bug#25851: 25.2; GTK warning when starting Emacs when desktop file has more than one frame

[martin rudalics]

> Unless Martin will be able to resolve the issue "properly",

I still fail to understand what Jan had in mind when he eliminated the
gtk_window_move call from xg_set_geometry with PPosition set.  We could
try to revert that change and see what happens.

> I guess
> the only way of shutting up the warning is to use
> g_log_set_writer_func to temporarily set the glib log writer function
> to a dummy one that does nothing, then restore the original writer
> function.  That's gross, but what else can be done when you deal with
> libraries which think they are smarter than you are?..

IIUC most of what GTK's gometry parsing does is trying to avoid that a
frame appears offscreen.  So it's not really about being smart.  Emacs
is asking for it.

martin