Comment 0 for bug 1453558

Sending a signal to a resource of type OS::Mistral::Workflow with params results in: ResourceFailure: AttributeError: 'NoneType' object has no attribute 'iteritems'.

The template and log are attached.

Reproduce by executing:

heat stack-create -f mistral-template.yaml Mistral

heat resource-signal Mistral workflow -D '{"params": {"task_name": "create_vm"}}'