diff options
Diffstat (limited to 'Lib/email/_policybase.py')
| -rw-r--r-- | Lib/email/_policybase.py | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/Lib/email/_policybase.py b/Lib/email/_policybase.py index 05736d0..6bc298b 100644 --- a/Lib/email/_policybase.py +++ b/Lib/email/_policybase.py @@ -64,10 +64,16 @@ class _PolicyBase: except for the changes passed in as keyword arguments. """ + newpolicy = self.__class__.__new__(self.__class__) for attr, value in self.__dict__.items(): - if attr not in kw: - kw[attr] = value - return self.__class__(**kw) + object.__setattr__(newpolicy, attr, value) + for attr, value in kw.items(): + if not hasattr(self, attr): + raise TypeError( + "{!r} is an invalid keyword argument for {}".format( + attr, self.__class__.__name__)) + object.__setattr__(newpolicy, attr, value) + return newpolicy def __setattr__(self, name, value): if hasattr(self, name): |