Issue #3108021 by alexpott, lauriii: Set $defaultTheme for install profiles...

Issue #3108021 by alexpott, lauriii: Set $defaultTheme for install profiles using configuration install

core/lib/Drupal/Core/Test/FunctionalTestSetupTrait.php

@@ -416,6 +416,13 @@ protected function installDefaultThemeFromClassProperty(ContainerInterface $cont
     // Use the install profile to determine the default theme if configured and
     // not already specified.
     $profile = $container->getParameter('install_profile');
+
+    $default_sync_path = drupal_get_path('profile', $profile) . '/config/sync';
+    $profile_config_storage = new FileStorage($default_sync_path, StorageInterface::DEFAULT_COLLECTION);
+    if (!isset($this->defaultTheme) && $profile_config_storage->exists('system.theme')) {
+      $this->defaultTheme = $profile_config_storage->read('system.theme')['default'];
+    }
+
     $default_install_path = drupal_get_path('profile', $profile) . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY;
     $profile_config_storage = new FileStorage($default_install_path, StorageInterface::DEFAULT_COLLECTION);
     if (!isset($this->defaultTheme) && $profile_config_storage->exists('system.theme')) {

core/tests/Drupal/FunctionalTests/Installer/InstallerExistingConfigMultilingualTest.php

@@ -9,11 +9,6 @@
  */
 class InstallerExistingConfigMultilingualTest extends InstallerExistingConfigTestBase {
 
-  /**
-   * {@inheritdoc}
-   */
-  protected $defaultTheme = 'stark';
-
   /**
    * {@inheritdoc}
    */

core/tests/Drupal/FunctionalTests/Installer/InstallerExistingConfigNoSystemSiteTest.php

@@ -9,11 +9,6 @@
  */
 class InstallerExistingConfigNoSystemSiteTest extends InstallerExistingConfigTestBase {
 
-  /**
-   * {@inheritdoc}
-   */
-  protected $defaultTheme = 'stark';
-
   /**
    * {@inheritdoc}
    */

core/tests/Drupal/FunctionalTests/Installer/InstallerExistingConfigProfileHookInstall.php

@@ -11,11 +11,6 @@ class InstallerExistingConfigProfileHookInstall extends InstallerExistingConfigT
 
   protected $profile = 'config_profile_with_hook_install';
 
-  /**
-   * {@inheritdoc}
-   */
-  protected $defaultTheme = 'stark';
-
   /**
    * {@inheritdoc}
    */

core/tests/Drupal/FunctionalTests/Installer/InstallerExistingConfigTest.php

@@ -9,11 +9,6 @@
  */
 class InstallerExistingConfigTest extends InstallerExistingConfigTestBase {
 
-  /**
-   * {@inheritdoc}
-   */
-  protected $defaultTheme = 'stark';
-
   /**
    * {@inheritdoc}
    */