GtkSeparatorMenuItem hack in _gtk_menu_item_is_selectable()

[Murray Cumming Comneon com]

As I discovered here,
http://bugzilla.gnome.org/show_bug.cgi?id=130570

there is a hack in GTK+ in _gtk_menu_item_is_selectable() to allow
glade/libglade to use GtkMenuItems without labels, instead of
GtkSeparatorMenuItems, for separator menu items:
http://cvs.gnome.org/lxr/source/gtk+/gtk/gtkmenuitem.c#1381

Changing the .glade files to use GtkSeparatorMenuItems seems to work, so I
wonder why this hack exists. I'd like to fix glade so that C++ developers
don't need to edit the .glade file manually:
http://bugzilla.gnome.org/show_bug.cgi?id=129848

Murray Cumming
www.murrayc.com
murrayc usa net