Bug 43669

Tomcat 5.5.x:
http://svn.apache.org/repos/asf/tomcat/container/tc5.5.x/catalina/src/share/org/apache/catalina/core/ApplicationDispatcher.java
  private void unwrapRequest(State state) {
    ...continue...
    // Advance to the next request in the chain
    previous = current;
    current = ((ServletRequestWrapper) current).getRequest(); // !! CAST ERROR
    ...continue...
  }

Exception is thrown when request is forwarded:
  "com.outerrim.servlet.OfflineHttpServletRequest cannot be cast to 
   javax.servlet.ServletRequestWrapper"

This is my offlineHttpServletRequest and Response classes:
  public class OfflineHttpServletRequest implements HttpServletRequest { ... }
  public class OfflineHttpServletResponse implements HttpServletResponse { ... }

They provide me a way to call servlet urls without the real webclient requests.
This is used in a background thread, that must trigger "dispatcher.forward(req,
res)" method call.
   RequestDispatcher dispatcher = ctx.getRequestDispatcher(url);
   dispatcher.forward(offReq, offRes);

Classes work fine in Tomcat5.0.x releases. 

Is it really a new requirement, that customized classes must inherit
ServletRequestWrapper/ServletResponseWrapper classes?