tests/dummysmtpd.py

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

"""dummy SMTP server for use in tests"""

from __future__ import absolute_import

import asyncore
import optparse
import smtpd
import ssl
import sys
import traceback

from mercurial import (
    pycompat,
    server,
    sslutil,
    ui as uimod,
)


def log(msg):
    sys.stdout.write(msg)
    sys.stdout.flush()


class dummysmtpserver(smtpd.SMTPServer):
    def __init__(self, localaddr):
        smtpd.SMTPServer.__init__(self, localaddr, remoteaddr=None)

    def process_message(self, peer, mailfrom, rcpttos, data, **kwargs):
        log('%s from=%s to=%s\n' % (peer[0], mailfrom, ', '.join(rcpttos)))

    def handle_error(self):
        # On Windows, a bad SSL connection sometimes generates a WSAECONNRESET.
        # The default handler will shutdown this server, and then both the
        # current connection and subsequent ones fail on the client side with
        # "No connection could be made because the target machine actively
        # refused it".  If we eat the error, then the client properly aborts in
        # the expected way, and the server is available for subsequent requests.
        traceback.print_exc()


class dummysmtpsecureserver(dummysmtpserver):
    def __init__(self, localaddr, certfile):
        dummysmtpserver.__init__(self, localaddr)
        self._certfile = certfile

    def handle_accept(self):
        pair = self.accept()
        if not pair:
            return
        conn, addr = pair
        ui = uimod.ui.load()
        try:
            # wrap_socket() would block, but we don't care
            conn = sslutil.wrapserversocket(conn, ui, certfile=self._certfile)
        except ssl.SSLError:
            log('%s ssl error\n' % addr[0])
            conn.close()
            return
        smtpd.SMTPChannel(self, conn, addr)


def run():
    try:
        asyncore.loop()
    except KeyboardInterrupt:
        pass


def _encodestrsonly(v):
    if isinstance(v, type(u'')):
        return v.encode('ascii')
    return v


def bytesvars(obj):
    unidict = vars(obj)
    bd = {k.encode('ascii'): _encodestrsonly(v) for k, v in unidict.items()}
    if bd[b'daemon_postexec'] is not None:
        bd[b'daemon_postexec'] = [
            _encodestrsonly(v) for v in bd[b'daemon_postexec']
        ]
    return bd


def main():
    op = optparse.OptionParser()
    op.add_option('-d', '--daemon', action='store_true')
    op.add_option('--daemon-postexec', action='append')
    op.add_option('-p', '--port', type=int, default=8025)
    op.add_option('-a', '--address', default='localhost')
    op.add_option('--pid-file', metavar='FILE')
    op.add_option('--tls', choices=['none', 'smtps'], default='none')
    op.add_option('--certificate', metavar='FILE')

    opts, args = op.parse_args()
    if opts.tls == 'smtps' and not opts.certificate:
        op.error('--certificate must be specified')

    addr = (opts.address, opts.port)

    def init():
        if opts.tls == 'none':
            dummysmtpserver(addr)
        else:
            dummysmtpsecureserver(addr, opts.certificate)
        log('listening at %s:%d\n' % addr)

    server.runservice(
        bytesvars(opts),
        initfn=init,
        runfn=run,
        runargs=[pycompat.sysexecutable, pycompat.fsencode(__file__)]
        + pycompat.sysargv[1:],
    )


if __name__ == '__main__':
    main()