Edit consistency group form has an exception

[wei.ying]

Env: devstack master branch

If old description is empty and submit edit consistency group form,it will throws an exception.

Exception info:
[06/Apr/2017 15:16:58] "GET /project/cgroups/671779c1-81de-4354-ac8c-db123f835afa/update/ HTTP/1.1" 200 2175
Internal Server Error: /project/cgroups/671779c1-81de-4354-ac8c-db123f835afa/update/
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py", line 132, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/stack/horizon/horizon/decorators.py", line 36, in dec
    return view_func(request, *args, **kwargs)
  File "/opt/stack/horizon/horizon/decorators.py", line 52, in dec
    return view_func(request, *args, **kwargs)
  File "/opt/stack/horizon/horizon/decorators.py", line 36, in dec
    return view_func(request, *args, **kwargs)
  File "/opt/stack/horizon/horizon/decorators.py", line 84, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/django/views/generic/base.py", line 71, in view
    return self.dispatch(request, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/django/views/generic/base.py", line 89, in dispatch
    return handler(request, *args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/django/views/generic/edit.py", line 214, in post
    if form.is_valid():
  File "/usr/local/lib/python2.7/dist-packages/django/forms/forms.py", line 184, in is_valid
    return self.is_bound and not self.errors
  File "/usr/local/lib/python2.7/dist-packages/django/forms/forms.py", line 176, in errors
    self.full_clean()
  File "/usr/local/lib/python2.7/dist-packages/django/forms/forms.py", line 393, in full_clean
    self._clean_form()
  File "/usr/local/lib/python2.7/dist-packages/django/forms/forms.py", line 417, in _clean_form
    cleaned_data = self.clean()
  File "/opt/stack/horizon/openstack_dashboard/dashboards/project/cgroups/forms.py", line 35, in clean
    if len(old_desc):
TypeError: object of type 'NoneType' has no len()

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/454238

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/454238
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=bfec68032237db3c50227da7a1121698a916b0c8
Submitter: Jenkins
Branch: master

commit bfec68032237db3c50227da7a1121698a916b0c8
Author: wei.ying <email address hidden>
Date: Thu Apr 6 23:28:12 2017 +0800

    Fix edit consistency group form error

    If cgroup old description is empty and also judge its length,
    it will throw an error. We should first whether is empty.

    Change-Id: Ic89232b22a3d4673b14115e65dd670dded26f0a1
    Closes-Bug: 1680506

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 12.0.0.0b1 development milestone.