I don't really know what JIRA is by the way, so hopefully nobody is upset by this post. I first mailed Gavin but he told me I should put it in JIRA.
alert("user: " + user);
alert("exception occured: " + ex.getMessage());
As the exception handler is optional, the change would not brake any client code. If you are interested in the change, you can reach me at heinzbeinz AT googlemail.com