Fixes #5186

On socket.io connection, all clients join a room pertaining to
their express session id. We use this room to keep track of any
sessions in different browser windows (but the same cookie jar),
so if a login/logout occurs, we can throw a session mismatch
modal.

This room can also be used to emit messages across windows/tabs...

public/src/app.js

@@ -88,6 +88,14 @@ app.cacheBuster = null;
 
 	app.logout = function () {
 		$(window).trigger('action:app.logout');
+
+		/*
+			Set session refresh flag (otherwise the session check will trip and throw invalid session modal)
+			We know the session is/will be invalid (uid mismatch) because the user is logging out
+		*/
+		app.flags = app.flags || {};
+		app.flags._sessionRefresh = true;
+
 		$.ajax(config.relative_path + '/logout', {
 			type: 'POST',
 			headers: {

public/src/client/login.js

@@ -23,6 +23,14 @@ define('forum/login', ['translator'], function (translator) {
 				}
 
 				submitEl.addClass('disabled');
+
+				/*
+					Set session refresh flag (otherwise the session check will trip and throw invalid session modal)
+					We know the session is/will be invalid (uid mismatch) because the user is attempting a login
+				*/
+				app.flags = app.flags || {};
+				app.flags._sessionRefresh = true;
+
 				formEl.ajaxSubmit({
 					headers: {
 						'x-csrf-token': config.csrf_token
@@ -37,6 +45,7 @@ define('forum/login', ['translator'], function (translator) {
 							errorEl.find('p').translateText(data.responseText);
 							errorEl.show();
 							submitEl.removeClass('disabled');
+							app.flags._sessionRefresh = false;
 
 							// Select the entire password if that field has focus
 							if ($('#password:focus').size()) {

src/controllers/authentication.js

@@ -15,6 +15,8 @@ var plugins = require('../plugins');
 var utils = require('../../public/src/utils');
 var Password = require('../password');
 
+var sockets = require('../socket.io');
+
 var authenticationController = {};
 
 authenticationController.register = function (req, res, next) {
@@ -326,6 +328,10 @@ authenticationController.onSuccessfulLogin = function (req, uid, callback) {
 		if (err) {
 			return callback(err);
 		}
+
+		// Force session check for all connected socket.io clients with the same session id
+		sockets.in('sess_' + req.sessionID).emit('checkSession', uid);
+
 		plugins.fireHook('action:user.loggedIn', uid);
 		callback();
 	});
@@ -405,7 +411,9 @@ authenticationController.localLogin = function (req, username, password, next) {
 authenticationController.logout = function (req, res, next) {
 	if (req.user && parseInt(req.user.uid, 10) > 0 && req.sessionID) {
 		var uid = parseInt(req.user.uid, 10);
-		user.auth.revokeSession(req.sessionID, uid, function (err) {
+		var sessionID = req.sessionID;
+
+		user.auth.revokeSession(sessionID, uid, function (err) {
 			if (err) {
 				return next(err);
 			}
@@ -416,6 +424,9 @@ authenticationController.logout = function (req, res, next) {
 
 			plugins.fireHook('static:user.loggedOut', {req: req, res: res, uid: uid}, function () {
 				res.status(200).send('');
+
+				// Force session check for all connected socket.io clients with the same session id
+				sockets.in('sess_' + sessionID).emit('checkSession', 0);
 			});
 		});
 	} else {

src/socket.io/index.js

@@ -57,6 +57,7 @@ var ratelimit = require('../middleware/ratelimit');
 			socket.join('online_guests');
 		}
 
+		socket.join('sess_' + socket.request.signedCookies[nconf.get('sessionKey')]);
 		io.sockets.sockets[socket.id].emit('checkSession', socket.uid);
 	}