From eedca6f641d2ea52fb1de5f12f61bc21b7c5f0d6 Mon Sep 17 00:00:00 2001
From: Dan Abramov <dan.abramov@gmail.com>
Date: Mon, 14 Nov 2016 18:24:30 +0000
Subject: [PATCH] Disable memoized props bailout when context might have
 changed

---
 scripts/fiber/tests-failing.txt                 |  2 --
 scripts/fiber/tests-passing.txt                 |  2 ++
 .../shared/fiber/ReactFiberBeginWork.js         |  8 +++++---
 src/renderers/shared/fiber/ReactFiberContext.js | 17 ++++++++++++-----
 4 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/scripts/fiber/tests-failing.txt b/scripts/fiber/tests-failing.txt
index 3367df108b..af870d39a1 100644
--- a/scripts/fiber/tests-failing.txt
+++ b/scripts/fiber/tests-failing.txt
@@ -425,8 +425,6 @@ src/renderers/shared/stack/reconciler/__tests__/ReactCompositeComponent-test.js
 * should warn about `setState` on unmounted components
 * should warn about `setState` in render
 * should warn about `setState` in getChildContext
-* should pass context when re-rendered for static child
-* should pass context when re-rendered for static child within a composite component
 * unmasked context propagates through updates
 * should trigger componentWillReceiveProps for context changes
 * should update refs if shouldComponentUpdate gives false
diff --git a/scripts/fiber/tests-passing.txt b/scripts/fiber/tests-passing.txt
index bae9086652..c763f784ea 100644
--- a/scripts/fiber/tests-passing.txt
+++ b/scripts/fiber/tests-passing.txt
@@ -1035,6 +1035,8 @@ src/renderers/shared/stack/reconciler/__tests__/ReactCompositeComponent-test.js
 * should warn when componentDidUnmount method is defined
 * should pass context to children when not owner
 * should skip update when rerendering element in container
+* should pass context when re-rendered for static child
+* should pass context when re-rendered for static child within a composite component
 * should pass context transitively
 * should pass context when re-rendered
 * only renders once if updated in componentWillReceiveProps
diff --git a/src/renderers/shared/fiber/ReactFiberBeginWork.js b/src/renderers/shared/fiber/ReactFiberBeginWork.js
index 155f951b61..02fd265aa9 100644
--- a/src/renderers/shared/fiber/ReactFiberBeginWork.js
+++ b/src/renderers/shared/fiber/ReactFiberBeginWork.js
@@ -28,6 +28,7 @@ var ReactTypeOfWork = require('ReactTypeOfWork');
 var {
   getMaskedContext,
   isContextProvider,
+  hasContextChanged,
   pushContextProvider,
   resetContext,
 } = require('ReactFiberContext');
@@ -200,7 +201,7 @@ module.exports = function<T, P, I, TI, C>(
     reconcileChildren(current, workInProgress, nextChildren);
     // Put context on the stack because we will work on children
     if (isContextProvider(workInProgress)) {
-      pushContextProvider(workInProgress);
+      pushContextProvider(workInProgress, true);
     }
     return workInProgress.child;
   }
@@ -361,7 +362,7 @@ module.exports = function<T, P, I, TI, C>(
     markChildAsProgressed(current, workInProgress, priorityLevel);
     // Put context on the stack because we will work on children
     if (isContextProvider(workInProgress)) {
-      pushContextProvider(workInProgress);
+      pushContextProvider(workInProgress, false);
     }
     return workInProgress.child;
   }
@@ -398,7 +399,8 @@ module.exports = function<T, P, I, TI, C>(
       workInProgress.memoizedProps !== null &&
       workInProgress.pendingProps === workInProgress.memoizedProps
       )) &&
-      workInProgress.updateQueue === null) {
+      workInProgress.updateQueue === null &&
+      !hasContextChanged()) {
       return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
 
diff --git a/src/renderers/shared/fiber/ReactFiberContext.js b/src/renderers/shared/fiber/ReactFiberContext.js
index eeb78e4f30..fbc478020f 100644
--- a/src/renderers/shared/fiber/ReactFiberContext.js
+++ b/src/renderers/shared/fiber/ReactFiberContext.js
@@ -28,13 +28,14 @@ if (__DEV__) {
 }
 
 let index = -1;
-const stack = [];
+const contextStack : Array<Object> = [];
+const didPerformWorkStack : Array<boolean> = [];
 
 function getUnmaskedContext() {
   if (index === -1) {
     return emptyObject;
   }
-  return stack[index];
+  return contextStack[index];
 }
 
 exports.getMaskedContext = function(fiber : Fiber) {
@@ -59,6 +60,10 @@ exports.getMaskedContext = function(fiber : Fiber) {
   return context;
 };
 
+exports.hasContextChanged = function() : boolean {
+  return index > -1 && didPerformWorkStack[index];
+};
+
 exports.isContextProvider = function(fiber : Fiber) : boolean {
   return (
     fiber.tag === ClassComponent &&
@@ -67,11 +72,12 @@ exports.isContextProvider = function(fiber : Fiber) : boolean {
 };
 
 exports.popContextProvider = function() : void {
-  stack[index] = emptyObject;
+  contextStack[index] = emptyObject;
+  didPerformWorkStack[index] = false;
   index--;
 };
 
-exports.pushContextProvider = function(fiber : Fiber) : void {
+exports.pushContextProvider = function(fiber : Fiber, didPerformWork : boolean) : void {
   const instance = fiber.stateNode;
   const childContextTypes = fiber.type.childContextTypes;
   const childContext = instance.getChildContext();
@@ -92,7 +98,8 @@ exports.pushContextProvider = function(fiber : Fiber) : void {
 
   const mergedContext = Object.assign({}, getUnmaskedContext(), childContext);
   index++;
-  stack[index] = mergedContext;
+  contextStack[index] = mergedContext;
+  didPerformWorkStack[index] = didPerformWork;
 };
 
 exports.resetContext = function() : void {