view mercurial/mail.py @ 48687:f8f2ecdde4b5

branchmap: skip obsolete revisions while computing heads

It's time to make this part of core Mercurial obsolescence-aware.

Not considering obsolete revisions when computing heads is clearly what
Mercurial should do. But there are a couple of small issues:

- Let's say tip of the repo is obsolete. There are two ways of finding tiprev
  for branchcache (both are in use): looking at input data for update() and
  looking at computed heads after update(). Previously, repo tip would be
  tiprev of the branchcache. With this patch, an obsolete revision can no
  longer be tiprev. And depending on what way we use for finding tiprev (input
  data vs computed heads) we'll get a different result. This is relevant when
  recomputing cache key from cache contents, and may lead to updating cache for
  obsolete revisions multiple times (not from scratch, because it still would
  be considered valid for a subset of revisions in the repo).

- If all commits on a branch are obsolete, the branchcache will include that
  branch, but the list of heads will be empty (that's why there's now `if not
  heads` when recomputing tiprev/tipnode from cache contents). Having an entry
  for every branch is currently required for notify extension (and
  test-notify.t to pass), because notify doesn't handle revsets in its
  subscription config very well and will throw an error if e.g. a branch
  doesn't exist.

- Cloning static HTTP repos may try to stat() a non-existent obsstore file. The
  issue is that we now care about obsolescence during clone, but statichttpvfs
  doesn't implement a stat method, so a regular vfs.stat() is used, and it
  assumes that file is local and calls os.stat().  During a clone, we're trying
  to stat() .hg/store/obsstore, but in static HTTP case we provide a literal
  URL to the obsstore file on the remote as if it were a local file path. On
  windows it actually results in a failure in test-static-http.t.

The first issue is going to be addressed in a series dedicated to making sure
branchcache is properly and timely written on disk (it wasn't perfect even
before this patch, but there aren't enough tests to demonstrate that). The
second issue will be addressed in a future patch for notify extension that will
make it not raise an exception if a branch doesn't exist. And the third one was
partially addressed in the previous patch in this series and will be properly
fixed in a future patch when this series is accepted.

filteredhash() grows a keyword argument to make sure that branchcache is also
invalidated when there are new obsolete revisions in its repo view. This way
the on-disk cache format is unchanged and compatible between versions (although
it will obviously be recomputed when switching versions before/after this patch
and the repo has obsolete revisions).

There's one test that uses plain `hg up` without arguments while updated to a
pruned commit. To make this test pass, simply return current working directory
parent. Later in this series this code will be replaced by what prune command
does: updating to the closest non-obsolete ancestor.

Test changes:

test-branch-change.t: update branch head and cache update message. The head of
default listed in hg heads is changed because revision 2 was rewritten as 7,
and 1 is the closest ancestor on the same branch, so it's the head of default
now.

The cache invalidation message appears now because of the cache hash change,
since we're now accounting for obsolete revisions. Here's some context:

"served.hidden" repo filter means everything is visible (no filtered
revisions), so before this series branch2-served.hidden file would not contain
any cache hash, only revnum and node. Now it also has a hash when there are
obsolete changesets in the repo. The command that the message appears for is
changing branch of 5 and 6, which are now obsolete, so the cache hash changes.

In general, when cache is simply out-of-date, it can be updated using the old
version as a base. But if cache hash differs, then the cache for that
particular repo filter is recomputed (at least with the current
implementation). This is what happens here.

test-obsmarker-template.t: the pull reports 2 heads changed, but after that the
repo correctly sees only 1. The new message could be better, but it's still an
improvement over the previous one where hg pull suggested merging with an
obsolete revision.

test-obsolete.t: we can see these revisions in hg log --hidden, but they
shouldn't be considered heads even with --hidden.

test-rebase-obsolete{,2}.t: there were new heads created previously after
making new orphan changesets, but they weren't detected. Now we are properly
detecting and reporting them.

test-rebase-obsolete4.t: there's only one head now because the other head is
pruned and was falsely reported before.

test-static-http.t: add obsstore to the list of requested files. This file
doesn't exist on the remotes, but clients want it anyway (they get 404). This
is fine, because there are other nonexistent files that clients request, like
.hg/bookmarks or .hg/cache/tags2-served.

Differential Revision: https://phab.mercurial-scm.org/D12097

# mail.py - mail sending bits for mercurial
#
# Copyright 2006 Olivia Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import email
import email.charset
import email.generator
import email.header
import email.message
import email.parser
import io
import os
import smtplib
import socket
import time

from .i18n import _
from .pycompat import (
    getattr,
    open,
)
from . import (
    encoding,
    error,
    pycompat,
    sslutil,
    util,
)
from .utils import (
    procutil,
    stringutil,
    urlutil,
)

if pycompat.TYPE_CHECKING:
    from typing import Any, List, Tuple, Union

    # keep pyflakes happy
    assert all((Any, List, Tuple, Union))


class STARTTLS(smtplib.SMTP):
    """Derived class to verify the peer certificate for STARTTLS.

    This class allows to pass any keyword arguments to SSL socket creation.
    """

    def __init__(self, ui, host=None, **kwargs):
        smtplib.SMTP.__init__(self, **kwargs)
        self._ui = ui
        self._host = host

    def starttls(self, keyfile=None, certfile=None):
        if not self.has_extn("starttls"):
            msg = b"STARTTLS extension not supported by server"
            raise smtplib.SMTPException(msg)
        (resp, reply) = self.docmd("STARTTLS")
        if resp == 220:
            self.sock = sslutil.wrapsocket(
                self.sock,
                keyfile,
                certfile,
                ui=self._ui,
                serverhostname=self._host,
            )
            self.file = self.sock.makefile("rb")
            self.helo_resp = None
            self.ehlo_resp = None
            self.esmtp_features = {}
            self.does_esmtp = 0
        return (resp, reply)


class SMTPS(smtplib.SMTP):
    """Derived class to verify the peer certificate for SMTPS.

    This class allows to pass any keyword arguments to SSL socket creation.
    """

    def __init__(self, ui, keyfile=None, certfile=None, host=None, **kwargs):
        self.keyfile = keyfile
        self.certfile = certfile
        smtplib.SMTP.__init__(self, **kwargs)
        self._host = host
        self.default_port = smtplib.SMTP_SSL_PORT
        self._ui = ui

    def _get_socket(self, host, port, timeout):
        if self.debuglevel > 0:
            self._ui.debug(b'connect: %r\n' % ((host, port),))
        new_socket = socket.create_connection((host, port), timeout)
        new_socket = sslutil.wrapsocket(
            new_socket,
            self.keyfile,
            self.certfile,
            ui=self._ui,
            serverhostname=self._host,
        )
        self.file = new_socket.makefile('rb')
        return new_socket


def _pyhastls():
    # type: () -> bool
    """Returns true iff Python has TLS support, false otherwise."""
    try:
        import ssl

        getattr(ssl, 'HAS_TLS', False)
        return True
    except ImportError:
        return False


def _smtp(ui):
    '''build an smtp connection and return a function to send mail'''
    local_hostname = ui.config(b'smtp', b'local_hostname')
    tls = ui.config(b'smtp', b'tls')
    # backward compatible: when tls = true, we use starttls.
    starttls = tls == b'starttls' or stringutil.parsebool(tls)
    smtps = tls == b'smtps'
    if (starttls or smtps) and not _pyhastls():
        raise error.Abort(_(b"can't use TLS: Python SSL support not installed"))
    mailhost = ui.config(b'smtp', b'host')
    if not mailhost:
        raise error.Abort(_(b'smtp.host not configured - cannot send mail'))
    if smtps:
        ui.note(_(b'(using smtps)\n'))
        s = SMTPS(ui, local_hostname=local_hostname, host=mailhost)
    elif starttls:
        s = STARTTLS(ui, local_hostname=local_hostname, host=mailhost)
    else:
        s = smtplib.SMTP(local_hostname=local_hostname)
    if smtps:
        defaultport = 465
    else:
        defaultport = 25
    mailport = urlutil.getport(ui.config(b'smtp', b'port', defaultport))
    ui.note(_(b'sending mail: smtp host %s, port %d\n') % (mailhost, mailport))
    s.connect(host=mailhost, port=mailport)
    if starttls:
        ui.note(_(b'(using starttls)\n'))
        s.ehlo()
        s.starttls()
        s.ehlo()
    if starttls or smtps:
        ui.note(_(b'(verifying remote certificate)\n'))
        sslutil.validatesocket(s.sock)

    try:
        _smtp_login(ui, s, mailhost, mailport)
    except smtplib.SMTPException as inst:
        raise error.Abort(stringutil.forcebytestr(inst))

    def send(sender, recipients, msg):
        try:
            return s.sendmail(sender, recipients, msg)
        except smtplib.SMTPRecipientsRefused as inst:
            recipients = [r[1] for r in inst.recipients.values()]
            raise error.Abort(b'\n' + b'\n'.join(recipients))
        except smtplib.SMTPException as inst:
            raise error.Abort(stringutil.forcebytestr(inst))

    return send


def _smtp_login(ui, smtp, mailhost, mailport):
    """A hook for the keyring extension to perform the actual SMTP login.

    An already connected SMTP object of the proper type is provided, based on
    the current configuration.  The host and port to which the connection was
    established are provided for accessibility, since the SMTP object doesn't
    provide an accessor.  ``smtplib.SMTPException`` is raised on error.
    """
    username = ui.config(b'smtp', b'username')
    password = ui.config(b'smtp', b'password')
    if username:
        if password:
            password = encoding.strfromlocal(password)
        else:
            password = ui.getpass()
            if password is not None:
                password = encoding.strfromlocal(password)
    if username and password:
        ui.note(_(b'(authenticating to mail server as %s)\n') % username)
        username = encoding.strfromlocal(username)
        smtp.login(username, password)


def _sendmail(ui, sender, recipients, msg):
    '''send mail using sendmail.'''
    program = ui.config(b'email', b'method')

    def stremail(x):
        return procutil.shellquote(stringutil.email(encoding.strtolocal(x)))

    cmdline = b'%s -f %s %s' % (
        program,
        stremail(sender),
        b' '.join(map(stremail, recipients)),
    )
    ui.note(_(b'sending mail: %s\n') % cmdline)
    fp = procutil.popen(cmdline, b'wb')
    fp.write(util.tonativeeol(msg))
    ret = fp.close()
    if ret:
        raise error.Abort(
            b'%s %s'
            % (
                os.path.basename(procutil.shellsplit(program)[0]),
                procutil.explainexit(ret),
            )
        )


def _mbox(mbox, sender, recipients, msg):
    '''write mails to mbox'''
    # TODO: use python mbox library for proper locking
    with open(mbox, b'ab+') as fp:
        # Should be time.asctime(), but Windows prints 2-characters day
        # of month instead of one. Make them print the same thing.
        date = time.strftime('%a %b %d %H:%M:%S %Y', time.localtime())
        fp.write(
            b'From %s %s\n'
            % (encoding.strtolocal(sender), encoding.strtolocal(date))
        )
        fp.write(msg)
        fp.write(b'\n\n')


def connect(ui, mbox=None):
    """make a mail connection. return a function to send mail.
    call as sendmail(sender, list-of-recipients, msg)."""
    if mbox:
        open(mbox, b'wb').close()
        return lambda s, r, m: _mbox(mbox, s, r, m)
    if ui.config(b'email', b'method') == b'smtp':
        return _smtp(ui)
    return lambda s, r, m: _sendmail(ui, s, r, m)


def sendmail(ui, sender, recipients, msg, mbox=None):
    send = connect(ui, mbox=mbox)
    return send(sender, recipients, msg)


def validateconfig(ui):
    '''determine if we have enough config data to try sending email.'''
    method = ui.config(b'email', b'method')
    if method == b'smtp':
        if not ui.config(b'smtp', b'host'):
            raise error.Abort(
                _(
                    b'smtp specified as email transport, '
                    b'but no smtp host configured'
                )
            )
    else:
        if not procutil.findexe(method):
            raise error.Abort(
                _(b'%r specified as email transport, but not in PATH') % method
            )


def codec2iana(cs):
    # type: (str) -> str
    ''' '''
    cs = email.charset.Charset(cs).input_charset.lower()

    # "latin1" normalizes to "iso8859-1", standard calls for "iso-8859-1"
    if cs.startswith("iso") and not cs.startswith("iso-"):
        return "iso-" + cs[3:]
    return cs


def mimetextpatch(s, subtype='plain', display=False):
    # type: (bytes, str, bool) -> email.message.Message
    """Return MIME message suitable for a patch.
    Charset will be detected by first trying to decode as us-ascii, then utf-8,
    and finally the global encodings. If all those fail, fall back to
    ISO-8859-1, an encoding with that allows all byte sequences.
    Transfer encodings will be used if necessary."""

    cs = [
        'us-ascii',
        'utf-8',
        pycompat.sysstr(encoding.encoding),
        pycompat.sysstr(encoding.fallbackencoding),
    ]
    if display:
        cs = ['us-ascii']
    for charset in cs:
        try:
            s.decode(charset)
            return mimetextqp(s, subtype, codec2iana(charset))
        except UnicodeDecodeError:
            pass

    return mimetextqp(s, subtype, "iso-8859-1")


def mimetextqp(body, subtype, charset):
    # type: (bytes, str, str) -> email.message.Message
    """Return MIME message.
    Quoted-printable transfer encoding will be used if necessary.
    """
    cs = email.charset.Charset(charset)
    msg = email.message.Message()
    msg.set_type('text/' + subtype)

    for line in body.splitlines():
        if len(line) > 950:
            cs.body_encoding = email.charset.QP
            break

    # On Python 2, this simply assigns a value. Python 3 inspects
    # body and does different things depending on whether it has
    # encode() or decode() attributes. We can get the old behavior
    # if we pass a str and charset is None and we call set_charset().
    # But we may get into  trouble later due to Python attempting to
    # encode/decode using the registered charset (or attempting to
    # use ascii in the absence of a charset).
    msg.set_payload(body, cs)

    return msg


def _charsets(ui):
    # type: (Any) -> List[str]
    '''Obtains charsets to send mail parts not containing patches.'''
    charsets = [
        pycompat.sysstr(cs.lower())
        for cs in ui.configlist(b'email', b'charsets')
    ]
    fallbacks = [
        pycompat.sysstr(encoding.fallbackencoding.lower()),
        pycompat.sysstr(encoding.encoding.lower()),
        'utf-8',
    ]
    for cs in fallbacks:  # find unique charsets while keeping order
        if cs not in charsets:
            charsets.append(cs)
    return [cs for cs in charsets if not cs.endswith('ascii')]


def _encode(ui, s, charsets):
    # type: (Any, bytes, List[str]) -> Tuple[bytes, str]
    """Returns (converted) string, charset tuple.
    Finds out best charset by cycling through sendcharsets in descending
    order. Tries both encoding and fallbackencoding for input. Only as
    last resort send as is in fake ascii.
    Caveat: Do not use for mail parts containing patches!"""
    sendcharsets = charsets or _charsets(ui)
    if not isinstance(s, bytes):
        # We have unicode data, which we need to try and encode to
        # some reasonable-ish encoding. Try the encodings the user
        # wants, and fall back to garbage-in-ascii.
        for ocs in sendcharsets:
            try:
                return s.encode(ocs), ocs
            except UnicodeEncodeError:
                pass
            except LookupError:
                ui.warn(
                    _(b'ignoring invalid sendcharset: %s\n')
                    % pycompat.sysbytes(ocs)
                )
        else:
            # Everything failed, ascii-armor what we've got and send it.
            return s.encode('ascii', 'backslashreplace'), 'us-ascii'
    # We have a bytes of unknown encoding. We'll try and guess a valid
    # encoding, falling back to pretending we had ascii even though we
    # know that's wrong.
    try:
        s.decode('ascii')
    except UnicodeDecodeError:
        for ics in (encoding.encoding, encoding.fallbackencoding):
            ics = pycompat.sysstr(ics)
            try:
                u = s.decode(ics)
            except UnicodeDecodeError:
                continue
            for ocs in sendcharsets:
                try:
                    return u.encode(ocs), ocs
                except UnicodeEncodeError:
                    pass
                except LookupError:
                    ui.warn(
                        _(b'ignoring invalid sendcharset: %s\n')
                        % pycompat.sysbytes(ocs)
                    )
    # if ascii, or all conversion attempts fail, send (broken) ascii
    return s, 'us-ascii'


def headencode(ui, s, charsets=None, display=False):
    # type: (Any, Union[bytes, str], List[str], bool) -> str
    '''Returns RFC-2047 compliant header from given string.'''
    if not display:
        # split into words?
        s, cs = _encode(ui, s, charsets)
        return email.header.Header(s, cs).encode()
    return encoding.strfromlocal(s)


def _addressencode(ui, name, addr, charsets=None):
    # type: (Any, str, str, List[str]) -> str
    addr = encoding.strtolocal(addr)
    name = headencode(ui, name, charsets)
    try:
        acc, dom = addr.split(b'@')
        acc.decode('ascii')
        dom = dom.decode(pycompat.sysstr(encoding.encoding)).encode('idna')
        addr = b'%s@%s' % (acc, dom)
    except UnicodeDecodeError:
        raise error.Abort(_(b'invalid email address: %s') % addr)
    except ValueError:
        try:
            # too strict?
            addr.decode('ascii')
        except UnicodeDecodeError:
            raise error.Abort(_(b'invalid local address: %s') % addr)
    return email.utils.formataddr((name, encoding.strfromlocal(addr)))


def addressencode(ui, address, charsets=None, display=False):
    # type: (Any, bytes, List[str], bool) -> str
    '''Turns address into RFC-2047 compliant header.'''
    if display or not address:
        return encoding.strfromlocal(address or b'')
    name, addr = email.utils.parseaddr(encoding.strfromlocal(address))
    return _addressencode(ui, name, addr, charsets)


def addrlistencode(ui, addrs, charsets=None, display=False):
    # type: (Any, List[bytes], List[str], bool) -> List[str]
    """Turns a list of addresses into a list of RFC-2047 compliant headers.
    A single element of input list may contain multiple addresses, but output
    always has one address per item"""
    straddrs = []
    for a in addrs:
        assert isinstance(a, bytes), '%r unexpectedly not a bytestr' % a
        straddrs.append(encoding.strfromlocal(a))
    if display:
        return [a.strip() for a in straddrs if a.strip()]

    result = []
    for name, addr in email.utils.getaddresses(straddrs):
        if name or addr:
            r = _addressencode(ui, name, addr, charsets)
            result.append(r)
    return result


def mimeencode(ui, s, charsets=None, display=False):
    # type: (Any, bytes, List[str], bool) -> email.message.Message
    """creates mime text object, encodes it if needed, and sets
    charset and transfer-encoding accordingly."""
    cs = 'us-ascii'
    if not display:
        s, cs = _encode(ui, s, charsets)
    return mimetextqp(s, 'plain', cs)


if pycompat.ispy3:

    Generator = email.generator.BytesGenerator

    def parse(fp):
        # type: (Any) -> email.message.Message
        ep = email.parser.Parser()
        # disable the "universal newlines" mode, which isn't binary safe.
        # I have no idea if ascii/surrogateescape is correct, but that's
        # what the standard Python email parser does.
        fp = io.TextIOWrapper(
            fp, encoding='ascii', errors='surrogateescape', newline=chr(10)
        )
        try:
            return ep.parse(fp)
        finally:
            fp.detach()

    def parsebytes(data):
        # type: (bytes) -> email.message.Message
        ep = email.parser.BytesParser()
        return ep.parsebytes(data)


else:

    Generator = email.generator.Generator

    def parse(fp):
        # type: (Any) -> email.message.Message
        ep = email.parser.Parser()
        return ep.parse(fp)

    def parsebytes(data):
        # type: (str) -> email.message.Message
        ep = email.parser.Parser()
        return ep.parsestr(data)


def headdecode(s):
    # type: (Union[email.header.Header, bytes]) -> bytes
    '''Decodes RFC-2047 header'''
    uparts = []
    for part, charset in email.header.decode_header(s):
        if charset is not None:
            try:
                uparts.append(part.decode(charset))
                continue
            except (UnicodeDecodeError, LookupError):
                pass
        # On Python 3, decode_header() may return either bytes or unicode
        # depending on whether the header has =?<charset>? or not
        if isinstance(part, type(u'')):
            uparts.append(part)
            continue
        try:
            uparts.append(part.decode('UTF-8'))
            continue
        except UnicodeDecodeError:
            pass
        uparts.append(part.decode('ISO-8859-1'))
    return encoding.unitolocal(u' '.join(uparts))