MultipartRequestHandler broken in nightly builds

[Mindaugas Idzelis]

Given the following code snippet:

        String operation = request.getParameter("op");
        if (operation==null) {
            // Maybe it's multipart
            java.util.Hashtable multipart =
form.getMultipartRequestHandler().getTextElements();
            operation = (String)multipart.get("op");
        }

Works in 1.0b1, broken in one of the April nightly builds (forgot exactly
which one) and in the current nightly build as well.

At the last line I get a ClassCastException. Even though what is returned by
multipart.get("op")'s toString function looks like a String, it isn't.