Index: /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java	(revision 4619)
+++ /trunk/src/org/openstreetmap/josm/actions/mapmode/ExtrudeAction.java	(revision 4620)
@@ -373,5 +373,5 @@
                     }
                 }
-                else if (e.getPoint().distance(initialMousePos) > 10 && newN1en != null) {
+                else if (e.getPoint().distance(initialMousePos) > 10 && newN1en != null && selectedSegment != null) {
                     // create extrusion