mercurial/rewriteutil.py

repository: introduce constant for treemanifest requirement and use it

In future we will like to much cleaner logic around which requirement is for
working copy and which can go in store. To start with that, we first need to
de-clutter the requirement values spread around and replace them with constants.

Differential Revision: https://phab.mercurial-scm.org/D8916

# 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=b'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 = _(b"cannot %s null changeset") % action
        hint = _(b"no changeset checked out")
        raise error.Abort(msg, hint=hint)

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

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

    newunstable = disallowednewunstable(repo, revs)
    if newunstable:
        raise error.Abort(_(b"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(b"(%ld::) - %ld", revs, revs)


def skip_empty_successor(ui, command):
    empty_successor = ui.config(b'rewrite', b'empty-successor')
    if empty_successor == b'skip':
        return True
    elif empty_successor == b'keep':
        return False
    else:
        raise error.ConfigError(
            _(
                b"%s doesn't know how to handle config "
                b"rewrite.empty-successor=%s (only 'skip' and 'keep' are "
                b"supported)"
            )
            % (command, empty_successor)
        )