Ticket #18670: 18670.patch

src/org/openstreetmap/josm/actions/UnGlueAction.java

@@ -465 +465 @@
             }
             notifyWayPartOfRelation(parentWays);
         } else {
+            boolean firstLastNode = selectedWay.isFirstLastNode(selectedNode);
             cmds.add(new ChangeCommand(selectedWay, modifyWay(selectedNode, selectedWay, cmds, newNodes)));
-            notifyWayPartOfRelation(Collections.singleton(selectedWay));
+            if (firstLastNode) {
+                notifyWayPartOfRelation(Collections.singleton(selectedWay));
+            }
         }
 
         if (dialog != null) {