Ignore ValueError when adding dependencies

When adding dependencies, we can ignore ValueError.

Change-Id: Iaca3d364d0f68f50eb3ce5243b5aa33cc54072e6
Closes-Bug: #1536515

heat/engine/stack.py

@@ -386,7 +386,10 @@ class Stack(collections.Mapping):
         """Return the dependency graph for a list of resources."""
         deps = dependencies.Dependencies()
         for res in resources:
-            res.add_dependencies(deps)
+            try:
+                res.add_dependencies(deps)
+            except ValueError:
+                pass
 
         return deps
 

heat/tests/test_resource.py

@@ -2343,6 +2343,22 @@ class ResourceDependenciesTest(common.HeatTestCase):
 
         self.assertIn(res, graph)
 
+    def test_hot_add_dep_error(self):
+        tmpl = template.Template({
+            'heat_template_version': '2013-05-23',
+            'resources': {
+                'foo': {'type': 'GenericResourceType'},
+                'bar': {'type': 'ResourceWithPropsType'}
+            }
+        })
+        stack = parser.Stack(utils.dummy_context(), 'test', tmpl)
+        res = stack['bar']
+        self.patchobject(res, 'add_dependencies',
+                         side_effect=ValueError)
+        graph = stack.dependencies.graph()
+        self.assertNotIn(res, graph)
+        self.assertIn(stack['foo'], graph)
+
     def test_ref(self):
         tmpl = template.Template({
             'HeatTemplateFormatVersion': '2012-12-12',