py3: stop normalizing .encode()/.decode() arguments to unicode Now that we don't byte transform string literals, we no longer need this transform. While we're here, we also drop some superfluous u'' prefix in existing callers. Differential Revision: https://phab.mercurial-scm.org/D7011

py3: manually import pycompat.delattr where it is needed And with this change, we no longer need the auto-inserted import statement in the source transformer, so it has been removed! Differential Revision: https://phab.mercurial-scm.org/D7010

py3: manually import getattr where it is needed The march continues. Differential Revision: https://phab.mercurial-scm.org/D7009

py3: stop injecting pycompat.hasattr into modules I only found a single user of this pattern, probably because we use util.hasattr everywhere. Differential Revision: https://phab.mercurial-scm.org/D7008

py3: manually import pycompat.setattr where it is needed Continuing to eliminate the implicit import of symbols in the Python 3 source transformer so we can eliminate it. Differential Revision: https://phab.mercurial-scm.org/D7007

py3: stop implicitly importing unicode We should be pycompat.unicode everywhere. It turns out we were doing this everywhere except for one place in templatefilters! Differential Revision: https://phab.mercurial-scm.org/D7006

py3: manually import pycompat.open into files that need it We want to eliminate the source transformer. Currently it inserts a `from mercurial.pycompat import ...` at the top of files to alias some builtins. This commit replaces the implicit import of `open` with an explicit import on files that need it and changes the source transformer to no longer import `open`. As part of this, we needed to store an explicit local for `open` in the Python 2 code path in `pycompat` so the import works. (Builtins that are automatically in scope cannot be imported.) Differential Revision: https://phab.mercurial-scm.org/D7005

import-checker: allow symbol imports from mercurial.pycompat Currently, the source transformer inserts `from mercurial.pycompat import delattr, getattr, hasattr, setattr, open, unicode` to the top of every file. As part of getting rid of the source transformer, we'll need to have source code call these wrappers directly. Rather than rewrite all call sites to call pycompat.*, I think it makes sense to import needed symbols via explicit imports. That requires loosening the import checker to allow this. Differential Revision: https://phab.mercurial-scm.org/D7004

contrib: add a fork of black (as "grey") that includes my changes This is black with https://github.com/psf/black/pull/826 applied as of today. The current git hash of black master is d9e71a75ccfefa3d9156a64c03313a0d4ad981e5, and the hash of my commit is dc1add6e94e212eff37bb3619e1422fb3c6d8dc8. In order to use this, you need to install `black` (from github master) and `typed-ast` using pip, preferably into python3, and then you can run `grey.py` with that Python and you'll have my patched version of black, which is how we've been formatting the codebase. Once my PR is merged, I'll follow up by removing this fork and updating instructions in the example config. # no-check-commit bad style Differential Revision: https://phab.mercurial-scm.org/D7002

rust-cpython: change license of ref_sharing.rs to MIT Since we plan to upstream this feature, it's better to continue further refactoring under the same license as rust-cpython crate. According to the file history, copyright holders are: - Raphaël Gomès <rgomes@octobus.net> - Valentin Gatien-Baron <valentin.gatienbaron@gmail.com> - Yuya Nishihara <yuya@tcha.org>