Fix incorrect logic to hide thread relations

src/components/structures/MessagePanel.tsx

@@ -460,7 +460,7 @@ 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.isThreadRoot && this.props.hideThreadedMessages
+        if (mxEv.isThreadRelation && this.props.hideThreadedMessages
                 && SettingsStore.getValue("feature_thread")) {
             return false;
         }

src/components/structures/ThreadView.tsx

@@ -48,10 +48,8 @@ interface IProps {
 }
 
 interface IState {
-    replyToEvent?: MatrixEvent;
     thread?: Thread;
     editState?: EditorStateTransfer;
-
 }
 
 @replaceableComponent("structures.ThreadView")
@@ -69,11 +67,16 @@ export default class ThreadView extends React.Component<IProps, IState> {
     public componentDidMount(): void {
         this.setupThread(this.props.mxEvent);
         this.dispatcherRef = dis.register(this.onAction);
+
+        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
+        room.on(ThreadEvent.New, this.onNewThread);
     }
 
     public componentWillUnmount(): void {
         this.teardownThread();
         dis.unregister(this.dispatcherRef);
+        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
+        room.on(ThreadEvent.New, this.onNewThread);
     }
 
     public componentDidUpdate(prevProps) {
@@ -135,11 +138,17 @@ export default class ThreadView extends React.Component<IProps, IState> {
         }
     };
 
+    private onNewThread = (thread: Thread) => {
+        if (thread.id === this.props.mxEvent.getId()) {
+            this.teardownThread();
+            this.setupThread(this.props.mxEvent);
+        }
+    };
+
     private updateThread = (thread?: Thread) => {
         if (thread) {
             this.setState({
                 thread,
-                replyToEvent: thread.replyToEvent,
             });
         }
 

src/components/views/rooms/EventTile.tsx

@@ -476,6 +476,9 @@ export default class EventTile extends React.Component<IProps, IState> {
             this.props.mxEvent.once(ThreadEvent.Ready, this.updateThread);
             this.props.mxEvent.on(ThreadEvent.Update, this.updateThread);
         }
+
+        const room = this.context.getRoom(this.props.mxEvent.getRoomId());
+        room.on(ThreadEvent.New, this.onNewThread);
     }
 
     private updateThread = (thread) => {
@@ -517,6 +520,9 @@ export default class EventTile extends React.Component<IProps, IState> {
             this.props.mxEvent.off(ThreadEvent.Ready, this.updateThread);
             this.props.mxEvent.off(ThreadEvent.Update, this.updateThread);
         }
+
+        const room = this.context.getRoom(this.props.mxEvent.getRoomId());
+        room.off(ThreadEvent.New, this.onNewThread);
     }
 
     componentDidUpdate(prevProps, prevState, snapshot) {
@@ -527,12 +533,32 @@ export default class EventTile extends React.Component<IProps, IState> {
         }
     }
 
+    private onNewThread = (thread: Thread) => {
+        if (thread.id === this.props.mxEvent.getId()) {
+            this.updateThread(thread);
+            const room = this.context.getRoom(this.props.mxEvent.getRoomId());
+            room.off(ThreadEvent.New, this.onNewThread);
+        }
+    };
+
     private renderThreadInfo(): React.ReactNode {
         if (!SettingsStore.getValue("feature_thread")) {
             return null;
         }
 
-        const thread = this.state.thread;
+        /**
+         * Accessing the threads value through the room due to a race condition
+         * that will be solved when there are proper backend support for threads
+         * We currently have no reliable way to discover than an event is a thread
+         * when we are at the sync stage
+         */
+        const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
+        const thread = room.threads.get(this.props.mxEvent.getId());
+
+        if (thread && !thread.ready) {
+            thread.addEvent(this.props.mxEvent, true);
+        }
+
         if (!thread || this.props.showThreadInfo === false || thread.length <= 1) {
             return null;
         }