From 8dda8838bad564c3e50216d9cc446d67537acda6 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Tue, 3 Mar 2015 09:37:52 +1100
Subject: [PATCH] check for body existence before length in dead code
 elimination transformer - fixes #931

---
 .../transformers/utility/dead-code-elimination.js               | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/babel/transformation/transformers/utility/dead-code-elimination.js b/src/babel/transformation/transformers/utility/dead-code-elimination.js
index 438a5fac7f..c25c1e4266 100644
--- a/src/babel/transformation/transformers/utility/dead-code-elimination.js
+++ b/src/babel/transformation/transformers/utility/dead-code-elimination.js
@@ -77,7 +77,7 @@ export var IfStatement = {
     //   if (foo) {} else { bar; } -> if (!foo) { bar; }
     //
 
-    if (t.blockStatement(consequent) && !consequent.body.length && t.isBlockStatement(alternate) && alternate.body.length) {
+    if (t.blockStatement(consequent) && consequent.body && !consequent.body.length && t.isBlockStatement(alternate) && alternate.body && alternate.body.length) {
       node.consequent = node.alternate;
       node.alternate  = null;
       node.test       = t.unaryExpression("!", test, true);