From c989d5463736a694683134bf122a24522860cf5c Mon Sep 17 00:00:00 2001
From: Andrew Attali <aattali@zaion.ai>
Date: Sun, 19 Jul 2026 00:27:19 +0200
Subject: [PATCH] fix: wait for room list to be loaded before fetching pack
 info

---
 .changeset/fix-sliding-sync-subspaces.md |  5 +++++
 src/client/slidingSync.test.ts           | 23 +++++++++++++++++++++++
 src/client/slidingSync.ts                | 10 ++++++++++
 3 files changed, 38 insertions(+)
 create mode 100644 .changeset/fix-sliding-sync-subspaces.md

diff --git a/.changeset/fix-sliding-sync-subspaces.md b/.changeset/fix-sliding-sync-subspaces.md
new file mode 100644
index 0000000000..5dcb5d2a08
--- /dev/null
+++ b/.changeset/fix-sliding-sync-subspaces.md
@@ -0,0 +1,5 @@
+---
+default: patch
+---
+
+Fix a regression making subspaces with emote packs being listed as separate spaces on sliding-sync.
diff --git a/src/client/slidingSync.test.ts b/src/client/slidingSync.test.ts
index 20bb1f6899..f710022e58 100644
--- a/src/client/slidingSync.test.ts
+++ b/src/client/slidingSync.test.ts
@@ -333,6 +333,7 @@ describe('SlidingSyncManager room subscription coordination', () => {
   it('uses the active subscription while a room is also an image-pack room', () => {
     const manager = makeManager(makeMockMx());
     const roomId = '!pack:example.com';
+    (manager as unknown as { listsFullyLoaded: boolean }).listsFullyLoaded = true;
 
     manager.setImagePackSubscriptions([roomId]);
     manager.subscribeToRoom(roomId);
@@ -346,6 +347,7 @@ describe('SlidingSyncManager room subscription coordination', () => {
   it('restores the image-pack subscription when the room is no longer active', () => {
     const manager = makeManager(makeMockMx());
     const roomId = '!pack:example.com';
+    (manager as unknown as { listsFullyLoaded: boolean }).listsFullyLoaded = true;
 
     manager.setImagePackSubscriptions([roomId]);
     manager.subscribeToRoom(roomId);
@@ -400,6 +402,7 @@ describe('SlidingSyncManager room subscription coordination', () => {
 
   it('removes image-pack subscriptions which are no longer configured', () => {
     const manager = makeManager(makeMockMx());
+    (manager as unknown as { listsFullyLoaded: boolean }).listsFullyLoaded = true;
 
     manager.setImagePackSubscriptions(['!old:example.com', '!current:example.com']);
     manager.setImagePackSubscriptions(['!current:example.com']);
@@ -409,6 +412,26 @@ describe('SlidingSyncManager room subscription coordination', () => {
     );
   });
 
+  it('defers image-pack subscriptions until lists are loaded so pack spaces get the composite key', () => {
+    const manager = makeManager(makeMockMx());
+    const roomId = '!spacepack:example.com';
+
+    manager.setImagePackSubscriptions([roomId]);
+    expect(mocks.slidingSyncInstance.modifyRoomSubscriptions).not.toHaveBeenCalled();
+
+    manager.setSpaceSubscriptions([roomId]);
+    (manager as unknown as { listsFullyLoaded: boolean }).listsFullyLoaded = true;
+    (manager as unknown as { flushDeferredSubscriptions: () => void }).flushDeferredSubscriptions();
+
+    expect(mocks.slidingSyncInstance.useCustomSubscription).toHaveBeenLastCalledWith(
+      roomId,
+      'space_image_packs'
+    );
+    expect(mocks.slidingSyncInstance.modifyRoomSubscriptions).toHaveBeenLastCalledWith(
+      new Set([roomId])
+    );
+  });
+
   it('registers the composite space+image-pack subscription', () => {
     makeManager(makeMockMx());
 
diff --git a/src/client/slidingSync.ts b/src/client/slidingSync.ts
index 031d9cffaf..a49da4555e 100644
--- a/src/client/slidingSync.ts
+++ b/src/client/slidingSync.ts
@@ -240,6 +240,8 @@ export class SlidingSyncManager {
 
   private readonly imagePackRoomSubscriptions = new Set<string>();
 
+  private deferredImagePackSubscriptions: Set<string> | null = null;
+
   private roomSubscriptionSyncQueued = false;
 
   private readonly roomTimelineLimit: number;
@@ -998,6 +1000,10 @@ export class SlidingSyncManager {
     const spaces = this.deferredSpaceSubscriptions;
     this.deferredSpaceSubscriptions = new Set();
     this.setSpaceSubscriptions(spaces);
+
+    const imagePacks = this.deferredImagePackSubscriptions;
+    this.deferredImagePackSubscriptions = null;
+    if (imagePacks) this.setImagePackSubscriptions(imagePacks);
   }
 
   private queueRoomSubscriptionSync(): void {
@@ -1053,6 +1059,10 @@ export class SlidingSyncManager {
   public setImagePackSubscriptions(roomIds: Iterable<string>): void {
     if (this.disposed) return;
     const next = new Set(roomIds);
+    if (!this.listsFullyLoaded) {
+      this.deferredImagePackSubscriptions = next;
+      return;
+    }
     const unchanged =
       next.size === this.imagePackRoomSubscriptions.size &&
       [...next].every((roomId) => this.imagePackRoomSubscriptions.has(roomId));