Index: /trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java	(revision 15167)
+++ /trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java	(revision 15168)
@@ -351,5 +351,5 @@
                 cmds.add(new DeleteCommand(nodesToDelete));
             }
-            return new SequenceCommand(/* for correct i18n of plural forms - see #9110 */
+            return cmds.isEmpty() ? null : new SequenceCommand(/* for correct i18n of plural forms - see #9110 */
                     trn("Merge {0} node", "Merge {0} nodes", nodes.size(), nodes.size()), cmds);
         } catch (UserCancelException ex) {