Index: trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java	(revision 15870)
+++ trunk/src/org/openstreetmap/josm/actions/MergeNodesAction.java	(revision 15872)
@@ -351,4 +351,6 @@
                 cmds.add(new DeleteCommand(nodesToDelete));
             }
+            if (cmds.size() == 1)
+                return cmds.get(0);
             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);