relnotes: add 6.4.1

sslutil: set context security level for legacy tls testing (issue6760) Current versions of OpenSSL do not allow the use of TLS <1.2 when the library's security level is >=1 (1 being the default on most distributions). Setting the security level in addition to the minimum protocol is therefore necessary for the legacy protocol tests. This is done here ONLY when testing, when: - explicitly setting the cipher string, or - using the "--insecure" flag, or - using the "devel.serverexactprotocol" testing option. See: https://github.com/openssl/openssl/blob/master/NEWS.md#major-changes-between-openssl-30-and-openssl-310-14-mar-2023

configitems: make devel.serverexactprotocol look dangerous Because it is.

rebase: do not cleanup the working copy when --dry-run is used (issue6802) Since we did not touch the working copy, we don't need to clean it up. This will avoid wiping exiting changes out.

rebase: add a test showing that --dry-run wipes working copy changes Eating people's data on --dry-run seems like a bad idea.

tests: automatically glob the discovery timing information Time is not stable in tests.

rhg: support `status --print0` This seems very easy to support, and useful because it makes it possible to parse the [hg status] output even if the user creates files with '\n' characters by accident.

stabletailgraph: implement stable-tail sort This adds the computation of the "stable-tail sort", an incremental node sorting method. It is a stepping stone for the implementation of faster label discovery (for example for obs markers) and more caching.

heptapod: add `.gitattributes` file to improve language detection I am fully aware of the irony.

match: match explicit file using a set The matcher as all the logic to do quick comparison against explicit patterns, however the pattern matcher was shadowing the code using that set and used the compiled regex pattern in all cases, which is quite slow. We restore the usage of the set based matching to boost performance. Building the regexp is still consuming a large amount of time (actually, the majority of the time), which is still silly. Maybe using re2 would help that, but this is a quest for another adventure. Another path to improve this is to have a pattern type dedicated to match the exact path to a file only (not a directory). This pattern could use the set matching only and be skipped in the regex all together. Benchmarks ========== In the following benchmark we are comparing the `hg cat` and `hg files` run time when matching against all files in the repository. They are run: - without the rust extensions - with the standard python engine (so without re2) Performance improvement in this series -------------------------------------- ###### hg files ############################################################### ### mercurial-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 0.230092 seconds prev-changeset: 0.230069 seconds this-changeset: 0.211425 seconds (-8.36%) ### mercurial-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 0.234235 seconds prev-changeset: 0.231165 seconds (-1.38%) this-changeset: 0.212300 seconds (-9.43%) ### pypy-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 0.613567 seconds prev-changeset: 0.616799 seconds this-changeset: 0.510852 seconds (-16.82%) ### pypy-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 0.801880 seconds prev-changeset: 0.616393 seconds (-23.22%) this-changeset: 0.511903 seconds (-36.23%) ### netbeans-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 21.541828 seconds prev-changeset: 21.586773 seconds this-changeset: 13.648347 seconds (-36.76%) ### netbeans-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 172.759857 seconds prev-changeset: 21.908197 seconds (-87.32%) this-changeset: 13.945110 seconds (-91.93%) ### mozilla-central-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 62.474221 seconds prev-changeset: 61.279490 seconds (-1.22%) this-changeset: 29.529469 seconds (-52.40%) ### mozilla-central-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 1364.180218 seconds prev-changeset: 62.473549 seconds (-95.40%) this-changeset: 30.625249 seconds (-97.75%) ###### hg cat ################################################################# ### mercurial-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 0.764407 seconds prev-changeset: 0.763883 seconds this-changeset: 0.737326 seconds (-3.68%) ### mercurial-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 0.768924 seconds prev-changeset: 0.765848 seconds this-changeset: 0.174d0b seconds (-4.44%) ### pypy-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 2.065220 seconds prev-changeset: 2.070498 seconds this-changeset: 1.939482 seconds (-6.08%) ### pypy-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 2.276388 seconds prev-changeset: 2.069197 seconds (-9.15%) this-changeset: 1.931746 seconds (-15.19%) ### netbeans-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 40.967983 seconds prev-changeset: 41.392423 seconds this-changeset: 32.181681 seconds (-22.20%) ### netbeans-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 216.388709 seconds prev-changeset: 41.648689 seconds (-80.88%) this-changeset: 32.580817 seconds (-85.04%) ### mozilla-central-2018-08-01-zstd-sparse-revlog ### sorted base-changeset: 105.228510 seconds prev-changeset: 103.315670 seconds (-1.23%) this-changeset: 69.416118 seconds (-33.64%) ### mozilla-central-2018-08-01-zstd-sparse-revlog ### shuffled base-changeset: 1448.722784 seconds prev-changeset: 104.369358 seconds (-92.80%) this-changeset: 70.554789 seconds (-95.13%) Different way to list the same data with this revision ------------------------------------------------------ ###### hg files ############################################################### ### mercurial-2018-08-01-zstd-sparse-revlog root: 0.119182 seconds glob: 0.120697 seconds (+1.27%) sorted: 0.211425 seconds (+77.40%) shuffled: 0.212300 seconds (+78.13%) ### pypy-2018-08-01-zstd-sparse-revlog root: 0.121986 seconds glob: 0.124822 seconds (+2.32%) sorted: 0.510852 seconds (+318.78%) shuffled: 0.511903 seconds (+319.64%) ### netbeans-2018-08-01-zstd-sparse-revlog root: 0.173984 seconds glob: 0.227203 seconds (+30.59%) sorted: 13.648347 seconds (+7744.59%) shuffled: 13.945110 seconds (+7915.16%) ### mozilla-central-2018-08-01-zstd-sparse-revlog root: 0.366463 seconds glob: 0.491030 seconds (+33.99%) sorted: 29.529469 seconds (+7957.96%) shuffled: 30.625249 seconds (+8256.97%) ###### hg cat ################################################################# ### mercurial-2018-08-01-zstd-sparse-revlog glob: 0.647471 seconds root: 0.643120 seconds shuffled: 0.174d0b seconds (+13.92%) sorted: 0.737326 seconds (+13.88%) ### mozilla-central-2018-08-01-zstd-sparse-revlog glob: 40.596983 seconds root: 40.129136 seconds shuffled: 70.554789 seconds (+73.79%) sorted: 69.416118 seconds (+70.99%) ### netbeans-2018-08-01-zstd-sparse-revlog glob: 18.777924 seconds root: 18.613905 seconds shuffled: 32.580817 seconds (+73.51%) sorted: 32.181681 seconds (+71.38%) ### pypy-2018-08-01-zstd-sparse-revlog glob: 1.555319 seconds root: 1.536534 seconds shuffled: 1.931746 seconds (+24.20%) sorted: 1.939482 seconds (+24.70%)

match: sort patterns before compiling them into a regex While investigating cripping performance for `hg cat` in some context, I discovered that, for large inputs, building a regex from out of order patterns result may result in a *much* slower regex and a much slower associated matcher's performance. So we are now sorting the patterns to help the regex engine. There is more to the story as we rely on regexp more than we should. See the next changeset for details. Benchmarks ========== In the following benchmark we are comparing the `hg cat` and `hg files` run time when matching against the full list of files in the repository. They are run: - without the rust extensions - with the standard python enfine (so without re2) sort vs non-sorted - Before this changeset (3f5137543773) --------------------------------------------------------- ###### hg files ############################################################### ### mercurial-2018-08-01-zstd-sparse-revlog sorted: 0.230092 seconds shuffled: 0.234235 seconds (+1.80%) ### pypy-2018-08-01-zstd-sparse-revlog sorted: 0.613567 seconds shuffled: 0.801880 seconds (+30.69%) ### mozilla-central-2018-08-01-zstd-sparse-revlog sorted: 62.474221 seconds shuffled: 1364.180218 seconds (+2083.59%) ### netbeans-2018-08-01-zstd-sparse-revlog sorted: 21.541828 seconds shuffled: 172.759857 seconds (+701.97%) ###### hg cat ################################################################# ### mercurial-2018-08-01-zstd-sparse-revlog sorted: 0.764407 seconds shuffled: 0.768924 seconds ### pypy-2018-08-01-zstd-sparse-revlog sorted: 2.065220 seconds shuffled: 2.276388 seconds (+10.22%) ### netbeans-2018-08-01-zstd-sparse-revlog sorted: 40.967983 seconds shuffled: 216.388709 seconds (+428.19%) ### mozilla-central-2018-08-01-zstd-sparse-revlog sorted: 105.228510 seconds shuffled: 1448.722784 seconds (+1276.74%) sort vs non-sorted - With this changeset ---------------------------------------- ###### hg files ############################################################### ### mercurial-2018-08-01-zstd-sparse-revlog all-list-pattern-sorted: 0.230069 all-list-pattern-shuffled: 0.231165 ### pypy-2018-08-01-zstd-sparse-revlog all-list-pattern-sorted: 0.616799 all-list-pattern-shuffled: 0.616393 ### netbeans-2018-08-01-zstd-sparse-revlog all-list-pattern-sorted: 21.586773 all-list-pattern-shuffled: 21.908197 ### mozilla-central-2018-08-01-zstd-sparse-revlog all-list-pattern-sorted: 61.279490 all-list-pattern-shuffled: 62.473549 ###### hg cat ################################################################# ### mercurial-2018-08-01-zstd-sparse-revlog sorted: 0.763883 seconds shuffled: 0.765848 seconds ### pypy-2018-08-01-zstd-sparse-revlog sorted: 2.070498 seconds shuffled: 2.069197 seconds ### netbeans-2018-08-01-zstd-sparse-revlog sorted: 41.392423 seconds shuffled: 41.648689 seconds ### mozilla-central-2018-08-01-zstd-sparse-revlog sorted: 103.315670 seconds shuffled: 104.369358 seconds

peer: rename makepeer() → _make_peer() In httppeer and sshpeer, there previously were makepeer() and make_peer(), which was confusing. Therefore, this changeset renames one of the functions. makepeer() was the internal function called by make_peer() and some debug command. This function is renamed to _make_peer().

rust: configure MSRV in Clippy This setting makes Clippy never apply lints that are meant for later versions. In case the target precise toolchain is the one running, it does not make a difference, but this gives us a machine-parseable specification that is pretty standard. The README and `hg help rust` are updated to state that `clippy.toml` is the single source of truth about that, also lifting a minor ambiguity: it is fine if the MSRV is lagging behind the version in Debian testing.

rust-readme: mentioned that format check is enforced by CI

rust-readme: mentioning clippy especially since there is a CI check for it.

rust-readme: rst fixes

chg: populate CHGHG if not set Normally, chg determines which `hg` executable to use by first consulting the `$CHGHG` and `$HG` environment variables, and if neither are present defaults to the `hg` found in the user's `$PATH`. If built with the `HGPATHREL` compiler flag, chg will instead assume that there exists an `hg` executable in the same directory as the `chg` binary and attempt to use that. This can cause problems in situations where there are multiple actively-used Mercurial installations on the same system. When a `chg` client connects to a running command server, the server process performs some basic validation to determine whether a new command server needs to be spawned. These checks include things like checking certain "sensitive" environment variables and config sections, as well as checking whether the mtime of the extensions, hg's `__version__.py` module, and the Python interpreter have changed. Crucially, the command server doesn't explicitly check whether the executable it is running from matches the executable that the `chg` client would have otherwise invoked had there been no existing command server process. Without `HGPATHREL`, this still gets implicitly checked during the validation step, because the only way to specify an alternate hg executable (apart from `$PATH`) is via the `$CHGHG` and `$HG` environment variables, both of which are checked. With `HGPATHREL`, however, the command server has no way of knowing which hg executable the client would have run. This means that a client located at `/version_B/bin/chg` will happily connect to a command server running `/version_A/bin/hg` instead of `/version_B/bin/hg` as expected. A simple solution is to have the client set `$CHGHG` itself, which then allows the command server's environment validation to work as intended. I have tested this manually using two locally built hg installations and it seems to work with no ill effects. That said, I'm not sure how to write an automated test for this since the `chg` available to the tests isn't even built with the `HGPATHREL` compiler flag to begin with.

run-tests: remove obsolete coverage check and packaging import (issue6805) This removes an obsolete `coverage` version check (version from a decade ago). This also conveniently removes the dependency over `packaging.version`, which requires some additional installation since Python 3.10.

test-tx-rollback: more lenient glob for kill status (issue6807) The "killed" message may have some prefix and/or suffix which differ depending on the platform. This makes the pinned test output more lenient to accept those.

rustdoc: nodemap doc refreshing Not pretending to be comprehensive. - correcting some inconsistencies - adding a few missing doc-comments - adding more cross references (in some cases it's right beside the current documentation item, but it will nevertheless also be useful, because `rustdoc` will warn us if inconsistencies arise).

rustdoc: fixed or introduced crossrefs in nodemap.rs

rustdoc: summary line for hg_path_to_os_string The main motivation of this change is to avoid the TODO being the summary line, even though this leads to a pretty obvious summary. Then doc-comments for the other functions are introduced for consistency.

rustdoc: wording for checkexec Notably separating the summary line for correct display at module level.

rustdoc: fixed warnings about links This is the minimal fix making those that actually were supposed to be links to work (including in private items).

rust-changelog: introduce ChangelogEntry parent entries accessors Straightforwards now that lifetimes are explicit in `RevlogEntry` parent accessors.

rust-revlog: fix lifetime problem for RevlogEntry parent entries accessors Without this, the lifetime of the result is equated to the lifetime of the `self` reference, preventing callers, e.g., to take a `RevlogEntry` and return its `p1_entry()`, as it looks like returning something that does not outlive the *reference to* the `RevlogEntry`.

rust-revlog: explicit naming for `RevlogEntry` lifetime This matches what has been done in `revlog::changelog::ChangelogRevisionData`, and has the advantage of making things clearer when we introduce other, shorter lived lifetimes.

rust-changelog: introducing an intermediate `ChangelogEntry` Before this change, client code needing to extract, e.g, the Node ID and the description from a changeset had no other choice than calling both `entry_for_rev()` and `data_for_rev()`. This duplicates some (limited) computation, and more importantly imposes bad hygiene for client code: at some point of developement, the client code would have to pass over both entry and data in its internal layers, which at some point of development would raise the question whether they are consistent. We introduce the intermediate `ChangelogEntry` from which both conversion to the generic `RevlogEntry` and extraction of `ChangelogRevisionData` are possible. It might grow some convenience methods in the future. We keep the `data_for_rev()` method of `Changelog` for compatibility, pointing users at the more powerful alternative.

rust-changelog: added a test for `NULL_REVISION` special case The result is due to `Revlog.get_rev_data()` returning an empty byte string for `NULL_REVISION`, followed by special case for emtpty byte strings in `ChangelogRevisionData::new()`.

rust-changelog: made doc-comments more consistent The most important is the one about `data_for_rev`, that looked like a copy-paste leftover (got me confused first time I read this code, before I actually learned there were both `Entry` and RevisionData`. In the comment for the `struct`, "changelog" was probably more about the format in general (as documented elsewhere) than as an identifier. Some of the "Return something" had "of", half had "for".