hg

help: add a mechanism to change flags' help depending on config

It seems reasonable to have a similar mechanism for the rest of the
help, but no such thing is implemented.

The goal is to make the help of commands clearer in the presence of
significant default changes, like tweakdefaults or with company-wide
hgrcs. In these cases, a user looking at the help of a command doesn't
exactly know what his hgrc is doing.

Apply to this to the --git option of commands that display diffs, as
this option in particular causes confusion for some reason.

Differential Revision: https://phab.mercurial-scm.org/D8100

#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# Copyright 2005-2007 Matt Mackall <[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.
from __future__ import absolute_import

import os
import sys

libdir = '@LIBDIR@'

if libdir != '@' 'LIBDIR' '@':
    if not os.path.isabs(libdir):
        libdir = os.path.join(
            os.path.dirname(os.path.realpath(__file__)), libdir
        )
        libdir = os.path.abspath(libdir)
    sys.path.insert(0, libdir)

from hgdemandimport import tracing

with tracing.log('hg script'):
    # enable importing on demand to reduce startup time
    try:
        if sys.version_info[0] < 3 or sys.version_info >= (3, 6):
            import hgdemandimport

            hgdemandimport.enable()
    except ImportError:
        sys.stderr.write(
            "abort: couldn't find mercurial libraries in [%s]\n"
            % ' '.join(sys.path)
        )
        sys.stderr.write("(check your install and PYTHONPATH)\n")
        sys.exit(-1)

    from mercurial import dispatch

    dispatch.run()