From 7c2dec5bd30bf404e3ae6385f9b897df45c84dd6 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@fiftythree.com>
Date: Tue, 10 Jun 2014 13:04:32 -0700
Subject: [PATCH] Prevent null reference access when unsetting styles

---
 src/browser/ui/ReactDOMComponent.js                | 2 +-
 src/browser/ui/__tests__/ReactDOMComponent-test.js | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/browser/ui/ReactDOMComponent.js b/src/browser/ui/ReactDOMComponent.js
index e8ecbbf230..b9719b3686 100644
--- a/src/browser/ui/ReactDOMComponent.js
+++ b/src/browser/ui/ReactDOMComponent.js
@@ -307,7 +307,7 @@ ReactDOMComponent.Mixin = {
           // Unset styles on `lastProp` but not on `nextProp`.
           for (styleName in lastProp) {
             if (lastProp.hasOwnProperty(styleName) &&
-                !nextProp.hasOwnProperty(styleName)) {
+                (!nextProp || !nextProp.hasOwnProperty(styleName))) {
               styleUpdates = styleUpdates || {};
               styleUpdates[styleName] = '';
             }
diff --git a/src/browser/ui/__tests__/ReactDOMComponent-test.js b/src/browser/ui/__tests__/ReactDOMComponent-test.js
index d4fb449923..72111cd5f6 100644
--- a/src/browser/ui/__tests__/ReactDOMComponent-test.js
+++ b/src/browser/ui/__tests__/ReactDOMComponent-test.js
@@ -97,6 +97,11 @@ describe('ReactDOMComponent', function() {
       expect(stubStyle.display).toEqual('block');
       expect(stubStyle.fontFamily).toEqual('Helvetica');
       expect(stubStyle.lineHeight).toEqual('0.5');
+
+      stub.receiveComponent({props: { style: undefined }}, transaction);
+      expect(stubStyle.display).toBe('');
+      expect(stubStyle.fontFamily).toBe('');
+      expect(stubStyle.lineHeight).toBe('');
     });
 
     it("should update styles if initially null", function() {