From 17e703cb9692c26795c794a54e2239f603ee090d Mon Sep 17 00:00:00 2001
From: Sergei Startsev <ai@programist.ru>
Date: Tue, 25 Sep 2018 18:24:23 +0300
Subject: [PATCH] Restore global window.event after event dispatching (#13688)
 (#13697)

---
 packages/shared/invokeGuardedCallbackImpl.js | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packages/shared/invokeGuardedCallbackImpl.js b/packages/shared/invokeGuardedCallbackImpl.js
index 70cedd4cb32d2..74ec54c871b0b 100644
--- a/packages/shared/invokeGuardedCallbackImpl.js
+++ b/packages/shared/invokeGuardedCallbackImpl.js
@@ -98,6 +98,13 @@ if (__DEV__) {
       // browsers that support it.
       let windowEvent = window.event;
 
+      // Keeps track of the descriptor of window.event to restore it after event
+      // dispatching: https://github.com/facebook/react/issues/13688
+      const windowEventDescriptor = Object.getOwnPropertyDescriptor(
+        window,
+        'event',
+      );
+
       // Create an event handler for our fake event. We will synchronously
       // dispatch our fake event using `dispatchEvent`. Inside the handler, we
       // call the user-provided callback.
@@ -172,6 +179,10 @@ if (__DEV__) {
       evt.initEvent(evtType, false, false);
       fakeNode.dispatchEvent(evt);
 
+      if (windowEventDescriptor) {
+        Object.defineProperty(window, 'event', windowEventDescriptor);
+      }
+
       if (didError) {
         if (!didSetError) {
           // The callback errored, but the error event never fired.