Use "Thread.current[:included_by]" instead of the Class variable,
"@@included_by".
The former will work on some newfangled multi-threaded Webserver stack,
which uses separate threads to handle multiple simlutaneous requests
(one request/thread). Dunno that the rest of the application is
thread-safe, but using a class variable, in this context, probably isn't.
Thanks to Sam Ruby for the suggestion.
Another very amusing 3-year old bug from the main Instiki Bug Tracker
(don't they ever fix anything?): the chunk-handling code was supposed
to prevent recursive [[!include ...]] statements. Alas, instead of
actually preventing them it would -- when it encountered a recursive
include -- churn away until Rails ran out of stack space.
Fixed.
