Improved threads stability (#7639)

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

Author: Germain

src/components/structures/MessagePanel.tsx

@@ -485,8 +485,11 @@ export default class MessagePanel extends React.Component<IProps, IState> {
 
         // Checking if the message has a "parentEventId" as we do not
         // want to hide the root event of the thread
-        if (mxEv.isThreadRelation && this.props.hideThreadedMessages
-                && SettingsStore.getValue("feature_thread")) {
+        if (mxEv.isThreadRelation &&
+            !mxEv.isThreadRoot &&
+            this.props.hideThreadedMessages &&
+            SettingsStore.getValue("feature_thread")
+        ) {
             return false;
         }
 

src/components/structures/ThreadView.tsx

@@ -139,7 +139,7 @@ export default class ThreadView extends React.Component<IProps, IState> {
     };
 
     private setupThread = (mxEv: MatrixEvent) => {
-        let thread = this.props.room.threads.get(mxEv.getId());
+        let thread = this.props.room.threads?.get(mxEv.getId());
         if (!thread) {
             thread = this.props.room.createThread([mxEv]);
         }

src/components/views/rooms/EventTile.tsx

@@ -383,7 +383,8 @@ export default class EventTile extends React.Component<IProps, IState> {
     constructor(props: IProps, context: React.ContextType<typeof MatrixClientContext>) {
         super(props, context);
 
-        const thread = this.props.mxEvent?.getThread();
+        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
+        const thread = room.threads?.get(this.props.mxEvent.getId());
 
         this.state = {
             // Whether the action bar is focused.