Sign in page should redirect authenticated users to the backend (#1131)

modules/backend/controllers/Auth.php

@@ -1,18 +1,18 @@
 <?php namespace Backend\Controllers;
 
-use Mail;
-use Flash;
+use ApplicationException;
 use Backend;
-use Request;
-use Validator;
 use BackendAuth;
-use Backend\Models\AccessLog;
 use Backend\Classes\Controller;
+use Backend\Models\AccessLog;
+use Config;
+use Exception;
+use Flash;
+use Mail;
+use Request;
 use System\Classes\UpdateManager;
-use ApplicationException;
 use ValidationException;
-use Exception;
-use Config;
+use Validator;
 use Winter\Storm\Foundation\Http\Middleware\CheckForTrustedHost;
 
 /**
@@ -52,6 +52,10 @@ public function index()
      */
     public function signin()
     {
+        if (BackendAuth::user()) {
+            return Backend::redirect('backend');
+        }
+
         $this->bodyClass = 'signin';
 
         // Clear Cache and any previous data to fix invalid security token issue