fix: #14147, dont create wrong backlinks

syncBacklinks expects raw post content, html was passed to it from onNewPost since it was switched to use getPostSummary
backlinkRegex was matching  ${nconf.get('url')}/topic/1aef954c-d0dc-45cf-acf2-e3a59f6cc134/foo and return tid=1 instead of the uuid

remove useless if check in syncBacklinks
fixed parseInts on tids
current - remove are both arrays use .length

src/topics/create.js

@@ -259,14 +259,14 @@ module.exports = function (Topics) {
 		return postData;
 	};
 
-	async function onNewPost({ pid, tid, uid: postOwner }, { uid, handle }) {
+	async function onNewPost({ pid, tid, content, uid: postOwner }, { uid, handle }) {
 		const [[postData], [userInfo]] = await Promise.all([
 			posts.getPostSummaryByPids([pid], uid, { extraFields: ['attachments'] }),
 			posts.getUserInfoForPosts([postOwner], uid),
 		]);
 		await Promise.all([
 			Topics.addParentPosts([postData], uid),
-			Topics.syncBacklinks(postData),
+			Topics.syncBacklinks({ ...postData, content }),
 			Topics.markAsRead([tid], uid),
 		]);
 		if (utils.isNumber(postOwner) && postData.category.cid === -1) {

src/topics/posts.js

@@ -14,7 +14,7 @@ const plugins = require('../plugins');
 const utils = require('../utils');
 const privileges = require('../privileges');
 
-const backlinkRegex = new RegExp(`(?:${nconf.get('url').replace('/', '\\/')}|\b|\\s)\\/topic\\/(\\d+)(?:\\/\\w+)?`, 'g');
+const backlinkRegex = new RegExp(`(?:${nconf.get('url').replace('/', '\\/')}|\b|\\s)\\/topic\\/([a-fA-F0-9-]+)(?=\\/|$|\\s)?`, 'g');
 
 module.exports = function (Topics) {
 	Topics.onNewPostMade = async function (postData) {
@@ -447,29 +447,27 @@ module.exports = function (Topics) {
 			throw new Error('[[error:invalid-data]]');
 		}
 
-
-		let { content } = postData;
+		let { pid, uid, content } = postData;
 		// ignore lines that start with `>`
 		content = (content || '').split('\n').filter(line => !line.trim().startsWith('>')).join('\n');
 		// Scan post content for topic links
 		const matches = [...content.matchAll(backlinkRegex)];
-		if (!matches) {
-			return 0;
-		}
 
-		const { pid, uid, tid } = postData;
-		let add = _.uniq(matches.map(match => match[1]).map(tid => parseInt(tid, 10)));
+		let add = _.uniq(matches.map(match => match[1]));
 
-		const now = Date.now();
-		const topicsExist = await Topics.exists(add);
-		const current = (await db.getSortedSetMembers(`pid:${pid}:backlinks`)).map(tid => parseInt(tid, 10));
+		const [topicsExist, current] = await Promise.all([
+			Topics.exists(add),
+			db.getSortedSetMembers(`pid:${pid}:backlinks`),
+		]);
 		const remove = current.filter(tid => !add.includes(tid));
-		add = add.filter((_tid, idx) => topicsExist[idx] && !current.includes(_tid) && tid !== _tid);
+		const postTid = String(postData.tid);
+		add = add.filter((_tid, idx) => topicsExist[idx] && !current.includes(_tid) && postTid !== _tid);
 
 		// Remove old backlinks
 		await db.sortedSetRemove(`pid:${pid}:backlinks`, remove);
 
 		// Add new backlinks
+		const now = Date.now();
 		await db.sortedSetAdd(`pid:${pid}:backlinks`, add.map(() => now), add);
 		await Promise.all(add.map(async (tid) => {
 			await Topics.events.log(tid, {
@@ -479,6 +477,6 @@ module.exports = function (Topics) {
 			});
 		}));
 
-		return add.length + (current - remove);
+		return add.length + (current.length - remove.length);
 	};
 };

test/posts.js

@@ -1152,12 +1152,10 @@ describe('Post\'s', () => {
 
 		describe('.syncBacklinks()', () => {
 			it('should error on invalid data', async () => {
-				try {
-					await topics.syncBacklinks();
-				} catch (e) {
-					assert(e);
-					assert.strictEqual(e.message, '[[error:invalid-data]]');
-				}
+				await assert.rejects(
+					topics.syncBacklinks(),
+					{ message: '[[error:invalid-data]]' },
+				);
 			});
 
 			it('should do nothing if the post does not contain a link to a topic', async () => {
@@ -1192,9 +1190,7 @@ describe('Post\'s', () => {
 				const backlinks = await db.getSortedSetMembers('pid:2:backlinks');
 
 				assert.strictEqual(count, 0);
-				assert(events);
 				assert.strictEqual(events.length, 1);
-				assert(backlinks);
 				assert.strictEqual(backlinks.length, 0);
 			});
 
@@ -1219,6 +1215,17 @@ describe('Post\'s', () => {
 				assert(backlinks);
 				assert.strictEqual(backlinks.length, 0);
 			});
+
+			it('should not create a wrong backlink to topic/1 with AP topic url', async () => {
+				const { postData } = await topics.post({
+					uid: 1,
+					cid,
+					title: 'Topic backlink testing - topic 2',
+					content: `testing ${nconf.get('url')}/topic/1aef954c-d0dc-45cf-acf2-e3a59f6cc134/foo`,
+				});
+				const backlinks = await db.getSortedSetMembers(`pid:${postData.pid}:backlinks`);
+				assert.strictEqual(backlinks.length, 0);
+			});
 		});
 
 		describe('integration tests', () => {