fix: closes #13624, update post fields before schedule code

tldr when reschedule was called it was still using the timestamp in the future when adding to cid:<cid>:pids causing that post to get stuck at the top of that zset, which led to the bug in this issue

src/posts/edit.js

@@ -49,12 +49,14 @@ module.exports = function (Posts) {
 			uid: data.uid,
 		});
 
+		// needs to be before editMainPost, otherwise scheduled topics use wrong timestamp
+		await Posts.setPostFields(data.pid, result.post);
+
 		const [editor, topic] = await Promise.all([
 			user.getUserFields(data.uid, ['username', 'userslug']),
 			editMainPost(data, postData, topicData),
 		]);
 
-		await Posts.setPostFields(data.pid, result.post);
 		const contentChanged = ((data.sourceContent || data.content) !== oldContent) ||
 			topic.renamed ||
 			topic.tagsupdated;

test/topics.js

@@ -2506,6 +2506,35 @@ describe('Topic\'s', () => {
 			const score = await db.sortedSetScore('topics:scheduled', topicData.tid);
 			assert(!score);
 		});
+
+		it('should properly update timestamp in cid:<cid>:pids after editing and posting immediately', async () => {
+			const scheduleTimestamp = Date.now() + (86400000 * 365);
+			const result = await topics.post({
+				cid: categoryObj.cid,
+				title: 'testing cid:<cid>:pids',
+				content: 'some content here',
+				uid: adminUid,
+				timestamp: scheduleTimestamp,
+			});
+			const { mainPid } = result.topicData;
+
+			assert.strictEqual(
+				await db.isSortedSetMember(`cid:${categoryObj.cid}:pids`, mainPid),
+				false,
+			);
+
+			// edit main post and publish
+			await posts.edit({
+				uid: adminUid,
+				pid: mainPid,
+				content: 'some content here - edited',
+				timestamp: Date.now(),
+			});
+
+			// the score in cid:<cid>:pids should be less than Date.now()
+			const score = await db.sortedSetScore(`cid:${categoryObj.cid}:pids`, mainPid);
+			assert(score < Date.now(), 'Post in cid:<cid>:pids has wrong score, it should not be in the future');
+		});
 	});
 });