From 123b33a2a46dd4a7852ea3992786059b45611332 Mon Sep 17 00:00:00 2001
From: Florian Duros <florianduros@element.io>
Date: Wed, 15 Jul 2026 15:29:31 +0200
Subject: [PATCH] Fix room list throwing an error when adding an existing room
 (#34281)

---
 apps/web/src/stores/room-list-v3/skip-list/RoomSkipList.ts | 6 ++++--
 .../stores/room-list-v3/skip-list/RoomSkipList-test.ts     | 7 +++++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/apps/web/src/stores/room-list-v3/skip-list/RoomSkipList.ts b/apps/web/src/stores/room-list-v3/skip-list/RoomSkipList.ts
index dfa5b678e0..5ee86aefc9 100644
--- a/apps/web/src/stores/room-list-v3/skip-list/RoomSkipList.ts
+++ b/apps/web/src/stores/room-list-v3/skip-list/RoomSkipList.ts
@@ -6,6 +6,7 @@ Please see LICENSE files in the repository root for full details.
 */
 
 import type { Room } from "matrix-js-sdk/src/matrix";
+import { logger } from "matrix-js-sdk/src/logger";
 import type { Sorter, SortingAlgorithm } from "./sorters";
 import type { Filter, FilterKey } from "./filters";
 import { RoomNode } from "./RoomNode";
@@ -115,12 +116,13 @@ export class RoomSkipList implements Iterable<Room> {
 
     /**
      * Adds a new room to the skiplist.
-     * This method will throw an error if the room is already in the skiplist.
+     * This method does nothing if the room is already in the skiplist.
      * @param room the room to add
      */
     public addNewRoom(room: Room): void {
         if (this.roomNodeMap.has(room.roomId)) {
-            throw new Error(`Can't add room to skiplist: ${room.roomId} is already in the skiplist!`);
+            logger.error(`Can't add room to skiplist: ${room.roomId} is already in the skiplist!`);
+            return;
         }
         this.insertRoom(room);
     }
diff --git a/apps/web/test/unit-tests/stores/room-list-v3/skip-list/RoomSkipList-test.ts b/apps/web/test/unit-tests/stores/room-list-v3/skip-list/RoomSkipList-test.ts
index 55daf541ca..a187266fdc 100644
--- a/apps/web/test/unit-tests/stores/room-list-v3/skip-list/RoomSkipList-test.ts
+++ b/apps/web/test/unit-tests/stores/room-list-v3/skip-list/RoomSkipList-test.ts
@@ -100,10 +100,13 @@ describe("RoomSkipList", () => {
         }
     });
 
-    it("Throws error when same room is added via addNewRoom", () => {
+    it("Room is not duplicated when same room is added via addNewRoom", () => {
         const { skipList, rooms } = generateSkipList();
         const room = rooms[5];
-        expect(() => skipList.addNewRoom(room)).toThrow("Can't add room to skiplist");
+        const sizeBefore = skipList.size;
+        skipList.addNewRoom(room);
+
+        expect(skipList.size).toEqual(sizeBefore);
     });
 
     it("Filters are applied to existing nodes when useNewFilters is called", () => {