Inline forms fail to delete objects when PK is a custom field

[max@…]

I have custom field type. It's a uuid. If I make an inline form in admin interface with a model that has this custom field as a primary key I can't delete it from the admin interface. I get an error that a NoneType doesn't have some attributes.

The problem is that in _construct_form the primary key is got via get_db_prep_lookup which will always return a string. But in _existing_object when it initializes self._object_dict is just takes an object. Which must not be of a string type.

Patch to eliminate it is attached.

[max@…]

patch to fix inline forms and custom field types

[Aymeric Augustin]

The patch doesn't contain a test case. Could you provide a minimal example that triggers the bug (custom field, model and admin definitions)? Or at least the full traceback? That would save us some guesswork! :)