tests: replace [[]] bashism with portable [] invocation In this case nothing fancy is required. Differential Revision: https://phab.mercurial-scm.org/D7596

rust-hg-path: implement `Display` for `HgPath` and `HgPathBuf` This is useful when debugging, to get a human readable output instead of an array of `u8`. Differential Revision: https://phab.mercurial-scm.org/D7523

rust-performance: introduce FastHashMap type alias for HashMap Rust's default hashing is slow, because it is meant for preventing collision attacks. For all of the current Rust code, we don't care about those attacks, because if an person with bad intentions has write access to your repo, you have other issues. I've chosen to use the TwoXHash crate because it was made by a reputable member of the Rust community and has very good benchmarks. For now it does not seem to improve performance by much for the current code, but it's something else to not worry about when benchmarking code: in a previous experiment with copytracing in Rust, it accounted for more than 10% of the time of the entire script. Differential Revision: https://phab.mercurial-scm.org/D7116

mail: use procutil.shellsplit instead of bytes.split to parse command Differential Revision: https://phab.mercurial-scm.org/D7541

annotate: describe --skip as taking a revset It's obvious to me, but probably wouldn't be obvious to a novice user. Differential Revision: https://phab.mercurial-scm.org/D7557

automation: use latest Windows AMI as base It looks like the previous base image no longer exists. I guess Amazon expires them or something. Let's switch to the newest version of the equivalent image. Differential Revision: https://phab.mercurial-scm.org/D7571

tests: stabilize test-extdiff.t on Windows This goes with 765a9c299c44. I'm not sure if we care about the missing file being spelled `nul`, so I removed it from the glob to be explicit about it. The line needed to be special cased anyway because of the quoting on Windows. Differential Revision: https://phab.mercurial-scm.org/D7572

exchange: fix an attempt to format a list into bytes This goes with 27c6d6f53d46. Differential Revision: https://phab.mercurial-scm.org/D7583

status: remove pointless filtering by alwaysmatcher in morestatus The code has been like this since it was imported from FB's hg-experimental repo. It has been like that even since it was added in that repo. So I don't know why it looks that way. Perhaps the idea was to one day filter the unresolved paths by any patterns provided by the user. We can add a matcher back if we ever decide to do that. Differential Revision: https://phab.mercurial-scm.org/D7591

tests: add test for Rust formatting We enforce formatting for Python and C. It makes sense to do it for Rust as well. Since our rustfmt.toml relies on unstable rustfmt features, we need to use a Nightly rustfmt with --unstable-features in order for it to work. This is a bit hacky and I would prefer we remove this requirement. But for now, this commit assumes this is the way things must be and we go out of our way to detect and use the rustfmt from the "nightly" toolchain, as installed via rustup. We had to add some environment variables to the tests to make the Rust binaries happy. Otherwise when running rustfmt we get an error about no default toolchain being installed. Differential Revision: https://phab.mercurial-scm.org/D7579