Index: trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 2503)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 2504)
@@ -511,11 +511,9 @@
      */
     private static  class RelationListModel extends AbstractListModel {
-        /** the list of relations managaged by this model. Should never be null */
-        private ArrayList<Relation> relations;
+        private final ArrayList<Relation> relations = new ArrayList<Relation>();
         private DefaultListSelectionModel selectionModel;
 
         public RelationListModel(DefaultListSelectionModel selectionModel) {
             this.selectionModel = selectionModel;
-            relations = new ArrayList<Relation>();
         }
 
@@ -526,12 +524,8 @@
         public synchronized void setRelations(Collection<Relation> relations) {
             List<Relation> sel =  getSelectedRelations();
-            if (relations == null) {
-                this.relations.clear();
-            } else {
-                this.relations = new ArrayList<Relation>(relations.size());
-                for (Relation r: relations) {
-                    if (! r.isDeleted() && r.isVisible() && !r.incomplete) {
-                        this.relations.add(r);
-                    }
+            this.relations.clear();
+            for (Relation r: relations) {
+                if (! r.isDeleted() && r.isVisible() && !r.incomplete) {
+                    this.relations.add(r);
                 }
             }
@@ -564,7 +558,4 @@
             if (addedPrimitives == null || addedPrimitives.isEmpty()) return;
             boolean added = false;
-            if (relations == null) {
-                relations = new ArrayList<Relation>();
-            }
             for (OsmPrimitive p: addedPrimitives) {
                 if (! (p instanceof Relation)) {