Unless there are objections, I intend to apply the attached changes in
the next days.  Their purpose is to restrain the handling of the text
area size of a frame to the function adjust_frame_size and have the
various front/backends setting frame sizes or receiving notifications
about them work with native frame sizes only.  This has the advantage
that storing the history of frame size changes and consequently tracking
bugs in the frame sizing code become much simpler.

The patch should fix Bug#46827 and I intend to add further bug fixes in
the following days.  Some of these fixes are controversial and I'd like
to push them separately in order to make bisecting easier.  Other than
that, there should be no user noticeable changes, so if you observe any
strange frame sizing behavior, please tell me.

I've tested the patch with xfwm4, gnome shell, kde plasma and Windows XP
but have given it only light testing with GNUstep.  Alan, if you see
anything fishy with the NS build, please tell me.  Yuuki, if you see any
problems with the pgtk build, please tell me too so we can resolve them
without causing greater conflicts.

Thanks for your attention, martin