contrib/hg-ssh

revset: raise RepoLookupError to make present() predicate continue the query

Before this patch, "bookmark()", "named()" and "tag()" predicates
raise "Abort", when the specified pattern doesn't match against
existing ones.

This prevents "present()" predicate from continuing the query, because
it only catches "RepoLookupError".

This patch raises "RepoLookupError" instead of "Abort", to make
"present()" predicate continue the query, even if "bookmark()",
"named()" or "tag()" in the sub-query of it are aborted.

This patch doesn't contain raising "RepoLookupError" for "re:" pattern
in "tag()", because "tag()" treats it differently from others. Actions
of each predicates at failure of pattern matching can be summarized as
below:

  predicate  "literal:"  "re:"
  ---------- ----------- ------------
  bookmark   abort       abort
  named      abort       abort
  tag        abort       continue (*1)

  branch     abort       continue (*2)
  ---------- ----------- ------------

"tag()" may have to abort in the (*1) case for similarity, but this
change may break backward compatibility of existing revset queries. It
seems to have to be changed on "default" branch (with "BC" ?).

On the other hand, (*2) seems to be reasonable, even though it breaks
similarity, because "branch()" in this case doesn't check exact
existence of branches, but does pick up revisions of which branch
matches against the pattern.

This patch also adds tests for "branch()" to clarify behavior around
"present()" of similar predicates, even though this patch doesn't
change "branch()".

#!/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/*"
"""

# enable importing on demand to reduce startup time
from mercurial import demandimport; demandimport.enable()

from mercurial import dispatch

import sys, os, shlex

def main():
    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, 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 = ['-R', repo, 'serve', '--stdio']
            if readonly:
                cmd += [
                    '--config',
                    'hooks.prechangegroup.hg-ssh=python:__main__.rejectpush',
                    '--config',
                    'hooks.prepushkey.hg-ssh=python:__main__.rejectpush'
                    ]
            dispatch.dispatch(dispatch.request(cmd))
        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("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()