fix: #11735, crash when making guest reply

to /api/compose route

src/controllers/composer.js

@@ -76,13 +76,20 @@ exports.post = async function (req, res) {
 		} else {
 			throw new Error('[[error:invalid-data]]');
 		}
+		if (!result) {
+			throw new Error('[[error:invalid-data]]');
+		}
 		if (result.queued) {
 			return res.redirect(`${nconf.get('relative_path') || '/'}?noScriptMessage=[[success:post-queued]]`);
 		}
-		const uid = result.uid ? result.uid : result.topicData.uid;
-		user.updateOnlineUsers(uid);
-		const path = result.pid ? `/post/${result.pid}` : `/topic/${result.topicData.slug}`;
-		res.redirect(nconf.get('relative_path') + path);
+		user.updateOnlineUsers(req.uid);
+		let path = nconf.get('relative_path');
+		if (result.pid) {
+			path += `/post/${result.pid}`;
+		} else if (result.topicData) {
+			path += `/topic/${result.topicData.slug}`;
+		}
+		res.redirect(path);
 	} catch (err) {
 		helpers.noScriptErrors(req, res, err.message, 400);
 	}

test/controllers.js

@@ -2682,6 +2682,42 @@ describe('Controllers', () => {
 				});
 			});
 		});
+
+		it('should create a new topic and reply by composer route as a guest', async () => {
+			const jar = request.jar();
+			const csrf_token = await helpers.getCsrfToken(jar);
+			const data = {
+				cid: cid,
+				title: 'no js is good',
+				content: 'a topic with noscript',
+				handle: 'guest1',
+			};
+
+			await privileges.categories.give(['groups:topics:create', 'groups:topics:reply'], cid, 'guests');
+
+			const result = await helpers.request('post', `/compose`, {
+				form: data,
+				jar,
+				headers: {
+					'x-csrf-token': csrf_token,
+				},
+			});
+			assert.strictEqual(result.res.statusCode, 302);
+
+			const replyResult = await helpers.request('post', `/compose`, {
+				form: {
+					tid: tid,
+					content: 'a new reply',
+					handle: 'guest2',
+				},
+				jar,
+				headers: {
+					'x-csrf-token': csrf_token,
+				},
+			});
+			assert.equal(replyResult.res.statusCode, 302);
+			await privileges.categories.rescind(['groups:topics:post', 'groups:topics:reply'], cid, 'guests');
+		});
 	});
 
 	describe('test routes', () => {