Index: trunk/src/plugins/rt_topo/crbs.c
===================================================================
--- trunk/src/plugins/rt_topo/crbs.c	(revision 1368)
+++ trunk/src/plugins/rt_topo/crbs.c	(revision 1369)
@@ -51,7 +51,7 @@
 		coll_ctn->coll = 1;
 }
 
-static grbs_2net_t *crbs_coll_check_arc_cb(grbs_t *grbs, grbs_2net_t *tn, grbs_arc_t *arc)
+static grbs_2net_t *crbs_coll_check_arc_cb(grbs_t *grbs, grbs_2net_t *tn, grbs_arc_t *arc, int new)
 {
 	crbs_point_t *pt = arc->parent_pt->user_data;
 
@@ -66,8 +66,14 @@
 			else
 				abort();
 /*printf(" (ACHK ang=%f arc=%f->%f) ", ang, arc->new_sa, arc->new_da);*/
-			if (grbs_angle_in_arc(arc->new_sa, arc->new_da, ang, 1))
-				return &tn_unknown;
+			if (new) {
+				if (grbs_angle_in_arc(arc->new_sa, arc->new_da, ang, 1))
+					return &tn_unknown;
+			}
+			else {
+				if (grbs_angle_in_arc(arc->sa, arc->da, ang, 1))
+					return &tn_unknown;
+			}
 		}
 	}
 	EDGELIST_FOREACH_END();