DisallowedModelAdminLookup raised when filtering with __isnull on a ForeignKey not listed in list_filters

[Stian Jensen]

A regression in Django 5.0 was previously reported and fixed, relating to filtering foreign keys in django-admin in the URL, when not manually declared in list_filters:
https://code.djangoproject.com/ticket/35087

There is at least one more issue I'm still having, that is still problematic in Django 5.0.2:

Filtering by whether or not a foreign key value is set also used to work for any foreign key on the model.
/admin/core/invoice/?client__isnull=True

In Django 5.0.2 this provides an error similar to the error reported in 35087.

[Mariusz Felisiak]

Thanks for the report.

Regression in f80669d2f5a5f1db9e9b73ca893fefba34f955e7 (Django 5.0.1)

[Hisham Mahmood]

​PR

[GitHub <noreply@…>]

In 8db593de:

Fixed #35173 -- Fixed ModelAdmin.lookup_allowed() for lookups on foreign keys when not included in ModelAdmin.list_filter.

Regression in f80669d2f5a5f1db9e9b73ca893fefba34f955e7.

Thanks Sarah Boyce for the review.

[Natalia <124304+nessita@…>]

In 3a54e64e:

[5.0.x] Fixed #35173 -- Fixed ModelAdmin.lookup_allowed() for lookups on foreign keys when not included in ModelAdmin.list_filter.

Regression in f80669d2f5a5f1db9e9b73ca893fefba34f955e7.

Thanks Sarah Boyce for the review.
Backport of 8db593de05c3516c939b7d4b9eb91e8791f4c79a from main