[Zope] zombies and popenN()

[Dennis Allison]

I use htmldoc to create pdf docs out of Zope.  Basically I construct 
the html page I want to print, and use popen3() to write the html to 
the htmldoc program and fetch the pdf file and error file (if any).

Most of the time it works fine.  But occasionally the pdf is produced, no
error message produced, and a Zombie process hanging around.  There seems
to be some correlation with the first print operation for a session
creating a zombie.

The python collector has several bugs related to the interaction of
threads and popenN(), but it's unclear if they apply or how one might 
work around the problem?  or even localize the problem?  

I suppose the simplest workaround would be to manage the pipes and htmldoc
process myself rather than delegating it to popenN().