Aidan Kehoe <kehoea@parhasard.net> writes:

>  Ar an fichiú lá de mí na Nollaig, scríobh Thomas Mittelstaedt: 
>
>  > tmstaedt@buildhp3$
>  > Fatal error: assertion failed, file window.c, line 2466, RECORD_TYPEP 
>  > (obj, lrecord_type_window)
>  > WARNING: Unable to auto-save your files properly.
>  > Some or all may in fact have been auto-saved.
>  > [...]
>  > 
>  > (gdb) bt
>  > #0  0xc01ffd40 in kill () from /usr/lib/libc.2
>  > #1  0x000dfcf0 in fatal_error_signal (sig=11) at emacs.c:3800
>  > #2  <signal handler called>
>  > #3  0x00312e28 in Fnext_window (window=1768846945, minibuf=1074144988, 
>  > which_frames=1074063364,
>  >     which_devices=1074063364) at window.c:2499
>
> This is the first “if” test here:
>
>       while (1)
> 	{
> 	  if (!NILP (XWINDOW (window)->hchild))
> 	    window = XWINDOW (window)->hchild;
> 	  else if (!NILP (XWINDOW (window)->vchild))
> 	    window = XWINDOW (window)->vchild;
> 	  else break;
> 	}
>
> So ‘window’ is something that isn’t a window. Mike, you had lots to do with
> the window code when rewriting the window configuration stuff in Lisp; do
> you have any idea what provoked this? 

That was mostly above that level, however, so I don't think I can
provide specific help.  However, doesn't the Lisp backtrace indicate
that the window is nil?

Lisp backtrace follows:

 # (unwind-protect ...)
 # (unwind-protect ...)
 # (unwind-protect ...)
 # (unwind-protect ...)
 # (unwind-protect ...)
 # (unwind-protect ...)
 # (unwind-protect ...)
 next-window(nil)