Response forwarding can lead to stackoverflow

For a customer project, the page-not-found mechanism is implemented such that attempts to retrieve non-existent content are redirected to a dedicated page-not-found document. If that document is missing, I experience stack-overflows, as HstFilter#processResolvedSiteMapItem() gets into an infinite recursion.

Of course, HstFilter cannot solve the problem of the missing document, but I wonder if it should be smart enough to detect the condition and issue a sensible log message rather than a few screens worth of stack backtrace (most of which are identitical).