bug#22301: 25.1.50; Emacs crashes while lisp debugging

[Eli Zaretskii <eliz@gnu.org>]

> From: Vincent Belaïche <vincentb1@users.sourceforge.net>
> Cc: Vincent Belaïche <vincent.belaiche@gmail.com> ,
>  22301@debbugs.gnu.org
> Date: Mon, 04 Jan 2016 23:49:53 +0100
> 
> (gdb) thread 1
> [Switching to thread 1 (Thread 11676.0x1edc)]
> #0  SDATA (string=1461725984) at lisp.h:1325
> 1325	  return XSTRING (string)->data;
> (gdb)  thread apply all bt
> 
> Thread 7 (Thread 11676.0x430):
> #0  0x771b8c51 in ntdll!DbgBreakPoint () from C:\WINDOWS\SYSTEM32\ntdll.dll
> #1  0x771e9e09 in ntdll!DbgUiRemoteBreakin ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #2  0xfb32daaf in ?? ()
> #3  0x771e9dd0 in ntdll!DbgUiIssueRemoteBreakin ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #4  0x760238f4 in KERNEL32!BaseThreadInitThunk ()
>    from C:\WINDOWS\SYSTEM32\kernel32.dll
> #5  0x771a56c3 in ntdll!RtlUnicodeStringToInteger ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #6  0x00000000 in ?? ()
> 
> Lisp Backtrace:
> "backtrace" (0xbfedac)
> "debugger-setup-buffer" (0xbfefe0)
> "debug" (0xbff1b4)
> "ses-relocate-all" (0xbff200)
> "let" (0xbff3bc)
> "ses-delete-row" (0xbff598)
> "funcall-interactively" (0xbff594)
> "call-interactively" (0xbff710)
> "command-execute" (0xbff8dc)
> 
> Thread 6 (Thread 11676.0x2aa0):
> #0  0x771b868c in ntdll!ZwWaitForWorkViaWorkerFactory ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #1  0x7718a246 in ntdll!EtwNotificationRegister ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #2  0x760238f4 in KERNEL32!BaseThreadInitThunk ()
>    from C:\WINDOWS\SYSTEM32\kernel32.dll
> #3  0x771a56c3 in ntdll!RtlUnicodeStringToInteger ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #4  0x00c844c0 in ?? ()
> #5  0x771a568e in ntdll!RtlUnicodeStringToInteger ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #6  0xffffffff in ?? ()
> #7  0x771cb6c3 in ntdll!RtlCaptureContext ()
>    from C:\WINDOWS\SYSTEM32\ntdll.dll
> #8  0x00000000 in ?? ()
> 
> --8<----8<----8<----8<----8<--  end  -->8---->8---->8---->8---->8----
> 
> Please note that I don't get again the debugger prompt --- I am running
> the debugger from an Emacs shell buffer, could it be some interaction
> that the buffer process sentinel could not capture ? Anyway, I am
> keeping the gdb session open, as you asked...

Do you get the GDB prompt back if you press F-12 or Ctrl-C?  If not,
this session is ruined, and you can stop it.

Next time when it happens, type these commands instead:

  (gdb) thread 1
  (gdb) bt

Better yet, run Emacs from GDB to begin with, it will make the
backtrace more reliable.

Thanks.