From the mailing list

I'm encountering an issue with JSF file uploads and ocpsoft Rewrite
where a native JSF 2.1 h:inputFile will not work if the URL it is
posting to is a rewritten URL.

This is somewhat known behavior per
http://www.ocpsoft.org/rewrite/docs/faq Which says:

"According to the Servlet spec HttpServletRequest.getParameter*() and
HttpServletRequest.getPart*() can only be called from special Servlets
for multipart/form-data request. Using these methods outside of such
Servlets results in undefined behavior."

The Rewrite FAQ suggests a setting in Tomcat that allows "Casual
Multipart Parsing" allowCasualMultipartParsing="true"

http://tomcat.apache.org/tomcat-7.0-doc/config/context.html#Common_Attributes

Is there a similar option for Undertow, or is this just a case where
multipart/form-data requests will not work on a rewritten URL?