Forwarded POST request becomes a GET request

POST requests that get forwarded (at least due to <security-constraint> rule) are reported as GET requests when the request arrives to the destination.

Now e.g. Vaadin login UI that sends POST request (XHR) to the "original" address dies as Vaadin servlet returns html instead of JSON.

The same setup works in JBoss 7.1 and Glassfish.

The issue (and workaround) is describe in the github project:
https://github.com/mstahv/vaadin-cdi-jaas-jbossas-example/