Fix thread switching sometimes stuck (#7079)

src/components/structures/ThreadView.tsx

@@ -100,10 +100,8 @@ export default class ThreadView extends React.Component<IProps, IState> {
 
     private onAction = (payload: ActionPayload): void => {
         if (payload.phase == RightPanelPhases.ThreadView && payload.event) {
-            if (payload.event !== this.props.mxEvent) {
-                this.teardownThread();
-                this.setupThread(payload.event);
-            }
+            this.teardownThread();
+            this.setupThread(payload.event);
         }
         switch (payload.action) {
             case Action.EditEvent:
@@ -135,12 +133,15 @@ export default class ThreadView extends React.Component<IProps, IState> {
         let thread = mxEv.getThread();
         if (!thread) {
             const client = MatrixClientPeg.get();
+            // Do not attach this thread object to the event for now
+            // TODO: When local echo gets reintroduced it will be important
+            // to add that back in, and the threads model should go through the
+            // same reconciliation algorithm as events
             thread = new Thread(
                 [mxEv],
                 this.props.room,
                 client,
             );
-            mxEv.setThread(thread);
         }
         thread.on(ThreadEvent.Update, this.updateThread);
         thread.once(ThreadEvent.Ready, this.updateThread);
@@ -226,7 +227,6 @@ export default class ThreadView extends React.Component<IProps, IState> {
                             timelineSet={this.state?.thread?.timelineSet}
                             showUrlPreview={true}
                             tileShape={TileShape.Thread}
-                            empty={<div>empty</div>}
                             layout={Layout.Group}
                             hideThreadedMessages={false}
                             hidden={false}

src/components/views/messages/MessageActionBar.tsx

@@ -24,7 +24,6 @@ import { _t } from '../../../languageHandler';
 import * as sdk from '../../../index';
 import dis from '../../../dispatcher/dispatcher';
 import { Action } from '../../../dispatcher/actions';
-import { RightPanelPhases } from '../../../stores/RightPanelStorePhases';
 import { aboveLeftOf, ContextMenu, ContextMenuTooltipButton, useContextMenu } from '../../structures/ContextMenu';
 import { isContentActionable, canEditContent } from '../../../utils/EventUtils';
 import RoomContext, { TimelineRenderingType } from "../../../contexts/RoomContext";
@@ -42,6 +41,7 @@ import classNames from 'classnames';
 import SettingsStore from '../../../settings/SettingsStore';
 import { RoomPermalinkCreator } from '../../../utils/permalinks/Permalinks';
 import ReplyChain from '../elements/ReplyChain';
+import { dispatchShowThreadEvent } from '../../../dispatcher/dispatch-actions/threads';
 
 interface IOptionsButtonProps {
     mxEvent: MatrixEvent;
@@ -196,14 +196,7 @@ export default class MessageActionBar extends React.PureComponent<IMessageAction
     };
 
     private onThreadClick = (): void => {
-        dis.dispatch({
-            action: Action.SetRightPanelPhase,
-            phase: RightPanelPhases.ThreadView,
-            allowClose: false,
-            refireParams: {
-                event: this.props.mxEvent,
-            },
-        });
+        dispatchShowThreadEvent(this.props.mxEvent);
     };
 
     private onEditClick = (ev: React.MouseEvent): void => {