bug#16681: mouse-autoselect-window missing when switching frames

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 07 Feb 2014 20:15:12 +0100
> From: martin rudalics <rudalics@gmx.at>
> Cc: 16681@debbugs.gnu.org
> 
>  > In a system with "focus follows mouse" do the following:
>  >
>  >    % src/emacs -Q --eval '(setq mouse-autoselect-window t)'
>  >    C-x 5 2
>  >    <place the two frames side by side>
>  >    C-x 2
>  >    <go to the second frame>
>  >    C-x 2
>  >
>  > Now move mouse "in circle":
>  > - top-left window, then top-right window, then bottom-right window, then
>  >   bottom-left window, and if you like it, you can keep doing it for a while.
>  > notice how this *should* select each one of the four windows in each cycle,
>  > but instead only 2 of those windows are selected: when crossing from one
>  > frame to the other the new frame is selected, but that frame's selected
>  > window is used as the new selected window instead of using that the
>  > window into which the mouse just entered.
> 
> Works without problems on Window XP.  On my Debian GTK build I have to
> set `focus-follows-mouse' to t to make it work.

On Windows XP here, it doesn't work unless I set focus-follows-mouse
non-nil.