Index: /applications/editors/josm/plugins/buildings_tools/src/org/openstreetmap/josm/plugins/buildings_tools/MergeAddrPointsAction.java
===================================================================
--- /applications/editors/josm/plugins/buildings_tools/src/org/openstreetmap/josm/plugins/buildings_tools/MergeAddrPointsAction.java	(revision 35569)
+++ /applications/editors/josm/plugins/buildings_tools/src/org/openstreetmap/josm/plugins/buildings_tools/MergeAddrPointsAction.java	(revision 35570)
@@ -174,5 +174,7 @@
             }
         }
-        cmds.add(new DeleteCommand(replaced.stream().map(p -> p.a).collect(Collectors.toList())));
+        if (!replaced.isEmpty()) {
+            cmds.add(new DeleteCommand(replaced.stream().map(p -> p.a).collect(Collectors.toList())));
+        }
 
         if (multi != 0)