From e06550b74877330ef31ebf74a65f9b0080e63a93 Mon Sep 17 00:00:00 2001
From: Michael Telatynski <7t3chguy@gmail.com>
Date: Wed, 28 Oct 2020 12:47:59 +0000
Subject: [PATCH] Watch replyToEvent at RoomView to prevent races

---
 src/components/structures/RoomView.tsx        |  3 +++
 src/components/views/rooms/MessageComposer.js | 17 ++---------------
 2 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/src/components/structures/RoomView.tsx b/src/components/structures/RoomView.tsx
index 4b2fa67c1c..32834469c3 100644
--- a/src/components/structures/RoomView.tsx
+++ b/src/components/structures/RoomView.tsx
@@ -129,6 +129,7 @@ export interface IState {
     initialEventPixelOffset?: number;
     // Whether to highlight the event scrolled to
     isInitialEventHighlighted?: boolean;
+    replyToEvent?: MatrixEvent;
     forwardingEvent?: MatrixEvent;
     numUnreadMessages: number;
     draggingFile: boolean;
@@ -315,6 +316,7 @@ export default class RoomView extends React.Component<IProps, IState> {
             joining: RoomViewStore.isJoining(),
             initialEventId: RoomViewStore.getInitialEventId(),
             isInitialEventHighlighted: RoomViewStore.isInitialEventHighlighted(),
+            replyToEvent: RoomViewStore.getQuotingEvent(),
             forwardingEvent: RoomViewStore.getForwardingEvent(),
             // we should only peek once we have a ready client
             shouldPeek: this.state.matrixClientIsReady && RoomViewStore.shouldPeek(),
@@ -1899,6 +1901,7 @@ export default class RoomView extends React.Component<IProps, IState> {
                     showApps={this.state.showApps}
                     e2eStatus={this.state.e2eStatus}
                     resizeNotifier={this.props.resizeNotifier}
+                    replyToEvent={this.state.replyToEvent}
                     permalinkCreator={this.getPermalinkCreatorForRoom(this.state.room)}
                 />;
         }
diff --git a/src/components/views/rooms/MessageComposer.js b/src/components/views/rooms/MessageComposer.js
index 40eaf77272..c260389eab 100644
--- a/src/components/views/rooms/MessageComposer.js
+++ b/src/components/views/rooms/MessageComposer.js
@@ -23,7 +23,6 @@ import CallHandler from '../../../CallHandler';
 import {MatrixClientPeg} from '../../../MatrixClientPeg';
 import * as sdk from '../../../index';
 import dis from '../../../dispatcher/dispatcher';
-import RoomViewStore from '../../../stores/RoomViewStore';
 import Stickerpicker from './Stickerpicker';
 import { makeRoomPermalink } from '../../../utils/permalinks/Permalinks';
 import ContentMessages from '../../../ContentMessages';
@@ -254,7 +253,6 @@ export default class MessageComposer extends React.Component {
         super(props);
         this.onInputStateChanged = this.onInputStateChanged.bind(this);
         this._onRoomStateEvents = this._onRoomStateEvents.bind(this);
-        this._onRoomViewStoreUpdate = this._onRoomViewStoreUpdate.bind(this);
         this._onTombstoneClick = this._onTombstoneClick.bind(this);
         this.renderPlaceholderText = this.renderPlaceholderText.bind(this);
         WidgetStore.instance.on(UPDATE_EVENT, this._onWidgetUpdate);
@@ -262,7 +260,6 @@ export default class MessageComposer extends React.Component {
         this._dispatcherRef = null;
 
         this.state = {
-            replyToEvent: RoomViewStore.getQuotingEvent(),
             tombstone: this._getRoomTombstone(),
             canSendMessages: this.props.room.maySendMessage(),
             showCallButtons: SettingsStore.getValue("showCallButtonsInComposer"),
@@ -294,7 +291,6 @@ export default class MessageComposer extends React.Component {
     componentDidMount() {
         this.dispatcherRef = dis.register(this.onAction);
         MatrixClientPeg.get().on("RoomState.events", this._onRoomStateEvents);
-        this._roomStoreToken = RoomViewStore.addListener(this._onRoomViewStoreUpdate);
         this._waitForOwnMember();
     }
 
@@ -318,9 +314,6 @@ export default class MessageComposer extends React.Component {
         if (MatrixClientPeg.get()) {
             MatrixClientPeg.get().removeListener("RoomState.events", this._onRoomStateEvents);
         }
-        if (this._roomStoreToken) {
-            this._roomStoreToken.remove();
-        }
         WidgetStore.instance.removeListener(UPDATE_EVENT, this._onWidgetUpdate);
         ActiveWidgetStore.removeListener('update', this._onActiveWidgetUpdate);
         dis.unregister(this.dispatcherRef);
@@ -341,12 +334,6 @@ export default class MessageComposer extends React.Component {
         return this.props.room.currentState.getStateEvents('m.room.tombstone', '');
     }
 
-    _onRoomViewStoreUpdate() {
-        const replyToEvent = RoomViewStore.getQuotingEvent();
-        if (this.state.replyToEvent === replyToEvent) return;
-        this.setState({ replyToEvent });
-    }
-
     onInputStateChanged(inputState) {
         // Merge the new input state with old to support partial updates
         inputState = Object.assign({}, this.state.inputState, inputState);
@@ -383,7 +370,7 @@ export default class MessageComposer extends React.Component {
     }
 
     renderPlaceholderText() {
-        if (this.state.replyToEvent) {
+        if (this.props.replyToEvent) {
             if (this.props.e2eStatus) {
                 return _t('Send an encrypted reply…');
             } else {
@@ -429,7 +416,7 @@ export default class MessageComposer extends React.Component {
                     placeholder={this.renderPlaceholderText()}
                     resizeNotifier={this.props.resizeNotifier}
                     permalinkCreator={this.props.permalinkCreator}
-                    replyToEvent={this.state.replyToEvent}
+                    replyToEvent={this.props.replyToEvent}
                 />,
                 <UploadButton key="controls_upload" roomId={this.props.room.roomId} />,
                 <EmojiButton key="emoji_button" addEmoji={this.addEmoji} />,