return null when a cache variable is not set

diff --git a/lib/cache/file.php b/lib/cache/file.php
index 02aad5187ee78c1a342c8477ecd1fc783b8b7237..a724b9682a87941e3c25d057c2c394e0f851d262 100644 (file)
--- a/lib/cache/file.php
+++ b/lib/cache/file.php
@@ -7,7 +7,7 @@
  */
 
 
-class OC_Cache_File {
+class OC_Cache_File extends OC_Cache {
        protected function getStorage() {
                if(OC_User::isLoggedIn()){
                        $subdir = 'cache';
@@ -28,11 +28,11 @@ class OC_Cache_File {
                        $mtime = $storage->filemtime($key);
                        if ($mtime < time()) {
                                $storage->unlink($key);
-                               return false;
+                               return null;
                        }
                        return $storage->file_get_contents($key);
                }
-               return false;
+               return null;
        }
 
        public function set($key, $value, $ttl) {