Error processing form

     invalid distribution file

Looks like this originates from:

     https://svn.python.org/packages/trunk/pypi/webui.py

down near the bottom in the file_upload() method. I can't figure out
which "invalid distribution file" error is being triggered, but in
looking around, I saw that is_distutils_file() in:

     https://svn.python.org/packages/trunk/pypi/verify_filetype.py

says:

     if filename.endswith('.exe'):
         # check for valid exe
         if filetype != 'bdist_wininst':
             return False

         try:
             t = StringIO.StringIO(content)
             t.filename = filename
             z = zipfile.ZipFile(t)
             l = z.namelist()
         except zipfile.error:
             return False

         for zipname in l:
             if not safe_zipnames.match(zipname):
                 return False

That seems a little weird to me. Are the bdist_wininst exe files really
zip files? Or did I just misunderstand what "content" is?