annotate mercurial/rewriteutil.py @ 43075:57875cf423c9

style: run a patched black on a subset of mercurial

This applied black to the 20 smallest files in mercurial/:

    ls -S1 mercurial/*.py | tail -n20 | xargs black --skip-string-normalization

Note that a few files failed to format, presumably due to a bug in my
patch. The intent is to be able to compare results to D5064 with
https://github.com/python/black/pull/826 applied to black.

I skipped string normalization on this patch for clarity - in reality
I think we'd want one pass without string normalization, followed by
another to normalize strings (which is basically replacing ' with "
globally.)

# skip-blame mass-reformatting only

Differential Revision: https://phab.mercurial-scm.org/D6342

# rewriteutil.py - utility functions for rewriting changesets
#
# Copyright 2017 Octobus <[e-mail]>
#
# 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 .i18n import _

from . import (
    error,
    node,
    obsolete,
    revset,
)


def precheck(repo, revs, action='rewrite'):
    """check if revs can be rewritten
    action is used to control the error message.

    Make sure this function is called after taking the lock.
    """
    if node.nullrev in revs:
        msg = _("cannot %s null changeset") % action
        hint = _("no changeset checked out")
        raise error.Abort(msg, hint=hint)

    if len(repo[None].parents()) > 1:
        raise error.Abort(_("cannot %s while merging") % action)

    publicrevs = repo.revs('%ld and public()', revs)
    if publicrevs:
        msg = _("cannot %s public changesets") % action
        hint = _("see 'hg help phases' for details")
        raise error.Abort(msg, hint=hint)

    newunstable = disallowednewunstable(repo, revs)
    if newunstable:
        raise error.Abort(_("cannot %s changeset with children") % action)


def disallowednewunstable(repo, revs):
    """Checks whether editing the revs will create new unstable changesets and
    are we allowed to create them.

    To allow new unstable changesets, set the config:
        `experimental.evolution.allowunstable=True`
    """
    allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
    if allowunstable:
        return revset.baseset()
    return repo.revs("(%ld::) - %ld", revs, revs)