title: What does the crossContext attribute do in Tomcat? Does it enable session sharing?
body: <p>All I can find in the <a href="http://tomcat.apache.org/tomcat-5.5-doc/config/context.html" rel="noreferrer">Tomcat 5.5 docs</a> is:</p>
  
  <blockquote>
    <p>Set to true if you want calls within this application to ServletContext.getContext() to successfully return a request dispatcher for other web applications running on this virtual host. Set to false (the default) in security conscious environments, to make getContext() always return null.</p>
  </blockquote>
  
  <p>I've found some forum posts that comment that setting <code>crossContext=true</code> also enables sharing the session object between different web applications, but I'm not able to find any official docs stating this.</p>
  
  <p>Is there a relation between Servlet.getContext() and the ability to share session state between different web applications?</p>
  
  <p>What does the <code>crossContext</code> attribute <strong>really</strong> do in Tomcat?</p>