From 4b51708ed2db6dd454bfa4ef2467402019f40842 Mon Sep 17 00:00:00 2001
From: Ben Alpert <spicyjalapeno@gmail.com>
Date: Mon, 28 Apr 2014 22:16:59 -0300
Subject: [PATCH] Actually fix transitioning to null

Test Plan: grunt fasttest
---
 src/addons/transitions/ReactTransitionGroup.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/addons/transitions/ReactTransitionGroup.js b/src/addons/transitions/ReactTransitionGroup.js
index f77f63a1cd..a29dc3d2c2 100644
--- a/src/addons/transitions/ReactTransitionGroup.js
+++ b/src/addons/transitions/ReactTransitionGroup.js
@@ -119,7 +119,7 @@ var ReactTransitionGroup = React.createClass({
       this.props.children
     );
 
-    if (!currentChildMapping.hasOwnProperty(key)) {
+    if (!currentChildMapping || !currentChildMapping.hasOwnProperty(key)) {
       // This was removed before it had fully entered. Remove it.
       this.performLeave(key);
     }
@@ -152,7 +152,7 @@ var ReactTransitionGroup = React.createClass({
       this.props.children
     );
 
-    if (currentChildMapping.hasOwnProperty(key)) {
+    if (currentChildMapping && currentChildMapping.hasOwnProperty(key)) {
       // This entered again before it fully left. Add it again.
       this.performEnter(key);
     } else {