From 5a6a000c2cca5dc1f18eb872f1ff584ccd795d8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A1n=20Mart=C3=ADnez?=
 <adrian.martinez@interactiv4.com>
Date: Tue, 9 May 2017 14:00:12 +0200
Subject: [PATCH] Fix PageCache: async rendering of blocks can corrupt layout
 cache #8554

---
 app/code/Magento/PageCache/Controller/Block.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/code/Magento/PageCache/Controller/Block.php b/app/code/Magento/PageCache/Controller/Block.php
index 5d4473d5472ec..1e13f4b8be41f 100644
--- a/app/code/Magento/PageCache/Controller/Block.php
+++ b/app/code/Magento/PageCache/Controller/Block.php
@@ -68,7 +68,9 @@ protected function _getBlocks()
         $blocks = $this->jsonSerializer->unserialize($blocks);
         $handles = $this->base64jsonSerializer->unserialize($handles);
 
-        $handles[] = $this->additionalPageCacheHandle;
+        if(is_array($handles)){
+            $handles[] = $this->additionalPageCacheHandle;
+        }
 
         $this->_view->loadLayout($handles, true, true, false);
         $data = [];