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

*** 255,264 ****
--- 255,267 ----
      private final IntDeque labeledBlockBreakLiveLocals = new IntDeque();
  
      //is this a rest of compilation
      private final int[] continuationEntryPoints;
  
+     // Scope object creators needed for for-of and for-in loops
+     private Deque<FieldObjectCreator<?>> scopeObjectCreators = new ArrayDeque<>();
+ 
      /**
       * Constructor.
       *
       * @param compiler
       */
*** 1295,1304 ****
--- 1298,1310 ----
      }
  
      private void popBlockScope(final Block block) {
          final Label breakLabel = block.getBreakLabel();
  
+         if (block.providesScopeCreator()) {
+             scopeObjectCreators.pop();
+         }
          if(!block.needsScope() || lc.isFunctionBody()) {
              emitBlockBreakLabel(breakLabel);
              return;
          }
  
*** 1810,1819 ****
--- 1816,1833 ----
                  }.emit();
              }
          }.store();
          body.accept(this);
  
+         if (forNode.needsScopeCreator() && lc.getCurrentBlock().providesScopeCreator()) {
+             // for-in loops with lexical declaration need a new scope for each iteration.
+             final FieldObjectCreator<?> creator = scopeObjectCreators.peek();
+             assert creator != null;
+             creator.createForInIterationScope(method);
+             method.storeCompilerConstant(SCOPE);
+         }
+ 
          if(method.isReachable()) {
              method._goto(continueLabel);
          }
          method.label(breakLabel);
      }
*** 1921,1936 ****
  
              /*
               * Create a new object based on the symbols and values, generate
               * bootstrap code for object
               */
!             new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
                  @Override
                  protected void loadValue(final Symbol value, final Type type) {
                      method.load(value, type);
                  }
!             }.makeObject(method);
              // program function: merge scope into global
              if (isFunctionBody && function.isProgram()) {
                  method.invoke(ScriptRuntime.MERGE_SCOPE);
              }
  
--- 1935,1954 ----
  
              /*
               * Create a new object based on the symbols and values, generate
               * bootstrap code for object
               */
!             final FieldObjectCreator<Symbol> creator = new FieldObjectCreator<Symbol>(this, tuples, true, hasArguments) {
                  @Override
                  protected void loadValue(final Symbol value, final Type type) {
                      method.load(value, type);
                  }
!             };
!             creator.makeObject(method);
!             if (block.providesScopeCreator()) {
!                 scopeObjectCreators.push(creator);
!             }
              // program function: merge scope into global
              if (isFunctionBody && function.isProgram()) {
                  method.invoke(ScriptRuntime.MERGE_SCOPE);
              }
  
*** 4478,4488 ****
                  @Override
                  public boolean enterIdentNode(final IdentNode node) {
                      final Symbol symbol = node.getSymbol();
                      assert symbol != null;
                      if (symbol.isScope()) {
!                         final int flags = getScopeCallSiteFlags(symbol);
                          if (isFastScope(symbol)) {
                              storeFastScopeVar(symbol, flags);
                          } else {
                              method.dynamicSet(node.getName(), flags, false);
                          }
--- 4496,4506 ----
                  @Override
                  public boolean enterIdentNode(final IdentNode node) {
                      final Symbol symbol = node.getSymbol();
                      assert symbol != null;
                      if (symbol.isScope()) {
!                         final int flags = getScopeCallSiteFlags(symbol) | (node.isDeclaredHere() ? CALLSITE_DECLARE : 0);
                          if (isFastScope(symbol)) {
                              storeFastScopeVar(symbol, flags);
                          } else {
                              method.dynamicSet(node.getName(), flags, false);
                          }