shalini jha
--- a/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+++ b/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+  }
+
+  /**
+   * Tests configuration translations after any module/theme install.
+   */
+  public function testConfigTranslationImport() {
-  public function testConfigTranslationImport() {
+  public function testConfigTranslationImport(): void {
--- a/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+++ b/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+    // Test this book config edit page for translation overrides or not.
+    $this->drupalGet('admin/structure/types/manage/book');
+    $this->drupalGet('/en/admin/structure/types/manage/book');
+    $this->assertSession()->fieldValueEquals('name', 'Book page');
+
+  }
+
+  /**
+   * Helper function: import a standalone .po file in a given language.
+   *
+   * @param string $contents
+   *   Contents of the .po file to import.
+   * @param array $options
+   *   (optional) Additional options to pass to the translation import form.
+   */
+  public function importPoFile($contents, array $options = []) {
-  public function importPoFile($contents, array $options = []) {
+  public function importPoFile(string $contents, array $options = []): void {
--- a/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+++ b/core/modules/locale/tests/src/Functional/ModuleInstallConfigTest.php 0 → 100644
+   *   (optional) Additional options to pass to the translation import form.
+   */
+  public function importPoFile($contents, array $options = []) {
+    $file_system = \Drupal::service('file_system');
+    $name = $file_system->tempnam('temporary://', "po_") . '.po';
+    file_put_contents($name, $contents);
+    $options['files[file]'] = $name;
+    $this->drupalGet('admin/config/regional/translate/import');
+    $this->submitForm($options, 'Import');
+    $file_system->unlink($name);
+  }
+
+  /**
+   * Helper function that returns a .po file with configuration translations.
+   */
+  public function getPoFileWithConfigDe() {
--- a/core/modules/locale/src/LocaleConfigManager.php
+++ b/core/modules/locale/src/LocaleConfigManager.php
        $config = $this->configFactory->reset($name)->getEditable($name);
        // Should only update if still exists in active configuration. If locale
        // module is enabled later, then some configuration may not exist anymore.
+        // Config will only be overridden if shipped language code is not available.
        if (!$config->isNew()) {
          $langcode = $config->get('langcode');
-          if (empty($langcode) || $langcode == 'en') {
+          $isAvailableLangcode = in_array($langcode, $available_langcodes);