tests/pullext.py

localrepo: stop doing special dirstate backup at transaction open

Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).

We needs some special code to deal with the initial empty checkout, but it is
not too complicated.

Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.

In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.

[1] https://xkcd.com/1134/

(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)

# pullext.py - Simple extension to test pulling
#
# Copyright 2018 Gregory Szorc <[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 mercurial.i18n import _
from mercurial import (
    commands,
    error,
    extensions,
    localrepo,
    requirements,
)


def clonecommand(orig, ui, repo, *args, **kwargs):
    if kwargs.get('include') or kwargs.get('exclude'):
        kwargs['narrow'] = True

    if kwargs.get('depth'):
        try:
            kwargs['depth'] = int(kwargs['depth'])
        except ValueError:
            raise error.Abort(_('--depth must be an integer'))

    return orig(ui, repo, *args, **kwargs)


def featuresetup(ui, features):
    features.add(requirements.NARROW_REQUIREMENT)


def extsetup(ui):
    entry = extensions.wrapcommand(commands.table, b'clone', clonecommand)

    hasinclude = any(x[1] == b'include' for x in entry[1])
    hasdepth = any(x[1] == b'depth' for x in entry[1])

    if not hasinclude:
        entry[1].append(
            (b'', b'include', [], _(b'pattern of file/directory to clone'))
        )
        entry[1].append(
            (b'', b'exclude', [], _(b'pattern of file/directory to not clone'))
        )

    if not hasdepth:
        entry[1].append(
            (b'', b'depth', b'', _(b'ancestry depth of changesets to fetch'))
        )

    localrepo.featuresetupfuncs.add(featuresetup)