Index: sketch_route.c
===================================================================
--- sketch_route.c	(revision 18482)
+++ sketch_route.c	(revision 18483)
@@ -484,10 +484,10 @@
 				edge_t *e = get_edge_from_points(wp->p, next_wp->p);
 				int list_num, n;
 
-				assert(prev_e->endp[1] == e->endp[0] || prev_e->endp[0] == e->endp[1]);
-				list_num = ((prev_e->endp[1] == wp->p) ^ (wp->side == SIDE_RIGHT) ? 1 : 0);
+				if (prev_e != e) { /* 3 subsequent points collinear */
+					assert(prev_e->endp[1] == e->endp[0] || prev_e->endp[0] == e->endp[1]);
+					list_num = ((prev_e->endp[1] == wp->p) ^ (wp->side == SIDE_RIGHT) ? 1 : 0);
 
-				if (prev_e != e) { /* 3 subsequent points collinear */
 					/* check if there was a wire, already attached to this point, that doesn't go through the same points
 					 * as the new wire and is on the opposite wirelist at this point */
 					if (pd->attached_wires[list_num^1] != NULL