dirstate: invalidate changes when parent-change fails When an error occurs during changing parents, we should invalidate all dirstate modifications and reload the dirstate. This is currently done by a `unlock` callback on the `wlock`. To fix this anomaly, we start dealing with the error directly in the context manager and its potential nesting. The "hard" part is to make sure that, when the parent-change context are nested, we and higher level nesting do not continue to use the invalidated dirstate. We introduce dedicated code to enforce that.

setup: Ensure target directory exists with building rust extension When the rust extension is the first to be build, the target directory may not exist so the copy fails.

filemerge: add union-other-first as internal merge tool See inline documentation for details.

rust: use `peek_mut` from the standard lib now that it's stable Just a little cleanup of a TODO found along the way.

clippy: actually fail if there are any warnings So far, only errors would trip the CI, this makes it so all warnings are elevated to errors, making it a CI fail if any warnings are present. This was the intended behavior, I just missed this when adding clippy.

rust-clippy: fix warning about nested ifs

debugshell: allow commands to be specified as a CLI argument Add a `--command` option to `hg debugshell` that allows the user to pass in Python code to evaluate directly from the command line. This was inspired by the `--command` option present in Facebook's Sapling fork of Mercurial, which in turn was inspired by the `-c` option of the Python interpreter itself. It is particularly useful for writing tests, especially for getting visibility into things that otherwise aren't exposed via debug commands.

heptapod-ci: add `clippy` to the CI This linter mostly makes our code more idiomatic, less surprising, has good suggestions and catches bugs. It's widely used in the Rust community and now part of the default toolchain when using `rustup`.

makefile: add `cargo clippy` to tests if cargo is available This linter mostly makes our code more idiomatic, less surprising, has good suggestions and catches bugs. It's widely used in the Rust community and now part of the default toolchain when using `rustup`.

rust-tests: run `cargo` tests inside the `rust` folder There is no reason to only run inside the `rust/hg-cpython` folder, even if the `cargo test --all` behavior ends up being the same.

rust-clippy: merge "revlog" module definition and struct implementation Module inception is confusing when looking for code and almost never the right choice.

rust-clippy: merge "config" module definition and struct implementation Module inception is confusing when looking for code and almost never the right choice.

rust-clippy: upgrade `bytes-cast` dependency I released a new version of `bytes-cast` to get rid of the clippy warning, and bump to edition 2021, so let's use it.

rust-clippy: remove redundant suffix from enum Same as last time, this makes the code clearer in this instance.

rust-clippy: fix remaining warnings in `hg-cpython`

rust-clippy: disable some lints crate-wide for `hg-cpython` `rust-cpython` creates some pretty funky code that also needs to be compatible with pretty old Rust. This makes clippy quite useless in `hg-cpython` unless you disable the lints that are always triggered by `py_class!` and related. Maybe `clippy` will allow one day to exclude a dependency from its linting, but this seems quite unlikely, so this is the best we've got at the moment.

rust-clippy: fix remaining warnings in `rhg` All of these are simple changes that for the most part are clear improvements and the rest are at most equivalent.

rust-clippy: fix most warnings in `hg-core` All of these are simple changes that for the most part are clear improvements and the rest are at most equivalent. The remaining warnings have to be fixed either with a bigger refactor like for the nested "revlog" module, or in the dependency `bytes-cast`, which we own. This will be done sometime in the future.

rust-utils: strip redundant prefix from enum This was highlighted by `clippy`, I think this makes the code cleaner.

rust-filepatterns: don't `Box` subincludes unnecessarily This was caught by `clippy`.

rust-nodemap: implement `PartialEq` without allocation This was caught by `clippy`. It's probable that this ends up optimized out by the compiler, but let's not rely on that.

rust-clippy: tell `clippy` we don't need to declare a default here This is a struct only useful for tests.

rust-clippy: refactor complex type This makes reading the signature a bit less tiring.

rust-clippy: simplify return type of debug function This makes the type a little bit more readable.

rust-clippy: add `is_empty` method to please the `clippy` gods I can see it being useful anyway.

rust: don't use a reference to a `Cow` This was caught by `clippy`.

rust-clippy: reassure `clippy` that 8 arguments is expected This API is a bit verbose, but refactoring it into a struct isn't better in this particular case IMO, and there is a lot of info to pass.

rust-clippy: use `write_all` since we're not expecting a partial write Clippy caught this. This is a good lint in general, but here this was not really a bug in this example code.

rust-clippy: tell clippy we want to keep those clauses separate This makes the cases more explicit, which is wanted in this specific instance.

rust-clippy: tell clippy we care about keeping those `if` clauses separate Thses were written this way because it spells out the logic in a more explicit manner.

rust-clippy: factor an `if` with the same duplicated clause Unlike the next changeset, this if is not really made clearer by keeping the cases separate.

rust: fix broken debug assertions These were caught by `clippy`. It appears no one uses the debug builds, which is how this wasn't caught before.

rust-narrow: fix loop that never loops This was caught by `clippy`. I guess the narrow tests leave something to be desired, since this previously only checked the first valid pattern.

rust: run `cargo clippy` These automatic fixes are good to have because they make the code more idiomatic and less surprising. The transform from `sort` -> `sort_unstable` is questionable, but this is only in a test, so it doesn't matter in our case.

rust: use `logging_timer` instead of `micro_timer` I am the author of `micro_timer`. I built it at the time because I couldn't find a crate that was simple to use and flexible to do function timing with. Turns out I just couldn't find it because crates.io's search isn't all that great, or maybe I didn't look hard enough. `logging_timer` is better in every way: - supports changing the logging level - supports start and end logging - supports intermediary messages - supports inline macros - supports formatting the output - better IDE/tree-sitter integration thanks to a more robust proc macro I also changed all uses to one-liners, so it's easier to copy-paste.

pathauditor: make _checkfs_exists a static method This fixes the bug detected by pytype where the auditor used in vfs.py may be a no-op auditor (vfs.py, line 398), which doesn't have the _checkfs_exists method.

merge: add mergeresult.mapaction to improve speed As a part of [hg update] we convert all [ACTION_CREATED] merge results into [ACTION_GET] actions, and that's slightly inefficient because every insertion pays the full cost of maintaining the [mergeresult] data structure up to date. This commit adds a function [mapaction], which is faster. (saves around 0.3s on a large update involving ~400k files)

merge: avoid dereferencing repo fields repeatedly

merge: skip syntactic path checks in [_checkunknownfile] We don't need to check the paths syntactically, since they are coming from diffing the revisions, so hopefully already checked on the way in. We still need to check what's on the filesystem, to avoid traversing the symlinks or subdirs, which we can't know about statically. Also, we use the directory audit to elide [isfileorlink], this removing ~all lstat calls from hg updates from-empty.

pathutil: use `finddirs_rev_noroot` instead of `parts` The benefit this brings is very tiny, if it's even there, since we still didn't get rid of the [parts] computation. It probably won't be worth it without the subsequent patch that adds one more use of [finddirs_rev_noroot]

pathutil: add the more efficient finddir iterator (to be used in subsequent commits)

typing: import unconditionally This is needed if we're writing python3 signatures.

tests: check how hgweb handles HEAD requests This test file is loosely based on test-hgweb.t. HEAD support originally implemented in fda5a4b853ab.

tests: test hg status --all with hgext/git There's a TODO item in git/dirstate.py about obtaining clean files in a more straightforward way, let's first test that status can and does show clean files at all.

tests: aborting on unknown revision emits exit code 10 even with hgext/git

worker: avoid reading 1 byte at a time from the OS pipe Apparently `pickle.load` does a lot of small reads, many of them literally 1-byte, so it benefits greatly from buffering. This change enables the buffering, at the cost of more complicated interaction with the `selector` API. On one repository with ~400k files this reduces the time by about ~30s, from ~60 to ~30s. The difference is so large because the actual updating work is parallellized, while these small reads are bottlenecking the central hg process.

diffutil: rewrite an ersatz ternary operator for building diffopts.text Pytype tends to get confused by these, but the real problem here is that if the caller passes `opts={}` as TortoiseHg has been doing, that is set as the value for `diffopts.text` when in reality it expects a boolean. When `None` is passed explicitly, the default value in `mdiff.defaultopts` is assigned.

mdiff: add a __str__ method to diffopts This makes it easier to debug by just formatting the object into `%s` to see the members and state, instead of the class and memory address.

debugshell: allow TortoiseHg builds to exit with the usual `quit()` command I've long been annoyed that `quit()` only randomly worked to exit the interpreter. When that happens, Ctrl+C doesn't work either (it simply prints "KeyboardInterrupt"), so then you have to `import sys` and `sys.exit()`. But it turns out that the behavior isn't random and it depended on which `hg.exe` was picked up on PATH first, because py2exe disables site initialization. I wasn't able to persuade the maintainer to allow an opt-in to initialization[1], but this works around it so that the behavior is now consistent however `hg.exe` is built. TortoiseHg 6.3.3 will be the first build that includes the site package, so handle the ImportError. [1] https://github.com/py2exe/py2exe/issues/154

doc: add a few comments

rhg: implement checkexec to support weird filesystems In particular, some of our repos are stored on a fileserver that simulates POSIX permissions poorly, in such a way that prevents the removal of execute permission. This causes rhg show a spurious unclean status, even though python hg reports the repo as clean. We fix this by making rhg implement the ~same checkexec logic that python hg does.

typing: use python3-style type annotation

merge: cache the fs checks made during [_checkunknownfiles] this ~halves the number of lstat calls made when updating from rev(-1) to a revision with lots of files

merge: disable the whole filesystem access loop if [_realfs] is false This makes it clearer that [auditeddir] is only relevant for [_realfs] checkers, and makes the non-realfs checkers more performant.

merge: short-circuit the _checkfs loop upon getting ENOENT This reduces the number of [lstat] calls when updating from rev(-1) to a rev with lots of files by a factor of several: for path foo/bar/baz/quux.txt without this patch we're lstatting: foo foo/bar foo/bar/baz foo/bar/baz/quux.txt and with this patch: foo foo/bar/baz/quux.txt

merge: don't pay for pathconflicts if there are none