Ticket #7194: 7194.patch

src/org/openstreetmap/josm/data/osm/DataSetMerger.java

@@ -178 +178 @@
 
                 List<OsmPrimitive> referrers = target.getReferrers();
                 if (referrers.isEmpty()) {
+                    if (target instanceof Way) { // fix #7194
+                        ((Way) target).setNodes(null);
+                    }
                     target.setDeleted(true);
                     target.mergeFrom(source);
                     it.remove();