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

*** 252,267 ****
      @Override
      public Node leaveForNode(final ForNode forNode) {
          ForNode newForNode = forNode;
  
          final Expression test = forNode.getTest();
!         if (!forNode.isForIn() && isAlwaysTrue(test)) {
              newForNode = forNode.setTest(lc, null);
          }
  
          newForNode = checkEscape(newForNode);
!         if(!es6 && newForNode.isForIn()) {
              // Wrap it in a block so its internally created iterator is restricted in scope, unless we are running
              // in ES6 mode, in which case the parser already created a block to capture let/const declarations.
              addStatementEnclosedInBlock(newForNode);
          } else {
              addStatement(newForNode);
--- 252,267 ----
      @Override
      public Node leaveForNode(final ForNode forNode) {
          ForNode newForNode = forNode;
  
          final Expression test = forNode.getTest();
!         if (!forNode.isForInOrOf() && isAlwaysTrue(test)) {
              newForNode = forNode.setTest(lc, null);
          }
  
          newForNode = checkEscape(newForNode);
!         if(!es6 && (newForNode.isForIn() || newForNode.isForOf())) {
              // Wrap it in a block so its internally created iterator is restricted in scope, unless we are running
              // in ES6 mode, in which case the parser already created a block to capture let/const declarations.
              addStatementEnclosedInBlock(newForNode);
          } else {
              addStatement(newForNode);