Index: src/route-rnd/rtpoly.c
===================================================================
--- src/route-rnd/rtpoly.c	(revision 1470)
+++ src/route-rnd/rtpoly.c	(revision 1471)
@@ -85,6 +85,18 @@
 {
 	rtp_vertex_t *v, *vn;
 
+	for(v = gdl_first(&poly->lst); v != NULL; v = gdl_next(&poly->lst, v)) {
+		vn = gdl_next(&poly->lst, v);
+		if (vn == NULL) vn = gdl_first(&poly->lst);
+		poly->area += (v->x - vn->x) * (v->y + vn->y);
+	}
+
+	/* make sure about the orientation */
+	if (poly->area < 0) {
+		gdl_reverse(&poly->lst);
+		poly->area = -poly->area;
+	}
+
 	poly->bbox = g2d_box_invalid();
 	for(v = gdl_first(&poly->lst); v != NULL; v = gdl_next(&poly->lst, v)) {
 		g2d_vect_t pt;
@@ -95,17 +107,11 @@
 		v->bbox.x2 = RTP_MAX(v->x, vn->x);
 		v->bbox.y2 = RTP_MAX(v->y, vn->y);
 		rtrnd_rtree_insert(&poly->tree, v, &v->bbox);
-		poly->area += (v->x - vn->x) * (v->y + vn->y);
 
 		pt.x = v->x; pt.y = v->y;
 		g2d_box_bump_pt(&poly->bbox, pt);
 	}
 
-	/* make sure about the orientation */
-	if (poly->area < 0) {
-		gdl_reverse(&poly->lst);
-		poly->area = -poly->area;
-	}
 
 	poly->area /= 2;
 	poly->valid = rtpoly_is_valid_selfi(poly) && (poly->lst.length > 2);