Add RedirectTo after login for Universal linking or deep linking to work (#6304)

webapp/components/login/login_controller.jsx

@@ -213,7 +213,7 @@ export default class LoginController extends React.Component {
     finishSignin(team) {
         const query = this.props.location.query;
         GlobalActions.loadCurrentLocale();
-        if (query.redirect_to) {
+        if (query.redirect_to && query.redirect_to.match(/^\//)) {
             browserHistory.push(query.redirect_to);
         } else if (team) {
             browserHistory.push(`/${team.name}`);

webapp/components/root.jsx

@@ -96,7 +96,7 @@ export default class Root extends React.Component {
             } else if (UserStore.getCurrentUser()) {
                 GlobalActions.redirectUserToDefaultTeam();
             } else {
-                browserHistory.push('/login');
+                browserHistory.push('/login' + window.location.search);
             }
         }
     }

webapp/routes/route_team.jsx

@@ -94,7 +94,7 @@ function preNeedsTeam(nextState, replace, callback) {
     const team = TeamStore.getByName(teamName);
 
     if (!team) {
-        browserHistory.push('/');
+        browserHistory.push('/?redirect_to=' + encodeURIComponent(nextState.location.pathname));
         return;
     }