Mercurial 6.9rc0

These are release notes for a release candidate version. Any and all points can be reverted before the final release.

New Features

• exchange: improve computation of relevant markers for large repos

• Add a Rust fast-path to speed up update (also for clone) from null (up to 4x faster)

• Introduced a new rev-branch-cache version (v2) that is mmap-resistant
• The branchmap's performance was improved
• Improved the performance of the fix for issue6528
• clonebundles: allow manifest to specify sha256 digest of bundles
• merge: improve working-copy mtime race handling
• profiling: add a py-spy profiling backend
• revlog: use an explicit config option to enable mmap usage for index
• revlog: use mmap by default is pre-population is available
• mmap: populate the mapping by default
• mmap: populate mapping in a background thread

Experimental features

• merge: add a config to allow conflict-free merge of changes on adjacent lines

Bug Fixes

• config.server.validate now also works on narrowed repositories

• convert: fix various leaked file descriptors
• stream: prefer keeping an open file handle to volatile file instead of copy
• dummysmtpd: fix EOF handling on newer versions of OpenSSL

• cext: correct the argument handling of b85encode()

• branchmap-v3: make sure we write the cache after detecting pure-topo mode
• rust: apply clippy lints
• copies: make sure deleted copy info do not overwriting unrelated ones
• rebase: don't call rewriteutil.precheck() with to-be-skipped commits

• phabricator: correct the default value of phabhunk.corpus

• linelog: correct the default value of annotateresult.lines

• largefiles: avoid a potentially undefined variable in exception case
• httppeer: move a variable to avoid a bad reference before assignment warning
• httppeer: avoid another bad reference before assignment warning
• tests: use packaging from setuptools instead of deprecated distutils
• manifest: type and fix unhexlify
• manifest: align some vfs option access on the fact we might not have options
• scmutils: read the requires file before writing to avoid unnecessary rewrite
• debugsparse: stop taking the store lock
• sparse: reliably avoid writing to store without a lock

• largefiles: sync up largefilesdirstate methods with dirstate base class

• shelve: raise an error when loading a corrupt state file in an impossible case
• monotone: replace %s interpolation with appropriate numeric specifiers

• shelve: consistently convert exception to bytes via stringutil.forcebytestr

• remotefilelog: honor the --format arg of the debugindex command

• remotefilelog: adapt the debugindex command to past API changes

• run-tests: add color to the progress output
• archive: defer opening the output until a file is matched

• help: add :config-doc:section.key shorthand to insert documentation

• censor: document the censor.policy option (issue6909)
• rust-revlog: don't try to open the data file if the index is empty
• bundlerepo: fix mismatches with repository and revlog classes

• revlog: make clearcaches() signature consistent with ManifestRevlog

• unionrepo: fix mismatches with revlog classes
• keepalive: fix a signature mismatch for a http.client.HTTPResponse subclass
• lfs: fix various signature mismatches for vfs subclasses
• store: fix a signature mismatch for a vfs subclass

• util: avoid a leaked file descriptor in util.makelock() exceptional case

• statichttprepo: fix httprangereader.read() for py3

• util: make mmapread() work on Windows again

• mdiff: tweak calls into bdiff.fixws to match its type hints

• base85: avoid a spurious use-before-initialized warning in pure module

• install: static data moved from setup.py to pyproject.toml
• upgrade: disable using the parallel workers optimization on macOS
• doc: generate separate commands/topics/extension pages
• extdiff: don't run gui programs when in a cli-only environment

• clonebundles: stop shell quoting HGCB_BUNDLE_BASENAME environment variable

• rev-branch-cache: disable mmapping by default on Windows

Backwards Compatibility Changes

• This release drops support for Python 3.6 and 3.7.

Internal API Changes

• manifest: deprecated readdelta and readfast

Miscellaneous

• http: reuse Python's implementation of read/readline/readinto
• http: use urllib's cookie handler
• rev-branch-cache: schedule a write of the "v2" format if we read from "v1"
• rev-branch-cache: have debugupdatecache warm rbc too
• rev-branch-cache: reenable memory mapping of the revision data
• debugwireproto: redo logging to also work for https

• rust: use .cargo/config.toml instead of .cargo/config

• A whole bunch of typing improvements, which in turn found many bugs
• Test suite improvements
• Various packaging improvements