py3: use a BytesParser in notify extension

This is the first step to make the "long line" case in test-notify.t
pass by fixing a UnicodeDecodeError on Python 3.

We alias a parsebytes() in mail module, similarly as we already have a
parse() function for Python 2 and Python 3 compatibility.

hgext/notify.py

@@ -1,574 +1,572 b''
 # notify.py - email notifications for mercurial
 #
 # Copyright 2006 Vadim Gelfer <[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.
 
 '''hooks for sending email push notifications
 
 This extension implements hooks to send email notifications when
 changesets are sent from or received by the local repository.
 
 First, enable the extension as explained in :hg:`help extensions`, and
 register the hook you want to run. ``incoming`` and ``changegroup`` hooks
 are run when changesets are received, while ``outgoing`` hooks are for
 changesets sent to another repository::
 
   [hooks]
   # one email for each incoming changeset
   incoming.notify = python:hgext.notify.hook
   # one email for all incoming changesets
   changegroup.notify = python:hgext.notify.hook
 
   # one email for all outgoing changesets
   outgoing.notify = python:hgext.notify.hook
 
 This registers the hooks. To enable notification, subscribers must
 be assigned to repositories. The ``[usersubs]`` section maps multiple
 repositories to a given recipient. The ``[reposubs]`` section maps
 multiple recipients to a single repository::
 
   [usersubs]
   # key is subscriber email, value is a comma-separated list of repo patterns
   user@host = pattern
 
   [reposubs]
   # key is repo pattern, value is a comma-separated list of subscriber emails
   pattern = user@host
 
 A ``pattern`` is a ``glob`` matching the absolute path to a repository,
 optionally combined with a revset expression. A revset expression, if
 present, is separated from the glob by a hash. Example::
 
   [reposubs]
   */widgets#branch(release) = [e-mail]
 
 This sends to ``[e-mail]`` whenever a changeset on the ``release``
 branch triggers a notification in any repository ending in ``widgets``.
 
 In order to place them under direct user management, ``[usersubs]`` and
 ``[reposubs]`` sections may be placed in a separate ``hgrc`` file and
 incorporated by reference::
 
   [notify]
   config = /path/to/subscriptionsfile
 
 Notifications will not be sent until the ``notify.test`` value is set
 to ``False``; see below.
 
 Notifications content can be tweaked with the following configuration entries:
 
 notify.test
   If ``True``, print messages to stdout instead of sending them. Default: True.
 
 notify.sources
   Space-separated list of change sources. Notifications are activated only
   when a changeset's source is in this list. Sources may be:
 
   :``serve``: changesets received via http or ssh
   :``pull``: changesets received via ``hg pull``
   :``unbundle``: changesets received via ``hg unbundle``
   :``push``: changesets sent or received via ``hg push``
   :``bundle``: changesets sent via ``hg unbundle``
 
   Default: serve.
 
 notify.strip
   Number of leading slashes to strip from url paths. By default, notifications
   reference repositories with their absolute path. ``notify.strip`` lets you
   turn them into relative paths. For example, ``notify.strip=3`` will change
   ``/long/path/repository`` into ``repository``. Default: 0.
 
 notify.domain
   Default email domain for sender or recipients with no explicit domain.
   It is also used for the domain part of the ``Message-Id`` when using
   ``notify.messageidseed``.
 
 notify.messageidseed
   Create deterministic ``Message-Id`` headers for the mails based on the seed
   and the revision identifier of the first commit in the changeset.
 
 notify.style
   Style file to use when formatting emails.
 
 notify.template
   Template to use when formatting emails.
 
 notify.incoming
   Template to use when run as an incoming hook, overriding ``notify.template``.
 
 notify.outgoing
   Template to use when run as an outgoing hook, overriding ``notify.template``.
 
 notify.changegroup
   Template to use when running as a changegroup hook, overriding
   ``notify.template``.
 
 notify.maxdiff
   Maximum number of diff lines to include in notification email. Set to 0
   to disable the diff, or -1 to include all of it. Default: 300.
 
 notify.maxdiffstat
   Maximum number of diffstat lines to include in notification email. Set to -1
   to include all of it. Default: -1.
 
 notify.maxsubject
   Maximum number of characters in email's subject line. Default: 67.
 
 notify.diffstat
   Set to True to include a diffstat before diff content. Default: True.
 
 notify.showfunc
   If set, override ``diff.showfunc`` for the diff content. Default: None.
 
 notify.merge
   If True, send notifications for merge changesets. Default: True.
 
 notify.mbox
   If set, append mails to this mbox file instead of sending. Default: None.
 
 notify.fromauthor
   If set, use the committer of the first changeset in a changegroup for
   the "From" field of the notification mail. If not set, take the user
   from the pushing repo.  Default: False.
 
 If set, the following entries will also be used to customize the
 notifications:
 
 email.from
   Email ``From`` address to use if none can be found in the generated
   email content.
 
 web.baseurl
   Root repository URL to combine with repository paths when making
   references. See also ``notify.strip``.
 
 '''
 from __future__ import absolute_import
 
 import email.errors as emailerrors
-import email.parser as emailparser
 import fnmatch
 import hashlib
 import socket
 import time
 
 from mercurial.i18n import _
 from mercurial import (
     encoding,
     error,
     logcmdutil,
     mail,
     patch,
     pycompat,
     registrar,
     util,
 )
 from mercurial.utils import (
     dateutil,
     stringutil,
 )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = b'ships-with-hg-core'
 
 configtable = {}
 configitem = registrar.configitem(configtable)
 
 configitem(
     b'notify', b'changegroup', default=None,
 )
 configitem(
     b'notify', b'config', default=None,
 )
 configitem(
     b'notify', b'diffstat', default=True,
 )
 configitem(
     b'notify', b'domain', default=None,
 )
 configitem(
     b'notify', b'messageidseed', default=None,
 )
 configitem(
     b'notify', b'fromauthor', default=None,
 )
 configitem(
     b'notify', b'incoming', default=None,
 )
 configitem(
     b'notify', b'maxdiff', default=300,
 )
 configitem(
     b'notify', b'maxdiffstat', default=-1,
 )
 configitem(
     b'notify', b'maxsubject', default=67,
 )
 configitem(
     b'notify', b'mbox', default=None,
 )
 configitem(
     b'notify', b'merge', default=True,
 )
 configitem(
     b'notify', b'outgoing', default=None,
 )
 configitem(
     b'notify', b'sources', default=b'serve',
 )
 configitem(
     b'notify', b'showfunc', default=None,
 )
 configitem(
     b'notify', b'strip', default=0,
 )
 configitem(
     b'notify', b'style', default=None,
 )
 configitem(
     b'notify', b'template', default=None,
 )
 configitem(
     b'notify', b'test', default=True,
 )
 
 # template for single changeset can include email headers.
 single_template = b'''
 Subject: changeset in {webroot}: {desc|firstline|strip}
 From: {author}
 
 changeset {node|short} in {root}
 details: {baseurl}{webroot}?cmd=changeset;node={node|short}
 description:
 \t{desc|tabindent|strip}
 '''.lstrip()
 
 # template for multiple changesets should not contain email headers,
 # because only first set of headers will be used and result will look
 # strange.
 multiple_template = b'''
 changeset {node|short} in {root}
 details: {baseurl}{webroot}?cmd=changeset;node={node|short}
 summary: {desc|firstline}
 '''
 
 deftemplates = {
     b'changegroup': multiple_template,
 }
 
 
 class notifier(object):
     '''email notification class.'''
 
     def __init__(self, ui, repo, hooktype):
         self.ui = ui
         cfg = self.ui.config(b'notify', b'config')
         if cfg:
             self.ui.readconfig(cfg, sections=[b'usersubs', b'reposubs'])
         self.repo = repo
         self.stripcount = int(self.ui.config(b'notify', b'strip'))
         self.root = self.strip(self.repo.root)
         self.domain = self.ui.config(b'notify', b'domain')
         self.mbox = self.ui.config(b'notify', b'mbox')
         self.test = self.ui.configbool(b'notify', b'test')
         self.charsets = mail._charsets(self.ui)
         self.subs = self.subscribers()
         self.merge = self.ui.configbool(b'notify', b'merge')
         self.showfunc = self.ui.configbool(b'notify', b'showfunc')
         self.messageidseed = self.ui.config(b'notify', b'messageidseed')
         if self.showfunc is None:
             self.showfunc = self.ui.configbool(b'diff', b'showfunc')
 
         mapfile = None
         template = self.ui.config(b'notify', hooktype) or self.ui.config(
             b'notify', b'template'
         )
         if not template:
             mapfile = self.ui.config(b'notify', b'style')
         if not mapfile and not template:
             template = deftemplates.get(hooktype) or single_template
         spec = logcmdutil.templatespec(template, mapfile)
         self.t = logcmdutil.changesettemplater(self.ui, self.repo, spec)
 
     def strip(self, path):
         '''strip leading slashes from local path, turn into web-safe path.'''
 
         path = util.pconvert(path)
         count = self.stripcount
         while count > 0:
             c = path.find(b'/')
             if c == -1:
                 break
             path = path[c + 1 :]
             count -= 1
         return path
 
     def fixmail(self, addr):
         '''try to clean up email addresses.'''
 
         addr = stringutil.email(addr.strip())
         if self.domain:
             a = addr.find(b'@localhost')
             if a != -1:
                 addr = addr[:a]
             if b'@' not in addr:
                 return addr + b'@' + self.domain
         return addr
 
     def subscribers(self):
         '''return list of email addresses of subscribers to this repo.'''
         subs = set()
         for user, pats in self.ui.configitems(b'usersubs'):
             for pat in pats.split(b','):
                 if b'#' in pat:
                     pat, revs = pat.split(b'#', 1)
                 else:
                     revs = None
                 if fnmatch.fnmatch(self.repo.root, pat.strip()):
                     subs.add((self.fixmail(user), revs))
         for pat, users in self.ui.configitems(b'reposubs'):
             if b'#' in pat:
                 pat, revs = pat.split(b'#', 1)
             else:
                 revs = None
             if fnmatch.fnmatch(self.repo.root, pat):
                 for user in users.split(b','):
                     subs.add((self.fixmail(user), revs))
         return [
             (mail.addressencode(self.ui, s, self.charsets, self.test), r)
             for s, r in sorted(subs)
         ]
 
     def node(self, ctx, **props):
         '''format one changeset, unless it is a suppressed merge.'''
         if not self.merge and len(ctx.parents()) > 1:
             return False
         self.t.show(
             ctx,
             changes=ctx.changeset(),
             baseurl=self.ui.config(b'web', b'baseurl'),
             root=self.repo.root,
             webroot=self.root,
             **props
         )
         return True
 
     def skipsource(self, source):
         '''true if incoming changes from this source should be skipped.'''
         ok_sources = self.ui.config(b'notify', b'sources').split()
         return source not in ok_sources
 
     def send(self, ctx, count, data):
         '''send message.'''
 
         # Select subscribers by revset
         subs = set()
         for sub, spec in self.subs:
             if spec is None:
                 subs.add(sub)
                 continue
             revs = self.repo.revs(b'%r and %d:', spec, ctx.rev())
             if len(revs):
                 subs.add(sub)
                 continue
         if len(subs) == 0:
             self.ui.debug(
                 b'notify: no subscribers to selected repo and revset\n'
             )
             return
 
-        p = emailparser.Parser()
         try:
-            msg = p.parsestr(encoding.strfromlocal(data))
+            msg = mail.parsebytes(data)
         except emailerrors.MessageParseError as inst:
             raise error.Abort(inst)
 
         # store sender and subject
         sender = msg[r'From']
         subject = msg[r'Subject']
         if sender is not None:
             sender = encoding.strtolocal(sender)
         if subject is not None:
             subject = encoding.strtolocal(subject)
         del msg[r'From'], msg[r'Subject']
 
         if not msg.is_multipart():
             # create fresh mime message from scratch
             # (multipart templates must take care of this themselves)
             headers = msg.items()
             payload = msg.get_payload()
             # for notification prefer readability over data precision
             msg = mail.mimeencode(self.ui, payload, self.charsets, self.test)
             # reinstate custom headers
             for k, v in headers:
                 msg[k] = v
 
         msg[r'Date'] = encoding.strfromlocal(
             dateutil.datestr(format=b"%a, %d %b %Y %H:%M:%S %1%2")
         )
 
         # try to make subject line exist and be useful
         if not subject:
             if count > 1:
                 subject = _(b'%s: %d new changesets') % (self.root, count)
             else:
                 s = ctx.description().lstrip().split(b'\n', 1)[0].rstrip()
                 subject = b'%s: %s' % (self.root, s)
         maxsubject = int(self.ui.config(b'notify', b'maxsubject'))
         if maxsubject:
             subject = stringutil.ellipsis(subject, maxsubject)
         msg[r'Subject'] = encoding.strfromlocal(
             mail.headencode(self.ui, subject, self.charsets, self.test)
         )
 
         # try to make message have proper sender
         if not sender:
             sender = self.ui.config(b'email', b'from') or self.ui.username()
         if b'@' not in sender or b'@localhost' in sender:
             sender = self.fixmail(sender)
         msg[r'From'] = encoding.strfromlocal(
             mail.addressencode(self.ui, sender, self.charsets, self.test)
         )
 
         msg[r'X-Hg-Notification'] = r'changeset %s' % ctx
         if not msg[r'Message-Id']:
             msg[r'Message-Id'] = messageid(ctx, self.domain, self.messageidseed)
         msg[r'To'] = encoding.strfromlocal(b', '.join(sorted(subs)))
 
         msgtext = msg.as_bytes() if pycompat.ispy3 else msg.as_string()
         if self.test:
             self.ui.write(msgtext)
             if not msgtext.endswith(b'\n'):
                 self.ui.write(b'\n')
         else:
             self.ui.status(
                 _(b'notify: sending %d subscribers %d changes\n')
                 % (len(subs), count)
             )
             mail.sendmail(
                 self.ui,
                 stringutil.email(msg[r'From']),
                 subs,
                 msgtext,
                 mbox=self.mbox,
             )
 
     def diff(self, ctx, ref=None):
 
         maxdiff = int(self.ui.config(b'notify', b'maxdiff'))
         prev = ctx.p1().node()
         if ref:
             ref = ref.node()
         else:
             ref = ctx.node()
         diffopts = patch.diffallopts(self.ui)
         diffopts.showfunc = self.showfunc
         chunks = patch.diff(self.repo, prev, ref, opts=diffopts)
         difflines = b''.join(chunks).splitlines()
 
         if self.ui.configbool(b'notify', b'diffstat'):
             maxdiffstat = int(self.ui.config(b'notify', b'maxdiffstat'))
             s = patch.diffstat(difflines)
             # s may be nil, don't include the header if it is
             if s:
                 if maxdiffstat >= 0 and s.count(b"\n") > maxdiffstat + 1:
                     s = s.split(b"\n")
                     msg = _(b'\ndiffstat (truncated from %d to %d lines):\n\n')
                     self.ui.write(msg % (len(s) - 2, maxdiffstat))
                     self.ui.write(b"\n".join(s[:maxdiffstat] + s[-2:]))
                 else:
                     self.ui.write(_(b'\ndiffstat:\n\n%s') % s)
 
         if maxdiff == 0:
             return
         elif maxdiff > 0 and len(difflines) > maxdiff:
             msg = _(b'\ndiffs (truncated from %d to %d lines):\n\n')
             self.ui.write(msg % (len(difflines), maxdiff))
             difflines = difflines[:maxdiff]
         elif difflines:
             self.ui.write(_(b'\ndiffs (%d lines):\n\n') % len(difflines))
 
         self.ui.write(b"\n".join(difflines))
 
 
 def hook(ui, repo, hooktype, node=None, source=None, **kwargs):
     '''send email notifications to interested subscribers.
 
     if used as changegroup hook, send one email for all changesets in
     changegroup. else send one email per changeset.'''
 
     n = notifier(ui, repo, hooktype)
     ctx = repo.unfiltered()[node]
 
     if not n.subs:
         ui.debug(b'notify: no subscribers to repository %s\n' % n.root)
         return
     if n.skipsource(source):
         ui.debug(b'notify: changes have source "%s" - skipping\n' % source)
         return
 
     ui.pushbuffer()
     data = b''
     count = 0
     author = b''
     if hooktype == b'changegroup' or hooktype == b'outgoing':
         for rev in repo.changelog.revs(start=ctx.rev()):
             if n.node(repo[rev]):
                 count += 1
                 if not author:
                     author = repo[rev].user()
             else:
                 data += ui.popbuffer()
                 ui.note(
                     _(b'notify: suppressing notification for merge %d:%s\n')
                     % (rev, repo[rev].hex()[:12])
                 )
                 ui.pushbuffer()
         if count:
             n.diff(ctx, repo[b'tip'])
     elif ctx.rev() in repo:
         if not n.node(ctx):
             ui.popbuffer()
             ui.note(
                 _(b'notify: suppressing notification for merge %d:%s\n')
                 % (ctx.rev(), ctx.hex()[:12])
             )
             return
         count += 1
         n.diff(ctx)
         if not author:
             author = ctx.user()
 
     data += ui.popbuffer()
     fromauthor = ui.config(b'notify', b'fromauthor')
     if author and fromauthor:
         data = b'\n'.join([b'From: %s' % author, data])
 
     if count:
         n.send(ctx, count, data)
 
 
 def messageid(ctx, domain, messageidseed):
     if domain and messageidseed:
         host = domain
     else:
         host = encoding.strtolocal(socket.getfqdn())
     if messageidseed:
         messagehash = hashlib.sha512(ctx.hex() + messageidseed)
         messageid = b'<hg.%s@%s>' % (
             pycompat.sysbytes(messagehash.hexdigest()[:64]),
             host,
         )
     else:
         messageid = b'<hg.%s.%d.%d@%s>' % (
             ctx,
             int(time.time()),
             hash(ctx.repo().root),
             host,
         )
     return encoding.strfromlocal(messageid)

mercurial/mail.py

@@ -1,474 +1,481 b''
 # mail.py - mail sending bits for mercurial
 #
 # Copyright 2006 Matt 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,
 )
 
 
 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(r'rb')
         return new_socket
 
 
 def _pyhastls():
     """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 = util.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)
     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 username and password:
         ui.note(_(b'(authenticating to mail server as %s)\n') % username)
         username = encoding.strfromlocal(username)
         try:
             s.login(username, password)
         except smtplib.SMTPException as inst:
             raise error.Abort(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(inst)
 
     return send
 
 
 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(program.split(None, 1)[0]),
                 procutil.explainexit(ret),
             )
         )
 
 
 def _mbox(mbox, sender, recipients, msg):
     '''write mails to mbox'''
     fp = open(mbox, b'ab+')
     # Should be time.asctime(), but Windows prints 2-characters day
     # of month instead of one. Make them print the same thing.
     date = time.strftime(r'%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')
     fp.close()
 
 
 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):
     ''''''
     cs = pycompat.sysbytes(email.charset.Charset(cs).input_charset.lower())
 
     # "latin1" normalizes to "iso8859-1", standard calls for "iso-8859-1"
     if cs.startswith(b"iso") and not cs.startswith(b"iso-"):
         return b"iso-" + cs[3:]
     return cs
 
 
 def mimetextpatch(s, subtype=b'plain', display=False):
     '''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 = [b'us-ascii', b'utf-8', encoding.encoding, encoding.fallbackencoding]
     if display:
         cs = [b'us-ascii']
     for charset in cs:
         try:
             s.decode(pycompat.sysstr(charset))
             return mimetextqp(s, subtype, codec2iana(charset))
         except UnicodeDecodeError:
             pass
 
     return mimetextqp(s, subtype, b"iso-8859-1")
 
 
 def mimetextqp(body, subtype, charset):
     '''Return MIME message.
     Quoted-printable transfer encoding will be used if necessary.
     '''
     cs = email.charset.Charset(charset)
     msg = email.message.Message()
     msg.set_type(pycompat.sysstr(b'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):
     '''Obtains charsets to send mail parts not containing patches.'''
     charsets = [cs.lower() for cs in ui.configlist(b'email', b'charsets')]
     fallbacks = [
         encoding.fallbackencoding.lower(),
         encoding.encoding.lower(),
         b'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(b'ascii')]
 
 
 def _encode(ui, s, charsets):
     '''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(pycompat.sysstr(ocs)), ocs
             except UnicodeEncodeError:
                 pass
             except LookupError:
                 ui.warn(_(b'ignoring invalid sendcharset: %s\n') % ocs)
         else:
             # Everything failed, ascii-armor what we've got and send it.
             return s.encode('ascii', 'backslashreplace')
     # 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):
             try:
                 u = s.decode(ics)
             except UnicodeDecodeError:
                 continue
             for ocs in sendcharsets:
                 try:
                     return u.encode(pycompat.sysstr(ocs)), ocs
                 except UnicodeEncodeError:
                     pass
                 except LookupError:
                     ui.warn(_(b'ignoring invalid sendcharset: %s\n') % ocs)
     # if ascii, or all conversion attempts fail, send (broken) ascii
     return s, b'us-ascii'
 
 
 def headencode(ui, s, charsets=None, display=False):
     '''Returns RFC-2047 compliant header from given string.'''
     if not display:
         # split into words?
         s, cs = _encode(ui, s, charsets)
         return encoding.strtolocal(email.header.Header(s, cs).encode())
     return s
 
 
 def _addressencode(ui, name, addr, charsets=None):
     assert isinstance(addr, bytes)
     name = encoding.strfromlocal(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 pycompat.bytesurl(
         email.utils.formataddr((name, encoding.strfromlocal(addr)))
     )
 
 
 def addressencode(ui, address, charsets=None, display=False):
     '''Turns address into RFC-2047 compliant header.'''
     if display or not address:
         return address or b''
     name, addr = email.utils.parseaddr(encoding.strfromlocal(address))
     return _addressencode(ui, name, encoding.strtolocal(addr), charsets)
 
 
 def addrlistencode(ui, addrs, charsets=None, display=False):
     '''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'''
     for a in addrs:
         assert isinstance(a, bytes), r'%r unexpectedly not a bytestr' % a
     if display:
         return [a.strip() for a in addrs if a.strip()]
 
     result = []
     for name, addr in email.utils.getaddresses(
         [encoding.strfromlocal(a) for a in addrs]
     ):
         if name or addr:
             r = _addressencode(ui, name, encoding.strtolocal(addr), charsets)
             result.append(r)
     return result
 
 
 def mimeencode(ui, s, charsets=None, display=False):
     '''creates mime text object, encodes it if needed, and sets
     charset and transfer-encoding accordingly.'''
     cs = b'us-ascii'
     if not display:
         s, cs = _encode(ui, s, charsets)
     return mimetextqp(s, b'plain', cs)
 
 
 if pycompat.ispy3:
 
     Generator = email.generator.BytesGenerator
 
     def parse(fp):
         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=r'ascii', errors=r'surrogateescape', newline=chr(10)
         )
         try:
             return ep.parse(fp)
         finally:
             fp.detach()
 
+    def parsebytes(data):
+        ep = email.parser.BytesParser()
+        return ep.parsebytes(data)
 
 else:
 
     Generator = email.generator.Generator
 
     def parse(fp):
         ep = email.parser.Parser()
         return ep.parse(fp)
 
+    def parsebytes(data):
+        ep = email.parser.Parser()
+        return ep.parsestr(data)
+
 
 def headdecode(s):
     '''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))