From f8b4adef234c4df77ccc27281cd7e7e0062f2bd7 Mon Sep 17 00:00:00 2001
From: Jonathan Johnson <jon.johnson@ucsf.edu>
Date: Wed, 20 Mar 2019 14:51:06 -0700
Subject: [PATCH] Ensure key exists before checking array value

---
 src/Symfony/Component/Cache/Traits/PhpFilesTrait.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php b/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php
index b57addb54fb1..37d25f87a98f 100644
--- a/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php
+++ b/src/Symfony/Component/Cache/Traits/PhpFilesTrait.php
@@ -133,7 +133,7 @@ protected function doFetch(array $ids)
      */
     protected function doHave($id)
     {
-        if ($this->appendOnly && $this->values[$id]) {
+        if ($this->appendOnly && isset($this->values[$id])) {
             return true;
         }