Index: trunk/src/org/openstreetmap/josm/command/MoveCommand.java
===================================================================
--- trunk/src/org/openstreetmap/josm/command/MoveCommand.java	(revision 2434)
+++ trunk/src/org/openstreetmap/josm/command/MoveCommand.java	(revision 2435)
@@ -2,4 +2,5 @@
 package org.openstreetmap.josm.command;
 
+import static org.openstreetmap.josm.tools.I18n.tr;
 import static org.openstreetmap.josm.tools.I18n.trn;
 
@@ -92,4 +93,8 @@
     @Override public boolean executeCommand() {
         for (Node n : nodes) {
+            // in case #3892 happens again
+            //
+            assert n!= null : tr("null detected in node list");
+            assert n.getEastNorth() != null : tr("unexpected null value for n.getEastNorth(). id of n is", n.getUniqueId());
             n.setEastNorth(n.getEastNorth().add(x, y));
             n.setModified(true);