Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java	(revision 11061)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/DuplicateNode.java	(revision 11062)
@@ -390,5 +390,6 @@
         if (testError.getCode() == DUPLICATE_NODE) return false;
         // cannot merge nodes outside download area
-        if (testError.getPrimitives().iterator().next().isOutsideDownloadArea()) return false;
+        final Iterator<? extends OsmPrimitive> it = testError.getPrimitives().iterator();
+        if (!it.hasNext() || it.next().isOutsideDownloadArea()) return false;
         // everything else is ok to merge
         return true;