Bug 676362 - _gdk_quartz_image_copy_to_image always returns black...
Bug 676362 - _gdk_quartz_image_copy_to_image always returns black...

Implement a special case for the root window, which has to be handled
differently on OS X.

Contains some bit fiddling corrections by Kristian Rietveld.

Distrotech/gtk,Distrotech/gtk,Distrotech/gtk,johne53/MB3Gtk-2,Distrotech/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2,Distrotech/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2