view contrib/hg-ssh @ 44758:45f3f35cefe7

copies: fix the changeset based algorithm regarding merge

In 99ebde4fec99, we changed the list of files stored into the `files` field.
This lead to the changeset centric copy algorithm to break in various merge
situation involving merge. Older information could reach the merge through
`p1`, and while information from `p2` was strictly fresher, it would get
overwritten anyway.

We update the situation with more details about which revision introduces rename
information. This help use making the right decision in case of merge.

We are now running a more comprehensive suite of test with include this kind of
situation. The behavior differ slightly from the filelog based in a couple of
instance. There is mostly two distinct cases:

1) there are conflicting rename information in a merge (different rename history
on each side). In this case the filelog based implementation arbitrarily pick a
side based on the file-revision-number. So it depends on a local factor. The
changeset centric algorithm will use a deterministic approach, by picking the
information coming from the first parent of the merge. This is stable across
different clone.

2) rename information related to file that exist in both source and destination.
The filelog based implementation do not even try to detect these, however the
changeset centric one get them for "free" (it is simpler to detect them than
not).

The new implementation focus on correctness. Performance improvement will come
later.

Differential Revision: https://phab.mercurial-scm.org/D8244

#!/usr/bin/env python
#
# Copyright 2005-2007 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.

"""
hg-ssh - a wrapper for ssh access to a limited set of mercurial repos

To be used in ~/.ssh/authorized_keys with the "command" option, see sshd(8):
command="hg-ssh path/to/repo1 /path/to/repo2 ~/repo3 ~user/repo4" ssh-dss ...
(probably together with these other useful options:
 no-port-forwarding,no-X11-forwarding,no-agent-forwarding)

This allows pull/push over ssh from/to the repositories given as arguments.

If all your repositories are subdirectories of a common directory, you can
allow shorter paths with:
command="cd path/to/my/repositories && hg-ssh repo1 subdir/repo2"

You can use pattern matching of your normal shell, e.g.:
command="cd repos && hg-ssh user/thomas/* projects/{mercurial,foo}"

You can also add a --read-only flag to allow read-only access to a key, e.g.:
command="hg-ssh --read-only repos/*"
"""
from __future__ import absolute_import

import os
import shlex
import sys

# enable importing on demand to reduce startup time
import hgdemandimport

hgdemandimport.enable()

from mercurial import (
    dispatch,
    pycompat,
    ui as uimod,
)


def main():
    # Prevent insertion/deletion of CRs
    dispatch.initstdio()

    cwd = os.getcwd()
    readonly = False
    args = sys.argv[1:]
    while len(args):
        if args[0] == '--read-only':
            readonly = True
            args.pop(0)
        else:
            break
    allowed_paths = [
        os.path.normpath(os.path.join(cwd, os.path.expanduser(path)))
        for path in args
    ]
    orig_cmd = os.getenv('SSH_ORIGINAL_COMMAND', '?')
    try:
        cmdargv = shlex.split(orig_cmd)
    except ValueError as e:
        sys.stderr.write('Illegal command "%s": %s\n' % (orig_cmd, e))
        sys.exit(255)

    if cmdargv[:2] == ['hg', '-R'] and cmdargv[3:] == ['serve', '--stdio']:
        path = cmdargv[2]
        repo = os.path.normpath(os.path.join(cwd, os.path.expanduser(path)))
        if repo in allowed_paths:
            cmd = [b'-R', pycompat.fsencode(repo), b'serve', b'--stdio']
            req = dispatch.request(cmd)
            if readonly:
                if not req.ui:
                    req.ui = uimod.ui.load()
                req.ui.setconfig(
                    b'hooks',
                    b'pretxnopen.hg-ssh',
                    b'python:__main__.rejectpush',
                    b'hg-ssh',
                )
                req.ui.setconfig(
                    b'hooks',
                    b'prepushkey.hg-ssh',
                    b'python:__main__.rejectpush',
                    b'hg-ssh',
                )
            dispatch.dispatch(req)
        else:
            sys.stderr.write('Illegal repository "%s"\n' % repo)
            sys.exit(255)
    else:
        sys.stderr.write('Illegal command "%s"\n' % orig_cmd)
        sys.exit(255)


def rejectpush(ui, **kwargs):
    ui.warn((b"Permission denied\n"))
    # mercurial hooks use unix process conventions for hook return values
    # so a truthy return means failure
    return True


if __name__ == '__main__':
    main()