view mercurial/stack.py @ 39166:484c9fe570a7

setdiscovery: use a revset instead of dagutil.descendantset()

This is the only use of descendantset() in the repo.

Strictly speaking, the revset behaves slightly differently than
dagutil. The reason is that dagutil is using revlog.index for
DAG traversal and this data structure isn't aware of visibility /
filtering. So it can operate on revisions it shouldn't operate on.

But our test coverage of this code is pretty comprehensive and
this change causes no tests to fail. So I think we are good.

Also, the revset parser failed to parse `%ld:: - %ld::`, hence
the use of descendants(). I'm not sure if that is a feature or
a bug.

Differential Revision: https://phab.mercurial-scm.org/D4314

# 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