Index: trunk/src/find.h
===================================================================
--- trunk/src/find.h	(revision 30848)
+++ trunk/src/find.h	(revision 30849)
@@ -43,7 +43,11 @@
 typedef struct pcb_find_s pcb_find_t;
 struct pcb_find_s {
 	/* public config - all-zero uses the original method, except for flag set */
+	/* low level (will work with isc calls): */
 	pcb_coord_t bloat;              /* perform intersection tests with one object bloated up by this amount (can be negative for shrinking) */
+	unsigned ignore_clearance:1;    /* a flag dictated clearance is no excuse for intersection - useful for overlap calculation between objects on different layers */
+
+	/* high level (ignored by isc calls): */
 	unsigned stay_layergrp:1;       /* do not leave the layer (no padstack hop) */
 	unsigned allow_noncopper:1;     /* also run on non-copper objects */
 	unsigned list_found:1;          /* allow adding objects in the ->found vector */
Index: trunk/src/find_geo.c
===================================================================
--- trunk/src/find_geo.c	(revision 30848)
+++ trunk/src/find_geo.c	(revision 30849)
@@ -651,7 +651,7 @@
 	pcb_box_t *Box = (pcb_box_t *) Arc;
 
 	/* arcs with clearance never touch polys */
-	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLY, Polygon) && PCB_OBJ_HAS_CLEARANCE(Arc))
+	if (!ctx->ignore_clearance && PCB_FLAG_TEST(PCB_FLAG_CLEARPOLY, Polygon) && PCB_OBJ_HAS_CLEARANCE(Arc))
 		return pcb_false;
 	if (!Polygon->Clipped)
 		return pcb_false;
@@ -698,7 +698,7 @@
 	pcb_polyarea_t *lp;
 
 	/* lines with clearance never touch polygons */
-	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLY, Polygon) && PCB_OBJ_HAS_CLEARANCE(Line))
+	if (!ctx->ignore_clearance && PCB_FLAG_TEST(PCB_FLAG_CLEARPOLY, Polygon) && PCB_OBJ_HAS_CLEARANCE(Line))
 		return pcb_false;
 	if (!Polygon->Clipped)
 		return pcb_false;
@@ -757,11 +757,11 @@
 
 	/* cheat: poly-clear-poly means we did generate the clearance; this
 	   shall happen only if there's exactly one poly that is clearing the other */
-	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, P1)) {
+	if (!ctx->ignore_clearance && PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, P1)) {
 		pcp_cnt++;
 		pcp_gap = P1->Clearance / 2.0;
 	}
-	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, P2)) {
+	if (!ctx->ignore_clearance && PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, P2)) {
 		pcp_cnt++;
 		pcp_gap = P2->Clearance / 2.0;
 	}