Issue #3275491 by dewalt, murz, pooja_sharma, avpaderno, Nicolas Bouteille,...

Issue #3275491 by dewalt, murz, pooja_sharma, avpaderno, Nicolas Bouteille, dmitry.korhov: External application is redirected to frontpage in maintenance mode

core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php

@@ -537,6 +537,8 @@ public function testRead(): void {
     // Test that user gets logged out when hitting non-jsonapi route.
     $this->drupalGet('/some/normal/route');
     $this->assertFalse($this->drupalUserIsLoggedIn($this->userCanViewProfiles));
+    $this->assertSession()->statusCodeEquals(503);
+    $this->assertSession()->responseContains('Site under maintenance');
     $this->container->get('state')->set('system.maintenance_mode', FALSE);
     $this->drupalResetSession();
 

core/modules/user/src/EventSubscriber/MaintenanceModeSubscriber.php

@@ -5,9 +5,7 @@
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Site\MaintenanceModeEvents;
 use Drupal\Core\Site\MaintenanceModeInterface;
-use Drupal\Core\Url;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 
 /**
@@ -52,10 +50,6 @@ public function onMaintenanceModeRequest(RequestEvent $event) {
     // If the site is offline, log out unprivileged users.
     if ($this->account->isAuthenticated()) {
       user_logout();
-      // Redirect to homepage.
-      $event->setResponse(
-        new RedirectResponse(Url::fromRoute('<front>')->toString())
-      );
     }
   }