Index: trunk/src/flag.h
===================================================================
--- trunk/src/flag.h	(revision 11665)
+++ trunk/src/flag.h	(revision 11666)
@@ -78,6 +78,7 @@
 	PCB_FLAG_ONSOLDER     = 0x00080, /*!< For elements and pads, indicates that they are on the solder side. */
 	PCB_FLAG_AUTO         = 0x00080, /*!< For lines and vias, indicates that these were created by the autorouter. */
 	PCB_FLAG_SQUARE       = 0x00100, /*!< For pins and pads, indicates a square (vs round) pin/pad. */
+	PCB_FLAG_CLEARPOLYPOLY= 0x00100, /*!< For polygons, apply clearance to nearby polygons */
 	PCB_FLAG_RUBBEREND    = 0x00200, /*!< For lines, used internally for rubber band moves: indicates one end already rubber banding. */
 	PCB_FLAG_WARN         = 0x00200, /*!< For pins, vias, and pads, set to indicate a warning. */
 	PCB_FLAG_USETHERMAL   = 0x00400, /*!< Obsolete, indicates that pins/vias should be drawn with thermal fingers. */
Index: trunk/src/obj_subc.c
===================================================================
--- trunk/src/obj_subc.c	(revision 11665)
+++ trunk/src/obj_subc.c	(revision 11666)
@@ -193,10 +193,32 @@
 		dst = pcb_subc_layer_create_buff(sc, src);
 
 		while((line = linelist_first(&src->Line)) != NULL) {
-			linelist_remove(line);
-			linelist_append(&dst->Line, line);
-			PCB_SET_PARENT(line, layer, dst);
-			PCB_FLAG_CLEAR(PCB_FLAG_WARN | PCB_FLAG_FOUND | PCB_FLAG_SELECTED, line);
+			char *sq;
+
+			sq = pcb_attribute_get(&line->Attributes, "elem_smash_shape_square");
+			if ((sq != NULL) && (*sq == '1')) { /* convert to polygon */
+				pcb_coord_t x[4], y[4];
+				int n;
+
+				pcb_sqline_to_rect(line, x, y);
+
+				poly = pcb_poly_new(dst, pcb_no_flags());
+				for(n = 0; n < 4; n++)
+					pcb_poly_point_new(poly, x[n], y[n]);
+				pcb_add_polygon_on_layer(dst, poly);
+/*				pcb_poly_init_clip(st->pcb->Data, dst, poly);*/
+				PCB_FLAG_SET(PCB_FLAG_CLEARPOLYPOLY, poly);
+				pcb_attribute_copy_all(&poly->Attributes, &line->Attributes);
+
+				pcb_line_free(line);
+			}
+			else {
+				/* copy the line */
+				linelist_remove(line);
+				linelist_append(&dst->Line, line);
+				PCB_SET_PARENT(line, layer, dst);
+				PCB_FLAG_CLEAR(PCB_FLAG_WARN | PCB_FLAG_FOUND | PCB_FLAG_SELECTED, line);
+			}
 		}
 
 		while((arc = arclist_first(&src->Arc)) != NULL) {