1b58d5681df00ee3bed5ee1a47f61689009ba55f patch
diff --git a/core/lib/Drupal/Core/Validation/DrupalTranslator.php b/core/lib/Drupal/Core/Validation/DrupalTranslator.php
index ba1a1f9..6a9cd1b 100644
--- a/core/lib/Drupal/Core/Validation/DrupalTranslator.php
+++ b/core/lib/Drupal/Core/Validation/DrupalTranslator.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Validation;
 
 use Drupal\Component\Utility\SafeStringInterface;
+use Drupal\Core\StringTranslation\TranslationWrapper;
 
 /**
  * Translates strings using Drupal's translation system.
@@ -28,7 +29,9 @@ class DrupalTranslator implements TranslatorInterface {
    */
   public function trans($id, array $parameters = array(), $domain = NULL, $locale = NULL) {
 
-    return t($id, $this->processParameters($parameters), $this->getOptions($domain, $locale));
+    // If a TranslationWrapper is passed as $id, return it (since the messag
+    // has already been translated).
+    return $id instanceof TranslationWrapper ? $id : t($id, $this->processParameters($parameters), $this->getOptions($domain, $locale));
   }
 
   /**