Index: trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java	(revision 3055)
+++ trunk/src/org/openstreetmap/josm/data/osm/OsmPrimitive.java	(revision 3056)
@@ -955,4 +955,5 @@
         // Returns only referrers that are members of the same dataset (primitive can have some fake references, for example
         // when way is cloned
+        checkDataset();
         List<OsmPrimitive> result = new ArrayList<OsmPrimitive>();
         if (referrers != null) {