view hgext/githelp.py @ 36671:34e2ff1f9cd8

xdiff: vendor xdiff library from git

Vendor git's xdiff library from git commit
d7c6c2369d7c6c2369ac21141b7c6cceaebc6414ec3da14ad using GPL2+ license.

There is another recent user report that hg diff generates suboptimal
result. It seems the fix to issue4074 isn't good enough. I crafted some
other interesting cases, and hg diff barely has any advantage compared with
gnu diffutils or git diff.

| testcase | gnu diffutils |      hg diff |   git diff |
|          |    lines time |   lines time | lines time |
| patience |        6 0.00 |     602 0.08 |     6 0.00 |
|   random |    91772 0.90 |  109462 0.70 | 91772 0.24 |
|     json |        2 0.03 | 1264814 1.81 |     2 0.29 |

"lines" means the size of the output, i.e. the count of "+/-" lines. "time"
means seconds needed to do the calculation. Both are the smaller the better.
"hg diff" counts Python startup overhead.

Git and GNU diffutils generate optimal results. For the "json" case, git can
have an optimization that does a scan for common prefix and suffix first,
and match them if the length is greater than half of the text. See
https://neil.fraser.name/news/2006/03/12/. That would make git the fastest
for all above cases.

About testcases:

patience:
Aiming for the weakness of the greedy "patience diff" algorithm.  Using
git's patience diff option would also get suboptimal result. Generated using
the Python script:

```
open('a', 'w').write('\n'.join(list('a' + 'x' * 300 + 'u' + 'x' * 700 + 'a\n')))
open('b', 'w').write('\n'.join(list('b' + 'x' * 700 + 'u' + 'x' * 300 + 'b\n')))
```

random:
Generated using the script in `test-issue4074.t`. It practically makes the
algorithm suffer. Impressively, git wins in both performance and diff
quality.

json:
The recent user reported case. It's a single line movement near the end of a
very large (800K lines) JSON file.

Test Plan:
Code taken as-is.

Differential Revision: https://phab.mercurial-scm.org/D2572

# no-check-commit for vendored code

# githelp.py - Try to map Git commands to Mercurial equivalents.
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""try mapping git commands to Mercurial commands

Tries to map a given git command to a Mercurial command:

  $ hg githelp -- git checkout master
  hg update master

If an unknown command or parameter combination is detected, an error is
produced.
"""

from __future__ import absolute_import

import getopt
import re

from mercurial.i18n import _
from mercurial import (
    encoding,
    error,
    fancyopts,
    registrar,
    util,
)

# 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'

cmdtable = {}
command = registrar.command(cmdtable)

def convert(s):
    if s.startswith("origin/"):
        return s[7:]
    if 'HEAD' in s:
        s = s.replace('HEAD', '.')
    # HEAD~ in git is .~1 in mercurial
    s = re.sub('~$', '~1', s)
    return s

@command('^githelp|git', [
    ], _('hg githelp'))
def githelp(ui, repo, *args, **kwargs):
    '''suggests the Mercurial equivalent of the given git command

    Usage: hg githelp -- <git command>
    '''

    if len(args) == 0 or (len(args) == 1 and args[0] =='git'):
        raise error.Abort(_('missing git command - '
                            'usage: hg githelp -- <git command>'))

    if args[0] == 'git':
        args = args[1:]

    cmd = args[0]
    if not cmd in gitcommands:
        raise error.Abort("error: unknown git command %s" % (cmd))

    ui.pager('githelp')
    args = args[1:]
    return gitcommands[cmd](ui, repo, *args, **kwargs)

def parseoptions(ui, cmdoptions, args):
    cmdoptions = list(cmdoptions)
    opts = {}
    args = list(args)
    while True:
        try:
            args = fancyopts.fancyopts(list(args), cmdoptions, opts, True)
            break
        except getopt.GetoptError as ex:
            flag = None
            if "requires argument" in ex.msg:
                raise
            if ('--' + ex.opt) in ex.msg:
                flag = '--' + ex.opt
            elif ('-' + ex.opt) in ex.msg:
                flag = '-' + ex.opt
            else:
                raise error.Abort("unknown option %s" % ex.opt)
            try:
                args.remove(flag)
            except Exception:
                raise error.Abort(
                    "unknown option {0} packed with other options\n"
                    "Please try passing the option as it's own flag: -{0}" \
                    .format(ex.opt))

            ui.warn(_("ignoring unknown option %s\n") % flag)

    args = list([convert(x) for x in args])
    opts = dict([(k, convert(v)) if isinstance(v, str) else (k, v)
                                 for k, v in opts.iteritems()])

    return args, opts

class Command(object):
    def __init__(self, name):
        self.name = name
        self.args = []
        self.opts = {}

    def __bytes__(self):
        cmd = "hg " + self.name
        if self.opts:
            for k, values in sorted(self.opts.iteritems()):
                for v in values:
                    if v:
                        cmd += " %s %s" % (k, v)
                    else:
                        cmd += " %s" % (k,)
        if self.args:
            cmd += " "
            cmd += " ".join(self.args)
        return cmd

    __str__ = encoding.strmethod(__bytes__)

    def append(self, value):
        self.args.append(value)

    def extend(self, values):
        self.args.extend(values)

    def __setitem__(self, key, value):
        values = self.opts.setdefault(key, [])
        values.append(value)

    def __and__(self, other):
        return AndCommand(self, other)

class AndCommand(object):
    def __init__(self, left, right):
        self.left = left
        self.right = right

    def __str__(self):
        return "%s && %s" % (self.left, self.right)

    def __and__(self, other):
        return AndCommand(self, other)

def add(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('A', 'all', None, ''),
        ('p', 'patch', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if (opts.get('patch')):
        ui.status(_("note: Mercurial will commit when complete, "
                    "as there is no staging area in Mercurial\n\n"))
        cmd = Command('commit --interactive')
    else:
        cmd = Command("add")

        if not opts.get('all'):
            cmd.extend(args)
        else:
            ui.status(_("note: use hg addremove to remove files that have "
                        "been deleted.\n\n"))

    ui.status((bytes(cmd)), "\n")

def am(ui, repo, *args, **kwargs):
    cmdoptions=[
    ]
    args, opts = parseoptions(ui, cmdoptions, args)
    cmd = Command('import')
    ui.status(bytes(cmd), "\n")

def apply(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('p', 'p', int, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('import --no-commit')
    if (opts.get('p')):
        cmd['-p'] = opts.get('p')
    cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def bisect(ui, repo, *args, **kwargs):
    ui.status(_("See 'hg help bisect' for how to use bisect.\n\n"))

def blame(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)
    cmd = Command('annotate -udl')
    cmd.extend([convert(v) for v in args])
    ui.status((bytes(cmd)), "\n")

def branch(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'set-upstream', None, ''),
        ('', 'set-upstream-to', '', ''),
        ('d', 'delete', None, ''),
        ('D', 'delete', None, ''),
        ('m', 'move', None, ''),
        ('M', 'move', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command("bookmark")

    if opts.get('set_upstream') or opts.get('set_upstream_to'):
        ui.status(_("Mercurial has no concept of upstream branches\n"))
        return
    elif opts.get('delete'):
        cmd = Command("strip")
        for branch in args:
            cmd['-B'] = branch
        else:
            cmd['-B'] = None
    elif opts.get('move'):
        if len(args) > 0:
            if len(args) > 1:
                old = args.pop(0)
            else:
                # shell command to output the active bookmark for the active
                # revision
                old = '`hg log -T"{activebookmark}" -r .`'
        new = args[0]
        cmd['-m'] = old
        cmd.append(new)
    else:
        if len(args) > 1:
            cmd['-r'] = args[1]
            cmd.append(args[0])
        elif len(args) == 1:
            cmd.append(args[0])
    ui.status((bytes(cmd)), "\n")

def ispath(repo, string):
    """
    The first argument to git checkout can either be a revision or a path. Let's
    generally assume it's a revision, unless it's obviously a path. There are
    too many ways to spell revisions in git for us to reasonably catch all of
    them, so let's be conservative.
    """
    if string in repo:
        # if it's definitely a revision let's not even check if a file of the
        # same name exists.
        return False

    cwd = repo.getcwd()
    if cwd == '':
        repopath = string
    else:
        repopath = cwd + '/' + string

    exists = repo.wvfs.exists(repopath)
    if exists:
        return True

    manifest = repo['.'].manifest()

    didexist = (repopath in manifest) or manifest.hasdir(repopath)

    return didexist

def checkout(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('b', 'branch', '', ''),
        ('B', 'branch', '', ''),
        ('f', 'force', None, ''),
        ('p', 'patch', None, ''),
    ]
    paths = []
    if '--' in args:
        sepindex = args.index('--')
        paths.extend(args[sepindex + 1:])
        args = args[:sepindex]

    args, opts = parseoptions(ui, cmdoptions, args)

    rev = None
    if args and ispath(repo, args[0]):
        paths = args + paths
    elif args:
        rev = args[0]
        paths = args[1:] + paths

    cmd = Command('update')

    if opts.get('force'):
        if paths or rev:
            cmd['-C'] = None

    if opts.get('patch'):
        cmd = Command('revert')
        cmd['-i'] = None

    if opts.get('branch'):
        if len(args) == 0:
            cmd = Command('bookmark')
            cmd.append(opts.get('branch'))
        else:
            cmd.append(args[0])
            bookcmd = Command('bookmark')
            bookcmd.append(opts.get('branch'))
            cmd = cmd & bookcmd
    # if there is any path argument supplied, use revert instead of update
    elif len(paths) > 0:
        ui.status(_("note: use --no-backup to avoid creating .orig files\n\n"))
        cmd = Command('revert')
        if opts.get('patch'):
            cmd['-i'] = None
        if rev:
            cmd['-r'] = rev
        cmd.extend(paths)
    elif rev:
        if opts.get('patch'):
            cmd['-r'] = rev
        else:
            cmd.append(rev)
    elif opts.get('force'):
        cmd = Command('revert')
        cmd['--all'] = None
    else:
        raise error.Abort("a commit must be specified")

    ui.status((bytes(cmd)), "\n")

def cherrypick(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'continue', None, ''),
        ('', 'abort', None, ''),
        ('e', 'edit', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('graft')

    if opts.get('edit'):
        cmd['--edit'] = None
    if opts.get('continue'):
        cmd['--continue'] = None
    elif opts.get('abort'):
        ui.status(_("note: hg graft does not have --abort.\n\n"))
        return
    else:
        cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def clean(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('d', 'd', None, ''),
        ('f', 'force', None, ''),
        ('x', 'x', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('purge')
    if opts.get('x'):
        cmd['--all'] = None
    cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def clone(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'bare', None, ''),
        ('n', 'no-checkout', None, ''),
        ('b', 'branch', '', ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if len(args) == 0:
        raise error.Abort("a repository to clone must be specified")

    cmd = Command('clone')
    cmd.append(args[0])
    if len(args) > 1:
        cmd.append(args[1])

    if opts.get('bare'):
        cmd['-U'] = None
        ui.status(_("note: Mercurial does not have bare clones. " +
            "-U will clone the repo without checking out a commit\n\n"))
    elif opts.get('no_checkout'):
        cmd['-U'] = None

    if opts.get('branch'):
        cocmd = Command("update")
        cocmd.append(opts.get('branch'))
        cmd = cmd & cocmd

    ui.status((bytes(cmd)), "\n")

def commit(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('a', 'all', None, ''),
        ('m', 'message', '', ''),
        ('p', 'patch', None, ''),
        ('C', 'reuse-message', '', ''),
        ('F', 'file', '', ''),
        ('', 'author', '', ''),
        ('', 'date', '', ''),
        ('', 'amend', None, ''),
        ('', 'no-edit', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('commit')
    if opts.get('patch'):
        cmd = Command('commit --interactive')

    if opts.get('amend'):
        if opts.get('no_edit'):
            cmd = Command('amend')
        else:
            cmd['--amend'] = None

    if opts.get('reuse_message'):
        cmd['-M'] = opts.get('reuse_message')

    if opts.get('message'):
        cmd['-m'] = "'%s'" % (opts.get('message'),)

    if opts.get('all'):
        ui.status(_("note: Mercurial doesn't have a staging area, " +
            "so there is no --all. -A will add and remove files " +
            "for you though.\n\n"))

    if opts.get('file'):
        cmd['-l'] = opts.get('file')

    if opts.get('author'):
        cmd['-u'] = opts.get('author')

    if opts.get('date'):
        cmd['-d'] = opts.get('date')

    cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def deprecated(ui, repo, *args, **kwargs):
    ui.warn(_('This command has been deprecated in the git project, ' +
        'thus isn\'t supported by this tool.\n\n'))

def diff(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('a', 'all', None, ''),
        ('', 'cached', None, ''),
        ('R', 'reverse', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('diff')

    if opts.get('cached'):
        ui.status(_('note: Mercurial has no concept of a staging area, ' +
            'so --cached does nothing.\n\n'))

    if opts.get('reverse'):
        cmd['--reverse'] = None

    for a in list(args):
        args.remove(a)
        try:
            repo.revs(a)
            cmd['-r'] = a
        except Exception:
            cmd.append(a)

    ui.status((bytes(cmd)), "\n")

def difftool(ui, repo, *args, **kwargs):
    ui.status(_('Mercurial does not enable external difftool by default. You '
        'need to enable the extdiff extension in your .hgrc file by adding\n'
        'extdiff =\n'
        'to the [extensions] section and then running\n\n'
        'hg extdiff -p <program>\n\n'
        'See \'hg help extdiff\' and \'hg help -e extdiff\' for more '
        'information.\n'))

def fetch(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'all', None, ''),
        ('f', 'force', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('pull')

    if len(args) > 0:
        cmd.append(args[0])
        if len(args) > 1:
            ui.status(_("note: Mercurial doesn't have refspecs. " +
                "-r can be used to specify which commits you want to pull. " +
                "-B can be used to specify which bookmark you want to pull." +
                "\n\n"))
            for v in args[1:]:
                if v in repo._bookmarks:
                    cmd['-B'] = v
                else:
                    cmd['-r'] = v

    ui.status((bytes(cmd)), "\n")

def grep(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('grep')

    # For basic usage, git grep and hg grep are the same. They both have the
    # pattern first, followed by paths.
    cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def init(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('init')

    if len(args) > 0:
        cmd.append(args[0])

    ui.status((bytes(cmd)), "\n")

def log(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'follow', None, ''),
        ('', 'decorate', None, ''),
        ('n', 'number', '', ''),
        ('1', '1', None, ''),
        ('', 'pretty', '', ''),
        ('', 'format', '', ''),
        ('', 'oneline', None, ''),
        ('', 'stat', None, ''),
        ('', 'graph', None, ''),
        ('p', 'patch', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)
    ui.status(_('note: -v prints the entire commit message like Git does. To ' +
              'print just the first line, drop the -v.\n\n'))
    ui.status(_("note: see hg help revset for information on how to filter " +
        "log output.\n\n"))

    cmd = Command('log')
    cmd['-v'] = None

    if opts.get('number'):
        cmd['-l'] = opts.get('number')
    if opts.get('1'):
        cmd['-l'] = '1'
    if opts.get('stat'):
        cmd['--stat'] = None
    if opts.get('graph'):
        cmd['-G'] = None
    if opts.get('patch'):
        cmd['-p'] = None

    if opts.get('pretty') or opts.get('format') or opts.get('oneline'):
        format = opts.get('format', '')
        if 'format:' in format:
            ui.status(_("note: --format format:??? equates to Mercurial's " +
                "--template. See hg help templates for more info.\n\n"))
            cmd['--template'] = '???'
        else:
            ui.status(_("note: --pretty/format/oneline equate to Mercurial's " +
                "--style or --template. See hg help templates for more info." +
                "\n\n"))
            cmd['--style'] = '???'

    if len(args) > 0:
        if '..' in args[0]:
            since, until = args[0].split('..')
            cmd['-r'] = "'%s::%s'" % (since, until)
            del args[0]
        cmd.extend(args)

    ui.status((bytes(cmd)), "\n")

def lsfiles(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('c', 'cached', None, ''),
        ('d', 'deleted', None, ''),
        ('m', 'modified', None, ''),
        ('o', 'others', None, ''),
        ('i', 'ignored', None, ''),
        ('s', 'stage', None, ''),
        ('z', '_zero', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if (opts.get('modified') or opts.get('deleted')
        or opts.get('others') or opts.get('ignored')):
        cmd = Command('status')
        if opts.get('deleted'):
            cmd['-d'] = None
        if opts.get('modified'):
            cmd['-m'] = None
        if opts.get('others'):
            cmd['-o'] = None
        if opts.get('ignored'):
            cmd['-i'] = None
    else:
        cmd = Command('files')
    if opts.get('stage'):
        ui.status(_("note: Mercurial doesn't have a staging area, ignoring "
                  "--stage\n"))
    if opts.get('_zero'):
        cmd['-0'] = None
    cmd.append('.')
    for include in args:
        cmd['-I'] = util.shellquote(include)

    ui.status((bytes(cmd)), "\n")

def merge(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('merge')

    if len(args) > 0:
        cmd.append(args[len(args) - 1])

    ui.status((bytes(cmd)), "\n")

def mergebase(ui, repo, *args, **kwargs):
    cmdoptions = []
    args, opts = parseoptions(ui, cmdoptions, args)

    if len(args) != 2:
        args = ['A', 'B']

    cmd = Command("log -T '{node}\\n' -r 'ancestor(%s,%s)'"
                  % (args[0], args[1]))

    ui.status(_('NOTE: ancestors() is part of the revset language.\n'),
              _("Learn more about revsets with 'hg help revsets'\n\n"))
    ui.status((bytes(cmd)), "\n")

def mergetool(ui, repo, *args, **kwargs):
    cmdoptions = []
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command("resolve")

    if len(args) == 0:
        cmd['--all'] = None
    cmd.extend(args)
    ui.status((bytes(cmd)), "\n")

def mv(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('f', 'force', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('mv')
    cmd.extend(args)

    if opts.get('force'):
        cmd['-f'] = None

    ui.status((bytes(cmd)), "\n")

def pull(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'all', None, ''),
        ('f', 'force', None, ''),
        ('r', 'rebase', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('pull')
    cmd['--rebase'] = None

    if len(args) > 0:
        cmd.append(args[0])
        if len(args) > 1:
            ui.status(_("note: Mercurial doesn't have refspecs. " +
                "-r can be used to specify which commits you want to pull. " +
                "-B can be used to specify which bookmark you want to pull." +
                "\n\n"))
            for v in args[1:]:
                if v in repo._bookmarks:
                    cmd['-B'] = v
                else:
                    cmd['-r'] = v

    ui.status((bytes(cmd)), "\n")

def push(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'all', None, ''),
        ('f', 'force', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('push')

    if len(args) > 0:
        cmd.append(args[0])
        if len(args) > 1:
            ui.status(_("note: Mercurial doesn't have refspecs. " +
                "-r can be used to specify which commits you want to push. " +
                "-B can be used to specify which bookmark you want to push." +
                "\n\n"))
            for v in args[1:]:
                if v in repo._bookmarks:
                    cmd['-B'] = v
                else:
                    cmd['-r'] = v

    if opts.get('force'):
        cmd['-f'] = None

    ui.status((bytes(cmd)), "\n")

def rebase(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'all', None, ''),
        ('i', 'interactive', None, ''),
        ('', 'onto', '', ''),
        ('', 'abort', None, ''),
        ('', 'continue', None, ''),
        ('', 'skip', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if opts.get('interactive'):
        ui.status(_("note: hg histedit does not perform a rebase. " +
            "It just edits history.\n\n"))
        cmd = Command('histedit')
        if len(args) > 0:
            ui.status(_("also note: 'hg histedit' will automatically detect"
                      " your stack, so no second argument is necessary.\n\n"))
        ui.status((bytes(cmd)), "\n")
        return

    if opts.get('skip'):
        cmd = Command('revert --all -r .')
        ui.status((bytes(cmd)), "\n")

    cmd = Command('rebase')

    if opts.get('continue') or opts.get('skip'):
        cmd['--continue'] = None
    if opts.get('abort'):
        cmd['--abort'] = None

    if opts.get('onto'):
        ui.status(_("note: if you're trying to lift a commit off one branch, " +
            "try hg rebase -d <destination commit> -s <commit to be lifted>" +
            "\n\n"))
        cmd['-d'] = convert(opts.get('onto'))
        if len(args) < 2:
            raise error.Abort("Expected format: git rebase --onto X Y Z")
        cmd['-s'] = "'::%s - ::%s'" % (convert(args[1]), convert(args[0]))
    else:
        if len(args) == 1:
            cmd['-d'] = convert(args[0])
        elif len(args) == 2:
            cmd['-d'] = convert(args[0])
            cmd['-b'] = convert(args[1])

    ui.status((bytes(cmd)), "\n")

def reflog(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'all', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('journal')
    if opts.get('all'):
        cmd['--all'] = None
    if len(args) > 0:
        cmd.append(args[0])

    ui.status(bytes(cmd), "\n\n")
    ui.status(_("note: in hg commits can be deleted from repo but we always"
              " have backups.\n"))

def reset(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'soft', None, ''),
        ('', 'hard', None, ''),
        ('', 'mixed', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    commit = convert(args[0] if len(args) > 0 else '.')
    hard = opts.get('hard')

    if opts.get('mixed'):
        ui.status(_('NOTE: --mixed has no meaning since Mercurial has no '
                    'staging area\n\n'))
    if opts.get('soft'):
        ui.status(_('NOTE: --soft has no meaning since Mercurial has no '
                    'staging area\n\n'))

    cmd = Command('update')
    if hard:
        cmd.append('--clean')

    cmd.append(commit)

    ui.status((bytes(cmd)), "\n")

def revert(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if len(args) > 1:
        ui.status(_("note: hg backout doesn't support multiple commits at " +
                    "once\n\n"))

    cmd = Command('backout')
    if args:
        cmd.append(args[0])

    ui.status((bytes(cmd)), "\n")

def revparse(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'show-cdup', None, ''),
        ('', 'show-toplevel', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if opts.get('show_cdup') or opts.get('show_toplevel'):
        cmd = Command('root')
        if opts.get('show_cdup'):
            ui.status(_("note: hg root prints the root of the repository\n\n"))
        ui.status((bytes(cmd)), "\n")
    else:
        ui.status(_("note: see hg help revset for how to refer to commits\n"))

def rm(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('f', 'force', None, ''),
        ('n', 'dry-run', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('rm')
    cmd.extend(args)

    if opts.get('force'):
        cmd['-f'] = None
    if opts.get('dry_run'):
        cmd['-n'] = None

    ui.status((bytes(cmd)), "\n")

def show(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'name-status', None, ''),
        ('', 'pretty', '', ''),
        ('U', 'unified', int, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if opts.get('name_status'):
        if opts.get('pretty') == 'format:':
            cmd = Command('status')
            cmd['--change'] = '.'
        else:
            cmd = Command('log')
            cmd.append('--style status')
            cmd.append('-r .')
    elif len(args) > 0:
        if ispath(repo, args[0]):
            cmd = Command('cat')
        else:
            cmd = Command('export')
        cmd.extend(args)
        if opts.get('unified'):
            cmd.append('--config diff.unified=%d' % (opts['unified'],))
    elif opts.get('unified'):
        cmd = Command('export')
        cmd.append('--config diff.unified=%d' % (opts['unified'],))
    else:
        cmd = Command('export')

    ui.status((bytes(cmd)), "\n")

def stash(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('shelve')
    action = args[0] if len(args) > 0 else None

    if action == 'list':
        cmd['-l'] = None
    elif action == 'drop':
        cmd['-d'] = None
        if len(args) > 1:
            cmd.append(args[1])
        else:
            cmd.append('<shelve name>')
    elif action == 'pop' or action == 'apply':
        cmd = Command('unshelve')
        if len(args) > 1:
            cmd.append(args[1])
        if action == 'apply':
            cmd['--keep'] = None
    elif (action == 'branch' or action == 'show' or action == 'clear'
        or action == 'create'):
        ui.status(_("note: Mercurial doesn't have equivalents to the " +
            "git stash branch, show, clear, or create actions.\n\n"))
        return
    else:
        if len(args) > 0:
            if args[0] != 'save':
                cmd['--name'] = args[0]
            elif len(args) > 1:
                cmd['--name'] = args[1]

    ui.status((bytes(cmd)), "\n")

def status(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('', 'ignored', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('status')
    cmd.extend(args)

    if opts.get('ignored'):
        cmd['-i'] = None

    ui.status((bytes(cmd)), "\n")

def svn(ui, repo, *args, **kwargs):
    svncmd = args[0]
    if not svncmd in gitsvncommands:
        ui.warn(_("error: unknown git svn command %s\n") % (svncmd))

    args = args[1:]
    return gitsvncommands[svncmd](ui, repo, *args, **kwargs)

def svndcommit(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('push')

    ui.status((bytes(cmd)), "\n")

def svnfetch(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('pull')
    cmd.append('default-push')

    ui.status((bytes(cmd)), "\n")

def svnfindrev(ui, repo, *args, **kwargs):
    cmdoptions = [
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    cmd = Command('log')
    cmd['-r'] = args[0]

    ui.status((bytes(cmd)), "\n")

def svnrebase(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('l', 'local', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    pullcmd = Command('pull')
    pullcmd.append('default-push')
    rebasecmd = Command('rebase')
    rebasecmd.append('tip')

    cmd = pullcmd & rebasecmd

    ui.status((bytes(cmd)), "\n")

def tag(ui, repo, *args, **kwargs):
    cmdoptions = [
        ('f', 'force', None, ''),
        ('l', 'list', None, ''),
        ('d', 'delete', None, ''),
    ]
    args, opts = parseoptions(ui, cmdoptions, args)

    if opts.get('list'):
        cmd = Command('tags')
    else:
        cmd = Command('tag')
        cmd.append(args[0])
        if len(args) > 1:
            cmd['-r'] = args[1]

        if opts.get('delete'):
            cmd['--remove'] = None

        if opts.get('force'):
            cmd['-f'] = None

    ui.status((bytes(cmd)), "\n")

gitcommands = {
    'add': add,
    'am': am,
    'apply': apply,
    'bisect': bisect,
    'blame': blame,
    'branch': branch,
    'checkout': checkout,
    'cherry-pick': cherrypick,
    'clean': clean,
    'clone': clone,
    'commit': commit,
    'diff': diff,
    'difftool': difftool,
    'fetch': fetch,
    'grep': grep,
    'init': init,
    'log': log,
    'ls-files': lsfiles,
    'merge': merge,
    'merge-base': mergebase,
    'mergetool': mergetool,
    'mv': mv,
    'pull': pull,
    'push': push,
    'rebase': rebase,
    'reflog': reflog,
    'reset': reset,
    'revert': revert,
    'rev-parse': revparse,
    'rm': rm,
    'show': show,
    'stash': stash,
    'status': status,
    'svn': svn,
    'tag': tag,
    'whatchanged': deprecated,
}

gitsvncommands = {
    'dcommit': svndcommit,
    'fetch': svnfetch,
    'find-rev': svnfindrev,
    'rebase': svnrebase,
}