bug#25943: 21.5 Frame Display Difficulties

[martin rudalics <rudalics@gmx.at>]

 > I am hoping that these screenshots will throw some light on problem 3.
 > The key question now appears to address why the main emacs frame is not
 > filled properly, my popups can be eliminated as the cause of the problem.

The only thing that comes to my mind without investigating this more
deeply is that you do some sort of scaling on that display.  Have you
anywhere set GDK_SCALE (or GDK_DPI_SCALE) to something greater 1?  GTK
Emacsen can't digest that yet and it will take some time to teach them
the right way.

Otherwise, as a first step please do any experiments with emacs -Q only
(we'll deal with your init file later) so we can see see how menu and
toll bars relate to the problem.  Then tell me the return value of the
following forms evaluated for the maximized (cream colored) frame.

(display-monitor-attributes-list)
(frame-geometry)
(frame-edges nil 'outer-edges)
(frame-edges nil 'native-edges)
(frame-edges nil 'internal-edges)

Thanks, martin