Index: net_len.c
===================================================================
--- net_len.c	(revision 34987)
+++ net_len.c	(revision 34988)
@@ -230,7 +230,7 @@
 	if (conns == 0) {
 		if (dist == NULL) {
 			pcb_any_obj_t *hub = junction_hub(new_obj, new_end, arrived_from, old_end, thr);
-			rnd_trace("NSL: junction at: middle of #%ld (#%ld vs. #%ld)\n", hub->ID, new_obj->ID, arrived_from->ID);
+			rnd_trace("NSL: junction at: middle of #%ld (#%ld vs. #%ld)\n", hub==NULL ? 0 : hub->ID, new_obj->ID, arrived_from->ID);
 			*hub_out = hub;
 		}
 		return -2;
@@ -327,7 +327,13 @@
 				int cnt;
 
 				/* remove from arrived_from: removes the hub object */
-				remove_offender_from_open(fctx, arrived_from);
+				if (hub_obj == NULL) {
+					remove_offender_from_open(fctx, arrived_from);
+					ctx->seglen->has_invalid_hub = 1;
+				}
+				else
+					remove_offender_from_open(fctx, hub_obj);
+
 				remove_offender_from_closed(fctx, new_obj, arrived_from);
 
 
@@ -348,9 +354,10 @@
 				/* plus remove anything but the first object that is in contact with it
 				   (this removes started outgoing threads but not the object we once
 				   came from to reach arrived_from) */
+				if (hub_obj != NULL)
 				for(n = 0, cnt = 0; n < ctx->ec->tmplst.used; n++) {
 					pcb_any_obj_t *o = ctx->ec->tmplst.array[n];
-					if (pcb_intersect_obj_obj(fctx, o, arrived_from)) {
+					if (pcb_intersect_obj_obj(fctx, o, hub_obj)) {
 						cnt++;
 						if (cnt > 1) {
 							rnd_trace(" REMOVE4: #%ld (from #%ld)\n", ((pcb_any_obj_t *)(ctx->ec->tmplst.array[n]))->ID, new_obj->ID);
Index: net_len.h
===================================================================
--- net_len.h	(revision 34987)
+++ net_len.h	(revision 34988)
@@ -4,6 +4,7 @@
 	vtp0_t objs;
 	unsigned has_junction:1;
 	unsigned has_nontrace:1;
+	unsigned has_invalid_hub:1;
 	pcb_any_obj_t *junction[3]; /* object with a junction on it before and after the list; 0..1 are ordered as objs; 2 is a spare field for internal use */
 	pcb_any_obj_t *junc_at[3];  /* our last object (part of the seg) that faces the given junction */
 	unsigned hub:1;             /* when set, this segment is a junction hub with more than 2 connected segments */