I just created this issue https://issues.jboss.org/browse/AS7-2739
Coming from a Tomcat background, I know this works properly in Tomcat 7.0.22
I was looking at the code as I understand Jboss uses the Tomcat servlet engine, to see what bug fixes may not have come through to Jboss.
But the code of many packages e.g. org.apache.coyote is now quite different between Jboss and Tomcat.