hgext/children.py

revlog: extract function for getting node from known-to-exist rev

Many of the calls to index_node() (which converts a rev to a nodeid)
are done with a rev that's know to exist. If the function fails,
there's something really wrong and we should just abort. This was done
in only one place. This patch starts by extracting that code to a
function that we can reuse in later patches.

Differential Revision: https://phab.mercurial-scm.org/D3456

# Mercurial extension to provide the 'hg children' command
#
# Copyright 2007 by Intevation GmbH <[e-mail]>
#
# Author(s):
# Thomas Arendsen Hein <[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.

'''command to display child changesets (DEPRECATED)

This extension is deprecated. You should use :hg:`log -r
"children(REV)"` instead.
'''

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    logcmdutil,
    pycompat,
    registrar,
    scmutil,
)

templateopts = cmdutil.templateopts

cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

@command('children',
    [('r', 'rev', '.',
     _('show children of the specified revision'), _('REV')),
    ] + templateopts,
    _('hg children [-r REV] [FILE]'),
    inferrepo=True)
def children(ui, repo, file_=None, **opts):
    """show the children of the given or working directory revision

    Print the children of the working directory's revisions. If a
    revision is given via -r/--rev, the children of that revision will
    be printed. If a file argument is given, revision in which the
    file was last changed (after the working directory revision or the
    argument to --rev if given) is printed.

    Please use :hg:`log` instead::

        hg children => hg log -r "children(.)"
        hg children -r REV => hg log -r "children(REV)"

    See :hg:`help log` and :hg:`help revsets.children`.

    """
    opts = pycompat.byteskwargs(opts)
    rev = opts.get('rev')
    ctx = scmutil.revsingle(repo, rev)
    if file_:
        fctx = repo.filectx(file_, changeid=ctx.rev())
        childctxs = [fcctx.changectx() for fcctx in fctx.children()]
    else:
        childctxs = ctx.children()

    displayer = logcmdutil.changesetdisplayer(ui, repo, opts)
    for cctx in childctxs:
        displayer.show(cctx)
    displayer.close()