[FIX] Default server language not being applied (#11719)

* Fix default server language not being applied

* Always set user's language on localStorage

client/startup/i18n.js

@@ -56,29 +56,25 @@ Meteor.startup(() => {
 		loadMomentLocale(language).then(locale => moment.locale(locale), error => console.error(error));
 	};
 
-	const setLanguage = language => {
-		currentLanguage.set(filterLanguage(language));
-		localStorage.setItem('userLanguage', currentLanguage.get());
+	const setLanguage = (language) => {
+		const lang = filterLanguage(language);
+		currentLanguage.set(lang);
+		localStorage.setItem('userLanguage', lang);
 	};
-
 	window.setLanguage = setLanguage;
 
-	window.defaultUserLanguage = () => RocketChat.settings.get('Language') || getBrowserLanguage() || 'en';
+	const defaultUserLanguage = () => RocketChat.settings.get('Language') || getBrowserLanguage() || 'en';
+	window.defaultUserLanguage = defaultUserLanguage;
 
 	Tracker.autorun(() => {
-		const user = RocketChat.models.Users.findOne(Meteor.userId(), { fields: { username: 1 }});
-		const userLanguage = user && user.language;
-
-		const defaultLanguage = userLanguage || RocketChat.settings.get('Language') || 'en';
+		const user = RocketChat.models.Users.findOne(Meteor.userId(), { fields: { language: 1 }});
 
-		if (!currentLanguage.get()) {
-			setLanguage(defaultLanguage);
-		}
+		setLanguage((user && user.language) || defaultUserLanguage());
+	});
 
-		if (userLanguage && userLanguage !== currentLanguage.get()) {
-			setLanguage(userLanguage);
+	Tracker.autorun(() => {
+		if (currentLanguage.get()) {
+			applyLanguage(currentLanguage.get());
 		}
-
-		applyLanguage(currentLanguage.get());
 	});
 });

packages/rocketchat-ui-login/client/login/form.js

@@ -1,4 +1,4 @@
-/*globals OnePassword, device, setLanguage */
+/*globals OnePassword, device */
 import _ from 'underscore';
 import s from 'underscore.string';
 import toastr from 'toastr';
@@ -133,7 +133,6 @@ Template.loginForm.events({
 					loginMethod = 'loginWithCrowd';
 				}
 				return Meteor[loginMethod](s.trim(formData.emailOrUsername), formData.pass, function(error) {
-					const user = Meteor.user();
 					instance.loading.set(false);
 					if (error != null) {
 						if (error.error === 'no-valid-email') {
@@ -144,10 +143,6 @@ Template.loginForm.events({
 						return;
 					}
 					Session.set('forceLogin', false);
-					if (user && user.language) {
-						localStorage.setItem('userLanguage', user.language);
-						return setLanguage(Meteor.user().language);
-					}
 				});
 			}
 		}