view relnotes/next @ 46472:98e39f04d60e

upgrade: implement partial upgrade for upgrading persistent-nodemap

Upgrading repositories to use persistent nodemap should be fast and easy as it
requires only two things:

1) Updating the requirements
2) Writing a persistent-nodemap on disk

For both of the steps above, we don't need to edit existing revlogs.

This patch makes upgrade only do the above mentioned two steps if we are
only upgarding to use persistent-nodemap feature.

Since `nodemap.persist_nodemap()` assumes that there exists a nodemap file for
the given revlog if we are trying to call it, this patch adds `force` argument
to create a file if does not exist which is true in our upgrade case.

The test changes demonstrate that we no longer write nodemap files for manifest
after upgrade which I think is desirable.

Differential Revision: https://phab.mercurial-scm.org/D9936

== New Features ==
 
 * `hg purge` is now a core command using `--confirm` by default.
 
 * The `rev-branch-cache` is now updated incrementally whenever changesets
   are added.


== New Experimental Features ==

 * `hg diff` now takes an experimental `--merge` flag which causes `hg
    diff --change` to show the changes relative to an automerge for
    merge changesets. This makes it easier to detect and review manual
    changes performed in merge changesets.


== Bug Fixes ==



== Backwards Compatibility Changes ==


== Internal API Changes ==

 * `changelog.branchinfo` is deprecated and will be removed after 5.8.
   It is superseded by `changelogrevision.branchinfo`.