view contrib/hgclient.py @ 46527:018d622e814d

test-copies: reinstall initial identical (empty) files for chained copied

This effectively back out changeset deeb215be337. Changeset deeb215be33 does not
really include a justification for its change and make mes uncomfortable. I have
been thinking about it and they are two options:

- either having empty/full files does not make a difference, and deeb215be337 is
  a gratuitous changes.

- either having empty/full files do make a difference and deeb215be33 silently
  change the test coverage. In such situation if we want the "not empty" case to
  be tested, we should add new cases to cover them

In practice, we know that the "file content did not change, but merge still need
to create a new filenode" case exists (for example if merging result in similar
content but both parent of the file need to be recorded), and that such case are
easy to miss/mess-up in the tests. Having all the file using the same (empty)
content was done on purpose to increase the coverage of such corner case.

As a result I am reinstalling the previous test situation. To
increase the coverage of some case involving content-merge in
test-copies-chain-merge.t, we will add a new, dedicated, cases later in this
series, once various cleanup and test improvement have been set in place.

This changeset starts with reinstalling the previous situation as (1) it is more
fragile, so I am more confided getting it back in the initial situation, (2) I
have specific test further down the line that are base on these one.

The next changeset will slightly alter the test to use non-empty files for these
tests (with identical content). It should help to make the initial intent "merge file with identical
content" clearer. I am still using a two steps (backout, then change content)
approach to facilitate careful validation of the output change.

Doing so has a large impact on the output of the "copy info in changeset extra" variant
added in 5e72827dae1e (2 changesets after deeb215be33). It seems to highlight
various breakage when merge without content change are involved, this is a good
example of why we want to explicitly test theses cases. Because the different
-do- matters a lot.

Fixing the "copy info in changeset extra" is not a priority here. Because (1)
this changeset does not break anything, it only highlight that they were always
broken. (2) the only people using "copy info in changeset extra" do not have
merge.

Differential Revision: https://phab.mercurial-scm.org/D9587

# A minimal client for Mercurial's command server

from __future__ import absolute_import, print_function

import io
import os
import re
import signal
import socket
import struct
import subprocess
import sys
import time

if sys.version_info[0] >= 3:
    stdout = sys.stdout.buffer
    stderr = sys.stderr.buffer
    stringio = io.BytesIO

    def bprint(*args):
        # remove b'' as well for ease of test migration
        pargs = [re.sub(br'''\bb(['"])''', br'\1', b'%s' % a) for a in args]
        stdout.write(b' '.join(pargs) + b'\n')


else:
    import cStringIO

    stdout = sys.stdout
    stderr = sys.stderr
    stringio = cStringIO.StringIO
    bprint = print


def connectpipe(path=None, extraargs=()):
    cmdline = [b'hg', b'serve', b'--cmdserver', b'pipe']
    if path:
        cmdline += [b'-R', path]
    cmdline.extend(extraargs)

    def tonative(cmdline):
        if os.name != 'nt':
            return cmdline
        return [arg.decode("utf-8") for arg in cmdline]

    server = subprocess.Popen(
        tonative(cmdline), stdin=subprocess.PIPE, stdout=subprocess.PIPE
    )

    return server


class unixconnection(object):
    def __init__(self, sockpath):
        self.sock = sock = socket.socket(socket.AF_UNIX)
        sock.connect(sockpath)
        self.stdin = sock.makefile('wb')
        self.stdout = sock.makefile('rb')

    def wait(self):
        self.stdin.close()
        self.stdout.close()
        self.sock.close()


class unixserver(object):
    def __init__(self, sockpath, logpath=None, repopath=None):
        self.sockpath = sockpath
        cmdline = [b'hg', b'serve', b'--cmdserver', b'unix', b'-a', sockpath]
        if repopath:
            cmdline += [b'-R', repopath]
        if logpath:
            stdout = open(logpath, 'a')
            stderr = subprocess.STDOUT
        else:
            stdout = stderr = None
        self.server = subprocess.Popen(cmdline, stdout=stdout, stderr=stderr)
        # wait for listen()
        while self.server.poll() is None:
            if os.path.exists(sockpath):
                break
            time.sleep(0.1)

    def connect(self):
        return unixconnection(self.sockpath)

    def shutdown(self):
        os.kill(self.server.pid, signal.SIGTERM)
        self.server.wait()


def writeblock(server, data):
    server.stdin.write(struct.pack(b'>I', len(data)))
    server.stdin.write(data)
    server.stdin.flush()


def readchannel(server):
    data = server.stdout.read(5)
    if not data:
        raise EOFError
    channel, length = struct.unpack('>cI', data)
    if channel in b'IL':
        return channel, length
    else:
        return channel, server.stdout.read(length)


def sep(text):
    return text.replace(b'\\', b'/')


def runcommand(
    server, args, output=stdout, error=stderr, input=None, outfilter=lambda x: x
):
    bprint(b'*** runcommand', b' '.join(args))
    stdout.flush()
    server.stdin.write(b'runcommand\n')
    writeblock(server, b'\0'.join(args))

    if not input:
        input = stringio()

    while True:
        ch, data = readchannel(server)
        if ch == b'o':
            output.write(outfilter(data))
            output.flush()
        elif ch == b'e':
            error.write(data)
            error.flush()
        elif ch == b'I':
            writeblock(server, input.read(data))
        elif ch == b'L':
            writeblock(server, input.readline(data))
        elif ch == b'm':
            bprint(b"message: %r" % data)
        elif ch == b'r':
            (ret,) = struct.unpack('>i', data)
            if ret != 0:
                bprint(b' [%d]' % ret)
            return ret
        else:
            bprint(b"unexpected channel %c: %r" % (ch, data))
            if ch.isupper():
                return


def check(func, connect=connectpipe):
    stdout.flush()
    server = connect()
    try:
        return func(server)
    finally:
        server.stdin.close()
        server.wait()


def checkwith(connect=connectpipe, **kwargs):
    def wrap(func):
        return check(func, lambda: connect(**kwargs))

    return wrap