Index: trunk/src/org/openstreetmap/josm/actions/JoinNodeWayAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/JoinNodeWayAction.java	(revision 2430)
+++ trunk/src/org/openstreetmap/josm/actions/JoinNodeWayAction.java	(revision 2431)
@@ -60,7 +60,10 @@
         Collection<Command> cmds = new LinkedList<Command>();
         for (Map.Entry<Way, List<Integer>> insertPoint : insertPoints.entrySet()) {
+            List<Integer> is = insertPoint.getValue();
+            if (is.size() == 0)
+                continue;
+
             Way w = insertPoint.getKey();
             List<Node> nodesToAdd = w.getNodes();
-            List<Integer> is = insertPoint.getValue();
             pruneSuccsAndReverse(is);
             for (int i : is) {
@@ -71,4 +74,7 @@
             cmds.add(new ChangeCommand(w, wnew));
         }
+
+        if (cmds.size() == 0)
+            return;
 
         Main.main.undoRedo.add(new SequenceCommand(tr("Join Node and Line"), cmds));