fix: only remove deleted tag, closes #11515

src/topics/tags.js

@@ -232,10 +232,15 @@ module.exports = function (Topics) {
 			if (!tids.length) {
 				return;
 			}
+			let topicsTags = await Topics.getTopicsTags(tids);
+			topicsTags = topicsTags.map(
+				topicTags => topicTags.filter(topicTag => topicTag && topicTag !== tag)
+			);
 
-			await db.deleteObjectFields(
-				tids.map(tid => `topic:${tid}`),
-				['tags'],
+			await db.setObjectBulk(
+				tids.map((tid, index) => ([
+					`topic:${tid}`, { tags: topicsTags[index].join(',') },
+				]))
 			);
 		});
 	}

test/topics.js

@@ -1932,6 +1932,14 @@ describe('Topic\'s', () => {
 			});
 		});
 
+		it('should only delete one tag from topic', async () => {
+			const result1 = await topics.post({ uid: adminUid, tags: ['deleteme1', 'deleteme2', 'deleteme3'], title: 'topic tagged with plugins', content: 'topic 1 content', cid: topic.categoryId });
+			await topics.deleteTag('deleteme2');
+			const topicData = await topics.getTopicData(result1.topicData.tid);
+			const tags = topicData.tags.map(t => t.value);
+			assert.deepStrictEqual(tags, ['deleteme1', 'deleteme3']);
+		});
+
 		it('should delete tag', (done) => {
 			topics.deleteTag('javascript', (err) => {
 				assert.ifError(err);