branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
== New Features ==
* `hg config` now has a `--source` option to show where each
configuration value comes from.
* Introduced a command (debug-repair-issue6528) to repair repositories affected
by issue6528 where certain files would show up as modified even if they were
clean due to an issue in the copy-tracing code.
== Default Format Change ==
These changes affect newly created repositories (or new clone) done with
Mercurial 5.9.
== New Experimental Features ==
* A `changelogv2` format has been introduced. It is not ready for use yet, but
will be used later to address some of the weaknesses of the current revlog
format.
* Initial experiment and support for `dirstatev2`, a new dirstate format that
addresses some of the weaknesses of the current dirstate format. Python + C
and Rust support are being implemented, but the Rust solution is the one
currently getting the attention for performance.
* Initial support for `rhg status`. `rhg` is the Rust wrapper executable for hg
that shortcuts some commands for faster execution speed.
== Bug Fixes ==
* Fixed committing empty files with `narrow`
* Allow overriding `pip`'s pep517 compliance to build C or Rust extensions
* Fixed regression on outgoing email when not specifying revisions
* Fixed a regression causing bookmarks to disappear when using Rust persistent nodemap
* Fixed a regression (in 5.9.1) introduced in 5.9 when cloning repos with
deep filenames
* Fixed detection of directories becoming symlinks, but only when using the
Rust extensions.
* Fixed ignore and include not composing in the Rust status
* `hg commit --interactive` now handles deselecting edits of a rename
* Fixed a case where `hg evolve` gives different results when interrupted
* Fixed a memory leak in phases computation
* `histedit` and `shelve` don't swallow errors when updating the working copy
anymore
* Improve error message when detecting content-divergence with a hidden
common predecessor
* No longer re-order parents in filelog, see issue6533
* Fix revisions affected by issue6533 on the fly during exchange
* Many Windows fixes for stability and py3 compatibility improvements
* Many other miscellaneous fixes
== Backwards Compatibility Changes ==
== Internal API Changes ==
The Dirstate API have been updated as the previous function leaked some
internal details and did not distinguish between two important cases: "We are
changing parent and need to adjust the dirstate" and "some command is changing
which file is tracked". To clarify the situation:
* the following functions have been deprecated,
- `dirstate.add`,
- `dirstate.normal`,
- `dirstate.normallookup`,
- `dirstate.merge`,
- `dirstate.otherparent`,
- `dirstate.remove`,
- `dirstate.drop`,
- `dirstateitem.__getitem__`,
* these new functions are added for the "adjusting parents" use-case:
- `dirstate.update_file`,
- `dirstate.update_file_p1`,
* these new function are added for the "adjusting wc file" use-case":
- `dirstate.set_tracked`,
- `dirstate.set_untracked`,
- `dirstate.set_clean`,
- `dirstate.set_possibly_dirty`,
See inline documentation of the new functions for details.
* Additionally, the following have been deprecated:
- `urlutil.getpath` function
- `localrepository.updatecaches`' `full` argument
* The following have been removed:
- `revlog.revlogio` has been removed