[FE-discuss] SimpleFormValidator doesn't work with schema.from_python({}, None)

[Yap Sok Ann]

Hi,

Should SimpleFormValidator inherit from FormValidator instead of
FancyValidator? Otherwise, when used as a chained validator, a call to
schema.from_python({}, None) will raise an exception, as
FancyValidator.from_python({}, None) returns None and fails the dict
assertion. OTOH, FormValidator.from_python({}, None) returns {} as is.

Regards,
Yap