Index: trunk/src/find_geo.c
===================================================================
--- trunk/src/find_geo.c	(revision 34997)
+++ trunk/src/find_geo.c	(revision 34998)
@@ -1152,10 +1152,22 @@
 {
 	pcb_pstk_shape_t *shape;
 	pcb_pstk_proto_t *proto;
+	rnd_coord_t clr;
 
 	if (anylayer)
 		PCB_ISC_PSTK_ANYLAYER(ps, pcb_isc_pstk_poly_shp(ctx, ps, poly, &tshp->shape[n]));
 
+	/* optimization: if thre's a clearance between the padstack and the poly, no
+	   need to calculate anything */
+	clr = pcb_obj_clearance_at(PCB, (pcb_any_obj_t *)ps, poly->parent.layer);
+	if (clr > 0) {
+		unsigned char *thr = pcb_pstk_get_thermal(ps, pcb_layer2id(PCB->Data, poly->parent.layer), 0);
+
+		/* but only if there's no thermal that'd connect it through the clearance */
+		if ((thr == NULL) || (!(*thr & PCB_THERMAL_ON) || ((*thr & 0x07) == PCB_THERMAL_NOSHAPE)))
+			return rnd_false;
+	}
+
 	shape = pcb_pstk_shape_at(PCB, ps, poly->parent.layer);
 	if (pcb_isc_pstk_poly_shp(ctx, ps, poly, shape))
 		return rnd_true;