From 2aeab2bc10f45e479d7c3c3218b937c1e0a19ca8 Mon Sep 17 00:00:00 2001
From: "Daniel Boelzle [:dbo]" <dbo@boelzle.org>
Date: Wed, 18 Jan 2017 14:39:28 +0100
Subject: [PATCH 1/3] Check write-access on prototype.

---
 client/patch-react.js | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/client/patch-react.js b/client/patch-react.js
index b16b8bb9d8fcc..fc8698a4cb920 100644
--- a/client/patch-react.js
+++ b/client/patch-react.js
@@ -3,6 +3,15 @@
 
 import React from 'react'
 
+const isWritable = (obj, p) => {
+  const descr = Object.getOwnPropertyDescriptor(obj, p)
+  if (descr) {
+    return descr.writable
+  }
+  const proto = Object.getPrototypeOf(obj)
+  return proto ? isWritable(proto, p) : false
+}
+
 let patched = false
 
 export default (handleError = () => {}) => {
@@ -18,7 +27,9 @@ export default (handleError = () => {}) => {
     if (typeof Component === 'function') {
       const { prototype } = Component
       if (prototype && prototype.render) {
-        prototype.render = wrapRender(prototype.render)
+        if (isWritable(prototype, 'render')) {
+          prototype.render = wrapRender(prototype.render)
+        }
       } else {
         // stateless component
         Component = wrapRender(Component)

From 5bc571d0111f18eafd9447cd359cb039b0500c83 Mon Sep 17 00:00:00 2001
From: "Daniel Boelzle [:dbo]" <dbo@boelzle.org>
Date: Wed, 18 Jan 2017 14:53:41 +0100
Subject: [PATCH 2/3] Write on correct prototype.

---
 client/patch-react.js | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/client/patch-react.js b/client/patch-react.js
index fc8698a4cb920..34b10ba701056 100644
--- a/client/patch-react.js
+++ b/client/patch-react.js
@@ -3,13 +3,13 @@
 
 import React from 'react'
 
-const isWritable = (obj, p) => {
+const getWritableProto = (obj, p) => {
   const descr = Object.getOwnPropertyDescriptor(obj, p)
   if (descr) {
-    return descr.writable
+    return descr.writable ? obj : null
   }
   const proto = Object.getPrototypeOf(obj)
-  return proto ? isWritable(proto, p) : false
+  return proto ? getWritableProto(proto, p) : null
 }
 
 let patched = false
@@ -25,9 +25,10 @@ export default (handleError = () => {}) => {
 
   React.createElement = function (Component, ...rest) {
     if (typeof Component === 'function') {
-      const { prototype } = Component
+      let { prototype } = Component
       if (prototype && prototype.render) {
-        if (isWritable(prototype, 'render')) {
+        prototype = getWritableProto(prototype, 'render')
+        if (prototype) {
           prototype.render = wrapRender(prototype.render)
         }
       } else {

From 996f34250d992a26e7161de25fb50096102a7607 Mon Sep 17 00:00:00 2001
From: "Daniel Boelzle [:dbo]" <dbo@boelzle.org>
Date: Sat, 21 Jan 2017 10:14:11 +0100
Subject: [PATCH 3/3] Add comments to prototype lookup.

---
 client/patch-react.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/client/patch-react.js b/client/patch-react.js
index 34b10ba701056..5e70db0808f7f 100644
--- a/client/patch-react.js
+++ b/client/patch-react.js
@@ -3,6 +3,10 @@
 
 import React from 'react'
 
+/**
+ * Traverses the prototype chain, returning the prototype object
+ * on which the property is defined.
+ */
 const getWritableProto = (obj, p) => {
   const descr = Object.getOwnPropertyDescriptor(obj, p)
   if (descr) {
@@ -27,6 +31,9 @@ export default (handleError = () => {}) => {
     if (typeof Component === 'function') {
       let { prototype } = Component
       if (prototype && prototype.render) {
+        /**
+         * Get the prototype object on which `render` is defined.
+         */
         prototype = getWritableProto(prototype, 'render')
         if (prototype) {
           prototype.render = wrapRender(prototype.render)