hgext/patchbomb.py
author Gregory Szorc <gregory.szorc@gmail.com>
Sat, 24 Dec 2016 13:56:36 -0700
changeset 30760 753b9d43ca81
parent 30635 a150173da1c1
child 30838 eb78ec9e97b7
permissions -rw-r--r--
internals: document compression negotiation As part of adding zstd support to all of the things, we'll need to teach the wire protocol to support non-zlib compression formats. This commit documents how we'll implement that. To understand how we arrived at this proposal, let's look at how things are done today. The wire protocol today doesn't have a unified format. Instead, there is a limited facility for differentiating replies as successful or not. And, each command essentially defines its own response format. A significant deficiency in the current protocol is the lack of payload framing over the SSH transport. In the HTTP transport, chunked transfer is used and the end of an HTTP response body (and the end of a Mercurial command response) can be identified by a 0 length chunk. This is how HTTP chunked transfer works. But in the SSH transport, there is no such framing, at least for certain responses (notably the response to "getbundle" requests). Clients can't simply read until end of stream because the socket is persistent and reused for multiple requests. Clients need to know when they've encountered the end of a request but there is nothing simple for them to key off of to detect this. So what happens is the client must decode the payload (as opposed to being dumb and forwarding frames/packets). This means the payload itself needs to support identifying end of stream. In some cases (bundle2), it also means the payload can encode "error" or "interrupt" events telling the client to e.g. abort processing. The lack of framing on the SSH transport and the transfer of its responsibilities to e.g. bundle2 is a massive layering violation and a wart on the protocol architecture. It needs to be fixed someday by inventing a proper framing protocol. So about compression. The client transport abstractions have a "_callcompressable()" API. This API is called to invoke a remote command that will send a compressible response. The response is essentially a "streaming" response (no framing data at the Mercurial layer) that is fed into a decompressor. On the HTTP transport, the decompressor is zlib and only zlib. There is currently no mechanism for the client to specify an alternate compression format. And, clients don't advertise what compression formats they support or ask the server to send a specific compression format. Instead, it is assumed that non-error responses to "compressible" commands are zlib compressed. On the SSH transport, there is no compression at the Mercurial protocol layer. Instead, compression must be handled by SSH itself (e.g. `ssh -C`) or within the payload data (e.g. bundle compression). For the HTTP transport, adding new compression formats is pretty straightforward. Once you know what decompressor to use, you can stream data into the decompressor until you reach a 0 size HTTP chunk, at which point you are at end of stream. So our wire protocol changes for the HTTP transport are pretty straightforward: the client and server advertise what compression formats they support and an appropriate compression format is chosen. We introduce a new HTTP media type to hold compressed payloads. The header of the payload defines the compression format being used. Whoever is on the receiving end can sniff the first few bytes route to an appropriate decompressor. Support for multiple compression formats is advertised on both server and client. The server advertises a "compression" capability saying which compression formats it supports and in what order they are preferred. Clients advertise their support for multiple compression formats and media types via the introduced "X-HgProto" request header. Strictly speaking, servers don't need to advertise which compression formats they support. But doing so allows clients to fail fast if they don't support any of the formats the server does. This is useful in situations like sending bundles, where the client may have to perform expensive computation before sending data to the server. Rather than simply advertise a list of supported compression formats, we introduce an additional "httpmediatype" server capability advertising which media types the server supports. This means servers are explicit about what formats they exchange. IMO, this is superior to inferring support from other capabilities (like "compression"). By advertising compression support on each request in the "X-HgProto" header and media type and direction at the server level, we are able to gradually transition existing commands/responses to the new media type and possibly compression. Contrast with the old world, where we only supported a single media type and the use of compression was built-in to the semantics of the command on both client and server. In the new world, if "application/mercurial-0.2" is supported, compression is supported. It's that simple. It's worth noting that we explicitly don't use "Accept," "Accept-Encoding," "Content-Encoding," or "Transfer-Encoding" for content negotiation and compression. People knowledgeable of the HTTP specifications will say that we should use these because that's what they are designed to be used for. They have a point and I sympathize with the argument. Earlier versions of this commit even defined supported media types in the "Accept" header. However, my years of experience rolling out services leveraging HTTP has taught me to not trust the HTTP layer, especially if you are going outside the normal spec (such as using a custom "Content-Encoding" value to represent zstd streams). I've seen load balancers, proxies, and other network devices do very bad and unexpected things to HTTP messages (like insisting zlib compressed content is decoded and then re-encoded at a different compression level or even stripping compression completely). I've found that the best way to avoid surprises when writing protocols on top of HTTP is to use HTTP as a dumb transport as much as possible to minimize the chances that an "intelligent" agent between endpoints will muck with your data. While the widespread use of TLS is mitigating many intermediate network agents interfering with HTTP, there are still problems at the edges, with e.g. the origin HTTP server needing to convert HTTP to and from WSGI and buggy or feature-lacking HTTP client implementations. I've found the best way to avoid these problems is to avoid using headers like "Content-Encoding" and to bake as much logic as possible into media types and HTTP message bodies. The protocol changes in this commit do rely on a custom HTTP request header and the "Content-Type" headers. But we used them before, so we shouldn't be increasing our exposure to "bad" HTTP agents. For the SSH transport, we can't easily implement content negotiation to determine compression formats because the SSH transport has no content negotiation capabilities today. And without a framing protocol, we don't know how much data to feed into a decompressor. So in order to implement compression support on the SSH transport, we'd need to invent a mechanism to represent content types and an outer framing protocol to stream data robustly. While I'm fully capable of doing that, it is a lot of work and not something that should be undertaken lightly. My opinion is that if we're going to change the SSH transport protocol, we should take a long hard look at implementing a grand unified protocol that attempts to address all the deficiencies with the existing protocol. While I want this to happen, that would be massive scope bloat standing in the way of zstd support. So, I've decided to take the easy solution: the SSH transport will not gain support for multiple compression formats. Keep in mind it doesn't support *any* compression today. So essentially nothing is changing on the SSH front.

# patchbomb.py - sending Mercurial changesets as patch emails
#
#  Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''command to send changesets as (a series of) patch emails

The series is started off with a "[PATCH 0 of N]" introduction, which
describes the series as a whole.

Each patch email has a Subject line of "[PATCH M of N] ...", using the
first line of the changeset description as the subject text. The
message contains two or three body parts:

- The changeset description.
- [Optional] The result of running diffstat on the patch.
- The patch itself, as generated by :hg:`export`.

Each message refers to the first in the series using the In-Reply-To
and References headers, so they will show up as a sequence in threaded
mail and news readers, and in mail archives.

To configure other defaults, add a section like this to your
configuration file::

  [email]
  from = My Name <my@email>
  to = recipient1, recipient2, ...
  cc = cc1, cc2, ...
  bcc = bcc1, bcc2, ...
  reply-to = address1, address2, ...

Use ``[patchbomb]`` as configuration section name if you need to
override global ``[email]`` address settings.

Then you can use the :hg:`email` command to mail a series of
changesets as a patchbomb.

You can also either configure the method option in the email section
to be a sendmail compatible mailer or fill out the [smtp] section so
that the patchbomb extension can automatically send patchbombs
directly from the commandline. See the [email] and [smtp] sections in
hgrc(5) for details.

By default, :hg:`email` will prompt for a ``To`` or ``CC`` header if
you do not supply one via configuration or the command line.  You can
override this to never prompt by configuring an empty value::

  [email]
  cc =

You can control the default inclusion of an introduction message with the
``patchbomb.intro`` configuration option. The configuration is always
overwritten by command line flags like --intro and --desc::

  [patchbomb]
  intro=auto   # include introduction message if more than 1 patch (default)
  intro=never  # never include an introduction message
  intro=always # always include an introduction message

You can set patchbomb to always ask for confirmation by setting
``patchbomb.confirm`` to true.
'''
from __future__ import absolute_import

import email as emailmod
import errno
import os
import socket
import tempfile

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    commands,
    encoding,
    error,
    hg,
    mail,
    node as nodemod,
    patch,
    scmutil,
    util,
)
stringio = util.stringio

cmdtable = {}
command = cmdutil.command(cmdtable)
# 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 = 'ships-with-hg-core'

def _addpullheader(seq, ctx):
    """Add a header pointing to a public URL where the changeset is available
    """
    repo = ctx.repo()
    # experimental config: patchbomb.publicurl
    # waiting for some logic that check that the changeset are available on the
    # destination before patchbombing anything.
    pullurl = repo.ui.config('patchbomb', 'publicurl')
    if pullurl is not None:
        return ('Available At %s\n'
                '#              hg pull %s -r %s' % (pullurl, pullurl, ctx))
    return None

def uisetup(ui):
    cmdutil.extraexport.append('pullurl')
    cmdutil.extraexportmap['pullurl'] = _addpullheader


def prompt(ui, prompt, default=None, rest=':'):
    if default:
        prompt += ' [%s]' % default
    return ui.prompt(prompt + rest, default)

def introwanted(ui, opts, number):
    '''is an introductory message apparently wanted?'''
    introconfig = ui.config('patchbomb', 'intro', 'auto')
    if opts.get('intro') or opts.get('desc'):
        intro = True
    elif introconfig == 'always':
        intro = True
    elif introconfig == 'never':
        intro = False
    elif introconfig == 'auto':
        intro = 1 < number
    else:
        ui.write_err(_('warning: invalid patchbomb.intro value "%s"\n')
                     % introconfig)
        ui.write_err(_('(should be one of always, never, auto)\n'))
        intro = 1 < number
    return intro

def makepatch(ui, repo, patchlines, opts, _charsets, idx, total, numbered,
              patchname=None):

    desc = []
    node = None
    body = ''

    for line in patchlines:
        if line.startswith('#'):
            if line.startswith('# Node ID'):
                node = line.split()[-1]
            continue
        if line.startswith('diff -r') or line.startswith('diff --git'):
            break
        desc.append(line)

    if not patchname and not node:
        raise ValueError

    if opts.get('attach') and not opts.get('body'):
        body = ('\n'.join(desc[1:]).strip() or
                'Patch subject is complete summary.')
        body += '\n\n\n'

    if opts.get('plain'):
        while patchlines and patchlines[0].startswith('# '):
            patchlines.pop(0)
        if patchlines:
            patchlines.pop(0)
        while patchlines and not patchlines[0].strip():
            patchlines.pop(0)

    ds = patch.diffstat(patchlines)
    if opts.get('diffstat'):
        body += ds + '\n\n'

    addattachment = opts.get('attach') or opts.get('inline')
    if not addattachment or opts.get('body'):
        body += '\n'.join(patchlines)

    if addattachment:
        msg = emailmod.MIMEMultipart.MIMEMultipart()
        if body:
            msg.attach(mail.mimeencode(ui, body, _charsets, opts.get('test')))
        p = mail.mimetextpatch('\n'.join(patchlines), 'x-patch',
                               opts.get('test'))
        binnode = nodemod.bin(node)
        # if node is mq patch, it will have the patch file's name as a tag
        if not patchname:
            patchtags = [t for t in repo.nodetags(binnode)
                         if t.endswith('.patch') or t.endswith('.diff')]
            if patchtags:
                patchname = patchtags[0]
            elif total > 1:
                patchname = cmdutil.makefilename(repo, '%b-%n.patch',
                                                 binnode, seqno=idx,
                                                 total=total)
            else:
                patchname = cmdutil.makefilename(repo, '%b.patch', binnode)
        disposition = 'inline'
        if opts.get('attach'):
            disposition = 'attachment'
        p['Content-Disposition'] = disposition + '; filename=' + patchname
        msg.attach(p)
    else:
        msg = mail.mimetextpatch(body, display=opts.get('test'))

    flag = ' '.join(opts.get('flag'))
    if flag:
        flag = ' ' + flag

    subj = desc[0].strip().rstrip('. ')
    if not numbered:
        subj = '[PATCH%s] %s' % (flag, opts.get('subject') or subj)
    else:
        tlen = len(str(total))
        subj = '[PATCH %0*d of %d%s] %s' % (tlen, idx, total, flag, subj)
    msg['Subject'] = mail.headencode(ui, subj, _charsets, opts.get('test'))
    msg['X-Mercurial-Node'] = node
    msg['X-Mercurial-Series-Index'] = '%i' % idx
    msg['X-Mercurial-Series-Total'] = '%i' % total
    return msg, subj, ds

def _getpatches(repo, revs, **opts):
    """return a list of patches for a list of revisions

    Each patch in the list is itself a list of lines.
    """
    ui = repo.ui
    prev = repo['.'].rev()
    for r in revs:
        if r == prev and (repo[None].files() or repo[None].deleted()):
            ui.warn(_('warning: working directory has '
                      'uncommitted changes\n'))
        output = stringio()
        cmdutil.export(repo, [r], fp=output,
                     opts=patch.difffeatureopts(ui, opts, git=True))
        yield output.getvalue().split('\n')
def _getbundle(repo, dest, **opts):
    """return a bundle containing changesets missing in "dest"

    The `opts` keyword-arguments are the same as the one accepted by the
    `bundle` command.

    The bundle is a returned as a single in-memory binary blob.
    """
    ui = repo.ui
    tmpdir = tempfile.mkdtemp(prefix='hg-email-bundle-')
    tmpfn = os.path.join(tmpdir, 'bundle')
    btype = ui.config('patchbomb', 'bundletype')
    if btype:
        opts['type'] = btype
    try:
        commands.bundle(ui, repo, tmpfn, dest, **opts)
        return util.readfile(tmpfn)
    finally:
        try:
            os.unlink(tmpfn)
        except OSError:
            pass
        os.rmdir(tmpdir)

def _getdescription(repo, defaultbody, sender, **opts):
    """obtain the body of the introduction message and return it

    This is also used for the body of email with an attached bundle.

    The body can be obtained either from the command line option or entered by
    the user through the editor.
    """
    ui = repo.ui
    if opts.get('desc'):
        body = open(opts.get('desc')).read()
    else:
        ui.write(_('\nWrite the introductory message for the '
                   'patch series.\n\n'))
        body = ui.edit(defaultbody, sender)
        # Save series description in case sendmail fails
        msgfile = repo.vfs('last-email.txt', 'wb')
        msgfile.write(body)
        msgfile.close()
    return body

def _getbundlemsgs(repo, sender, bundle, **opts):
    """Get the full email for sending a given bundle

    This function returns a list of "email" tuples (subject, content, None).
    The list is always one message long in that case.
    """
    ui = repo.ui
    _charsets = mail._charsets(ui)
    subj = (opts.get('subject')
            or prompt(ui, 'Subject:', 'A bundle for your repository'))

    body = _getdescription(repo, '', sender, **opts)
    msg = emailmod.MIMEMultipart.MIMEMultipart()
    if body:
        msg.attach(mail.mimeencode(ui, body, _charsets, opts.get('test')))
    datapart = emailmod.MIMEBase.MIMEBase('application', 'x-mercurial-bundle')
    datapart.set_payload(bundle)
    bundlename = '%s.hg' % opts.get('bundlename', 'bundle')
    datapart.add_header('Content-Disposition', 'attachment',
                        filename=bundlename)
    emailmod.Encoders.encode_base64(datapart)
    msg.attach(datapart)
    msg['Subject'] = mail.headencode(ui, subj, _charsets, opts.get('test'))
    return [(msg, subj, None)]

def _makeintro(repo, sender, patches, **opts):
    """make an introduction email, asking the user for content if needed

    email is returned as (subject, body, cumulative-diffstat)"""
    ui = repo.ui
    _charsets = mail._charsets(ui)
    tlen = len(str(len(patches)))

    flag = opts.get('flag') or ''
    if flag:
        flag = ' ' + ' '.join(flag)
    prefix = '[PATCH %0*d of %d%s]' % (tlen, 0, len(patches), flag)

    subj = (opts.get('subject') or
            prompt(ui, '(optional) Subject: ', rest=prefix, default=''))
    if not subj:
        return None         # skip intro if the user doesn't bother

    subj = prefix + ' ' + subj

    body = ''
    if opts.get('diffstat'):
        # generate a cumulative diffstat of the whole patch series
        diffstat = patch.diffstat(sum(patches, []))
        body = '\n' + diffstat
    else:
        diffstat = None

    body = _getdescription(repo, body, sender, **opts)
    msg = mail.mimeencode(ui, body, _charsets, opts.get('test'))
    msg['Subject'] = mail.headencode(ui, subj, _charsets,
                                     opts.get('test'))
    return (msg, subj, diffstat)

def _getpatchmsgs(repo, sender, patches, patchnames=None, **opts):
    """return a list of emails from a list of patches

    This involves introduction message creation if necessary.

    This function returns a list of "email" tuples (subject, content, None).
    """
    ui = repo.ui
    _charsets = mail._charsets(ui)
    msgs = []

    ui.write(_('this patch series consists of %d patches.\n\n')
             % len(patches))

    # build the intro message, or skip it if the user declines
    if introwanted(ui, opts, len(patches)):
        msg = _makeintro(repo, sender, patches, **opts)
        if msg:
            msgs.append(msg)

    # are we going to send more than one message?
    numbered = len(msgs) + len(patches) > 1

    # now generate the actual patch messages
    name = None
    for i, p in enumerate(patches):
        if patchnames:
            name = patchnames[i]
        msg = makepatch(ui, repo, p, opts, _charsets, i + 1,
                        len(patches), numbered, name)
        msgs.append(msg)

    return msgs

def _getoutgoing(repo, dest, revs):
    '''Return the revisions present locally but not in dest'''
    ui = repo.ui
    url = ui.expandpath(dest or 'default-push', dest or 'default')
    url = hg.parseurl(url)[0]
    ui.status(_('comparing with %s\n') % util.hidepassword(url))

    revs = [r for r in revs if r >= 0]
    if not revs:
        revs = [len(repo) - 1]
    revs = repo.revs('outgoing(%s) and ::%ld', dest or '', revs)
    if not revs:
        ui.status(_("no changes found\n"))
    return revs

emailopts = [
    ('', 'body', None, _('send patches as inline message text (default)')),
    ('a', 'attach', None, _('send patches as attachments')),
    ('i', 'inline', None, _('send patches as inline attachments')),
    ('', 'bcc', [], _('email addresses of blind carbon copy recipients')),
    ('c', 'cc', [], _('email addresses of copy recipients')),
    ('', 'confirm', None, _('ask for confirmation before sending')),
    ('d', 'diffstat', None, _('add diffstat output to messages')),
    ('', 'date', '', _('use the given date as the sending date')),
    ('', 'desc', '', _('use the given file as the series description')),
    ('f', 'from', '', _('email address of sender')),
    ('n', 'test', None, _('print messages that would be sent')),
    ('m', 'mbox', '', _('write messages to mbox file instead of sending them')),
    ('', 'reply-to', [], _('email addresses replies should be sent to')),
    ('s', 'subject', '', _('subject of first message (intro or single patch)')),
    ('', 'in-reply-to', '', _('message identifier to reply to')),
    ('', 'flag', [], _('flags to add in subject prefixes')),
    ('t', 'to', [], _('email addresses of recipients'))]

@command('email',
    [('g', 'git', None, _('use git extended diff format')),
    ('', 'plain', None, _('omit hg patch header')),
    ('o', 'outgoing', None,
     _('send changes not found in the target repository')),
    ('b', 'bundle', None, _('send changes not in target as a binary bundle')),
    ('', 'bundlename', 'bundle',
     _('name of the bundle attachment file'), _('NAME')),
    ('r', 'rev', [], _('a revision to send'), _('REV')),
    ('', 'force', None, _('run even when remote repository is unrelated '
       '(with -b/--bundle)')),
    ('', 'base', [], _('a base changeset to specify instead of a destination '
       '(with -b/--bundle)'), _('REV')),
    ('', 'intro', None, _('send an introduction email for a single patch')),
    ] + emailopts + commands.remoteopts,
    _('hg email [OPTION]... [DEST]...'))
def email(ui, repo, *revs, **opts):
    '''send changesets by email

    By default, diffs are sent in the format generated by
    :hg:`export`, one per message. The series starts with a "[PATCH 0
    of N]" introduction, which describes the series as a whole.

    Each patch email has a Subject line of "[PATCH M of N] ...", using
    the first line of the changeset description as the subject text.
    The message contains two or three parts. First, the changeset
    description.

    With the -d/--diffstat option, if the diffstat program is
    installed, the result of running diffstat on the patch is inserted.

    Finally, the patch itself, as generated by :hg:`export`.

    With the -d/--diffstat or --confirm options, you will be presented
    with a final summary of all messages and asked for confirmation before
    the messages are sent.

    By default the patch is included as text in the email body for
    easy reviewing. Using the -a/--attach option will instead create
    an attachment for the patch. With -i/--inline an inline attachment
    will be created. You can include a patch both as text in the email
    body and as a regular or an inline attachment by combining the
    -a/--attach or -i/--inline with the --body option.

    With -o/--outgoing, emails will be generated for patches not found
    in the destination repository (or only those which are ancestors
    of the specified revisions if any are provided)

    With -b/--bundle, changesets are selected as for --outgoing, but a
    single email containing a binary Mercurial bundle as an attachment
    will be sent. Use the ``patchbomb.bundletype`` config option to
    control the bundle type as with :hg:`bundle --type`.

    With -m/--mbox, instead of previewing each patchbomb message in a
    pager or sending the messages directly, it will create a UNIX
    mailbox file with the patch emails. This mailbox file can be
    previewed with any mail user agent which supports UNIX mbox
    files.

    With -n/--test, all steps will run, but mail will not be sent.
    You will be prompted for an email recipient address, a subject and
    an introductory message describing the patches of your patchbomb.
    Then when all is done, patchbomb messages are displayed. If the
    PAGER environment variable is set, your pager will be fired up once
    for each patchbomb message, so you can verify everything is alright.

    In case email sending fails, you will find a backup of your series
    introductory message in ``.hg/last-email.txt``.

    The default behavior of this command can be customized through
    configuration. (See :hg:`help patchbomb` for details)

    Examples::

      hg email -r 3000          # send patch 3000 only
      hg email -r 3000 -r 3001  # send patches 3000 and 3001
      hg email -r 3000:3005     # send patches 3000 through 3005
      hg email 3000             # send patch 3000 (deprecated)

      hg email -o               # send all patches not in default
      hg email -o DEST          # send all patches not in DEST
      hg email -o -r 3000       # send all ancestors of 3000 not in default
      hg email -o -r 3000 DEST  # send all ancestors of 3000 not in DEST

      hg email -b               # send bundle of all patches not in default
      hg email -b DEST          # send bundle of all patches not in DEST
      hg email -b -r 3000       # bundle of all ancestors of 3000 not in default
      hg email -b -r 3000 DEST  # bundle of all ancestors of 3000 not in DEST

      hg email -o -m mbox &&    # generate an mbox file...
        mutt -R -f mbox         # ... and view it with mutt
      hg email -o -m mbox &&    # generate an mbox file ...
        formail -s sendmail \\   # ... and use formail to send from the mbox
          -bm -t < mbox         # ... using sendmail

    Before using this command, you will need to enable email in your
    hgrc. See the [email] section in hgrc(5) for details.
    '''

    _charsets = mail._charsets(ui)

    bundle = opts.get('bundle')
    date = opts.get('date')
    mbox = opts.get('mbox')
    outgoing = opts.get('outgoing')
    rev = opts.get('rev')
    # internal option used by pbranches
    patches = opts.get('patches')

    if not (opts.get('test') or mbox):
        # really sending
        mail.validateconfig(ui)

    if not (revs or rev or outgoing or bundle or patches):
        raise error.Abort(_('specify at least one changeset with -r or -o'))

    if outgoing and bundle:
        raise error.Abort(_("--outgoing mode always on with --bundle;"
                           " do not re-specify --outgoing"))

    if outgoing or bundle:
        if len(revs) > 1:
            raise error.Abort(_("too many destinations"))
        if revs:
            dest = revs[0]
        else:
            dest = None
        revs = []

    if rev:
        if revs:
            raise error.Abort(_('use only one form to specify the revision'))
        revs = rev

    revs = scmutil.revrange(repo, revs)
    if outgoing:
        revs = _getoutgoing(repo, dest, revs)
    if bundle:
        opts['revs'] = [str(r) for r in revs]

    # check if revision exist on the public destination
    publicurl = repo.ui.config('patchbomb', 'publicurl')
    if publicurl is not None:
        repo.ui.debug('checking that revision exist in the public repo')
        try:
            publicpeer = hg.peer(repo, {}, publicurl)
        except error.RepoError:
            repo.ui.write_err(_('unable to access public repo: %s\n')
                              % publicurl)
            raise
        if not publicpeer.capable('known'):
            repo.ui.debug('skipping existence checks: public repo too old')
        else:
            out = [repo[r] for r in revs]
            known = publicpeer.known(h.node() for h in out)
            missing = []
            for idx, h in enumerate(out):
                if not known[idx]:
                    missing.append(h)
            if missing:
                if 1 < len(missing):
                    msg = _('public "%s" is missing %s and %i others')
                    msg %= (publicurl, missing[0], len(missing) - 1)
                else:
                    msg = _('public url %s is missing %s')
                    msg %= (publicurl, missing[0])
                revhint = ' '.join('-r %s' % h
                                  for h in repo.set('heads(%ld)', missing))
                hint = _("use 'hg push %s %s'") % (publicurl, revhint)
                raise error.Abort(msg, hint=hint)

    # start
    if date:
        start_time = util.parsedate(date)
    else:
        start_time = util.makedate()

    def genmsgid(id):
        return '<%s.%s@%s>' % (id[:20], int(start_time[0]), socket.getfqdn())

    # deprecated config: patchbomb.from
    sender = (opts.get('from') or ui.config('email', 'from') or
              ui.config('patchbomb', 'from') or
              prompt(ui, 'From', ui.username()))

    if patches:
        msgs = _getpatchmsgs(repo, sender, patches, opts.get('patchnames'),
                             **opts)
    elif bundle:
        bundledata = _getbundle(repo, dest, **opts)
        bundleopts = opts.copy()
        bundleopts.pop('bundle', None)  # already processed
        msgs = _getbundlemsgs(repo, sender, bundledata, **bundleopts)
    else:
        _patches = list(_getpatches(repo, revs, **opts))
        msgs = _getpatchmsgs(repo, sender, _patches, **opts)

    showaddrs = []

    def getaddrs(header, ask=False, default=None):
        configkey = header.lower()
        opt = header.replace('-', '_').lower()
        addrs = opts.get(opt)
        if addrs:
            showaddrs.append('%s: %s' % (header, ', '.join(addrs)))
            return mail.addrlistencode(ui, addrs, _charsets, opts.get('test'))

        # not on the command line: fallback to config and then maybe ask
        addr = (ui.config('email', configkey) or
                ui.config('patchbomb', configkey))
        if not addr:
            specified = (ui.hasconfig('email', configkey) or
                         ui.hasconfig('patchbomb', configkey))
            if not specified and ask:
                addr = prompt(ui, header, default=default)
        if addr:
            showaddrs.append('%s: %s' % (header, addr))
            return mail.addrlistencode(ui, [addr], _charsets, opts.get('test'))
        else:
            return default

    to = getaddrs('To', ask=True)
    if not to:
        # we can get here in non-interactive mode
        raise error.Abort(_('no recipient addresses provided'))
    cc = getaddrs('Cc', ask=True, default='') or []
    bcc = getaddrs('Bcc') or []
    replyto = getaddrs('Reply-To')

    confirm = ui.configbool('patchbomb', 'confirm')
    confirm |= bool(opts.get('diffstat') or opts.get('confirm'))

    if confirm:
        ui.write(_('\nFinal summary:\n\n'), label='patchbomb.finalsummary')
        ui.write(('From: %s\n' % sender), label='patchbomb.from')
        for addr in showaddrs:
            ui.write('%s\n' % addr, label='patchbomb.to')
        for m, subj, ds in msgs:
            ui.write(('Subject: %s\n' % subj), label='patchbomb.subject')
            if ds:
                ui.write(ds, label='patchbomb.diffstats')
        ui.write('\n')
        if ui.promptchoice(_('are you sure you want to send (yn)?'
                             '$$ &Yes $$ &No')):
            raise error.Abort(_('patchbomb canceled'))

    ui.write('\n')

    parent = opts.get('in_reply_to') or None
    # angle brackets may be omitted, they're not semantically part of the msg-id
    if parent is not None:
        if not parent.startswith('<'):
            parent = '<' + parent
        if not parent.endswith('>'):
            parent += '>'

    sender_addr = emailmod.Utils.parseaddr(sender)[1]
    sender = mail.addressencode(ui, sender, _charsets, opts.get('test'))
    sendmail = None
    firstpatch = None
    for i, (m, subj, ds) in enumerate(msgs):
        try:
            m['Message-Id'] = genmsgid(m['X-Mercurial-Node'])
            if not firstpatch:
                firstpatch = m['Message-Id']
            m['X-Mercurial-Series-Id'] = firstpatch
        except TypeError:
            m['Message-Id'] = genmsgid('patchbomb')
        if parent:
            m['In-Reply-To'] = parent
            m['References'] = parent
        if not parent or 'X-Mercurial-Node' not in m:
            parent = m['Message-Id']

        m['User-Agent'] = 'Mercurial-patchbomb/%s' % util.version()
        m['Date'] = emailmod.Utils.formatdate(start_time[0], localtime=True)

        start_time = (start_time[0] + 1, start_time[1])
        m['From'] = sender
        m['To'] = ', '.join(to)
        if cc:
            m['Cc']  = ', '.join(cc)
        if bcc:
            m['Bcc'] = ', '.join(bcc)
        if replyto:
            m['Reply-To'] = ', '.join(replyto)
        if opts.get('test'):
            ui.status(_('displaying '), subj, ' ...\n')
            ui.flush()
            if 'PAGER' in encoding.environ and not ui.plain():
                fp = util.popen(encoding.environ['PAGER'], 'w')
            else:
                fp = ui
            generator = emailmod.Generator.Generator(fp, mangle_from_=False)
            try:
                generator.flatten(m, 0)
                fp.write('\n')
            except IOError as inst:
                if inst.errno != errno.EPIPE:
                    raise
            if fp is not ui:
                fp.close()
        else:
            if not sendmail:
                sendmail = mail.connect(ui, mbox=mbox)
            ui.status(_('sending '), subj, ' ...\n')
            ui.progress(_('sending'), i, item=subj, total=len(msgs),
                        unit=_('emails'))
            if not mbox:
                # Exim does not remove the Bcc field
                del m['Bcc']
            fp = stringio()
            generator = emailmod.Generator.Generator(fp, mangle_from_=False)
            generator.flatten(m, 0)
            sendmail(sender_addr, to + bcc + cc, fp.getvalue())

    ui.progress(_('writing'), None)
    ui.progress(_('sending'), None)