Index: undo_old.c
===================================================================
--- undo_old.c	(revision 15873)
+++ undo_old.c	(revision 15874)
@@ -95,6 +95,7 @@
 static pcb_bool UndoChangeClearSize(UndoListTypePtr);
 static pcb_bool UndoClearPoly(UndoListTypePtr);
 
+#define PCB_OBJECT_ID(p) (((pcb_any_obj_t *) p)->ID)
 
 static void pcb_undo_old_free(void *udata);
 static int pcb_undo_old_undo(void *udata);