bug#11177: 24.0.95; gtk_window_parse_geometry warning

[Ken Brown]

When emacs is built with gtk3 and the window geometry is specified on the 
command line or in .Xdefaults, the following warning appears in the terminal 
from which emacs was started:

Gtk-WARNING **: gtk_window_parse_geometry() called on a window with no visible 
children; the window should be set up before gtk_window_parse_geometry() is 
called.

To reproduce:

1. Build emacs with the configure option --with-x-toolkit=gtk3.

2. emacs -Q --geometry=80x34+340+40 &

I don't know enough about gtk to know whether this warning can safely be 
ignored, but here's a quote from the source file gtk/gtkwindow.c in which 
gtk_window_parse_geometry is defined:

 * Note that for gtk_window_parse_geometry() to work as expected, it has
 * to be called when the window has its "final" size, i.e. after calling
 * gtk_widget_show_all() on the contents and gtk_window_set_geometry_hints()
 * on the window.


In GNU Emacs 24.0.95.1 (i686-pc-cygwin, GTK+ Version 3.2.3)
 of 2012-04-04 on fiona
Windowing system distributor `The Cygwin/X Project', version 11.0.11200000
Configured using:
 `configure
 '--srcdir=/home/kbrown/src/cygemacs/emacs-24.0.95-3/src/emacs-24.0.95'
 '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin'
 '--sbindir=/usr/sbin' '--libexecdir=/usr/lib' '--datadir=/usr/share'
 '--localstatedir=/var' '--sysconfdir=/etc' '--datarootdir=/usr/share'
 '--docdir=/usr/share/doc/emacs' '-C' '--with-x-toolkit=gtk3' 'CC=gcc'
 'CFLAGS=-g -O2 -pipe ' 'LDFLAGS=-L/usr/lib/ncursesw' 'LIBS='
 'CPPFLAGS=-I/usr/include/ncursesw''