mercurial/stack.py

upgrade: allow upgrade to repository using sidedata

Repository can now be migrated to support sidedata. More requirements and
migration will be needed to actual side-data usage. This is a step in that
direction.

To test the feature, we leverage the test extension. It make sure the `update`
part of the side-data migration actually works.

Differential Revision: https://phab.mercurial-scm.org/D6942

# stack.py - Mercurial functions for stack definition
#
#  Copyright Matt Mackall <[e-mail]> and other
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import


def getstack(repo, rev=None):
    """return a sorted smartrev of the stack containing either rev if it is
    not None or the current working directory parent.

    The stack will always contain all drafts changesets which are ancestors to
    the revision and are not merges.
    """
    if rev is None:
        rev = b'.'

    revspec = b'only(%s) and not public() and not ::merge()'
    revisions = repo.revs(revspec, rev)
    revisions.sort()
    return revisions