Index: wp-admin/edit-form-advanced.php
===================================================================
--- wp-admin/edit-form-advanced.php	(revision 22735)
+++ wp-admin/edit-form-advanced.php	(working copy)
@@ -423,8 +423,9 @@
 <script type="text/javascript">
 (function($){
 	function getFieldsContent() {
-		return ($('#title').val() || '') + ($('#attachment_caption').val() || '') +
-		($('#attachment_alt').val() || '') + ($('#attachment_content').val() || '') + ($('#post_name').val() || '');
+		return $('#title, #attachment_caption, #attachment_alt, #attachment_content, #post_name').map( function() {
+			return $(this).val();
+		}).get().join(',');
 	}
 
 	var initial = getFieldsContent();