Doesn't duplicate with custom id

[gerbyzation]

A model with a custom id field is not duplicated:

the Branch model has the id id = models.UUIDField(primary_key=True, default=uuid4)

>>> base_branch = Branch.objects.create(name='Main branch', parent=None, is_master=True, status=Branch.DRAFT)
>>> base_branch.pk
UUID('7a613f9d-90fe-4116-b897-69505cd4ff5c')
>>> clone = base_branch.make_clone()
>>> clone.pk
UUID('7a613f9d-90fe-4116-b897-69505cd4ff5c')

I think this is because the custom id shows up in _meta.concrete_fields the value is copied over, preventing it from generating a new PK.

>>> base_branch._meta.concrete_fields
(<django.db.models.fields.UUIDField: id>, <django.db.models.fields.CharField: name>, <django.db.models.fields.BooleanField: is_master>, <django.db.models.fields.related.ForeignKey: parent>, <django.db.models.fields.CharField: status>)

The primary key field can be found through instance._meta.pk, filtering this out of the fields to copy should resolve this problem I think.

[jackton1]

@all-contributors please add @gerbyzation for bug, tests and code

[allcontributors]

@jackton1

I've put up a pull request to add @gerbyzation! 🎉