Index: /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java
===================================================================
--- /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java	(revision 35071)
+++ /applications/editors/josm/plugins/merge-overlap/src/mergeoverlap/MergeOverlapAction.java	(revision 35072)
@@ -230,7 +230,9 @@
 
         // Commit
-        UndoRedoHandler.getInstance().add(new SequenceCommand(tr("Merge Overlap (combine)"), cmds));
-        getLayerManager().getEditDataSet().setSelected(sel);
-        MainApplication.getMap().repaint();
+        if (!cmds.isEmpty()) {
+            UndoRedoHandler.getInstance().add(new SequenceCommand(tr("Merge Overlap (combine)"), cmds));
+            getLayerManager().getEditDataSet().setSelected(sel);
+            MainApplication.getMap().repaint();
+        }
 
         relations.clear();