Call exit() to prevent further code execution if directory does not exist

apps/files/index.php

@@ -40,6 +40,7 @@ $dir = isset( $_GET['dir'] ) ? stripslashes($_GET['dir']) : '';
 // Redirect if directory does not exist
 if(!OC_Filesystem::is_dir($dir.'/')) {
 	header('Location: '.$_SERVER['PHP_SELF'].'');
+	exit();
 }
 
 $files = array();