From fae3e5308bca79da4f7acc2d06b8adc3fbb1ea27 Mon Sep 17 00:00:00 2001
From: Sebastian Markbage <sema@fb.com>
Date: Tue, 11 Oct 2016 15:52:11 -0700
Subject: [PATCH] Use memoizedState in componentDidUpdate

We forgot to clone this value so it didn't work before.
This is covered by existing tests in ReactDOMProduction.
---
 src/renderers/shared/fiber/ReactFiber.js           | 1 +
 src/renderers/shared/fiber/ReactFiberCommitWork.js | 4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/renderers/shared/fiber/ReactFiber.js b/src/renderers/shared/fiber/ReactFiber.js
index 6c1d557325..0eee40f1b3 100644
--- a/src/renderers/shared/fiber/ReactFiber.js
+++ b/src/renderers/shared/fiber/ReactFiber.js
@@ -253,6 +253,7 @@ exports.cloneFiber = function(fiber : Fiber, priorityLevel : PriorityLevel) : Fi
   alt.pendingWorkPriority = priorityLevel;
 
   alt.memoizedProps = fiber.memoizedProps;
+  alt.memoizedState = fiber.memoizedState;
   alt.output = fiber.output;
 
   return alt;
diff --git a/src/renderers/shared/fiber/ReactFiberCommitWork.js b/src/renderers/shared/fiber/ReactFiberCommitWork.js
index 837f12d00c..a972dc5623 100644
--- a/src/renderers/shared/fiber/ReactFiberCommitWork.js
+++ b/src/renderers/shared/fiber/ReactFiberCommitWork.js
@@ -289,9 +289,7 @@ module.exports = function<T, P, I, TI, C>(config : HostConfig<T, P, I, TI, C>) {
         } else {
           if (typeof instance.componentDidUpdate === 'function') {
             const prevProps = current.memoizedProps;
-            // TODO: This is the new state. We don't currently have the previous
-            // state anymore.
-            const prevState = instance.state || null;
+            const prevState = current.memoizedState;
             instance.componentDidUpdate(prevProps, prevState);
           }
         }