Modifying an object passed to a mocked function corrupts call_args_list

[TiphaineLAURENT]

Bug description:

# test.py

# src

def my_function(message: dict) -> None:
    pass

def main() -> None:
    # Consider that message is a heavier object, hence the need to update it instead of copying
    message = {"channel": "first_channel"}
    my_function(message)

    message["channel"] = "second_channel"
    my_function(message)


# tests

import unittest.mock


def test() -> None:
    with unittest.mock.patch("test.my_function") as my_function_mock:
        main()

        for call_arg, expected_channel in zip(my_function_mock.call_args_list, ["first_channel", "second_channel"]):
            assert (
                call_arg.args[0]["channel"] == expected_channel
            )  # Fails as call_arg.args[0]["channel"] is always equal to the last call to `my_function`, which is "second_channel"

Run it through pytest test.py

This is a problem as the object we mutate is a bit more heavy that just a dict with 1 field, hence the need to update it.
I would expected call_args_list to copy the call args / kwargs instead of keeping a reference to it.

The code has been tested in productions and works as expected.

CPython versions tested on:

3.13

Operating systems tested on:

Linux

[lpyu001]

it's maybe same as #76813