bug#12251: 24.2.50; crash in note_mouse_highlight

[Eli Zaretskii <eliz@gnu.org>]

> From: Sam Steingold <sds@gnu.org>
> Cc: 12251@debbugs.gnu.org
> Date: Tue, 21 Aug 2012 22:43:49 -0400
> 
> #8  0x00000000004f5da5 in cmd_error_internal (data=68832822, context=0x7fffffffcf30 "") at /home/sds/src/emacs/trunk/src/keyboard.c:1147
> 1147          bitch_at_user ();
> (gdb) p data
> $1 = 68832822
> (gdb) xtype
> Lisp_Cons
> (gdb) xcons
> $2 = (struct Lisp_Cons *) 0x41a4e30
> {
>   car = 0xb7c612, 
>   u = {
>     cdr = 0x41a4e56, 
>     chain = 0x41a4e56
>   }
> }
> (gdb) p 0xb7c612
> $3 = 12043794
> (gdb) xtype
> Lisp_Symbol
> (gdb) xsymbol 
> $4 = (struct Lisp_Symbol *) 0xb7c610
> "error"
> (gdb) p 0x41a4e56
> $5 = 68832854
> (gdb) xtype
> Lisp_Cons
> (gdb) xcons
> $6 = (struct Lisp_Cons *) 0x41a4e50
> {
>   car = 0x3032031, 
>   u = {
>     cdr = 0xb6fbd2, 
>     chain = 0xb6fbd2
>   }
> }
> (gdb) p 0x3032031
> $7 = 50536497
> (gdb) xtype
> Lisp_String
> (gdb) xstring 
> $8 = (struct Lisp_String *) 0x3032030
> "#<window 139> is not a valid window"
> (gdb) p 0xb6fbd2
> $9 = 11992018
> (gdb) xtype
> Lisp_Symbol
> (gdb) xsymbol 
> $10 = (struct Lisp_Symbol *) 0xb6fbd0
> "nil"
> (gdb) 

Martin, could this be due to your changes in revision 109644?

Sam, if you revert that commit, does the problem go away?

Anyway, I think the crash with a mouse is not the root cause here.  We
are somehow hitting a dead window, and then trying to activate mouse
highlight on that window.