From 4eb1a45f0218bbd7d9e08f6397ac6a41e5d2731c Mon Sep 17 00:00:00 2001
From: kpdecker <kpdecker@gmail.com>
Date: Mon, 20 Jul 2015 11:06:09 +0300
Subject: [PATCH] Handle _blockHoist value of zero safely

---
 packages/babel/src/traversal/scope/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel/src/traversal/scope/index.js b/packages/babel/src/traversal/scope/index.js
index e588276c68..0d577152b4 100644
--- a/packages/babel/src/traversal/scope/index.js
+++ b/packages/babel/src/traversal/scope/index.js
@@ -829,7 +829,7 @@ export default class Scope {
 
     var unique = opts.unique;
     var kind   = opts.kind || "var";
-    var blockHoist = opts._blockHoist || 2;
+    var blockHoist = opts._blockHoist == null ? 2 : opts._blockHoist;
 
     var dataKey = `declaration:${kind}:${blockHoist}`;
     var declar  = !unique && path.getData(dataKey);