tests: enable pytype checking on `mercurial/unionrepo.py`

unionrepo: fix mismatches with revlog classes This is a subset of cfd30df0f8e4, applied to `unionrepository`. There are none of the `write()` method overrides here, like `bundlerepository`. With these changes, pytype flags the `unionrevlog` constructor: File "/mnt/c/Users/Matt/hg/mercurial/unionrepo.py", line 55, in __init__: No attribute '_revlog' on mercurial.changelog.changelog [attribute-error] Called from (traceback): line 207, in __init__ File "/mnt/c/Users/Matt/hg/mercurial/unionrepo.py", line 55, in __init__: No attribute '_revlog' on mercurial.revlog.revlog [attribute-error] Called from (traceback): line 232, in __init__ But it turns out that both `changelog.changelog` and `revlog.revlog` do have a `target` attribute, so they wouldn't trip over this. It seems weird that the second caller to be flagged is passing the private `_revlog`, but maybe that's how it needs to be.

typing: make `unionrepository` subclass `localrepository` while type checking This is the same change as 9d4ad05bc91c made for `bundlerepository`, for the same reasons. Also, add a comment here to suppress the PyCharm warning that the superclass constructor is not called, that is new now that there's a simulated superclass. That lack of a call is by design- `makeunionrepository()` does magic that PyCharm isn't aware of. But PyCharm has been better at catching problems than pytype in a lot of cases, so I'd like to reduce the bogus things it flags, to make the real issues stand out.

tests: enable pytype checking on `mercurial/bundlerepo.py`

revlog: make `clearcaches()` signature consistent with ManifestRevlog I'm not sure if this a newly added bug, because of using a different version of pytype, or if the recent work around avoiding the zope interface types in the type checking phase (see 5eb98ea78fd7 and friends)... but pytype 2023.11.21 started flagging this series since it was last pushed ~6 weeks ago: File "/mnt/c/Users/Matt/hg/mercurial/bundlerepo.py", line 204, in <module>: Overriding method signature mismatch [signature-mismatch] Base signature: 'def mercurial.manifest.ManifestRevlog.clearcaches(self, clear_persisted_data: Any = ...) -> None'. Subclass signature: 'def mercurial.revlog.revlog.clearcaches(self) -> None'. Not enough positional parameters in overriding method. Maybe the multiple inheritance in `bundlerepo.bundlemanifest` is bad, but it seems like a `ManifestRevlog` is-a `revlog`, even though the class hierarchy isn't coded that way. Additionally, it looks like `revlog.clearcaches()` is dealing with some persistent data, so maybe this is useful to have there anyway. Also sprinkle some trivial type hints on the method, because there are other `clearcaches()` definitions in the codebase with these hints, and I don't feel like waiting for another pytype run to see if it cares that specifically about the signature matching.

bundlerepo: fix mismatches with repository and revlog classes Both pytype and PyCharm complained that `write()` and `_write()` in the bundlephasecache class aren't proper overrides- indeed they seem to be missing an argument that the base class has. PyCharm and pytype also complained that the `revlog.revlog` class doesn't have a `_chunk()` method. That looks like it was moved from revlog to `_InnerRevlog` back in e8ad6d8de8b8, and wasn't caught because this module wasn't type checked. However, I couldn't figure out a syntax with `revlog.revlog._inner._chunk(self, rev)`, as it complained about passing too many args. `bundlerevlog._rawtext()` uses this `super(...)` style to call the super class, so hopefully that works, even with the wonky dynamic subclassing. The revlog class needed the `_InnerRevlog` field typed because it isn't set in the constructor. Finally, the vfs type hints look broken. This initially failed with: File "/mnt/c/Users/Matt/hg/mercurial/bundlerepo.py", line 65, in __init__: Function readonlyvfs.__init__ was called with the wrong arguments [wrong-arg-types] Expected: (self, vfs: mercurial.vfs.vfs) Actually passed: (self, vfs: Callable) Called from (traceback): line 232, in dirlog line 214, in __init__ I don't see a raw Callable, but I tried changing some of the vfs args to be typed as `vfsmod.abstractvfs`, but that class doesn't have `options`, so it failed elsewhere. `readonlyvfs` isn't a subclass of `vfs` (it's a subclass of `abstractvfs`), so I'm not sure how to handle that. It would be a shame to have to make a union of vfs subclasses (but not all of them have `options` either).

typing: make `bundlerepository` subclass `localrepository` while type checking Currently, `mercurial/bundlerepo.py` is excluded from pytype, mostly because it complains that various `ui` and `vfs` fields in `localrepository` are missing. (`bundlerepository` dynamically subclasses `localrepository` when it is instantiated, so it works at runtime.) This makes that class hierarchy known to pytype. Having a protocol for `Repository` is probably the right thing to do, but that will be a lot of work and this still reflects the class at runtime. Subclassing also has the benefit of making sure any method overrides have a matching signature, so maybe this is a situation where we do both of these things. (I'm not sure how clear the diagnostics are if a class *almost* implements a protocol, but is missing a method argument or similar.) The subclassing is not done outside of type checking runs to avoid any side effects on already complex code.

rust: bump rust-cpython version to 0.7.2 This version supports Python 3.12 while 0.7.1 did not.

rust: add Vfs trait This will allow for the use of multiple vfs like in the Python implementation, as well as hiding the details of the upcoming Python vfs wrapper to hg-core.

rust: use new revlog configs in all revlog opening code This centralizes the more complex logic needed for the upcoming code and creates stronger APIs with fewer booleans. We also reuse `RevlogType` where needed.

rust-revlog: don't try to open the data file if the index is empty This will cover the case where the data file is not present.

rust-revlog: add revlog-specific config objects These will be used by the upcoming Rust `InnerRevlog` to better centralize config information that is relevant to revlogs.

typing: add `from __future__ import annotations` to remaining source files Most of these look newer than when the original imports referenced in the previous commit were dropped, so these weren't covered by the backout. These were found with: hg files mercurial hgext hgext3rd -I '**.py' -X '**/thirdparty' \ | xargs grep -L 'from __future__ import annotations' All of the `__init__.py` files that finds are empty, so those were ignored and the rest manually edited.

typing: add `from __future__ import annotations` to most files Now that py36 is no longer supported, we can postpone annotation evaluation. This means that the quoting is usually optional (for things imported under the guard of `if typing.TYPE_CHECKING:` to avoid circular imports), and there's less overhead on startup[1]. There may be some missing here. I backed out 6000f5b25c9b (which removed the `from __future__ import ...` that was supporting py2), reverted the changes in `contrib/`, `doc/`, and `tests/`, and then ran: $ hg status -n --change . | \ xargs sed -i -e 's/from __future__ import .*$/from __future__ import annotations/' There were some minor tweaks needed when reviewing (mostly making the spacing around the import consistent, and `mercurial/testing/__init__.py` had a multiline import that wasn't fully rewritten. [1] https://docs.python.org/3/whatsnew/3.7.html#pep-563-postponed-evaluation-of-annotations

format: add many "missing" comma Black was not adding them until the next changeset introduced a bunch of `from __future__ import annotations` to most file. Since it make the next changeset hard to read we introduce them in advance.

typing: simplify archive.gz writing and drop a few pytype suppressions I was waiting until 3.8 to use `Literal` to fix this, but there's also the ":" and "|" characters that are passed along here, meant only for the non-gz archive types. But manipulating what the local caller passes is silly- we know we're writing, so just open it for writing. As an added bonus, PyCharm stops flagging the call too (since it doesn't know about pytype suppression comments).

typing: explicitly set the return type of `_InnerRevLog.raw_text()` Somewhere between cd72a88c5599 and 2fd44b3dcc33, pytype changed the return type from `Tuple[_T1, Any, bool]` to `Any`. Both are wrong. `mdiff.patches()` is an alias for `mpatch.patches()`, which is selected via module policy (and breaks the ability to infer the types). However, `cext`, `cffi`, and `pure` implementations all agree it returns bytes.

typing: add explicit hints for recent pytype regressions Somewhere between 454feddab720 and cd72a88c5599, pytype changed how it inferred the return type in `extdiff.py` from Tuple[Any, List[Tuple[bytes, Any, os.stat_result]]] to Tuple[Any, List[nothing]] It also changed the return type in `archival.py` from `Any` to `NoReturn`. Fix those up, and also the obvious parameter types while we're here.

revlog: use the method to check if the revlog is being written to This was probably fine, but it could become not fine at some point.

revlog: add an early return for getting sidedata No point in trying to fetch sidedata if there isn't a sidedata file.

revlog: simplify rawtext return value We're always returning a tuple even though only the raw text is being used, and we're rebuilding another tuple again higher. As a bonus, this will remove one tuple creation and deletion per `raw_text` call, hence fewer gc calls, etc.

revlog: cleanup some outdated docstrings

rust-inner-revlog: always inline `get_entry` This is a very hot function.

rust-inner-revlog: derive Debug for IndexHeaderFlags

rust-inner-revlog: drop some outdated comment

rust-config: add more ways of reading the config These will be needed for future patches of this series to interpret more complex/different config values.

util: make buffer readonly There is no use of writable buffers anywhere in the code, and this helps us make sure we don't get into unsound territory when sharing memory with Rust. This `toreadonly` method was not available in Python 3.6, but we dropped the support for it earlier that week, so no need for any compatibility code.

setup: avoid the deprecated `distutils.spawn.find_executable` I noticed this was flagged with `DeprecationWarning` in py3.12 with `setuptools` 74.1.2, and it suggested `shutil.which()` instead. The signatures aren't the same, but the additional `mode` argument in the middle of the latter defaults to `os.F_OK | os.X_OK`, which maintains the same semantics.

setup: drop the hack to disable linker warning 4197 on Windows I don't see this when building on Windows with py3.8 or py3.12, so either the code was fixed, or (more likely) the compiler stopped warning about it some time after VS 2008. If we do have to put this back, it would probably be better to put a `#pragma` in a header file somewhere, and avoid `setuptools` technical debt.

ci: also offer to test 3.12 with rust The rust-cpython binding got 3.12 support very recently, it is worse keeping on a tighter watch.