Thanks to Andriy Sokolovskiy for the report and Tim Graham for the review.

In that case, the content of INSTALLED_APPS will be ignored until it's
fixed and the autoreloader kicks in. I confirmed this behavior manually.
As explained on the ticket it's hard to write a test for this case

The test session without an expiration date added in refs #22938 wasn't
always deleted on Windows because get_expiry_age() returns zero and the
file backend didn't consider that an expired session.

Thanks to Ali Lotfi for the initial report and patch
and Tim Graham for the review.

Some third-party database backends (MSSQL) have custom
delete_model() requirements that must be executed.

Thanks Michael Manfre for the initial patch and review.

Co-Authored-By: Gavin Wahl <gwahl@fusionbox.com>

Check that the foreign object `from_fields` are a subset of any unique
constraints on the foreign model.

Thanks to Tim for the review.

Prior to this change proxy models reverse fields didn't include the
reverse fields pointing to their concrete model.

Thanks to James Murty for his work on an alternate patch.

This isn't required anymore now that reverse foreign keys
from proxy models are propagated to their concrete model.

Thanks to Anssi for the review.

Thanks Bibhas Debnath for the report and Tim Graham for the review.

The removed test was added in the original select_related() validation
patch (45d4e43d2d25b902e3821b612209afa951a8bcb8), but there doesn't
seem to be any reason for it.

Thanks Claude Paroz for help and review.

Forward port of 86dc4889 from master.

Forward port of 60471c96 from stable/1.9.x.

Fixed on other backends by 134ca4d4.

Thanks Mariusz Felisiak for the solution.

Forward port of f717cb2a from stable/1.9.x.

Thanks Bibhas Debnath for the report and Tim Graham for the review.

Fixed in c9a96075.

Fixed in f403653c.