From c40a938ead3662aedc823e70f12f68e98985c8b7 Mon Sep 17 00:00:00 2001
From: Spencer Ahrens <sahrens@fb.com>
Date: Tue, 23 Apr 2019 16:00:44 -0700
Subject: [PATCH] Fix infinite `setState` in `VirtualizedList`

Reviewed By: larrylin28

Differential Revision: D14990686

fbshipit-source-id: 632fa0e4e11feff9dcfb4ac62ba8bc7a6c0393a5
---
 Libraries/Lists/VirtualizedList.js | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/Libraries/Lists/VirtualizedList.js b/Libraries/Lists/VirtualizedList.js
index 72686db4e322c1..67abdc1765877c 100644
--- a/Libraries/Lists/VirtualizedList.js
+++ b/Libraries/Lists/VirtualizedList.js
@@ -982,7 +982,19 @@ class VirtualizedList extends React.PureComponent<Props, State> {
         tuple.viewabilityHelper.resetViewableIndices();
       });
     }
+    // The `this._hiPriInProgress` is guaranteeing a hiPri cell update will only happen
+    // once per fiber update. The `_scheduleCellsToRenderUpdate` will set it to true
+    // if a hiPri update needs to perform. If `componentDidUpdate` is triggered with
+    // `this._hiPriInProgress=true`, means it's triggered by the hiPri update. The
+    // `_scheduleCellsToRenderUpdate` will check this condition and not perform
+    // another hiPri update.
+    const hiPriInProgress = this._hiPriInProgress;
     this._scheduleCellsToRenderUpdate();
+    // Make sure setting `this._hiPriInProgress` back to false after `componentDidUpdate`
+    // is triggered with `this._hiPriInProgress = true`
+    if (hiPriInProgress) {
+      this._hiPriInProgress = false;
+    }
   }
 
   _averageCellLength = 0;
@@ -993,13 +1005,14 @@ class VirtualizedList extends React.PureComponent<Props, State> {
   _frames = {};
   _footerLength = 0;
   _hasDataChangedSinceEndReached = true;
+  _hasDoneInitialScroll = false;
   _hasInteracted = false;
   _hasMore = false;
   _hasWarned = {};
-  _highestMeasuredFrameIndex = 0;
   _headerLength = 0;
+  _hiPriInProgress: boolean = false; // flag to prevent infinite hiPri cell limit update
+  _highestMeasuredFrameIndex = 0;
   _indicesToKeys: Map<number, string> = new Map();
-  _hasDoneInitialScroll = false;
   _nestedChildLists: Map<
     string,
     {ref: ?VirtualizedList, state: ?ChildListState},
@@ -1422,7 +1435,10 @@ class VirtualizedList extends React.PureComponent<Props, State> {
     // Otherwise, it would just render as many cells as it can (of zero dimension),
     // each time through attempting to render more (limited by maxToRenderPerBatch),
     // starving the renderer from actually laying out the objects and computing _averageCellLength.
-    if (hiPri && this._averageCellLength) {
+    // If this is triggered in an `componentDidUpdate` followed by a hiPri cellToRenderUpdate
+    // We shouldn't do another hipri cellToRenderUpdate
+    if (hiPri && this._averageCellLength && !this._hiPriInProgress) {
+      this._hiPriInProgress = true;
       // Don't worry about interactions when scrolling quickly; focus on filling content as fast
       // as possible.
       this._updateCellsToRenderBatcher.dispose({abort: true});