fix: closes #14062

on topic purge remove them from uid:<uid>:inboxes
upgrade script to cleanup inboxes

src/topics/delete.js

@@ -96,8 +96,10 @@ module.exports = function (Topics) {
 			t.tags = t.tags.map(tag => tag.value);
 		});
 
-		await deleteFromFollowersIgnorers(tidsToDelete);
+		await Promise.all([
-
+			deleteFromFollowersIgnorers(tidsToDelete),
+			deleteFromUserInboxes(tidsToDelete),
+		]);
 		const remoteTids = [];
 		const localTids = [];
 
@@ -163,6 +165,18 @@ module.exports = function (Topics) {
 		await db.sortedSetRemoveBulk(bulkRemove);
 	}
 
+	async function deleteFromUserInboxes(tids) {
+		const recipients = await db.getSortedSetsMembers(tids.map(tid => `tid:${tid}:recipients`));
+		const bulkRemove = [];
+		tids.forEach((tid, index) => {
+			const tidRecipients = recipients[index];
+			tidRecipients.forEach((uid) => {
+				bulkRemove.push([`uid:${uid}:inbox`, tid]);
+			});
+		});
+		await db.sortedSetRemoveBulk(bulkRemove);
+	}
+
 	async function deleteKeys(tids) {
 		await db.deleteAll([
 			...tids.map(tid => `tid:${tid}:followers`),
@@ -171,6 +185,7 @@ module.exports = function (Topics) {
 			...tids.map(tid => `tid:${tid}:posts:votes`),
 			...tids.map(tid => `tid:${tid}:bookmarks`),
 			...tids.map(tid => `tid:${tid}:posters`),
+			...tids.map(tid => `tid:${tid}:recipients`),
 		]);
 	}
 

src/upgrades/4.9.2/clean_tid_recipients_zsets.js

@@ -0,0 +1,36 @@
+'use strict';
+
+const db = require('../../database');
+const batch = require('../../batch');
+
+module.exports = {
+	name: 'Delete pruned tids from user inboxes and delete tid:<tid>:recipients sorted sets',
+	timestamp: Date.UTC(2026, 2, 5),
+	method: async function () {
+		const { progress } = this;
+		progress.total = await db.sortedSetCard('users:joindate');
+
+		await batch.processSortedSet('users:joindate', async (uids) => {
+			const userInboxes = await db.getSortedSetsMembers(uids.map(uid => `uid:${uid}:inbox`));
+			const exists = await Promise.all(
+				userInboxes.map(userTids => db.exists(userTids.map(tid => `topic:${tid}`)))
+			);
+
+			const bulkRemove = [];
+			const deleteTids = new Set();
+			uids.forEach((uid, index) => {
+				const userTids = userInboxes[index];
+				userTids.forEach((tid, tidIndex) => {
+					if (!exists[index][tidIndex]) {
+						bulkRemove.push([`uid:${uid}:inbox`, tid]);
+						deleteTids.add(tid);
+					}
+				});
+			});
+			await db.deleteAll(Array.from(deleteTids).map(tid => `tid:${tid}:recipients`));
+			progress.incr(uids.length);
+		}, {
+			batch: 500,
+		});
+	},
+};