From b81386a431095f766575436f57c72cbaac7d492e Mon Sep 17 00:00:00 2001
From: Simon Welsh <simon@simon.geek.nz>
Date: Mon, 18 Feb 2013 17:35:17 +1300
Subject: [PATCH] Correct check for File subclass

---
 filesystem/File.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/filesystem/File.php b/filesystem/File.php
index a66bd562b..392a7c516 100644
--- a/filesystem/File.php
+++ b/filesystem/File.php
@@ -936,7 +936,7 @@ class File extends DataObject {
 		if(!is_array($exts)) $exts = array($exts);
 		
 		foreach($exts as $ext) {
-			if(is_subclass_of($ext, 'File')) {
+			if(!is_subclass_of($ext, 'File')) {
 				throw new InvalidArgumentException(
 					sprintf('Class "%s" (for extension "%s") is not a valid subclass of File', $class, $ext)
 				);