Index: trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 2505)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/RelationListDialog.java	(revision 2506)
@@ -525,4 +525,10 @@
             List<Relation> sel =  getSelectedRelations();
             this.relations.clear();
+            if (relations == null) {
+                selectionModel.clearSelection();
+                fireContentsChanged(this,0,getSize());
+                return;
+
+            }
             for (Relation r: relations) {
                 if (! r.isDeleted() && r.isVisible() && !r.incomplete) {
@@ -657,5 +663,5 @@
         public synchronized void setSelectedRelations(List<Relation> sel) {
             selectionModel.clearSelection();
-            if (sel == null || sel.isEmpty() || relations == null)
+            if (sel == null || sel.isEmpty())
                 return;
             for (Relation r: sel) {