ZipException - duplicate class workaround, another jythonc problem

In attempting to follow an article on using Jython with Ant
(http://www.pycs.net/users/0000177/stories/11.html),
I ran in to an issue I had seen mentioned twice before this year
on this mailing list. That issue had to do with running jythonc and
running into a ZipException that complained about a duplicate class
entry.  The questions about the issue didn't appear to elicit any 
response.   
I investigated the problem and came up with a work-around to address
the immediate problem, however, I'm sure I didn't uncover the root cause
of the issue.

I was able to reproduce the problem and dug around to figure out what
was happening.  The problem strike point is in jython/Tools/jythonc/jar.py
in the JarArchive.dumpFiles method where it loops through a sequence
of packages and adds each package via the JarArchive.addPackage method
call.  In that method, a for loop using the result of a call to
util.listAllClasses is attempted; within the loop, the call to
self.zipfile.putNextEntry is where the exception occurs.  
I was able to put in a workaround in the addPackage method that uses a
'done' dictionary to record what has already been added to the zip file
and checks for the target entry before attempting the add.
I thought that was kind of a hacky solution and chased the problem upstream
one step to the util.listAllClasses function.  In that function,
a call is made to get classes using sys.packageManager.doDir() and from
_ypm.doDir() but no duplicate detection is done.  My workaround is
to add the duplicate detection in this function.  Perhaps the problem should
be chased upstream further but I did not do so as the trail became more
obscure for me to track.

The workaround code (inserted just before the classes.extend(classes2)
statement in util.listAllClasses):

   #
   # Identify and eliminate duplication of class names
   #
   dups = [className for className in classes2 if className in classes]
   for className in dups:
       classes2.remove(className)

Anyway, that workaround "fixes" the problem with the ZipException when
using jythonc.

Even so, I'm still not able to execute the jython ant task (from the 
article).  
An exception stating that there is no public execute method is emitted.  
And indeed, in the jythonc generated Java code (SimpleTask.java) for the
Jython script SimpleTask.py, there is no such beast.  The Java method 
signature
spec using  the "@sig ..." notation is present in the docstring for the
execute method so I don't know why the generated Java code doesn't have
"public static PyObject execute(...)".  The closest method to that is
"private static PyObject execute$1(PyFrame frame)" which is followed by
the Java comment /* @sig public void execute() */ that presumably came from
the docstring in SimpleTask.py for the execute method.

I'm using J2SDK 1.4.2_07 on a Windows98 box. I tried this using Jython 
2.1 and the latest from CVS.

Anybody have insight into what the problem is (and the solution)?

--
Kip Lehman
kipster <dash> t <at> earthlink <dot> net


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