commit 9ba79219b2ff239ffe69716d113bc4177de0c53d
Author: Joel Pittet <joel@pittet.ca>
Date:   Thu Apr 18 12:41:44 2013 -0700

    rolled with 1867090-25

diff --git a/core/lib/Drupal/Core/Template/TwigTemplate.php b/core/lib/Drupal/Core/Template/TwigTemplate.php
index 429131d..288ebb8 100644
--- a/core/lib/Drupal/Core/Template/TwigTemplate.php
+++ b/core/lib/Drupal/Core/Template/TwigTemplate.php
@@ -51,6 +51,13 @@
       return NULL;
     }
 
+    // Turn off references for looped items.
+    // @todo hide, show is not supported for them for now.
+    // @see http://drupal.org/node/1867090 Nested loops behaving strange.
+    if (isset($context['_seq'])) {
+      return $context[$item];
+    }
+
     // The first test also finds empty / null render arrays
     if (!$context[$item] || isset($this->is_no_reference[$item])) {
       return $context[$item];