Mercurial 3.9 release

Features

• ui.textwidth can now be set to define width of help text
• separate() template function added

• ui.rollback can be set to false to disable the hg rollback command

• fail-<command> hooks now run when a command fails

• experimental.graphstyle.* config options to control styling of graphs in console
• experimental.histedit.autoverb allows histedit lines beginning with "verb!" to be interpreted as histedit actions
• [hostsecurity] config section for defining advanced per-host security settings
• ability to define the SHA-256 and SHA-512 hashes of pinned server certificates
• ability to define CA certificates on a per-host basis

• sort() revset can now perform topological sorts using the topo option

• hgweb can now render JSON for filelog, filerevision, summary, and search web commands

• [paths] entries can now define a pushrev sub-option to control which revisions to push by default

Improvements

This release includes many improvements, including (but not limited to):

• performance of hg diff has been improved

• chg now detects more changes to the configuration and execution environment
• SSL/TLS code has been significantly refactored and now is consistent across all consumers (HTTPS, SMTPS)
• performance improvements to server communication (particularly for the largefiles and remotefilelog extensions)
• connections to servers whose certificate authority (CA) is unknown are now refused
• fingerprints of server certificates are now printed using SHA-256 instead of SHA-1

• reads and writes to certain files is now robust and avoids more race conditions and edge cases (see ExactCacheValidationPlan)

• performance improvements to certain revsets
• cloning will no longer prompt for a password multiple times when cloning from a server that requires a password
• hgweb now highlights data for the current revision in annotate view
• hgweb now displays blame info once per block instead of every file in that block

A full overview is available on WhatsNew.