Transition.py: add comment.

product/ERP5Workflow/Document/Transition.py

@@ -91,6 +91,7 @@ class Transition(IdAsReferenceMixin("transition_", "prefix"), XMLObject):
     self.generateGuard()
     if not self.guard.roles or self.guard.roles == []:
       reasonable_roles = self.getParent().getManagedRoleList()
+      # Make sure we do not give rights to anonymous users when no guard is defined
       reasonable_roles.remove('Anonymous')
       self.guard.roles = reasonable_roles
     return self.guard