Resolve #2473989 "Lack of dynamic"

Closes #2473989

core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/LanguageFormatter.php

@@ -117,9 +117,15 @@ protected function viewValue(FieldItemInterface $item) {
     // storage by LanguageManager::getLanguages()) or in its native language
     // name. That only depends on formatter settings and no language condition.
     $languages = $this->getSetting('native_language') ? $this->languageManager->getNativeLanguages(LanguageInterface::STATE_ALL) : $this->languageManager->getLanguages(LanguageInterface::STATE_ALL);
-    return [
-      '#plain_text' => $item->language && isset($languages[$item->language->getId()]) ? $languages[$item->language->getId()]->getName() : '',
-    ];
+    // \Drupal\Core\Language\LanguageInterface::LANGCODE_NOT_SPECIFIED
+    // and \Drupal\Core\Language\LanguageInterface::LANGCODE_NOT_APPLICABLE are
+    // not returned from the language manager above.
+    $value = [];
+    if (isset($item->language)) {
+      $name = isset($languages[$item->language->getId()]) ? $languages[$item->language->getId()]->getName() : $item->language->getId();
+      $value = ['#plain_text' => $name];
+    }
+    return $value;
   }
 
 }