made the object/class cast checks much more descriptive, based on
Sat Mar 7 20:20:53 1998 Tim Janik <timj@gimp.org>
* gtk/gtkobject.c:
(gtk_object_check_cast):
(gtk_object_check_class_cast):
made the object/class cast checks much more descriptive, based on
gtk-draco-980305-2.patch.gz and gtk-draco-980306-1.patch.gz but
optimized for common code path.
* gtk/gtkpreview.c: added a few extra checks for the visual
(gtk-draco-980305-0.patch.gz).
* gdk/gdk.c (gdk_signal): abort() on a signal if G_ENABLE_DEBUG
is defined, so we dump core (gtk-draco-980305-0.patch.gz).