tests/test-sshserver.py

test: add test-transaction-rollback-on-sigpipe.t demonstrating py3 regression

When an hg push is interrupted with C-c, the remote [hg serve] command
receives SIGPIPE.

If a pretxnchangegroup hook fails, the remote hg then tries to
rollback the transaction. It begins by printing "transaction
abort!\n". This returns EPIPE, but ui.py ignores that error.

In python3 (but not python2), this "transaction abort!\n" message
stays in a buffer, so future flushes of stderr will try to print the
message again, and so those flushes will also hit EPIPE.

This test demonstrates such a case where this EPIPE causes the
transaction rollback to fail, leaving behind an abandoned transaction.

Differential Revision: https://phab.mercurial-scm.org/D9151

from __future__ import absolute_import, print_function

import io
import unittest

import silenttestrunner

from mercurial import (
    wireprotoserver,
    wireprotov1server,
)

from mercurial.utils import procutil


class SSHServerGetArgsTests(unittest.TestCase):
    def testparseknown(self):
        tests = [
            (b'* 0\nnodes 0\n', [b'', {}]),
            (
                b'* 0\nnodes 40\n1111111111111111111111111111111111111111\n',
                [b'1111111111111111111111111111111111111111', {}],
            ),
        ]
        for input, expected in tests:
            self.assertparse(b'known', input, expected)

    def assertparse(self, cmd, input, expected):
        server = mockserver(input)
        proto = wireprotoserver.sshv1protocolhandler(
            server._ui, server._fin, server._fout
        )
        _func, spec = wireprotov1server.commands[cmd]
        self.assertEqual(proto.getargs(spec), expected)


def mockserver(inbytes):
    ui = mockui(inbytes)
    repo = mockrepo(ui)
    return wireprotoserver.sshserver(ui, repo)


class mockrepo(object):
    def __init__(self, ui):
        self.ui = ui


class mockui(object):
    def __init__(self, inbytes):
        self.fin = io.BytesIO(inbytes)
        self.fout = io.BytesIO()
        self.ferr = io.BytesIO()

    def protectfinout(self):
        return self.fin, self.fout

    def restorefinout(self, fin, fout):
        pass


if __name__ == '__main__':
    # Don't call into msvcrt to set BytesIO to binary mode
    procutil.setbinary = lambda fp: True
    silenttestrunner.main(__name__)