? 883338.image.invoke-hook_file_download.patch
Index: image.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/image/Attic/image.module,v
retrieving revision 1.322.2.3
diff -u -p -r1.322.2.3 image.module
--- image.module	3 Aug 2010 17:43:00 -0000	1.322.2.3
+++ image.module	15 Aug 2010 07:13:06 -0000
@@ -670,7 +670,7 @@ function image_fetch($nid = 0, $size = I
 
       if (isset($node->images[$size])) {
         $file = $node->images[$size];
-        $headers = image_file_download($file);
+        $headers = module_invoke_all('file_download', $file);
         if ($headers == -1) {
           return drupal_access_denied();
         }