Non-admins cannot change PPA privacy after creation

Although anyone with a commercial subscription may *create* a private PPA, only commercial administrators and admins may change the 'private' attribute of a PPA. In particular, the creator of a private PPA may not make that PPA public without (commercial) admin intervention.

This is because the 'private' attribute of IArchive requires 'launchpad.Commercial' level permissions on the archive.

I do not think it appropriate to grant PPA owners who are commercial subscribers full launchpad.Commercial permissions, as these include the ability to set authorized_size, build_debug_symbols, buildd_secret, enabled_restricted_families, external_dependencies and require_virtualized, as well as private.

Some solutions occur to me:

 1. Make setting 'private' require only 'launchpad.Edit', and check for commercial subscriptions in the property.
 2. Create a new permission level meaning something like "I have paid for extra privileges", and have 'private' require that.
 3. Use the existing, strange permission 'launchpad.Special'.
 4. Move the current permissions granted by 'launchpad.Commercial' into a different permission level. Perhaps 'launchpad.Moderate'.

1 is essentially ignoring the Zope permission system. 2 has been deprecated in past conversations with the technical architect. 3 seems wrong. 4 is very high impact and rather risky.

How to reproduce the problem:

  from launchpadlib.launchpad import Launchpad
  import os

  APP_NAME = 'create-commercial-ppa'
  CACHE_DIR = os.path.expanduser('~/.launchpadlib/cache')
  LP_INSTANCE = 'production'

  lp = Launchpad.login_with(APP_NAME, LP_INSTANCE, CACHE_DIR, version="devel")
  jml = lp.people['jml']
  ppa = jml.getPPAByName(name='ca-tools')
  ppa.private = False
  ppa.lp_save()

Produces the following output:
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/resource.py", line 732, in lp_save
      URI(self.self_link), representation, headers)
    File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 336, in patch
      'PATCH', extra_headers=extra_headers)
    File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 281, in _request
      raise error
  lazr.restfulclient.errors.Unauthorized: HTTP Error 401: Unauthorized
  Response headers:
  ---
  -content-encoding: gzip
  connection: close
  content-length: 60
  content-type: text/plain
  date: Thu, 14 Jun 2012 17:53:07 GMT
  server: zope.server.http (HTTP)
  status: 401
  strict-transport-security: max-age=2592000
  vary: Accept,Accept-Encoding
  via: 1.1 api.launchpad.net
  x-content-type-options: nosniff
  x-frame-options: SAMEORIGIN
  x-lazr-notifications: []
  x-powered-by: Zope (www.zope.org), Python (www.python.org)
  x-xss-protection: 1; mode=block
  ---
  Response body:
  ---
  (<Archive at 0x13dcd110>, 'private', 'launchpad.Commercial')
  ---