Index: trunk/src/org/openstreetmap/josm/actions/UnGlueAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/UnGlueAction.java	(revision 9469)
+++ trunk/src/org/openstreetmap/josm/actions/UnGlueAction.java	(revision 9470)
@@ -701,4 +701,8 @@
             }
         }
+        if (affectedRelations.isEmpty()) {
+            return;
+        }
+
         final String msg1 = trn("Unglueing affected {0} relation: {1}", "Unglueing affected {0} relations: {1}",
                 affectedRelations.size(), affectedRelations.size(), Utils.joinAsHtmlUnorderedList(affectedRelations));