hgext/commitextras.py

mergetool: warn if ui.merge points to nonexistent tool

This adds a warning when ui.merge is configured but points to an
executable that doesn't exist. It gets printed once per fail, but that
seems to be how our other warnings about merge tools are reported.

Differential Revision: https://phab.mercurial-scm.org/D3975

# commitextras.py
#
# 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.

'''adds a new flag extras to commit (ADVANCED)'''

from __future__ import absolute_import

import re

from mercurial.i18n import _
from mercurial import (
    commands,
    error,
    extensions,
    registrar,
)

cmdtable = {}
command = registrar.command(cmdtable)
testedwith = 'ships-with-hg-core'

usedinternally = {
    'amend_source',
    'branch',
    'close',
    'histedit_source',
    'topic',
    'rebase_source',
    'intermediate-source',
    '__touch-noise__',
    'source',
    'transplant_source',
}

def extsetup(ui):
    entry = extensions.wrapcommand(commands.table, 'commit', _commit)
    options = entry[1]
    options.append(('', 'extra', [],
        _('set a changeset\'s extra values'), _("KEY=VALUE")))

def _commit(orig, ui, repo, *pats, **opts):
    origcommit = repo.commit
    try:
        def _wrappedcommit(*innerpats, **inneropts):
            extras = opts.get(r'extra')
            if extras:
                for raw in extras:
                    if '=' not in raw:
                        msg = _("unable to parse '%s', should follow "
                                "KEY=VALUE format")
                        raise error.Abort(msg % raw)
                    k, v = raw.split('=', 1)
                    if not k:
                        msg = _("unable to parse '%s', keys can't be empty")
                        raise error.Abort(msg % raw)
                    if re.search('[^\w-]', k):
                        msg = _("keys can only contain ascii letters, digits,"
                                " '_' and '-'")
                        raise error.Abort(msg)
                    if k in usedinternally:
                        msg = _("key '%s' is used internally, can't be set "
                                "manually")
                        raise error.Abort(msg % k)
                    inneropts[r'extra'][k] = v
            return origcommit(*innerpats, **inneropts)

        # This __dict__ logic is needed because the normal
        # extension.wrapfunction doesn't seem to work.
        repo.__dict__[r'commit'] = _wrappedcommit
        return orig(ui, repo, *pats, **opts)
    finally:
        del repo.__dict__[r'commit']