Index: trunk/src/find_any_isect.c
===================================================================
--- trunk/src/find_any_isect.c	(revision 14077)
+++ trunk/src/find_any_isect.c	(revision 14078)
@@ -37,6 +37,12 @@
 
 pcb_bool pcb_intersect_obj_obj(pcb_any_obj_t *a, pcb_any_obj_t *b)
 {
+	/* produce the clopped version for polygons to compare */
+	if ((a->type == PCB_OBJ_POLY) && (((pcb_poly_t *)a)->Clipped == NULL))
+		pcb_poly_init_clip(a->parent.layer->parent, a->parent.layer, (pcb_poly_t *)a);
+	if ((b->type == PCB_OBJ_POLY) && (((pcb_poly_t *)b)->Clipped == NULL))
+		pcb_poly_init_clip(b->parent.layer->parent, b->parent.layer, (pcb_poly_t *)b);
+
 	switch(a->type) {
 		case PCB_OBJ_VOID: return pcb_false;
 		case PCB_OBJ_LINE: