accessing session when invoked from another context

[erezharari]

say i access WAR2 from WAR1:
ServletContext c=application.getContext("/WAR2");
RequestDispatcher disp=c.getRequestDispatcher("/test.jsp");
disp.include(request,response);

in WAR2/test.jsp i cannot get the session:
request.getSession() throws java.lang.NullPointerException
at org.apache.catalina.core.ApplicationHttpRequest.getSessionApplicationHttpRequest.java:546)
at org.apache.catalina.core.ApplicationHttpRequest.getSessionApplicationHttpRequest.java:512)
at javax.servlet.http.HttpServletRequestWrapper.getSessionHttpServletRequestWrapper.java:268)