Index: trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/ConditionFactory.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/ConditionFactory.java	(revision 14006)
+++ trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/ConditionFactory.java	(revision 14007)
@@ -23,4 +23,5 @@
 import org.openstreetmap.josm.data.osm.Way;
 import org.openstreetmap.josm.data.osm.search.SearchCompiler.InDataSourceArea;
+import org.openstreetmap.josm.data.osm.visitor.paint.relations.Multipolygon;
 import org.openstreetmap.josm.data.osm.visitor.paint.relations.MultipolygonCache;
 import org.openstreetmap.josm.gui.mappaint.Cascade;
@@ -764,6 +765,8 @@
             if (e.osm instanceof Way && ((Way) e.osm).isClosed())
                 return true;
-            if (e.osm instanceof Relation && ((Relation) e.osm).isMultipolygon())
-                return MultipolygonCache.getInstance().get((Relation) e.osm).getOpenEnds().isEmpty();
+            if (e.osm instanceof Relation && ((Relation) e.osm).isMultipolygon()) {
+                Multipolygon multipolygon = MultipolygonCache.getInstance().get((Relation) e.osm);
+                return multipolygon != null && multipolygon.getOpenEnds().isEmpty();
+            }
             return false;
         }