Index: trunk/src/change.c
===================================================================
--- trunk/src/change.c	(revision 11677)
+++ trunk/src/change.c	(revision 11678)
@@ -202,6 +202,7 @@
 static pcb_opfunc_t ChangeJoinFunctions = {
 	pcb_lineop_change_join,
 	pcb_textop_change_join,
+	pcb_polyop_change_join,
 	NULL,
 	NULL,
 	NULL,
@@ -209,7 +210,6 @@
 	NULL,
 	NULL,
 	NULL,
-	NULL,
 	pcb_arcop_change_join,
 	NULL,
 	NULL,
Index: trunk/src/change.h
===================================================================
--- trunk/src/change.h	(revision 11677)
+++ trunk/src/change.h	(revision 11678)
@@ -62,7 +62,7 @@
 	(PCB_TYPE_ELEMENT | PCB_TYPE_SUBC | PCB_TYPE_PIN | PCB_TYPE_VIA | PCB_TYPE_SUBC_PART)
 
 #define PCB_CHANGEJOIN_TYPES	\
-	(PCB_TYPE_ARC | PCB_TYPE_LINE | PCB_TYPE_TEXT)
+	(PCB_TYPE_ARC | PCB_TYPE_LINE | PCB_TYPE_TEXT | PCB_TYPE_POLYGON)
 
 #define PCB_CHANGETHERMAL_TYPES	\
 	(PCB_TYPE_PIN | PCB_TYPE_VIA | PCB_TYPE_SUBC_PART)
Index: trunk/src/obj_poly.c
===================================================================
--- trunk/src/obj_poly.c	(revision 11677)
+++ trunk/src/obj_poly.c	(revision 11678)
@@ -461,6 +461,26 @@
 	return (&Polygon->Points[ctx->insert.idx]);
 }
 
+/* changes the clearance flag of a line */
+void *pcb_polyop_change_join(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_polygon_t *poly)
+{
+	if (PCB_FLAG_TEST(PCB_FLAG_LOCK, poly))
+		return (NULL);
+	pcb_line_invalidate_erase(poly);
+	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, poly)) {
+		pcb_undo_add_obj_to_clear_poly(PCB_TYPE_POLYGON, Layer, poly, poly, pcb_false);
+		pcb_poly_restore_to_poly(PCB->Data, PCB_TYPE_POLYGON, Layer, poly);
+	}
+	pcb_undo_add_obj_to_flag(poly);
+	PCB_FLAG_TOGGLE(PCB_FLAG_CLEARPOLYPOLY, poly);
+	if (PCB_FLAG_TEST(PCB_FLAG_CLEARPOLYPOLY, poly)) {
+		pcb_undo_add_obj_to_clear_poly(PCB_TYPE_POLYGON, Layer, poly, poly, pcb_true);
+		pcb_poly_clear_from_poly(PCB->Data, PCB_TYPE_POLYGON, Layer, poly);
+	}
+	pcb_line_invalidate_draw(Layer, poly);
+	return poly;
+}
+
 /* low level routine to move a polygon */
 void pcb_poly_move(pcb_polygon_t *Polygon, pcb_coord_t DX, pcb_coord_t DY)
 {
Index: trunk/src/obj_poly_op.h
===================================================================
--- trunk/src/obj_poly_op.h	(revision 11677)
+++ trunk/src/obj_poly_op.h	(revision 11678)
@@ -46,5 +46,6 @@
 void *pcb_polyop_rotate90(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_polygon_t *Polygon);
 void *pcb_polyop_change_flag(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_polygon_t *Polygon);
 void *pcb_polyop_invalidate_label(pcb_opctx_t *ctx, pcb_layer_t *layer, pcb_polygon_t *poly);
+void *pcb_polyop_change_join(pcb_opctx_t *ctx, pcb_layer_t *Layer, pcb_polygon_t *poly);