bug#28189: 26.0.50; Emacs uses deprecated function gtk_window_parse_geometry

[martin rudalics]

> Code in src/gtkutil.c calls gtk_window_parse_geometry, which is
> deprecated
> 
(https://developer.gnome.org/gtk3/stable/GtkWindow.html#gtk-window-parse-geometry)
> and has been removed in unstable
> 
(https://git.gnome.org/browse/gtk+/diff/gtk/gtkwindow.h?id=c2125e80a345af13d5d886d4ae56fba2926dc267).
> Emacs needs to stop using this function.

By default we don't call gtk_window_parse_geometry any more so this
should not be grave.  The more annoying aspect is that they apparently
removed gtk_window_set_geometry_hints as well and we now have to either
use gdk_window_set_geometry_hints (which has a different signature) or
copy the old definition of gtk_window_set_geometry_hints to our sources.

Can you build with unstable?

martin