bug#12251: 24.2.50; crash in note_mouse_highlight

[Eli Zaretskii]

> Date: Thu, 23 Aug 2012 10:48:43 +0200
> From: martin rudalics <rudalics@gmx.at>
> CC: sds@gnu.org, 12251@debbugs.gnu.org
> 
>  >> "#<window 139> is not a valid window"
> 
> The above means that we've been running Lisp code on a dead window and
> that call was rejected with an error by `window-normalize-window'.  If
> this happens during a call from C, we have a problem.

I don't think this error was thrown from C.  Most probably, it was
thrown from Lisp, but since that unwinds the stack, there's no Lisp
backtrace that could confirm that.

I guess we need more checks in the mouse-highlight code, to account
for such cases.