From 3213da1c77c8a193c9706d08159303f50bda9eff Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Wed, 26 Mar 2025 12:28:10 -0400
Subject: [PATCH] fix: #13255, remote user-to-category migration should not
 move shares that are already in an existing cid

---
 src/activitypub/actors.js  |  6 ++++--
 test/activitypub/actors.js | 30 ++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/activitypub/actors.js b/src/activitypub/actors.js
index e86efb0fbc..58f52ac101 100644
--- a/src/activitypub/actors.js
+++ b/src/activitypub/actors.js
@@ -409,9 +409,11 @@ async function _migratePersonToGroup(categoryObjs) {
 
 	await Promise.all(ids.map(async (id) => {
 		const shares = await db.getSortedSetMembers(`uid:${id}:shares`);
-		const exists = await topics.exists(shares);
+		let cids = await topics.getTopicsFields(shares, ['cid']);
+		cids = cids.map(o => o.cid);
 		await Promise.all(shares.map(async (share, idx) => {
-			if (exists[idx]) {
+			const cid = cids[idx];
+			if (cid === -1) {
 				await topics.tools.move(share, {
 					cid: id,
 					uid: 'system',
diff --git a/test/activitypub/actors.js b/test/activitypub/actors.js
index 6cfa93de27..ab793a6235 100644
--- a/test/activitypub/actors.js
+++ b/test/activitypub/actors.js
@@ -126,6 +126,36 @@ describe('Actor asserton', () => {
 				assert.strictEqual(post_count, 2);
 			});
 
+			it('should not migrate shares by that user that already belong to a local category', async () => {
+				const { id } = helpers.mocks.person();
+				await activitypub.actors.assert([id]);
+
+				const { cid } = await categories.create({ name: utils.generateUUID() });
+
+				// Two shares, one moved to local cid
+				for (let x = 0; x < 2; x++) {
+					const { id: pid } = helpers.mocks.note();
+					// eslint-disable-next-line no-await-in-loop
+					const { tid } = await activitypub.notes.assert(0, pid, { skipChecks: 1 });
+					// eslint-disable-next-line no-await-in-loop
+					await db.sortedSetAdd(`uid:${id}:shares`, Date.now(), tid);
+
+					if (!x) {
+						await topics.tools.move(tid, {
+							cid,
+							uid: 'system',
+						});
+					}
+				}
+
+				helpers.mocks.group({ id });
+				await activitypub.actors.assertGroup([id]);
+
+				const { topic_count, post_count } = await categories.getCategoryData(id);
+				assert.strictEqual(topic_count, 1);
+				assert.strictEqual(post_count, 1);
+			});
+
 			it('should migrate any local followers into category watches', async () => {
 				const { id } = helpers.mocks.person();
 				await activitypub.actors.assert([id]);