Documentation for implication of renaming a model for resource registry / RBAC

[AlanCoding]

Consider renaming a model, Cow in test_app to Cow2. After doing that experimentally locally and migrating:

from django.contrib.contenttypes.models import ContentType
from django.contrib.auth.models import Permission

ContentType.objects.filter(model__icontains='cow')
Permission.objects.filter(content_type__model__icontains='cow')

After migration, you will find that ContentType handles this gracefully. The Django Permission class does not:

In [4]: list(Permission.objects.filter(content_type__model__icontains='cow').values_list('codename', flat=True))
Out[4]: 
['add_cow',
 'add_cow2',
 'change_cow',
 'change_cow2',
 'delete_cow',
 'delete_cow2',
 'say_cow',
 'view_cow',
 'view_cow2']

In [10]: Permission.objects.filter(content_type__model__icontains='cow')[2].codename
Out[10]: 'change_cow'

In [11]: Permission.objects.filter(content_type__model__icontains='cow')[2].content_type
Out[11]: <ContentType: test_app | cow2>

The old permissions reference the new model but keep the old entries.

Given that this is unsolved in the standard permission model, I think it is a bad idea to embark on on fix in this project (you should fix it in Django itself first). So this should be handled by documenting the behavior and what is needed to work around.