Since the logout page isn't displayed directy by Struts, you can't use a tile definition directly. However, I'd try specifying a Struts action as my logout exit page, and then have that action forward to the tile you want.
is this a situation where I should have the logout form point to an action declared in the local struts config file which then redirects to a JSP in a completely different WAR?
Joined: Feb 15, 2005
I suspect it may not be Struts, but IBM that is modifying the URL. I don't know what the rules are for this "magical logout form", but I suspect that one of them may be that the URL of the page must be in the same web application.
I like your idea of calling a Struts action in the same application that forwards to a page in the common application. In this forward, make sure you specify redirect="true". Unless you do so, you won't be able to forward to a page outside the application.