hgext/notify.py

mdiff/patch: fix bad hunk handling for unified diffs with zero context

Prior to this patch "hg diff -U0", i.e., zero lines of context, would
output hunk headers with a start line one greater than what GNU patch
and git output. Guido van Rossum documents the unified diff format[1]
as having a start line value "one lower than one would expect" for
zero length hunks.

Comparing the behaviour of the three systems prior to this patch in
transforming

  c1
  c3

to

  c1
  c2
  c3

- GNU "diff -U0" reports the hunk as "@@ -1,0 +2 @@"
- "git diff -U0" reports the hunk as "@@ -1,0 +2 @@"
- "hg diff -U0" reports the hunk as "@@ -2,0 +2,1 @@"

After this patch, "hg diff -U0" reports "@@ -1,0 +2,1 @@".

Since "hg export --config diff.unified=0" outputs zero-context unified
diffs, "hg import" has also been updated to account for start lines
one less than expected for zero length hunk ranges.

[1]: http://www.artima.com/weblogs/viewpost.jsp?thread=164293

# 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 let you run hooks sending email notifications when
changesets are being pushed, from the sending or receiving side.

First, enable the extension as explained in :hg:`help extensions`, and
register the hook you want to run. ``incoming`` and ``outgoing`` hooks
are run by the changesets receiver while the ``outgoing`` one is for
the sender::

  [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

Now the hooks are running, subscribers must be assigned to
repositories. Use the ``[usersubs]`` section to map repositories to a
given email or the ``[reposubs]`` section to map emails to a single
repository::

  [usersubs]
  # key is subscriber email, value is a comma-separated list of glob
  # patterns
  user@host = pattern

  [reposubs]
  # key is glob pattern, value is a comma-separated list of subscriber
  # emails
  pattern = user@host

Glob patterns are matched against absolute path to repository
root. The subscriptions can be defined in their own file and
referenced with::

  [notify]
  config = /path/to/subscriptionsfile

Alternatively, they can be added to Mercurial configuration files by
setting the previous entry to an empty value.

At this point, notifications should be generated but will not be sent until you
set the ``notify.test`` entry to ``False``.

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 sent only
  if it includes the incoming or outgoing changes source. Incoming
  sources can be ``serve`` for changes coming from http or ssh,
  ``pull`` for pulled changes, ``unbundle`` for changes added by
  :hg:`unbundle` or ``push`` for changes being pushed
  locally. Outgoing sources are the same except for ``unbundle`` which
  is replaced by ``bundle``. Default: serve.

notify.strip
  Number of leading slashes to strip from url paths. By default, notifications
  references repositories with their absolute path. ``notify.strip`` let you
  turn them into relative paths. For example, ``notify.strip=3`` will change
  ``/long/path/repository`` into ``repository``. Default: 0.

notify.domain
  If subscribers emails or the from email have no domain set, complete them
  with this value.

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 incoming hook, override ``notify.template``.

notify.outgoing
  Template to use when run as outgoing hook, override ``notify.template``.

notify.changegroup
  Template to use when running as changegroup hook, override
  ``notify.template``.

notify.maxdiff
  Maximum number of diff lines to include in notification email. Set to 0
  to disable the diff, -1 to include all of it. Default: 300.

notify.maxsubject
  Maximum number of characters in emails subject line. Default: 67.

notify.diffstat
  Set to True to include a diffstat before diff content. Default: True.

notify.merge
  If True, send notifications for merge changesets. Default: True.

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 generated email content.

web.baseurl
  Root repository browsing URL to combine with repository paths when making
  references. See also ``notify.strip``.

'''

from mercurial.i18n import _
from mercurial import patch, cmdutil, templater, util, mail
import email.Parser, email.Errors, fnmatch, socket, time

# template for single changeset can include email headers.
single_template = '''
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 = '''
changeset {node|short} in {root}
details: {baseurl}{webroot}?cmd=changeset;node={node|short}
summary: {desc|firstline}
'''

deftemplates = {
    'changegroup': multiple_template,
}

class notifier(object):
    '''email notification class.'''

    def __init__(self, ui, repo, hooktype):
        self.ui = ui
        cfg = self.ui.config('notify', 'config')
        if cfg:
            self.ui.readconfig(cfg, sections=['usersubs', 'reposubs'])
        self.repo = repo
        self.stripcount = int(self.ui.config('notify', 'strip', 0))
        self.root = self.strip(self.repo.root)
        self.domain = self.ui.config('notify', 'domain')
        self.test = self.ui.configbool('notify', 'test', True)
        self.charsets = mail._charsets(self.ui)
        self.subs = self.subscribers()
        self.merge = self.ui.configbool('notify', 'merge', True)

        mapfile = self.ui.config('notify', 'style')
        template = (self.ui.config('notify', hooktype) or
                    self.ui.config('notify', 'template'))
        self.t = cmdutil.changeset_templater(self.ui, self.repo,
                                             False, None, mapfile, False)
        if not mapfile and not template:
            template = deftemplates.get(hooktype) or single_template
        if template:
            template = templater.parsestring(template, quoted=False)
            self.t.use_template(template)

    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('/')
            if c == -1:
                break
            path = path[c + 1:]
            count -= 1
        return path

    def fixmail(self, addr):
        '''try to clean up email addresses.'''

        addr = util.email(addr.strip())
        if self.domain:
            a = addr.find('@localhost')
            if a != -1:
                addr = addr[:a]
            if '@' not in addr:
                return addr + '@' + 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('usersubs'):
            for pat in pats.split(','):
                if fnmatch.fnmatch(self.repo.root, pat.strip()):
                    subs.add(self.fixmail(user))
        for pat, users in self.ui.configitems('reposubs'):
            if fnmatch.fnmatch(self.repo.root, pat):
                for user in users.split(','):
                    subs.add(self.fixmail(user))
        return [mail.addressencode(self.ui, s, self.charsets, self.test)
                for s 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('web', '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('notify', 'sources', 'serve').split()
        return source not in ok_sources

    def send(self, ctx, count, data):
        '''send message.'''

        p = email.Parser.Parser()
        try:
            msg = p.parsestr(data)
        except email.Errors.MessageParseError, inst:
            raise util.Abort(inst)

        # store sender and subject
        sender, subject = msg['From'], msg['Subject']
        del msg['From'], msg['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['Date'] = util.datestr(format="%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 = _('%s: %d new changesets') % (self.root, count)
            else:
                s = ctx.description().lstrip().split('\n', 1)[0].rstrip()
                subject = '%s: %s' % (self.root, s)
        maxsubject = int(self.ui.config('notify', 'maxsubject', 67))
        if maxsubject:
            subject = util.ellipsis(subject, maxsubject)
        msg['Subject'] = mail.headencode(self.ui, subject,
                                         self.charsets, self.test)

        # try to make message have proper sender
        if not sender:
            sender = self.ui.config('email', 'from') or self.ui.username()
        if '@' not in sender or '@localhost' in sender:
            sender = self.fixmail(sender)
        msg['From'] = mail.addressencode(self.ui, sender,
                                         self.charsets, self.test)

        msg['X-Hg-Notification'] = 'changeset %s' % ctx
        if not msg['Message-Id']:
            msg['Message-Id'] = ('<hg.%s.%s.%s@%s>' %
                                 (ctx, int(time.time()),
                                  hash(self.repo.root), socket.getfqdn()))
        msg['To'] = ', '.join(self.subs)

        msgtext = msg.as_string()
        if self.test:
            self.ui.write(msgtext)
            if not msgtext.endswith('\n'):
                self.ui.write('\n')
        else:
            self.ui.status(_('notify: sending %d subscribers %d changes\n') %
                           (len(self.subs), count))
            mail.sendmail(self.ui, util.email(msg['From']),
                          self.subs, msgtext)

    def diff(self, ctx, ref=None):

        maxdiff = int(self.ui.config('notify', 'maxdiff', 300))
        prev = ctx.p1().node()
        ref = ref and ref.node() or ctx.node()
        chunks = patch.diff(self.repo, prev, ref, opts=patch.diffopts(self.ui))
        difflines = ''.join(chunks).splitlines()

        if self.ui.configbool('notify', 'diffstat', True):
            s = patch.diffstat(difflines)
            # s may be nil, don't include the header if it is
            if s:
                self.ui.write('\ndiffstat:\n\n%s' % s)

        if maxdiff == 0:
            return
        elif maxdiff > 0 and len(difflines) > maxdiff:
            msg = _('\ndiffs (truncated from %d to %d lines):\n\n')
            self.ui.write(msg % (len(difflines), maxdiff))
            difflines = difflines[:maxdiff]
        elif difflines:
            self.ui.write(_('\ndiffs (%d lines):\n\n') % len(difflines))

        self.ui.write("\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[node]

    if not n.subs:
        ui.debug('notify: no subscribers to repository %s\n' % n.root)
        return
    if n.skipsource(source):
        ui.debug('notify: changes have source "%s" - skipping\n' % source)
        return

    ui.pushbuffer()
    data = ''
    count = 0
    if hooktype == 'changegroup' or hooktype == 'outgoing':
        start, end = ctx.rev(), len(repo)
        for rev in xrange(start, end):
            if n.node(repo[rev]):
                count += 1
            else:
                data += ui.popbuffer()
                ui.note(_('notify: suppressing notification for merge %d:%s\n') %
                        (rev, repo[rev].hex()[:12]))
                ui.pushbuffer()
        if count:
            n.diff(ctx, repo['tip'])
    else:
        if not n.node(ctx):
            ui.popbuffer()
            ui.note(_('notify: suppressing notification for merge %d:%s\n') %
                    (ctx.rev(), ctx.hex()[:12]))
            return
        count += 1
        n.diff(ctx)

    data += ui.popbuffer()
    if count:
        n.send(ctx, count, data)