formatting: drop a few extra double quotes in docstrings These were made obvious by the reformatting in D9430. Differential Revision: https://phab.mercurial-scm.org/D9432

copies: introduce the hg-cpython wrapper for `combine_changeset_copies` This patch focus on the `hg-cpython` part of this work. Bridging the python code with the new rust code in `hg-core`. The next patch will actually plug this in the python code. The rust code use multiple Python callback, python related error within this callback are not expected unless they are a programming error or a data corruption. In addition, these callback will slowly be replaced by native Rust code. For these reasons, we use will deal with unexpected error within this callback using rust Panic and let the `rust-cpython` layer deal with raising a Python exception. The code dealing with the ChangedFile instance is repeating itself a lot. I did not factor these duplication out because that whole code will get replaced by entirely different one in a handful of changesets. Differential Revision: https://phab.mercurial-scm.org/D9298

copies: introduce a basic Rust function for `combine_changeset_copies` This new function mirror the python code. This first implementation does a lot of data copies and is therefore quite slow. However my goal here is to create a simple "frame" from where to start adding optimization. This patch focus on the `hg-core` part of this work. Coming patches will do the necessary `hg-cpython` work to be able to use this from Python. Differential Revision: https://phab.mercurial-scm.org/D9297

hghave: adjust the detection of `pylint` for modern versions I have pylint 2.6.0 installed locally, and it only has a single space. I have no idea when this changed. Differential Revision: https://phab.mercurial-scm.org/D9431

formating: upgrade to black 20.8b1 This required a couple of small tweaks to un-confuse black, but now it works. Big formatting changes come from: * Dramatically improved collection-splitting logic upstream * Black having a strong (correct IMO) opinion that """ is better than ''' Differential Revision: https://phab.mercurial-scm.org/D9430

osutil: reformat triple-quoted string so black doesn't confuse itself Differential Revision: https://phab.mercurial-scm.org/D9429

merge: remove spurious ' and trailing whitespace from triple-quoted string Differential Revision: https://phab.mercurial-scm.org/D9428

cleanup: fix a few recent black formatting violations Differential Revision: https://phab.mercurial-scm.org/D9427

rhg: check that .hg/requires is ASCII Differential Revision: https://phab.mercurial-scm.org/D9400

rhg: exit with relevant code for unsupported requirements Differential Revision: https://phab.mercurial-scm.org/D9399

revlog: store new index entries as binary For a pure-Python unbundle of the current NetBSD test repository, this results in a 10% peak RSS reduction. Using the C revlog index, it shows 25% peak RSS reduction. This is a direct result of avoiding at least 8 objects per new changeset or 200 Bytes+ on AMD64. Differential Revision: https://phab.mercurial-scm.org/D9162

packaging: enable rust extensions on centos Test on CentOS 7, repository with ~170000 tracked files, no untracked files: 10 runs with this enabled: -- Run #0 time: 0.6519973278045654 -- Run #1 time: 0.6933724880218506 -- Run #2 time: 0.7512078285217285 -- Run #3 time: 0.7517638206481934 -- Run #4 time: 0.5966529846191406 -- Run #5 time: 0.5960886478424072 -- Run #6 time: 0.5940573215484619 -- Run #7 time: 0.5963726043701172 -- Run #8 time: 0.6048009395599365 -- Run #9 time: 0.603604793548584 10 runs without this enabled: -- Run #0 time: 2.127584457397461 -- Run #1 time: 2.066192865371704 -- Run #2 time: 2.0831892490386963 -- Run #3 time: 2.077716588973999 -- Run #4 time: 2.07608962059021 -- Run #5 time: 2.072899341583252 -- Run #6 time: 2.094369888305664 -- Run #7 time: 2.067504644393921 -- Run #8 time: 2.069610834121704 -- Run #9 time: 2.0567898750305176 Differential Revision: https://phab.mercurial-scm.org/D9294

tests: use `testrepohg` in one more place in test-check-code.t This is already used elsewhere in the test to access the current hg repo, and avoids an error about the unknown `revlog-compression-zstd` when C extensions aren't built. The only other such error is in test-check-interfaces.py, but I don't see a way to avoid it other than to create an empty scratch repo. Differential Revision: https://phab.mercurial-scm.org/D9364

setup: copy pythonXY.dll next to the hg.exe wrapper when building This avoids the problem of having the newly built binary complaining that it can't find the DLL. There is an option in the python.org installer to add the python install to PATH (which defaulted to "on" with py2, and therefore was not an issue up to this point), but that makes switching between python versions harder. This shouldn't be an issue with the PyOxidizer binary, but that current has issues running some of the tests, and took noticeably longer to build last time I tried it. Differential Revision: https://phab.mercurial-scm.org/D9362

exthelper: update the examples to be python3 complaint Differential Revision: https://phab.mercurial-scm.org/D9368