copies: consider nullrev a common ancestor
I've seen many bugs in the git codebase that were caused by it not
having a null revision and being forced to treat root commits
differently. Mercurial has a null revision and I think it's generally
a bug to treat it differently from other commits in graph algorithms.
This effectively undoes
83cfa1baf8ad (copies: don't report copies with
unrelated branch, 2010-01-01). The test cases that that commit added
still passes. I suspect some other fix after that commit made it
unnecessary.
Differential Revision: https://phab.mercurial-scm.org/D5594
# stack.py - Mercurial functions for stack definition
#
# Copyright Matt Mackall <mpm@selenic.com> 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