From 31f89617d80ce65ac9d3a89dca7f66a4485a9074 Mon Sep 17 00:00:00 2001
From: diondiondion <mail@diondiondion.com>
Date: Tue, 28 Apr 2026 17:25:17 +0200
Subject: [PATCH] Fix error when collection is `null` in collection
 notification (#38831)

---
 .../detail/revoke_collection_inclusion_modal.tsx           | 2 +-
 .../components/notification_collection.tsx                 | 7 ++++++-
 app/javascript/mastodon/models/notification_group.ts       | 4 ++--
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/app/javascript/mastodon/features/collections/detail/revoke_collection_inclusion_modal.tsx b/app/javascript/mastodon/features/collections/detail/revoke_collection_inclusion_modal.tsx
index a5fc887ff6..489a35f3ae 100644
--- a/app/javascript/mastodon/features/collections/detail/revoke_collection_inclusion_modal.tsx
+++ b/app/javascript/mastodon/features/collections/detail/revoke_collection_inclusion_modal.tsx
@@ -27,7 +27,7 @@ const messages = defineMessages({
   },
 });
 
-export function useConfirmRevoke(collection?: ApiCollectionJSON) {
+export function useConfirmRevoke(collection?: ApiCollectionJSON | null) {
   const dispatch = useAppDispatch();
   const { id, items = [] } = collection ?? {};
   const ownCollectionItemId = items.find((item) => item.account_id === me)?.id;
diff --git a/app/javascript/mastodon/features/notifications_v2/components/notification_collection.tsx b/app/javascript/mastodon/features/notifications_v2/components/notification_collection.tsx
index 6b70bf68cb..10466b5d3d 100644
--- a/app/javascript/mastodon/features/notifications_v2/components/notification_collection.tsx
+++ b/app/javascript/mastodon/features/notifications_v2/components/notification_collection.tsx
@@ -24,9 +24,14 @@ export const NotificationCollection: React.FC<{
   unread: boolean;
 }> = ({ notification, unread }) => {
   const { collection, type } = notification;
-  const collectionCreatorAccount = useAccount(collection.account_id);
+
+  const collectionCreatorAccount = useAccount(collection?.account_id);
   const confirmRevoke = useConfirmRevoke(collection);
 
+  if (!collection) {
+    return null;
+  }
+
   return (
     <div
       className={classNames(
diff --git a/app/javascript/mastodon/models/notification_group.ts b/app/javascript/mastodon/models/notification_group.ts
index bfb89d894e..de2d879012 100644
--- a/app/javascript/mastodon/models/notification_group.ts
+++ b/app/javascript/mastodon/models/notification_group.ts
@@ -91,11 +91,11 @@ export interface NotificationGroupAdminReport extends BaseNotification<'admin.re
 
 type Collection = ApiCollectionJSON;
 export interface NotificationGroupAddedToCollection extends BaseNotification<'added_to_collection'> {
-  collection: Collection;
+  collection: Collection | null;
 }
 
 export interface NotificationGroupCollectionUpdate extends BaseNotification<'collection_update'> {
-  collection: Collection;
+  collection: Collection | null;
 }
 
 export type NotificationGroup =