The jsp template renderer actually uses a forward in order to render jsps.
This is the primary problem for which the magnolia filter can't be mapped with "forward" dispatcher in web.xml and could cause other problems when integrating magnolia with other MVC frameworks.

We will change it in 3.1 in order to include jsps instead of forwaring to them.

The simple change is as following:

RequestDispatcher rd = request.getRequestDispatcher(requestReceiver);

• rd.forward(request, response);
  + rd.include(request, response);

Note that this could require updating any custom filter mapping (not the magnolia one) you may have mapped to *.jsp only, when upgrading a custom application based on a previous version of magnolia.