src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/ir/Block.java

*** 460,469 ****
--- 460,481 ----
              }
          }
          return next;
      }
  
+     /**
+      * Determine whether this block needs to provide its scope object creator for use by its child nodes.
+      * This is only necessary for synthetic parent blocks of for-in loops with lexical declarations.
+      *
+      * @return true if child nodes need access to this block's scope creator
+      */
+     public boolean providesScopeCreator() {
+         return needsScope() && isSynthetic()
+                 && (getLastStatement() instanceof ForNode)
+                 && ((ForNode) getLastStatement()).needsScopeCreator();
+     }
+ 
      @Override
      public boolean isBreakableWithoutLabel() {
          return false;
      }