From f325a98f0edfe03bab4b0c07295f2346ac2d271d Mon Sep 17 00:00:00 2001
From: Vladimir Matveev <vladima@microsoft.com>
Date: Wed, 6 Apr 2016 15:40:17 -0700
Subject: [PATCH] enable generated names for block-scoped binding in for-of

---
 src/compiler/transformers/es6.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/compiler/transformers/es6.ts b/src/compiler/transformers/es6.ts
index 648ad7c8ea..552690b15b 100644
--- a/src/compiler/transformers/es6.ts
+++ b/src/compiler/transformers/es6.ts
@@ -1564,6 +1564,9 @@ namespace ts {
             // var v = _a[_i];
             if (isVariableDeclarationList(initializer)) {
                 const firstDeclaration = firstOrUndefined(initializer.declarations);
+                if (initializer.flags & NodeFlags.BlockScoped) {
+                    enableSubstitutionsForBlockScopedBindings();
+                }
                 if (firstDeclaration && isBindingPattern(firstDeclaration.name)) {
                     // This works whether the declaration is a var, let, or const.
                     // It will use rhsIterationValue _a[_i] as the initializer.