From 5c51f2fe4612bd2499f830382dafebac85a661d3 Mon Sep 17 00:00:00 2001
From: Sebastian Markbage <sema@fb.com>
Date: Tue, 19 Aug 2014 23:16:53 -0700
Subject: [PATCH] Check if a function has a prototype first

Because somehow someone used a prototype less function with JSX.
---
 src/core/ReactLegacyDescriptor.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/core/ReactLegacyDescriptor.js b/src/core/ReactLegacyDescriptor.js
index ff882723b4..b4ce4883b3 100644
--- a/src/core/ReactLegacyDescriptor.js
+++ b/src/core/ReactLegacyDescriptor.js
@@ -49,6 +49,7 @@ function warnForLegacyFactoryCall() {
 
 function warnForPlainFunctionType(type) {
   var isReactClass =
+    type.prototype &&
     typeof type.prototype.mountComponent === 'function' &&
     typeof type.prototype.receiveComponent === 'function';
   if (isReactClass) {