Use server capabilities to determine how to build thread list (#7470)

src/components/structures/ThreadPanel.tsx

@@ -43,6 +43,10 @@ async function getThreadTimelineSet(
     room: Room,
     filterType = ThreadFilterType.All,
 ): Promise<EventTimelineSet> {
+    const capabilities = await client.getCapabilities();
+    const serverSupportsThreads = capabilities['io.element.thread']?.enabled;
+
+    if (serverSupportsThreads) {
         const myUserId = client.getUserId();
         const filter = new Filter(myUserId);
 
@@ -59,16 +63,12 @@ async function getThreadTimelineSet(
         }
 
         filter.setDefinition(definition);
-
-    let timelineSet;
-
-    try {
         const filterId = await client.getOrCreateFilter(
             `THREAD_PANEL_${room.roomId}_${filterType}`,
             filter,
         );
         filter.filterId = filterId;
-        timelineSet = room.getOrCreateFilteredTimelineSet(
+        const timelineSet = room.getOrCreateFilteredTimelineSet(
             filter,
             { prepopulateTimeline: false },
         );
@@ -78,21 +78,21 @@ async function getThreadTimelineSet(
             timelineSet.getLiveTimeline(),
             { backwards: true, limit: 20 },
         );
-    } catch (e) {
+        return timelineSet;
+    } else {
         // Filter creation fails if HomeServer does not support the new relation
         // filter fields. We fallback to the threads that have been discovered in
         // the main timeline
-        timelineSet = new EventTimelineSet(room, {});
+        const timelineSet = new EventTimelineSet(room, {});
         for (const [, thread] of room.threads) {
             const isOwnEvent = thread.rootEvent.getSender() === client.getUserId();
             if (filterType !== ThreadFilterType.My || isOwnEvent) {
-                timelineSet.getLiveTimeline().addEvent(thread.rootEvent);
+                timelineSet.getLiveTimeline().addEvent(thread.rootEvent, false);
             }
         }
-    }
-
         return timelineSet;
     }
+}
 
 interface IProps {
     roomId: string;