mercurial/stack.py

changegroup: reintroduce some comments that have gotten lost over the years

I got concerned about the correctness of the pruning logic, but I was
misreading it. I didn't figure that out until I walked all the way
back to 0252abaafb8a from 20111, where I was finally able to see (in
the deleted side of the change!) a complete explanation from
b6d9ea0bc107 in 2005.

Differential Revision: https://phab.mercurial-scm.org/D4686

# 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

from . import (
    revsetlang,
    scmutil,
)

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 = '.'

    revspec = 'reverse(only(%s) and not public() and not ::merge())'
    revset = revsetlang.formatspec(revspec, rev)
    revisions = scmutil.revrange(repo, [revset])
    revisions.sort()
    return revisions