From a9a5ab5e4bfef9acde8d45d04322081f44a3da47 Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Thu, 8 May 2025 13:41:43 -0400
Subject: [PATCH 1/3] fix: #13397, update getCidByHandle to work with remote
 categories, fix sync with handles causing issues with null entries

---
 src/api/activitypub.js  | 10 +++++++++-
 src/categories/index.js |  8 +++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/api/activitypub.js b/src/api/activitypub.js
index be6600d3a2..ed9e6f2f64 100644
--- a/src/api/activitypub.js
+++ b/src/api/activitypub.js
@@ -13,6 +13,7 @@ const winston = require('winston');
 
 const db = require('../database');
 const user = require('../user');
+const categories = require('../categories');
 const meta = require('../meta');
 const privileges = require('../privileges');
 const activitypub = require('../activitypub');
@@ -43,7 +44,14 @@ activitypubApi.follow = enabledCheck(async (caller, { type, id, actor } = {}) =>
 		throw new Error('[[error:activitypub.invalid-id]]');
 	}
 
-	actor = actor.includes('@') ? await user.getUidByUserslug(actor) : actor;
+	if (actor.includes('@')) {
+		const [uid, cid] = await Promise.all([
+			user.getUidByUserslug(actor),
+			categories.getCidByHandle(actor),
+		]);
+
+		actor = uid || cid;
+	}
 	const [handle, isFollowing] = await Promise.all([
 		user.getUserField(actor, 'username'),
 		db.isSortedSetMember(type === 'uid' ? `followingRemote:${id}` : `cid:${id}:following`, actor),
diff --git a/src/categories/index.js b/src/categories/index.js
index 308516cd97..de7ff6d769 100644
--- a/src/categories/index.js
+++ b/src/categories/index.js
@@ -85,7 +85,13 @@ Categories.getCategoryById = async function (data) {
 };
 
 Categories.getCidByHandle = async function (handle) {
-	return await db.sortedSetScore('categoryhandle:cid', handle);
+	let cid = await db.sortedSetScore('categoryhandle:cid', handle);
+	if (!cid) {
+		// remote cids
+		cid = await db.getObjectField('handle:cid', handle);
+	}
+
+	return cid;
 };
 
 Categories.getAllCidsFromSet = async function (key) {

From 401ff797c91217c4887b86f013f038b7d4e09b13 Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Thu, 8 May 2025 13:55:17 -0400
Subject: [PATCH 2/3] fix: #13392, regression from c6f2c87, unable to unfollow
 from pending follows

---
 src/api/activitypub.js | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/api/activitypub.js b/src/api/activitypub.js
index ed9e6f2f64..2752a50bc6 100644
--- a/src/api/activitypub.js
+++ b/src/api/activitypub.js
@@ -84,13 +84,22 @@ activitypubApi.unfollow = enabledCheck(async (caller, { type, id, actor }) => {
 		throw new Error('[[error:activitypub.invalid-id]]');
 	}
 
-	actor = actor.includes('@') ? await user.getUidByUserslug(actor) : actor;
-	const [handle, isFollowing] = await Promise.all([
+	if (actor.includes('@')) {
+		const [uid, cid] = await Promise.all([
+			user.getUidByUserslug(actor),
+			categories.getCidByHandle(actor),
+		]);
+
+		actor = uid || cid;
+	}
+
+	const [handle, isFollowing, isPending] = await Promise.all([
 		user.getUserField(actor, 'username'),
 		db.isSortedSetMember(type === 'uid' ? `followingRemote:${id}` : `cid:${id}:following`, actor),
+		db.isSortedSetMember(`followRequests:${type === 'uid' ? 'uid' : 'cid'}.${id}`, actor),
 	]);
 
-	if (!isFollowing) { // already not following
+	if (!isFollowing && !isPending) { // already not following/pending
 		return;
 	}
 

From 26e6a22278c426802e8f80e70cefcffc73653a25 Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Thu, 8 May 2025 13:55:42 -0400
Subject: [PATCH 3/3] fix: #13397, null values in category sync list

---
 src/upgrades/4.3.2/fix_category_sync_null_values.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 src/upgrades/4.3.2/fix_category_sync_null_values.js

diff --git a/src/upgrades/4.3.2/fix_category_sync_null_values.js b/src/upgrades/4.3.2/fix_category_sync_null_values.js
new file mode 100644
index 0000000000..e81590cf27
--- /dev/null
+++ b/src/upgrades/4.3.2/fix_category_sync_null_values.js
@@ -0,0 +1,12 @@
+'use strict';
+
+const db = require('../../database');
+
+module.exports = {
+	name: 'Fix null values in category synchronization list',
+	timestamp: Date.UTC(2025, 4, 8),
+	method: async () => {
+		const cids = await db.getSortedSetMembers('categories:cid');
+		await db.sortedSetsRemove(cids.map(cid => `followRequests:cid.${cid}`), 'null');
+	},
+};