fix: when registering through an invite, prepopulate the email field on /register/complete with the email

src/controllers/authentication.js

@@ -32,12 +32,12 @@ async function registerAndLoginUser(req, res, userData) {
 	if (deferRegistration) {
 		userData.register = true;
 		req.session.registration = userData;
-
+		const next = `${nconf.get('relative_path')}/register/complete`;
 		if (req.body?.noscript === 'true') {
-			res.redirect(`${nconf.get('relative_path')}/register/complete`);
+			res.redirect(next);
 			return;
 		}
-		res.json({ next: `${nconf.get('relative_path')}/register/complete` });
+		res.json({ next });
 		return;
 	}
 
@@ -71,6 +71,7 @@ async function registerAndLoginUser(req, res, userData) {
 	return complete;
 }
 
+// POST /register
 authenticationController.register = async function (req, res) {
 	const registrationType = meta.config.registrationType || 'normal';
 
@@ -109,6 +110,7 @@ authenticationController.register = async function (req, res) {
 	}
 };
 
+// POST /register/complete
 authenticationController.registerComplete = async function (req, res) {
 	try {
 		// For the interstitials that respond, execute the callback with the form body
@@ -185,6 +187,7 @@ authenticationController.registerComplete = async function (req, res) {
 	}
 };
 
+// POST /register/abort
 authenticationController.registerAbort = async (req, res) => {
 	if (req.uid && req.session.registration) {
 		// Email is the only cancelable interstitial
@@ -204,6 +207,7 @@ authenticationController.registerAbort = async (req, res) => {
 	});
 };
 
+// POST /login
 authenticationController.login = async (req, res, next) => {
 	let { strategy } = await plugins.hooks.fire('filter:login.override', { req, strategy: 'local' });
 	if (!passport._strategy(strategy)) {

src/controllers/index.js

@@ -192,6 +192,7 @@ Controllers.register = async function (req, res, next) {
 	}
 };
 
+// GET /register/complete
 Controllers.registerInterstitial = async function (req, res, next) {
 	if (!req.session.hasOwnProperty('registration')) {
 		return res.redirect(`${nconf.get('relative_path')}/register`);

src/user/interstitials.js

@@ -36,6 +36,8 @@ Interstitials.email = async (data) => {
 	let email;
 	if (data.userData.uid) {
 		email = await user.getUserField(data.userData.uid, 'email');
+	} else if (data.userData.token) {
+		email = await user.getEmailFromToken(data.userData.token);
 	}
 
 	data.interstitials.push({

src/user/invite.js

@@ -78,6 +78,11 @@ module.exports = function (User) {
 		return email && email === enteredEmail;
 	};
 
+	User.getEmailFromToken = async function (token) {
+		if (!token) return null;
+		return await db.getObjectField(`invitation:token:${token}`, 'email');
+	};
+
 	User.confirmIfInviteEmailIsUsed = async function (token, enteredEmail, uid) {
 		if (!enteredEmail) {
 			return;
@@ -100,11 +105,9 @@ module.exports = function (User) {
 			return;
 		}
 
-		if (!groupsToJoin || groupsToJoin.length < 1) {
-			return;
+		if (Array.isArray(groupsToJoin) && groupsToJoin.length) {
+			await groups.join(groupsToJoin, uid);
 		}
-
-		await groups.join(groupsToJoin, uid);
 	};
 
 	User.deleteInvitation = async function (invitedBy, email) {