Remove arguments from InheritanceQuerySetMixin._clone()

[mthuurne]

Problem

InheritanceQuerySetMixin._clone() accepts and then ignores a klass and setup argument, plus any keyword arguments. The QuerySet._clone() method has no arguments in either Django 3.2 or 4.1 and when using a static code checker like mypy, this is reported as incompatible base classes for InheritanceManager.

Solution

I'm assuming the arguments were necessary for a version of Django that is no longer supported by django-model-utils. Therefore I removed the extra arguments.

Commandments

• Write PEP8 compliant code.
• Cover it with tests. (The _clone() method was already covered.)
• Update CHANGES.rst file to describe the changes, and quote according issue with GH-<issue_number>.
• Pay attention to backward compatibility, or if it breaks it, explain why.
• Update documentation (if relevant).

I chose to not add an entry in CHANGES.rst, as this is a cleanup that should not be noticeable to users.

[codecov]

Codecov Report

Merging #567 (033fca4) into master (6154436) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #567   +/-   ##
=======================================
  Coverage   95.12%   95.12%           
=======================================
  Files           6        6           
  Lines         820      820           
=======================================
  Hits          780      780           
  Misses         40       40           

Impacted Files	Coverage Δ
model_utils/managers.py	98.08% <100.00%> (ø)

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[foarsitter]

This PR will break backwards compatibility right?

Is it an idea to just accept **kwargs and emit a DeprecationWarning when kwargs > 0?

[mthuurne]

This PR will break backwards compatibility right?

It doesn't break any existing functionality, but instead of any passed arguments being silently ignored, a TypeError will be raised. So it does have the potential to escalate pre-existing problems in calling code.

However, as _clone() is not a public method, the only caller would be QuerySet or a subclass of it. So the typical application code will not be calling it directly and Django 3.2 always calls it without arguments.

Is it an idea to just accept **kwargs and emit a DeprecationWarning when kwargs > 0?

Yes, but if we want to be that careful, probably it should catch both *args and **kwargs, because calling code might use positional arguments instead.

I'll leave the decision up to you: personally, I don't think it's likely this change will break any existing code, but if you prefer to be extra cautious, I'll make it accept *args and **kwargs and add the DeprecationWarning.

[foarsitter]

Extra cautiousness isn't necessary since your argument about the private nature of the method is a good one.