userdata environment garbage collection

[Timothy Hunter <rmagick@...>]

I'm trying to understand how garbage collection works for userdata environments.

I allocate a userdata and then call lua_setfenv to set an environment table for it. Then I allocate a 2nd userdata and store it in the environment table. Eventually Lua collects the 1st userdata. 

I assume that the 2nd userdata will not be collected until the reference in the environment table goes away. Is that correct? Do I need to do anything to allow the environment table to be collected? After the environment table is collected,  do I need to do anything to allow the 2nd userdata to be collected?

--
Tim