Handle getting the ds for Conditionals which may not be mixed in

lib/ansible/playbook/conditional.py

@@ -55,14 +55,21 @@ class Conditional:
         False if any of them evaluate as such.
         '''
 
+        # since this is a mixin, it may not have an underlying datastructure
+        # associated with it, so we pull it out now in case we need it for
+        # error reporting below
+        ds = None
+        if hasattr(self, 'get_ds'):
+            ds = self.get_ds()
+
         try:
             for conditional in self.when:
                 if not self._check_conditional(conditional, templar, all_vars):
                     return False
         except UndefinedError, e:
-            raise AnsibleError("The conditional check '%s' failed due to an undefined variable. The error was: %s" % (conditional, e), obj=self.get_ds())
+            raise AnsibleError("The conditional check '%s' failed due to an undefined variable. The error was: %s" % (conditional, e), obj=ds)
         except Exception, e:
-            raise AnsibleError("The conditional check '%s' failed. The error was: %s" % (conditional, e), obj=self.get_ds())
+            raise AnsibleError("The conditional check '%s' failed. The error was: %s" % (conditional, e), obj=ds)
 
         return True