hgext/narrow/narrowrepo.py

rhg: read [paths] for `--repository` value

hg parses `-R` and `--repository` CLI arguments "early" in order to know which
local repository to load config from. (Config can then affect whether or how to
fall back.)

The value of of those arguments can be not only a filesystem path, but also an
alias configured in the `[paths]` section. This part was missing in rhg and
this patch implements that.

The current patch still lacks functionality to read config of current repository
if we are not at root of repo. That will be fixed in upcoming patches.

A new crate `home` is added to get path of home directory.

Differential Revision: https://phab.mercurial-scm.org/D10296

# narrowrepo.py - repository which supports narrow revlogs, lazy loading
#
# Copyright 2017 Google, Inc.
#
# 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 mercurial import wireprototypes

from . import narrowdirstate


def wraprepo(repo):
    """Enables narrow clone functionality on a single local repository."""

    class narrowrepository(repo.__class__):
        def _makedirstate(self):
            dirstate = super(narrowrepository, self)._makedirstate()
            return narrowdirstate.wrapdirstate(self, dirstate)

        def peer(self):
            peer = super(narrowrepository, self).peer()
            peer._caps.add(wireprototypes.NARROWCAP)
            peer._caps.add(wireprototypes.ELLIPSESCAP)
            return peer

    repo.__class__ = narrowrepository