Tomcat 9.0.0M4 (and trunk) issue with Websockets (bug?)

[Francesco Bassi]

Hello everybody.

Tomcat 9 has a different behaviour than Tomcat 8, during the management of
MessageHandler.onMessage:

- in Tomcat 8:
  Thread.currentThread().getContextClassLoader() returns an instance of
org.apache.catalina.loader.WebappClassLoader

- in Tomcat 9
  Thread.currentThread().getContextClassLoader() returns an instance of
java.net.URLClassLoader
  (which doesn't resolve the WEB-INF/lib/* classes)

It seems to be related to the switch to ParallelWebappClassLoader.
Is it a bug or and intended behaviour?

Thanks,

--fb