The documentation for os.popen[234] states that the close
will 
return the rc of the process. This works well on
windows, but the 
unix code does not work, None is
returned.

The 
attached version of popen2.py fixes the problem
by wrapping 
the fromchild fd with an object that
implements the 
documented close() behaviour.

I have also extended the 
test() to cover testing the
rc and run on FreeBSD against 
2.2.1