tests/test-duplicateoptions.py

tests: add low-level SSH protocol tests

We don't really have good low-level tests for the behavior of the SSH
wire protocol. This commit attempts to establish some.

The added tests consist of a mixture of starting a server
with `hg serve --stdio` and sending bytes to it and using
`hg debugpeer` to go through the official client code. Having
insight into what raw bytes are exchanged as well as what the peer
does is useful.

We also introduce a test extension for modifying the behavior of
the SSH server and peer. For example, we change the server to
not recognize the "hello" command, simulating behavior of <0.9.1
servers.

These tests are generally useful to have. But the impetus for creating
them now is they will be needed for verifying behavior of old clients
and servers when a new SSH protocol is introduced.

Differential Revision: https://phab.mercurial-scm.org/D2026

# no-check-commit because of serve_forever()

from __future__ import absolute_import, print_function
import os
from mercurial import (
    commands,
    extensions,
    ui as uimod,
)

ignore = {b'highlight', b'win32text', b'factotum'}

if os.name != 'nt':
    ignore.add(b'win32mbcs')

disabled = [ext for ext in extensions.disabled().keys() if ext not in ignore]

hgrc = open(os.environ["HGRCPATH"], 'wb')
hgrc.write(b'[extensions]\n')

for ext in disabled:
    hgrc.write(ext + b'=\n')

hgrc.close()

u = uimod.ui.load()
extensions.loadall(u)

globalshort = set()
globallong = set()
for option in commands.globalopts:
    option[0] and globalshort.add(option[0])
    option[1] and globallong.add(option[1])

for cmd, entry in commands.table.items():
    seenshort = globalshort.copy()
    seenlong = globallong.copy()
    for option in entry[1]:
        if (option[0] and option[0] in seenshort) or \
           (option[1] and option[1] in seenlong):
            print("command '" + cmd + "' has duplicate option " + str(option))
        seenshort.add(option[0])
        seenlong.add(option[1])