bug#14180: PATCH Better fullscreen frame support on Windows

[martin rudalics]

> That's correct. The modeline scrollbar is slightly clipped.

It's because we currently do not distribute spare pixel lines to other
windows but simply append them at the end of the mode-line without,
however, storing the pixel height in the window.  The display engine
doesn't know anything about this and therefore cannot draw the scroll
bar long enough.  I suppose the remaining pixel lines of the screen are
cleared by Windows using FRAME_BACKGROUND_PIXEL but never checked that.
Here I changed the behavior by appending the extra pixel lines to the
windows that "most need it".

> I just doubled checked toggling scrollbars, menubar and toolbar on and off
> while in fullscreen and it all works as expected.
>
> Thanks for the reminder since I usually run with all those elements off :).

I intended to ask you that too.  At least some of these can have very
nasty delayed effects (at least with the old maximized/fullscreen mode).
In particular, independently setting margin widths and scrollbar widths
and the internal border widths of frames.

martin