Model.save() positional argument parsing slightly incorrect

[Adam Johnson]

Ticket #35060 introduced a deprecation pathway for positional arguments in Model.save(). The code introduced to match positional arguments is slightly incorrect, leading to some subtle behaviour changes:

1. Calling with extra positional arguments, such as Model.save(False, False, None, None, None), no longer raises a TypeError.
2. Calling with positional empty update_fields, such as Model.save(False, False, None, []), would try to save all fields, due to truthy-checking of arguments.

These are definitely edge cases, but we can easily avoid them with alternative parsing logic. PR incoming.

[Jacob Walls]

​PR

[GitHub <noreply@…>]

In 28522c3:

Fixed #35554, Refs #35060 -- Corrected deprecated *args parsing in Model.save()/asave().

The transitional logic added to deprecate the usage of *args for
Model.save()/asave() introduced two issues that this branch fixes:

• Passing extra positional arguments no longer raised TypeError.
• Passing a positional but empty update_fields would save all fields.

Co-authored-by: Natalia <124304+nessita@…>

[Natalia <124304+nessita@…>]

In 38717291:

[5.1.x] Fixed #35554, Refs #35060 -- Corrected deprecated *args parsing in Model.save()/asave().

The transitional logic added to deprecate the usage of *args for
Model.save()/asave() introduced two issues that this branch fixes:

• Passing extra positional arguments no longer raised TypeError.
• Passing a positional but empty update_fields would save all fields.

Co-authored-by: Natalia <124304+nessita@…>

Backport of 28522c3c8d5eb581347aececc3ac61c134528114 from main.