TypeError Exception during attemt to set some resource's parameter from `null` to some value

[Dmytro Dovbii]

Create murano-app workflow which updates stack template. Choose some parameter which was set to `null`.

for example:

...
# use base class of Instance
- $.instance.deploy()
- $template:
     resources:
       $.instance.name:
         type: 'OS::Nova::Server'
           properties:
             user_data: 'aaaa' # was `null`
- $environment: $.find(std:Environment).require()
- $environment.stack.updateTemplate($template)
- $environment.stack.push()

...

You will get TypeError() exception.

We need to modificate logic here to allow user modifcate 'null'-parameters:

https://github.com/openstack/murano/blob/master/murano/dsl/helpers.py#L84-L96

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/243088

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/243088
Committed: https://git.openstack.org/cgit/openstack/murano/commit/?id=b8fa64b8a254fe4e4a994cae704ee49ff71b6174
Submitter: Jenkins
Branch: master

commit b8fa64b8a254fe4e4a994cae704ee49ff71b6174
Author: liyingjun <email address hidden>
Date: Mon Nov 9 21:02:21 2015 +0800

    Fix TypeError set param from 'null' to some value

    TypeError Exception during attemt to set some resource's parameter from
    `null` to some value or value to `null`.

    Change-Id: Ib20218f6a8676669230f440a4a13dea61f2d4c6b
    Closes-bug: #1514364