src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/FieldObjectCreator.java

*** 118,127 ****
--- 118,146 ----
          } else {
              method.invoke(constructorNoLookup(className, PropertyMap.class));
          }
      }
  
+     /**
+      * Create a scope for a for-in/of loop as defined in ES6 13.7.5.13 step 5.g.iii
+      *
+      * @param method the method emitter
+      */
+     void createForInIterationScope(final MethodEmitter method) {
+         assert fieldObjectClass != null;
+         assert isScope();
+         assert getMap() != null;
+ 
+         final String className = getClassName();
+         method._new(fieldObjectClass).dup();
+         loadMap(method); //load the map
+         loadScope(method);
+         // We create a scope identical to the currently active one, so use its parent as our parent
+         method.invoke(ScriptObject.GET_PROTO);
+         method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class));
+     }
+ 
      @Override
      public void populateRange(final MethodEmitter method, final Type objectType, final int objectSlot, final int start, final int end) {
          method.load(objectType, objectSlot);
          // Set values.
          for (int i = start; i < end; i++) {