only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Database/InstallerObjectTest.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Drupal\Tests\Core\Database;
+
+use Composer\Autoload\ClassLoader;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * Tests the db_installer_object() function that is used during installation.
+ *
+ * These tests un in isolation since we don't want the database static to
+ * affect other tests.
+ *
+ * @covers ::db_installer_object
+ *
+ * @group Database
+ */
+class InstallerObjectTest extends UnitTestCase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    require_once __DIR__ . '/../../../../../includes/install.inc';
+    $additional_class_loader = new ClassLoader();
+    $additional_class_loader->addPsr4("Drupal\\Driver\\Database\\fake\\", __DIR__ . "/fixtures/driver/fake");
+    $additional_class_loader->addPsr4("Drupal\\Core\\Database\\Driver\\corefake\\", __DIR__ . "/fixtures/core-driver/corefake");
+    $additional_class_loader->addPsr4("Drupal\\Driver\\Database\\corefake\\", __DIR__ . "/fixtures/driver/corefake");
+    $additional_class_loader->register(TRUE);
+  }
+
+  /**
+   * @dataProvider providerDbInstallerObject
+   */
+  public function testDbInstallerObject($driver, $expected_class_name) {
+    $object = db_installer_object($driver);
+    $this->assertEquals(get_class($object), $expected_class_name);
+  }
+
+  /**
+   * Dataprovider for testDbUrltoConnectionConversion().
+   *
+   * @return array
+   *   Array of arrays with the following elements:
+   *   - driver: The driver name.
+   *   - class: The fully qualified class name of the expected install task.
+   */
+  public function providerDbInstallerObject() {
+    return [
+      // A driver only in the core namespace.
+      ['mysql', \Drupal\Core\Database\Driver\mysql\Install\Tasks::class],
+
+      // A driver only in the custom namespace.
+      ['fake', \Drupal\Driver\Database\fake\Install\Tasks::class],
+
+      // A driver in both namespaces. The custom one takes precedence.
+      ['corefake', \Drupal\Driver\Database\corefake\Install\Tasks::class],
+    ];
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Database/fixtures/core-driver/corefake/Install/Tasks.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Drupal\Core\Database\Driver\corefake\Install;
+
+use Drupal\Core\Database\Install\Tasks as InstallTasks;
+
+class Tasks extends InstallTasks {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function name() {
+    return 'corefake';
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Database/fixtures/driver/corefake/Install/Tasks.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Drupal\Driver\Database\corefake\Install;
+
+use Drupal\Core\Database\Driver\corefake\Install\Tasks as BaseInstallTasks;
+
+class Tasks extends BaseInstallTasks {
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Database/fixtures/driver/fake/Install/Tasks.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Drupal\Driver\Database\fake\Install;
+
+use Drupal\Core\Database\Install\Tasks as InstallTasks;
+
+class Tasks extends InstallTasks {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function name() {
+    return 'fake';
+  }
+
+}