Issue #2936435 by Berdir, alexpott: Better BC for deprecated container...

Issue #2936435 by Berdir, alexpott: Better BC for deprecated container parameter user.tempstore.expire

core/modules/user/src/UserServiceProvider.php

@@ -15,6 +15,11 @@ public function alter(ContainerBuilder $container) {
       @trigger_error('The container parameter "user.tempstore.expire" is deprecated. Use "tempstore.expire" instead. See https://www.drupal.org/node/2935639.', E_USER_DEPRECATED);
       $container->setParameter('tempstore.expire', $container->getParameter('user.tempstore.expire'));
     }
+    else {
+      // Ensure the user.tempstore.expire parameter is set to the same value
+      // for modules that still rely on it.
+      $container->setParameter('user.tempstore.expire', $container->getParameter('tempstore.expire'));
+    }
   }
 
 }

core/modules/user/tests/src/Kernel/UserServiceProviderFallbackTest.php

+<?php
+
+namespace Drupal\Tests\user\Kernel;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests \Drupal\user\UserServiceProvider.
+ *
+ * @group user
+ * @group legacy
+ */
+class UserServiceProviderFallbackTest extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['user'];
+
+  /**
+   * Tests that user.tempstore.expire equals tempstore.expire if not customized.
+   */
+  public function testUserServiceProvider() {
+    $this->assertEquals(1000, $this->container->getParameter('user.tempstore.expire'));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function register(ContainerBuilder $container) {
+    $container->setParameter('tempstore.expire', 1000);
+    parent::register($container);
+  }
+
+}