2  

     3  * `hg purge` is now a core command using `--confirm` by default.

     4  

     5  * The `rev-branch-cache` is now updated incrementally whenever changesets

     6    are added.

     8  * The new options `experimental.bundlecompthreads` and

     9    `experimental.bundlecompthreads.<engine>` can be used to instruct

    10    the compression engines for bundle operations to use multiple threads

    11    for compression. The default is single threaded operation. Currently

    12    only supported for zstd.

    15 

    16  * There's a new `diff.merge` config option to show the changes

    17     relative to an automerge for merge changesets. This makes it

    18     easier to detect and review manual changes performed in merge

    19     changesets. It is supported by `hg diff --change`, `hg log -p`

    20     `hg incoming -p`, and `hg outgoing -p` so far.

    29  * In normal repositories, the first parent of a changeset is not null,

    30    unless both parents are null (like the first changeset). Some legacy

    31    repositories violate this condition. The revlog code will now

    32    silentely swap the parents if this condition is tested. This can

    33    change the output of `hg log` when explicitly asking for first or

    34    second parent.

    35 

    39  * `changelog.branchinfo` is deprecated and will be removed after 5.8.

    40    It is superseded by `changelogrevision.branchinfo`.

    42  * Callbacks for revlog.addgroup and the changelog._nodeduplicatecallback hook

    43    now get a revision number as argument instead of a node.

    44 

    45  * revlog.addrevision returns the revision number instead of the node.

    46 

    47  * `nodes.nullid` and related constants are being phased out as part of

    48    the deprecation of SHA1. Repository instances and related classes

    49    provide access via `nodeconstants` and in some cases `nullid` attributes.