This is a security fix.

This is a security fix.

Thanks Tim Graham for the initial patch.

This allows bringing back the behavior of Django < 1.7.

Also fixed the check for the app registry being ready in
AppConfig.get_model(s), which was inconsistent with the equivalent check in
Apps.get_model(s). That part is a backwards-incompatible change.

Since AppConfig now has a reference to its parent Apps registry,
it can look up the models there instead of receiving them in argument.

It was inconsistent with the equivalent check in Apps.get_model(s)
because I made incorrect assumptions when I wrote that code and
needlessly complicated readiness checks.

This is a backwards-incompatible change.

Thanks Anssi Kääriäinen for the initial patch and Anssi, Simon Charette,
and Josh Smeaton for review.

This allows running tests w/o installing Django itself by only pointing
the Python path.

Thanks Tim Graham for the review and edits.

When a FileField is set to an instance of File that is not also an
instance of FieldFile, pre_save() passes that object as the contents to
Storage.save(). This allows the file to be moved rather than copied
to the upload destination.

This reverts commit 1ec1633c as it
doesn't handle ContentType's auth.Permission dependency. Thus, it
doesn't allow auth without migrations.

Fixed #27385 -- Fixed QuerySet.bulk_create() on PostgreSQL when the number of objects is a multiple plus one of batch_size.