Re: 23.0.50; crash in xdisp.c:15094

[Reiner Steib]

On Tue, Oct 23 2007, Richard Stallman wrote:

> Can you reproduce this?

No.  I don't even remember what I did just before the crash.

> Did you compile with -fno-cross-jump?

No, I compiled with the default options.

> If so, this line number
> #1  0x08084463 in try_window_id (w=0xa9063c8)
>     at [...]/cvs-HEAD/emacs/src/xdisp.c:15094
> is meaningful.  Otherwise it is meaningless.
>
>     #36 0x08159558 in Fbuffer_substring (start=0, end=24)
>
> That is a real error, passing 0 for START.
>
>     #77 0x08159558 in Fbuffer_substring (start=0, end=24)
>
> That is a real error, passing 0 for START.
>
> What Lisp code called Fbuffer_substring in frame 36?
> What Lisp code called it in frame 77?
>
>     #49 0x08161eb1 in Ffuncall (nargs=2, args=0xbf8834e0)
>       at [...]/cvs-HEAD/emacs/src/eval.c:3074
>     #50 0x0815f31d in Fcall_interactively (function=137987217, 
>       record_flag=137554121, keys=137602396)
>       at [...]/cvs-HEAD/emacs/src/callint.c:841
>
> What command is being called there, with what argument?
> And why was it called?  Did you run it with keyboard commands?

I'm not sure what you mean with "run it with keyboard commands".

> What command was called that entered the debugger in the outer
> invocation?

I will try to investigate this in the evening.  However, I'm not
experienced in C-level debugging (especially of Emacs code).  It would
safe us some much time if someone could write down the relevant gdb
commands for the current situation.  In the past, I sometimes
misinterpreted the textual descriptions so I provide useless
information to the list.

> `bt full' is rather useless in Emacs.  It is almost not worth using.

`bt full' is suggested by `M-x report-emacs-bug RET', maybe it should
be changed?

,----[ M-x report-emacs-bug RET ]
| If Emacs crashed, and you have the Emacs process in the gdb debugger,
| please include the output from the following gdb commands:
|     `bt full' and `xbacktrace'.
`----

> To get the important info, you need to go to the interesting frames,
> then use `pr' to print the crucial Lisp objects in Lisp syntax.
>
> Please see etc/DEBUG for more advice.

I will try to follow the instructions in "Getting Lisp-level backtrace
information within GDB".

Bye, Reiner.
-- 
PGP key available                               http://rsteib.home.pages.de/