contrib/simplemerge

revset: use '%' as an operator for 'only'

With this patch, we can make it much easier to specify 'only(A,B)' ->
A%B. Similarly, 'only(A)' -> A%.

On Windows, '%' is a semi-reserved symbol in the following way: using non-bash
shells (e.g. cmd.exe but NOT PowerShell, ConEmu, and cmder), %var% is only
expanded when 'var' exists and is surrounded by '%'.

That only leaves batch scripts which could prove to be problematic. I posit
that this isn't a big issue because any developer of batch scripts already
knows that to use '%' one needs to escape it by using a double '%%'.

Alternatives to '%' could be '=' but that might be limiting our future if we
ever decide to use temporary assignments in a revset.

#!/usr/bin/env python

from mercurial import demandimport
demandimport.enable()

import sys
from mercurial.i18n import _
from mercurial import simplemerge, fancyopts, util, ui

options = [('L', 'label', [], _('labels to use on conflict markers')),
           ('a', 'text', None, _('treat all files as text')),
           ('p', 'print', None,
            _('print results instead of overwriting LOCAL')),
           ('', 'no-minimal', None, _('no effect (DEPRECATED)')),
           ('h', 'help', None, _('display help and exit')),
           ('q', 'quiet', None, _('suppress output'))]

usage = _('''simplemerge [OPTS] LOCAL BASE OTHER

    Simple three-way file merge utility with a minimal feature set.

    Apply to LOCAL the changes necessary to go from BASE to OTHER.

    By default, LOCAL is overwritten with the results of this operation.
''')

class ParseError(Exception):
    """Exception raised on errors in parsing the command line."""

def showhelp():
    sys.stdout.write(usage)
    sys.stdout.write('\noptions:\n')

    out_opts = []
    for shortopt, longopt, default, desc in options:
        out_opts.append(('%2s%s' % (shortopt and '-%s' % shortopt,
                                    longopt and ' --%s' % longopt),
                         '%s' % desc))
    opts_len = max([len(opt[0]) for opt in out_opts])
    for first, second in out_opts:
        sys.stdout.write(' %-*s  %s\n' % (opts_len, first, second))

try:
    for fp in (sys.stdin, sys.stdout, sys.stderr):
        util.setbinary(fp)

    opts = {}
    try:
        args = fancyopts.fancyopts(sys.argv[1:], options, opts)
    except fancyopts.getopt.GetoptError, e:
        raise ParseError(e)
    if opts['help']:
        showhelp()
        sys.exit(0)
    if len(args) != 3:
            raise ParseError(_('wrong number of arguments'))
    sys.exit(simplemerge.simplemerge(ui.ui(), *args, **opts))
except ParseError, e:
    sys.stdout.write("%s: %s\n" % (sys.argv[0], e))
    showhelp()
    sys.exit(1)
except util.Abort, e:
    sys.stderr.write("abort: %s\n" % e)
    sys.exit(255)
except KeyboardInterrupt:
    sys.exit(255)