Bug in coroutine.running()

["Patrick Donnelly" <batrick.donnelly@...>]

The documentation states that coroutine.running() "Returns the running
coroutine, or nil when called by the main thread." Currently it
doesn't return anything when called by the main thread.

-- 
-Patrick Donnelly

"One of the lessons of history is that nothing is often a good thing
to do and always a clever thing to say."

-Will Durant