cext: correct the argument handling of `b85encode()`
The type stub indicated that this argument is `Optional`, which implies None is
allowed. I don't see in the documentation where that's the case for `i`[1], and
trying it in `hg debugshell` resulted in the method failing with a TypeError. I
guess it was typed as an `int` argument because the `p` format unit wasn't added
until Python 3.3[2].
In any event, 2 clients in core (`pvec` and `obsolete`) call this with no
argument supplied, and `mdiff` calls it with True. So I guess we've avoided the
None arg case, and when no arg is supplied, it defaults to the 0 initialization
of the `pad` variable in C. Since the `p` format unit accepts both `int` and
None, as well as `bool`, I'm not bothering to bump the module version- this code
is more permissive than it was, in addition to being more correct.
Interestingly, when I first imported the `cext` and `pure` methods in the same
manner as the previous commit, it dropped the `Optional` part of the argument
type when generating `util.pyi`. No idea why.
[1] https://docs.python.org/3/c-api/arg.html#numbers
[2] https://docs.python.org/3/c-api/arg.html#other-objects
[build-system]
requires = ["setuptools", "wheel"]
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true