It seems like jboss is only enabling multipart support for the request based on whether or not the original request path matches one of the servlets configured for multipart support, whereas it should be enabling support based on the path of the request it is currently handling (which might have been "included" by the RequestDispatcher).

More information can be found at: http://stackoverflow.com/questions/19297400/multipart-config-not-working-for-dynamic-added-servlet-in-a-curious-condition

and: http://stackoverflow.com/a/19447236/1400037

I took a fast read at the spec but did not find anything explicit about this behavior, but IMO ppl should have this kind of control.

The guy in the second link tested in Jetty version 8.1.13.v20130916 and it worked.