setup: relax -Werror for declaration-after-statement on Python 3.9 It turns out Python 3.9 introduces such declarations in the headers, eg cpython/abstract.h:189:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement] so we have to be more relaxed when compiling for 3.9. Differential Revision: https://phab.mercurial-scm.org/D8327

pvec: drop an unused `from __future__ import division` This module only uses the `//` operator (for integer division). Differential Revision: https://phab.mercurial-scm.org/D8326

py3: use integer division in histedit Histedit uses the `/` operator, which does type conversion to float in Python 3 instead of integer division likeon Python 2. Let's preserve the Python 2 behavior by importing and using the `//` operator. Differential Revision: https://phab.mercurial-scm.org/D8324

rust: update README to reflect use of `regex` crate Differential Revision: https://phab.mercurial-scm.org/D8325

rust: update all dependencies We do this periodically to say up to date. No major versions were crossed this time per se, but the `rand` is still in v0, and their 0.7x series broke three things: - Some distribution-related elements were moved to a separate crate, flashing a deprecation warning - The `LogNormal::new` associated function now returns a `Result` - Certain RNGs were updated to sample a `u32` instead of `usize` when their upper-bound is less than `u32::MAX` for better portability, which changed the output for 2 tests. Moreover, the recent use of the `regex` crate for ignore mechanisms prompted some benchmarking that revealed that `regex` was slower at compiling big regex than `Re2`. The author of `regex` was very quick to discover an optimization that yielded a 30% improvement. It's still slower than `Re2` in that regard, but less so in the 1.3.6 release. Differential Revision: https://phab.mercurial-scm.org/D8320

rust: update micro-timer dependency The new version uses a much more robust technique and should remove any existing risk of bad compiler error or performance hit. Differential Revision: https://phab.mercurial-scm.org/D8319

rust-status: only involve ignore mechanism when needed This prevents unnecessary fallbacks to Python, improving performance for `hg update` for instance. On Mozilla-Central a noop update goes from 1.6s down to 700ms. Differential Revision: https://phab.mercurial-scm.org/D8315

templater: fix cbor() filter to recursively convert smartset to list The previous attempt, e3e44e6e7245 "templater: fix cbor() filter to accept smartset", was incomplete since obj may be a collection containing a smartset. This works around the problem by converting smartsets recursively. Another option is to teach cborutil how to encode a smartset. That should be okay, but I hesitated to add "import smartset" to cborutil.py as the cborutil is pretty generic.

shelve: split up dounshelve() in unshelvecmd() and _dounshelve() I'd like to be able to override the new `_dounshelve()`, getting access to the name of the shelve to unshelve. `unshelvecmd()` seems to better match the existing `createcmd()`, `listcmd()` etc. Differential Revision: https://phab.mercurial-scm.org/D8322

rust-matchers: use the `regex` crate Instead of falling back to Python when a code path with "ignore" functionality is reached and `Re2` is not installed, the default compilation (i.e. without the `with-re2` feature) will use the `regex` crate for all regular expressions business. As with the introduction of `Re2` in a previous series, this yields a big performance boost compared to the Python + C code in `status`, `diff`, `commit`, `update`, and maybe others. For now `Re2` looks to be faster at compiling the DFA (1.5ms vs 5ms for Netbeans' `.hgignore`) and a bit faster in actual use: (123ms vs 137ms for the parallel traversal of Netbeans' clean repo). I am in talks with the author of `regex` to see whether that performance difference is a bug, a "won't fix", or a tuning issue. The `regex` crate is already one of our dependencies and using this code does not require any additional work from the end-user than to use the Rust extensions. Differential Revision: https://phab.mercurial-scm.org/D8323