From a6dc507612cc0ccf9799dd095926474a89e25685 Mon Sep 17 00:00:00 2001
From: Germain Souquet <germains@element.io>
Date: Mon, 21 Feb 2022 14:37:07 +0000
Subject: [PATCH] Null-guard for undefined rootEvent when creating a thread

---
 src/models/room.ts | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/models/room.ts b/src/models/room.ts
index 135ffb9c05c..e3cad8cb631 100644
--- a/src/models/room.ts
+++ b/src/models/room.ts
@@ -1398,12 +1398,17 @@ export class Room extends EventEmitter {
         this.emit(ThreadEvent.Update, thread);
     }
 
-    public createThread(rootEvent: MatrixEvent, events: MatrixEvent[] = []): Thread | undefined {
-        const tl = this.getTimelineForEvent(rootEvent.getId());
-        const relatedEvents = tl?.getTimelineSet().getAllRelationsEventForEvent(rootEvent.getId()) ?? [];
+    public createThread(rootEvent: MatrixEvent | undefined, events: MatrixEvent[] = []): Thread | undefined {
+        if (rootEvent) {
+            const tl = this.getTimelineForEvent(rootEvent.getId());
+            const relatedEvents = tl?.getTimelineSet().getAllRelationsEventForEvent(rootEvent.getId());
+            if (relatedEvents) {
+                events = events.concat(relatedEvents);
+            }
+        }
 
         const thread = new Thread(rootEvent, {
-            initialEvents: events.concat(relatedEvents),
+            initialEvents: events,
             room: this,
             client: this.client,
         });