, n=<value optimized out>, 
>     category=<value optimized out>) at dcigettext.c:1359
> #5  __dcigettext (domainname=0x7fa7e4afea1a "gtk20-properties", 
>     msgid1=<value optimized out>, msgid2=<value optimized out>, 
>     plural=<value optimized out>, n=<value optimized out>, 
>     category=<value optimized out>) at dcigettext.c:575
> #6  0x00007fa7e48a7a3a in ?? () from /usr/lib/libgtk-x11-2.0.so.0
> #7  0x00007fa7e2b429e5 in g_type_class_ref () from /usr/lib/libgobject-2.0.so.0
> #8  0x00007fa7e2b2659e in g_object_newv () from /usr/lib/libgobject-2.0.so.0
> #9  0x00007fa7e2b26e1c in g_object_new () from /usr/lib/libgobject-2.0.so.0
> #10 0x00007fa7e48a82bc in gtk_alignment_new ()
>    from /usr/lib/libgtk-x11-2.0.so.0

All of your reported crashes seem to be in a call to `getenv', which
is a library function, called by GTK routines deep in the GTK code.
It is hard to imagine that they could be Emacs problems, especially
since you see them since Emacs 22.

In any case, backtraces from optimized programs are unreliable.
Please try rebuilding Emacs with -O0 in CFLAGS, and if you can
reproduce these crashes in the unoptimized build, follow up here with
the backtrace.

> #22 0x00007fa7e49634c1 in gtk_main_iteration ()
>    from /usr/lib/libgtk-x11-2.0.so.0
> #23 0x00000000004aa33c in ?? ()
> #24 0x00000000004ef993 in ?? ()
> [...]

Could you please show the backtrace until it reaches Emacs code?

Thanks.