Check file handle exists before trying to read file

lib/filesystemview.php

@@ -137,6 +137,7 @@ class OC_FilesystemView {
 	}
 	public function readfile($path){
 		$handle=$this->fopen($path,'r');
+		if ($handle) {
 			$chunkSize = 1024*1024;// 1 MB chunks
 			while (!feof($handle)) {
 				echo fread($handle, $chunkSize);
@@ -145,6 +146,8 @@ class OC_FilesystemView {
 			}
 			return $this->filesize($path);
 		}
+		return false;
+	}
 	public function is_readable($path){
 		return $this->basicOperation('is_readable',$path);
 	}