Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 13521)
+++ wp-includes/functions.php	(working copy)
@@ -2282,6 +2282,8 @@
 	if ( ! $ifp )
 		return array( 'error' => sprintf( __( 'Could not write file %s' ), $new_file ) );
 
+	$bits = apply_filters( 'wp_upload_bits_data', $bits, $new_file );
+
 	@fwrite( $ifp, $bits );
 	fclose( $ifp );
 	// Set correct file permissions