G_IMPLEMENT_INTERFACE doesn't initialize all GInterfaceInfo fields, so gcc emits a warning about it when using -W option.

Index: gobject/gtype.h
===================================================================
RCS file: /cvs/gnome/glib/gobject/gtype.h,v
retrieving revision 1.66
diff -u -p -r1.66 gtype.h
--- gobject/gtype.h     2 May 2006 13:00:52 -0000       1.66
+++ gobject/gtype.h     11 May 2006 21:44:49 -0000
@@ -349,7 +349,9 @@ gpointer g_type_instance_get_private
  */
 #define G_IMPLEMENT_INTERFACE(TYPE_IFACE, iface_init)       { \
   static const GInterfaceInfo g_implement_interface_info = { \
-    (GInterfaceInitFunc) iface_init \
+    (GInterfaceInitFunc) iface_init, \
+    NULL, \
+    NULL \
   }; \
   g_type_add_interface_static (g_define_type_id, TYPE_IFACE, &g_implement_interface_info); \
 }