From d73509db7436fa36055240fa7091357c8cea9526 Mon Sep 17 00:00:00 2001
From: Nicolas Gallagher <nicolasgallagher@gmail.com>
Date: Tue, 6 Apr 2021 17:13:59 -0700
Subject: [PATCH] [fix] PanResponder move event filtering

Fix #1853
---
 .../vendor/react-native/PanResponder/index.js   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/packages/react-native-web/src/vendor/react-native/PanResponder/index.js b/packages/react-native-web/src/vendor/react-native/PanResponder/index.js
index fd76a7d9..8eb14221 100644
--- a/packages/react-native-web/src/vendor/react-native/PanResponder/index.js
+++ b/packages/react-native-web/src/vendor/react-native/PanResponder/index.js
@@ -432,6 +432,15 @@ const PanResponder = {
 
       onMoveShouldSetResponderCapture(event: PressEvent): boolean {
         const touchHistory = event.touchHistory;
+        // Responder system incorrectly dispatches should* to current responder
+        // Filter out any touch moves past the first one - we would have
+        // already processed multi-touch geometry during the first event.
+        if (
+          gestureState._accountsForMovesUpTo ===
+          touchHistory.mostRecentTimeStamp
+        ) {
+          return false;
+        }
         PanResponder._updateGestureStateOnMove(gestureState, touchHistory);
         return config.onMoveShouldSetPanResponderCapture
           ? config.onMoveShouldSetPanResponderCapture(event, gestureState)
@@ -489,6 +498,14 @@ const PanResponder = {
 
       onResponderMove(event: PressEvent): void {
         const touchHistory = event.touchHistory;
+        // Guard against the dispatch of two touch moves when there are two
+        // simultaneously changed touches.
+        if (
+          gestureState._accountsForMovesUpTo ===
+          touchHistory.mostRecentTimeStamp
+        ) {
+          return;
+        }
         // Filter out any touch moves past the first one - we would have
         // already processed multi-touch geometry during the first event.
         PanResponder._updateGestureStateOnMove(gestureState, touchHistory);