Deleting a collection should detach associated drafts from it (#5082)

Co-authored-by: Tom Moor <tom.moor@gmail.com>

server/models/helpers/NotificationHelper.ts

@@ -164,11 +164,12 @@ export default class NotificationHelper {
       const collectionIds = await recipient.collectionIds();
 
       // Check the recipient has access to the collection this document is in. Just
-      // because they are subscribed doesn't meant they "still have access to read
+      // because they are subscribed doesn't mean they still have access to read
       // the document.
       if (
         recipient.email &&
         !recipient.isSuspended &&
+        document.collectionId &&
         collectionIds.includes(document.collectionId)
       ) {
         filtered.push(recipient);

server/models/helpers/SearchHelper.ts

@@ -31,7 +31,7 @@ type SearchOptions = {
   /** The query offset for pagination */
   offset?: number;
   /** Limit results to a collection. Authorization is presumed to have been done before passing to this helper. */
-  collectionId?: string;
+  collectionId?: string | null;
   /** Limit results to a shared document. */
   share?: Share;
   /** Limit results to a date range. */