Check for encrypted_param_names key in environment

If unencrypted data exists in the database, there will be no
'encrypted_param_names' key in the environment.  Check for this key
before referencing it.

Change-Id: Ie8c593818a64d150e815487e1449a52173f1ab5d
Closes-Bug: #1456700

heat/objects/raw_template.py

@@ -47,8 +47,11 @@ class RawTemplate(
             tpl[field] = db_tpl[field]
 
         # If any of the parameters were encrypted, then decrypt them
+        if env_fmt.ENCRYPTED_PARAM_NAMES in tpl.environment:
             parameters = tpl.environment[env_fmt.PARAMETERS]
-        encrypted_param_names = tpl.environment[env_fmt.ENCRYPTED_PARAM_NAMES]
+            encrypted_param_names = tpl.environment[
+                env_fmt.ENCRYPTED_PARAM_NAMES]
+
             for param_name in encrypted_param_names:
                 decrypt_function_name = parameters[param_name][0]
                 decrypt_function = getattr(crypt, decrypt_function_name)

heat/tests/test_stack.py

@@ -2030,6 +2030,42 @@ class StackTest(common.HeatTestCase):
         self.assertEqual('foo', params.get('param1'))
         self.assertEqual('bar', params.get('param2'))
 
+    def test_parameters_stored_decrypted_successful_load(self):
+        '''
+        Test stack loading with disabled parameter value validation.
+        '''
+        tmpl = template_format.parse('''
+        heat_template_version: 2013-05-23
+        parameters:
+            param1:
+                type: string
+                description: value1.
+            param2:
+                type: string
+                description: value2.
+                hidden: true
+        resources:
+            a_resource:
+                type: GenericResourceType
+        ''')
+        env1 = environment.Environment({'param1': 'foo', 'param2': 'bar'})
+        self.stack = stack.Stack(self.ctx, 'test',
+                                 template.Template(tmpl, env=env1))
+        cfg.CONF.set_override('encrypt_parameters_and_properties', False)
+
+        # Verify that hidden parameters are stored decrypted
+        self.stack.store()
+        db_tpl = db_api.raw_template_get(self.ctx, self.stack.t.id)
+        db_params = db_tpl.environment['parameters']
+        self.assertEqual('foo', db_params['param1'])
+        self.assertEqual('bar', db_params['param2'])
+
+        # Verify that stack loads without error
+        loaded_stack = stack.Stack.load(self.ctx, stack_id=self.stack.id)
+        params = loaded_stack.t.env.params
+        self.assertEqual('foo', params.get('param1'))
+        self.assertEqual('bar', params.get('param2'))
+
 
 class StackKwargsForCloningTest(common.HeatTestCase):
     scenarios = [