py3: fix sorting of obsolete markers in obsutil (issue6217)

This is similar to 01e8eefd9434 and others. We move the sortedmarkers()
function from exchange module to obsutil.

mercurial/exchange.py

@@ -1,3090 +1,3086 b''
 # exchange.py - utility to exchange data between repos.
 #
 # Copyright 2005-2007 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 collections
 import hashlib
 
 from .i18n import _
 from .node import (
     hex,
     nullid,
     nullrev,
 )
 from .thirdparty import attr
 from . import (
     bookmarks as bookmod,
     bundle2,
     changegroup,
     discovery,
     error,
     exchangev2,
     lock as lockmod,
     logexchange,
     narrowspec,
     obsolete,
+    obsutil,
     phases,
     pushkey,
     pycompat,
     scmutil,
     sslutil,
     streamclone,
     url as urlmod,
     util,
     wireprototypes,
 )
 from .interfaces import repository
 from .utils import stringutil
 
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 _NARROWACL_SECTION = b'narrowacl'
 
 # Maps bundle version human names to changegroup versions.
 _bundlespeccgversions = {
     b'v1': b'01',
     b'v2': b'02',
     b'packed1': b's1',
     b'bundle2': b'02',  # legacy
 }
 
 # Maps bundle version with content opts to choose which part to bundle
 _bundlespeccontentopts = {
     b'v1': {
         b'changegroup': True,
         b'cg.version': b'01',
         b'obsolescence': False,
         b'phases': False,
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
     b'v2': {
         b'changegroup': True,
         b'cg.version': b'02',
         b'obsolescence': False,
         b'phases': False,
         b'tagsfnodescache': True,
         b'revbranchcache': True,
     },
     b'packed1': {b'cg.version': b's1'},
 }
 _bundlespeccontentopts[b'bundle2'] = _bundlespeccontentopts[b'v2']
 
 _bundlespecvariants = {
     b"streamv2": {
         b"changegroup": False,
         b"streamv2": True,
         b"tagsfnodescache": False,
         b"revbranchcache": False,
     }
 }
 
 # Compression engines allowed in version 1. THIS SHOULD NEVER CHANGE.
 _bundlespecv1compengines = {b'gzip', b'bzip2', b'none'}
 
 
 @attr.s
 class bundlespec(object):
     compression = attr.ib()
     wirecompression = attr.ib()
     version = attr.ib()
     wireversion = attr.ib()
     params = attr.ib()
     contentopts = attr.ib()
 
 
-def _sortedmarkers(markers):
-    # last item of marker tuple ('parents') may be None or a tuple
-    return sorted(markers, key=lambda m: m[:-1] + (m[-1] or (),))
-
-
 def parsebundlespec(repo, spec, strict=True):
     """Parse a bundle string specification into parts.
 
     Bundle specifications denote a well-defined bundle/exchange format.
     The content of a given specification should not change over time in
     order to ensure that bundles produced by a newer version of Mercurial are
     readable from an older version.
 
     The string currently has the form:
 
        <compression>-<type>[;<parameter0>[;<parameter1>]]
 
     Where <compression> is one of the supported compression formats
     and <type> is (currently) a version string. A ";" can follow the type and
     all text afterwards is interpreted as URI encoded, ";" delimited key=value
     pairs.
 
     If ``strict`` is True (the default) <compression> is required. Otherwise,
     it is optional.
 
     Returns a bundlespec object of (compression, version, parameters).
     Compression will be ``None`` if not in strict mode and a compression isn't
     defined.
 
     An ``InvalidBundleSpecification`` is raised when the specification is
     not syntactically well formed.
 
     An ``UnsupportedBundleSpecification`` is raised when the compression or
     bundle type/version is not recognized.
 
     Note: this function will likely eventually return a more complex data
     structure, including bundle2 part information.
     """
 
     def parseparams(s):
         if b';' not in s:
             return s, {}
 
         params = {}
         version, paramstr = s.split(b';', 1)
 
         for p in paramstr.split(b';'):
             if b'=' not in p:
                 raise error.InvalidBundleSpecification(
                     _(
                         b'invalid bundle specification: '
                         b'missing "=" in parameter: %s'
                     )
                     % p
                 )
 
             key, value = p.split(b'=', 1)
             key = urlreq.unquote(key)
             value = urlreq.unquote(value)
             params[key] = value
 
         return version, params
 
     if strict and b'-' not in spec:
         raise error.InvalidBundleSpecification(
             _(
                 b'invalid bundle specification; '
                 b'must be prefixed with compression: %s'
             )
             % spec
         )
 
     if b'-' in spec:
         compression, version = spec.split(b'-', 1)
 
         if compression not in util.compengines.supportedbundlenames:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s compression is not supported') % compression
             )
 
         version, params = parseparams(version)
 
         if version not in _bundlespeccgversions:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s is not a recognized bundle version') % version
             )
     else:
         # Value could be just the compression or just the version, in which
         # case some defaults are assumed (but only when not in strict mode).
         assert not strict
 
         spec, params = parseparams(spec)
 
         if spec in util.compengines.supportedbundlenames:
             compression = spec
             version = b'v1'
             # Generaldelta repos require v2.
             if b'generaldelta' in repo.requirements:
                 version = b'v2'
             # Modern compression engines require v2.
             if compression not in _bundlespecv1compengines:
                 version = b'v2'
         elif spec in _bundlespeccgversions:
             if spec == b'packed1':
                 compression = b'none'
             else:
                 compression = b'bzip2'
             version = spec
         else:
             raise error.UnsupportedBundleSpecification(
                 _(b'%s is not a recognized bundle specification') % spec
             )
 
     # Bundle version 1 only supports a known set of compression engines.
     if version == b'v1' and compression not in _bundlespecv1compengines:
         raise error.UnsupportedBundleSpecification(
             _(b'compression engine %s is not supported on v1 bundles')
             % compression
         )
 
     # The specification for packed1 can optionally declare the data formats
     # required to apply it. If we see this metadata, compare against what the
     # repo supports and error if the bundle isn't compatible.
     if version == b'packed1' and b'requirements' in params:
         requirements = set(params[b'requirements'].split(b','))
         missingreqs = requirements - repo.supportedformats
         if missingreqs:
             raise error.UnsupportedBundleSpecification(
                 _(b'missing support for repository features: %s')
                 % b', '.join(sorted(missingreqs))
             )
 
     # Compute contentopts based on the version
     contentopts = _bundlespeccontentopts.get(version, {}).copy()
 
     # Process the variants
     if b"stream" in params and params[b"stream"] == b"v2":
         variant = _bundlespecvariants[b"streamv2"]
         contentopts.update(variant)
 
     engine = util.compengines.forbundlename(compression)
     compression, wirecompression = engine.bundletype()
     wireversion = _bundlespeccgversions[version]
 
     return bundlespec(
         compression, wirecompression, version, wireversion, params, contentopts
     )
 
 
 def readbundle(ui, fh, fname, vfs=None):
     header = changegroup.readexactly(fh, 4)
 
     alg = None
     if not fname:
         fname = b"stream"
         if not header.startswith(b'HG') and header.startswith(b'\0'):
             fh = changegroup.headerlessfixup(fh, header)
             header = b"HG10"
             alg = b'UN'
     elif vfs:
         fname = vfs.join(fname)
 
     magic, version = header[0:2], header[2:4]
 
     if magic != b'HG':
         raise error.Abort(_(b'%s: not a Mercurial bundle') % fname)
     if version == b'10':
         if alg is None:
             alg = changegroup.readexactly(fh, 2)
         return changegroup.cg1unpacker(fh, alg)
     elif version.startswith(b'2'):
         return bundle2.getunbundler(ui, fh, magicstring=magic + version)
     elif version == b'S1':
         return streamclone.streamcloneapplier(fh)
     else:
         raise error.Abort(
             _(b'%s: unknown bundle version %s') % (fname, version)
         )
 
 
 def getbundlespec(ui, fh):
     """Infer the bundlespec from a bundle file handle.
 
     The input file handle is seeked and the original seek position is not
     restored.
     """
 
     def speccompression(alg):
         try:
             return util.compengines.forbundletype(alg).bundletype()[0]
         except KeyError:
             return None
 
     b = readbundle(ui, fh, None)
     if isinstance(b, changegroup.cg1unpacker):
         alg = b._type
         if alg == b'_truncatedBZ':
             alg = b'BZ'
         comp = speccompression(alg)
         if not comp:
             raise error.Abort(_(b'unknown compression algorithm: %s') % alg)
         return b'%s-v1' % comp
     elif isinstance(b, bundle2.unbundle20):
         if b'Compression' in b.params:
             comp = speccompression(b.params[b'Compression'])
             if not comp:
                 raise error.Abort(
                     _(b'unknown compression algorithm: %s') % comp
                 )
         else:
             comp = b'none'
 
         version = None
         for part in b.iterparts():
             if part.type == b'changegroup':
                 version = part.params[b'version']
                 if version in (b'01', b'02'):
                     version = b'v2'
                 else:
                     raise error.Abort(
                         _(
                             b'changegroup version %s does not have '
                             b'a known bundlespec'
                         )
                         % version,
                         hint=_(b'try upgrading your Mercurial client'),
                     )
             elif part.type == b'stream2' and version is None:
                 # A stream2 part requires to be part of a v2 bundle
                 requirements = urlreq.unquote(part.params[b'requirements'])
                 splitted = requirements.split()
                 params = bundle2._formatrequirementsparams(splitted)
                 return b'none-v2;stream=v2;%s' % params
 
         if not version:
             raise error.Abort(
                 _(b'could not identify changegroup version in bundle')
             )
 
         return b'%s-%s' % (comp, version)
     elif isinstance(b, streamclone.streamcloneapplier):
         requirements = streamclone.readbundle1header(fh)[2]
         formatted = bundle2._formatrequirementsparams(requirements)
         return b'none-packed1;%s' % formatted
     else:
         raise error.Abort(_(b'unknown bundle type: %s') % b)
 
 
 def _computeoutgoing(repo, heads, common):
     """Computes which revs are outgoing given a set of common
     and a set of heads.
 
     This is a separate function so extensions can have access to
     the logic.
 
     Returns a discovery.outgoing object.
     """
     cl = repo.changelog
     if common:
         hasnode = cl.hasnode
         common = [n for n in common if hasnode(n)]
     else:
         common = [nullid]
     if not heads:
         heads = cl.heads()
     return discovery.outgoing(repo, common, heads)
 
 
 def _checkpublish(pushop):
     repo = pushop.repo
     ui = repo.ui
     behavior = ui.config(b'experimental', b'auto-publish')
     if pushop.publish or behavior not in (b'warn', b'confirm', b'abort'):
         return
     remotephases = listkeys(pushop.remote, b'phases')
     if not remotephases.get(b'publishing', False):
         return
 
     if pushop.revs is None:
         published = repo.filtered(b'served').revs(b'not public()')
     else:
         published = repo.revs(b'::%ln - public()', pushop.revs)
     if published:
         if behavior == b'warn':
             ui.warn(
                 _(b'%i changesets about to be published\n') % len(published)
             )
         elif behavior == b'confirm':
             if ui.promptchoice(
                 _(b'push and publish %i changesets (yn)?$$ &Yes $$ &No')
                 % len(published)
             ):
                 raise error.Abort(_(b'user quit'))
         elif behavior == b'abort':
             msg = _(b'push would publish %i changesets') % len(published)
             hint = _(
                 b"use --publish or adjust 'experimental.auto-publish'"
                 b" config"
             )
             raise error.Abort(msg, hint=hint)
 
 
 def _forcebundle1(op):
     """return true if a pull/push must use bundle1
 
     This function is used to allow testing of the older bundle version"""
     ui = op.repo.ui
     # The goal is this config is to allow developer to choose the bundle
     # version used during exchanged. This is especially handy during test.
     # Value is a list of bundle version to be picked from, highest version
     # should be used.
     #
     # developer config: devel.legacy.exchange
     exchange = ui.configlist(b'devel', b'legacy.exchange')
     forcebundle1 = b'bundle2' not in exchange and b'bundle1' in exchange
     return forcebundle1 or not op.remote.capable(b'bundle2')
 
 
 class pushoperation(object):
     """A object that represent a single push operation
 
     Its purpose is to carry push related state and very common operations.
 
     A new pushoperation should be created at the beginning of each push and
     discarded afterward.
     """
 
     def __init__(
         self,
         repo,
         remote,
         force=False,
         revs=None,
         newbranch=False,
         bookmarks=(),
         publish=False,
         pushvars=None,
     ):
         # repo we push from
         self.repo = repo
         self.ui = repo.ui
         # repo we push to
         self.remote = remote
         # force option provided
         self.force = force
         # revs to be pushed (None is "all")
         self.revs = revs
         # bookmark explicitly pushed
         self.bookmarks = bookmarks
         # allow push of new branch
         self.newbranch = newbranch
         # step already performed
         # (used to check what steps have been already performed through bundle2)
         self.stepsdone = set()
         # Integer version of the changegroup push result
         # - None means nothing to push
         # - 0 means HTTP error
         # - 1 means we pushed and remote head count is unchanged *or*
         #   we have outgoing changesets but refused to push
         # - other values as described by addchangegroup()
         self.cgresult = None
         # Boolean value for the bookmark push
         self.bkresult = None
         # discover.outgoing object (contains common and outgoing data)
         self.outgoing = None
         # all remote topological heads before the push
         self.remoteheads = None
         # Details of the remote branch pre and post push
         #
         # mapping: {'branch': ([remoteheads],
         #                      [newheads],
         #                      [unsyncedheads],
         #                      [discardedheads])}
         # - branch: the branch name
         # - remoteheads: the list of remote heads known locally
         #                None if the branch is new
         # - newheads: the new remote heads (known locally) with outgoing pushed
         # - unsyncedheads: the list of remote heads unknown locally.
         # - discardedheads: the list of remote heads made obsolete by the push
         self.pushbranchmap = None
         # testable as a boolean indicating if any nodes are missing locally.
         self.incoming = None
         # summary of the remote phase situation
         self.remotephases = None
         # phases changes that must be pushed along side the changesets
         self.outdatedphases = None
         # phases changes that must be pushed if changeset push fails
         self.fallbackoutdatedphases = None
         # outgoing obsmarkers
         self.outobsmarkers = set()
         # outgoing bookmarks, list of (bm, oldnode | '', newnode | '')
         self.outbookmarks = []
         # transaction manager
         self.trmanager = None
         # map { pushkey partid -> callback handling failure}
         # used to handle exception from mandatory pushkey part failure
         self.pkfailcb = {}
         # an iterable of pushvars or None
         self.pushvars = pushvars
         # publish pushed changesets
         self.publish = publish
 
     @util.propertycache
     def futureheads(self):
         """future remote heads if the changeset push succeeds"""
         return self.outgoing.missingheads
 
     @util.propertycache
     def fallbackheads(self):
         """future remote heads if the changeset push fails"""
         if self.revs is None:
             # not target to push, all common are relevant
             return self.outgoing.commonheads
         unfi = self.repo.unfiltered()
         # I want cheads = heads(::missingheads and ::commonheads)
         # (missingheads is revs with secret changeset filtered out)
         #
         # This can be expressed as:
         #     cheads = ( (missingheads and ::commonheads)
         #              + (commonheads and ::missingheads))"
         #              )
         #
         # while trying to push we already computed the following:
         #     common = (::commonheads)
         #     missing = ((commonheads::missingheads) - commonheads)
         #
         # We can pick:
         # * missingheads part of common (::commonheads)
         common = self.outgoing.common
         nm = self.repo.changelog.nodemap
         cheads = [node for node in self.revs if nm[node] in common]
         # and
         # * commonheads parents on missing
         revset = unfi.set(
             b'%ln and parents(roots(%ln))',
             self.outgoing.commonheads,
             self.outgoing.missing,
         )
         cheads.extend(c.node() for c in revset)
         return cheads
 
     @property
     def commonheads(self):
         """set of all common heads after changeset bundle push"""
         if self.cgresult:
             return self.futureheads
         else:
             return self.fallbackheads
 
 
 # mapping of message used when pushing bookmark
 bookmsgmap = {
     b'update': (
         _(b"updating bookmark %s\n"),
         _(b'updating bookmark %s failed!\n'),
     ),
     b'export': (
         _(b"exporting bookmark %s\n"),
         _(b'exporting bookmark %s failed!\n'),
     ),
     b'delete': (
         _(b"deleting remote bookmark %s\n"),
         _(b'deleting remote bookmark %s failed!\n'),
     ),
 }
 
 
 def push(
     repo,
     remote,
     force=False,
     revs=None,
     newbranch=False,
     bookmarks=(),
     publish=False,
     opargs=None,
 ):
     '''Push outgoing changesets (limited by revs) from a local
     repository to remote. Return an integer:
       - None means nothing to push
       - 0 means HTTP error
       - 1 means we pushed and remote head count is unchanged *or*
         we have outgoing changesets but refused to push
       - other values as described by addchangegroup()
     '''
     if opargs is None:
         opargs = {}
     pushop = pushoperation(
         repo,
         remote,
         force,
         revs,
         newbranch,
         bookmarks,
         publish,
         **pycompat.strkwargs(opargs)
     )
     if pushop.remote.local():
         missing = (
             set(pushop.repo.requirements) - pushop.remote.local().supported
         )
         if missing:
             msg = _(
                 b"required features are not"
                 b" supported in the destination:"
                 b" %s"
             ) % (b', '.join(sorted(missing)))
             raise error.Abort(msg)
 
     if not pushop.remote.canpush():
         raise error.Abort(_(b"destination does not support push"))
 
     if not pushop.remote.capable(b'unbundle'):
         raise error.Abort(
             _(
                 b'cannot push: destination does not support the '
                 b'unbundle wire protocol command'
             )
         )
 
     # get lock as we might write phase data
     wlock = lock = None
     try:
         # bundle2 push may receive a reply bundle touching bookmarks
         # requiring the wlock. Take it now to ensure proper ordering.
         maypushback = pushop.ui.configbool(b'experimental', b'bundle2.pushback')
         if (
             (not _forcebundle1(pushop))
             and maypushback
             and not bookmod.bookmarksinstore(repo)
         ):
             wlock = pushop.repo.wlock()
         lock = pushop.repo.lock()
         pushop.trmanager = transactionmanager(
             pushop.repo, b'push-response', pushop.remote.url()
         )
     except error.LockUnavailable as err:
         # source repo cannot be locked.
         # We do not abort the push, but just disable the local phase
         # synchronisation.
         msg = b'cannot lock source repository: %s\n' % stringutil.forcebytestr(
             err
         )
         pushop.ui.debug(msg)
 
     with wlock or util.nullcontextmanager():
         with lock or util.nullcontextmanager():
             with pushop.trmanager or util.nullcontextmanager():
                 pushop.repo.checkpush(pushop)
                 _checkpublish(pushop)
                 _pushdiscovery(pushop)
                 if not _forcebundle1(pushop):
                     _pushbundle2(pushop)
                 _pushchangeset(pushop)
                 _pushsyncphase(pushop)
                 _pushobsolete(pushop)
                 _pushbookmark(pushop)
 
     if repo.ui.configbool(b'experimental', b'remotenames'):
         logexchange.pullremotenames(repo, remote)
 
     return pushop
 
 
 # list of steps to perform discovery before push
 pushdiscoveryorder = []
 
 # Mapping between step name and function
 #
 # This exists to help extensions wrap steps if necessary
 pushdiscoverymapping = {}
 
 
 def pushdiscovery(stepname):
     """decorator for function performing discovery before push
 
     The function is added to the step -> function mapping and appended to the
     list of steps.  Beware that decorated function will be added in order (this
     may matter).
 
     You can only use this decorator for a new step, if you want to wrap a step
     from an extension, change the pushdiscovery dictionary directly."""
 
     def dec(func):
         assert stepname not in pushdiscoverymapping
         pushdiscoverymapping[stepname] = func
         pushdiscoveryorder.append(stepname)
         return func
 
     return dec
 
 
 def _pushdiscovery(pushop):
     """Run all discovery steps"""
     for stepname in pushdiscoveryorder:
         step = pushdiscoverymapping[stepname]
         step(pushop)
 
 
 @pushdiscovery(b'changeset')
 def _pushdiscoverychangeset(pushop):
     """discover the changeset that need to be pushed"""
     fci = discovery.findcommonincoming
     if pushop.revs:
         commoninc = fci(
             pushop.repo,
             pushop.remote,
             force=pushop.force,
             ancestorsof=pushop.revs,
         )
     else:
         commoninc = fci(pushop.repo, pushop.remote, force=pushop.force)
     common, inc, remoteheads = commoninc
     fco = discovery.findcommonoutgoing
     outgoing = fco(
         pushop.repo,
         pushop.remote,
         onlyheads=pushop.revs,
         commoninc=commoninc,
         force=pushop.force,
     )
     pushop.outgoing = outgoing
     pushop.remoteheads = remoteheads
     pushop.incoming = inc
 
 
 @pushdiscovery(b'phase')
 def _pushdiscoveryphase(pushop):
     """discover the phase that needs to be pushed
 
     (computed for both success and failure case for changesets push)"""
     outgoing = pushop.outgoing
     unfi = pushop.repo.unfiltered()
     remotephases = listkeys(pushop.remote, b'phases')
 
     if (
         pushop.ui.configbool(b'ui', b'_usedassubrepo')
         and remotephases  # server supports phases
         and not pushop.outgoing.missing  # no changesets to be pushed
         and remotephases.get(b'publishing', False)
     ):
         # When:
         # - this is a subrepo push
         # - and remote support phase
         # - and no changeset are to be pushed
         # - and remote is publishing
         # We may be in issue 3781 case!
         # We drop the possible phase synchronisation done by
         # courtesy to publish changesets possibly locally draft
         # on the remote.
         pushop.outdatedphases = []
         pushop.fallbackoutdatedphases = []
         return
 
     pushop.remotephases = phases.remotephasessummary(
         pushop.repo, pushop.fallbackheads, remotephases
     )
     droots = pushop.remotephases.draftroots
 
     extracond = b''
     if not pushop.remotephases.publishing:
         extracond = b' and public()'
     revset = b'heads((%%ln::%%ln) %s)' % extracond
     # Get the list of all revs draft on remote by public here.
     # XXX Beware that revset break if droots is not strictly
     # XXX root we may want to ensure it is but it is costly
     fallback = list(unfi.set(revset, droots, pushop.fallbackheads))
     if not pushop.remotephases.publishing and pushop.publish:
         future = list(
             unfi.set(
                 b'%ln and (not public() or %ln::)', pushop.futureheads, droots
             )
         )
     elif not outgoing.missing:
         future = fallback
     else:
         # adds changeset we are going to push as draft
         #
         # should not be necessary for publishing server, but because of an
         # issue fixed in xxxxx we have to do it anyway.
         fdroots = list(
             unfi.set(b'roots(%ln  + %ln::)', outgoing.missing, droots)
         )
         fdroots = [f.node() for f in fdroots]
         future = list(unfi.set(revset, fdroots, pushop.futureheads))
     pushop.outdatedphases = future
     pushop.fallbackoutdatedphases = fallback
 
 
 @pushdiscovery(b'obsmarker')
 def _pushdiscoveryobsmarkers(pushop):
     if not obsolete.isenabled(pushop.repo, obsolete.exchangeopt):
         return
 
     if not pushop.repo.obsstore:
         return
 
     if b'obsolete' not in listkeys(pushop.remote, b'namespaces'):
         return
 
     repo = pushop.repo
     # very naive computation, that can be quite expensive on big repo.
     # However: evolution is currently slow on them anyway.
     nodes = (c.node() for c in repo.set(b'::%ln', pushop.futureheads))
     pushop.outobsmarkers = pushop.repo.obsstore.relevantmarkers(nodes)
 
 
 @pushdiscovery(b'bookmarks')
 def _pushdiscoverybookmarks(pushop):
     ui = pushop.ui
     repo = pushop.repo.unfiltered()
     remote = pushop.remote
     ui.debug(b"checking for updated bookmarks\n")
     ancestors = ()
     if pushop.revs:
         revnums = pycompat.maplist(repo.changelog.rev, pushop.revs)
         ancestors = repo.changelog.ancestors(revnums, inclusive=True)
 
     remotebookmark = bookmod.unhexlifybookmarks(listkeys(remote, b'bookmarks'))
 
     explicit = {
         repo._bookmarks.expandname(bookmark) for bookmark in pushop.bookmarks
     }
 
     comp = bookmod.comparebookmarks(repo, repo._bookmarks, remotebookmark)
     return _processcompared(pushop, ancestors, explicit, remotebookmark, comp)
 
 
 def _processcompared(pushop, pushed, explicit, remotebms, comp):
     """take decision on bookmarks to push to the remote repo
 
     Exists to help extensions alter this behavior.
     """
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = comp
 
     repo = pushop.repo
 
     for b, scid, dcid in advsrc:
         if b in explicit:
             explicit.remove(b)
         if not pushed or repo[scid].rev() in pushed:
             pushop.outbookmarks.append((b, dcid, scid))
     # search added bookmark
     for b, scid, dcid in addsrc:
         if b in explicit:
             explicit.remove(b)
             pushop.outbookmarks.append((b, b'', scid))
     # search for overwritten bookmark
     for b, scid, dcid in list(advdst) + list(diverge) + list(differ):
         if b in explicit:
             explicit.remove(b)
             pushop.outbookmarks.append((b, dcid, scid))
     # search for bookmark to delete
     for b, scid, dcid in adddst:
         if b in explicit:
             explicit.remove(b)
             # treat as "deleted locally"
             pushop.outbookmarks.append((b, dcid, b''))
     # identical bookmarks shouldn't get reported
     for b, scid, dcid in same:
         if b in explicit:
             explicit.remove(b)
 
     if explicit:
         explicit = sorted(explicit)
         # we should probably list all of them
         pushop.ui.warn(
             _(
                 b'bookmark %s does not exist on the local '
                 b'or remote repository!\n'
             )
             % explicit[0]
         )
         pushop.bkresult = 2
 
     pushop.outbookmarks.sort()
 
 
 def _pushcheckoutgoing(pushop):
     outgoing = pushop.outgoing
     unfi = pushop.repo.unfiltered()
     if not outgoing.missing:
         # nothing to push
         scmutil.nochangesfound(unfi.ui, unfi, outgoing.excluded)
         return False
     # something to push
     if not pushop.force:
         # if repo.obsstore == False --> no obsolete
         # then, save the iteration
         if unfi.obsstore:
             # this message are here for 80 char limit reason
             mso = _(b"push includes obsolete changeset: %s!")
             mspd = _(b"push includes phase-divergent changeset: %s!")
             mscd = _(b"push includes content-divergent changeset: %s!")
             mst = {
                 b"orphan": _(b"push includes orphan changeset: %s!"),
                 b"phase-divergent": mspd,
                 b"content-divergent": mscd,
             }
             # If we are to push if there is at least one
             # obsolete or unstable changeset in missing, at
             # least one of the missinghead will be obsolete or
             # unstable. So checking heads only is ok
             for node in outgoing.missingheads:
                 ctx = unfi[node]
                 if ctx.obsolete():
                     raise error.Abort(mso % ctx)
                 elif ctx.isunstable():
                     # TODO print more than one instability in the abort
                     # message
                     raise error.Abort(mst[ctx.instabilities()[0]] % ctx)
 
         discovery.checkheads(pushop)
     return True
 
 
 # List of names of steps to perform for an outgoing bundle2, order matters.
 b2partsgenorder = []
 
 # Mapping between step name and function
 #
 # This exists to help extensions wrap steps if necessary
 b2partsgenmapping = {}
 
 
 def b2partsgenerator(stepname, idx=None):
     """decorator for function generating bundle2 part
 
     The function is added to the step -> function mapping and appended to the
     list of steps.  Beware that decorated functions will be added in order
     (this may matter).
 
     You can only use this decorator for new steps, if you want to wrap a step
     from an extension, attack the b2partsgenmapping dictionary directly."""
 
     def dec(func):
         assert stepname not in b2partsgenmapping
         b2partsgenmapping[stepname] = func
         if idx is None:
             b2partsgenorder.append(stepname)
         else:
             b2partsgenorder.insert(idx, stepname)
         return func
 
     return dec
 
 
 def _pushb2ctxcheckheads(pushop, bundler):
     """Generate race condition checking parts
 
     Exists as an independent function to aid extensions
     """
     # * 'force' do not check for push race,
     # * if we don't push anything, there are nothing to check.
     if not pushop.force and pushop.outgoing.missingheads:
         allowunrelated = b'related' in bundler.capabilities.get(
             b'checkheads', ()
         )
         emptyremote = pushop.pushbranchmap is None
         if not allowunrelated or emptyremote:
             bundler.newpart(b'check:heads', data=iter(pushop.remoteheads))
         else:
             affected = set()
             for branch, heads in pycompat.iteritems(pushop.pushbranchmap):
                 remoteheads, newheads, unsyncedheads, discardedheads = heads
                 if remoteheads is not None:
                     remote = set(remoteheads)
                     affected |= set(discardedheads) & remote
                     affected |= remote - set(newheads)
             if affected:
                 data = iter(sorted(affected))
                 bundler.newpart(b'check:updated-heads', data=data)
 
 
 def _pushing(pushop):
     """return True if we are pushing anything"""
     return bool(
         pushop.outgoing.missing
         or pushop.outdatedphases
         or pushop.outobsmarkers
         or pushop.outbookmarks
     )
 
 
 @b2partsgenerator(b'check-bookmarks')
 def _pushb2checkbookmarks(pushop, bundler):
     """insert bookmark move checking"""
     if not _pushing(pushop) or pushop.force:
         return
     b2caps = bundle2.bundle2caps(pushop.remote)
     hasbookmarkcheck = b'bookmarks' in b2caps
     if not (pushop.outbookmarks and hasbookmarkcheck):
         return
     data = []
     for book, old, new in pushop.outbookmarks:
         data.append((book, old))
     checkdata = bookmod.binaryencode(data)
     bundler.newpart(b'check:bookmarks', data=checkdata)
 
 
 @b2partsgenerator(b'check-phases')
 def _pushb2checkphases(pushop, bundler):
     """insert phase move checking"""
     if not _pushing(pushop) or pushop.force:
         return
     b2caps = bundle2.bundle2caps(pushop.remote)
     hasphaseheads = b'heads' in b2caps.get(b'phases', ())
     if pushop.remotephases is not None and hasphaseheads:
         # check that the remote phase has not changed
         checks = [[] for p in phases.allphases]
         checks[phases.public].extend(pushop.remotephases.publicheads)
         checks[phases.draft].extend(pushop.remotephases.draftroots)
         if any(checks):
             for nodes in checks:
                 nodes.sort()
             checkdata = phases.binaryencode(checks)
             bundler.newpart(b'check:phases', data=checkdata)
 
 
 @b2partsgenerator(b'changeset')
 def _pushb2ctx(pushop, bundler):
     """handle changegroup push through bundle2
 
     addchangegroup result is stored in the ``pushop.cgresult`` attribute.
     """
     if b'changesets' in pushop.stepsdone:
         return
     pushop.stepsdone.add(b'changesets')
     # Send known heads to the server for race detection.
     if not _pushcheckoutgoing(pushop):
         return
     pushop.repo.prepushoutgoinghooks(pushop)
 
     _pushb2ctxcheckheads(pushop, bundler)
 
     b2caps = bundle2.bundle2caps(pushop.remote)
     version = b'01'
     cgversions = b2caps.get(b'changegroup')
     if cgversions:  # 3.1 and 3.2 ship with an empty value
         cgversions = [
             v
             for v in cgversions
             if v in changegroup.supportedoutgoingversions(pushop.repo)
         ]
         if not cgversions:
             raise error.Abort(_(b'no common changegroup version'))
         version = max(cgversions)
     cgstream = changegroup.makestream(
         pushop.repo, pushop.outgoing, version, b'push'
     )
     cgpart = bundler.newpart(b'changegroup', data=cgstream)
     if cgversions:
         cgpart.addparam(b'version', version)
     if b'treemanifest' in pushop.repo.requirements:
         cgpart.addparam(b'treemanifest', b'1')
     if b'exp-sidedata-flag' in pushop.repo.requirements:
         cgpart.addparam(b'exp-sidedata', b'1')
 
     def handlereply(op):
         """extract addchangegroup returns from server reply"""
         cgreplies = op.records.getreplies(cgpart.id)
         assert len(cgreplies[b'changegroup']) == 1
         pushop.cgresult = cgreplies[b'changegroup'][0][b'return']
 
     return handlereply
 
 
 @b2partsgenerator(b'phase')
 def _pushb2phases(pushop, bundler):
     """handle phase push through bundle2"""
     if b'phases' in pushop.stepsdone:
         return
     b2caps = bundle2.bundle2caps(pushop.remote)
     ui = pushop.repo.ui
 
     legacyphase = b'phases' in ui.configlist(b'devel', b'legacy.exchange')
     haspushkey = b'pushkey' in b2caps
     hasphaseheads = b'heads' in b2caps.get(b'phases', ())
 
     if hasphaseheads and not legacyphase:
         return _pushb2phaseheads(pushop, bundler)
     elif haspushkey:
         return _pushb2phasespushkey(pushop, bundler)
 
 
 def _pushb2phaseheads(pushop, bundler):
     """push phase information through a bundle2 - binary part"""
     pushop.stepsdone.add(b'phases')
     if pushop.outdatedphases:
         updates = [[] for p in phases.allphases]
         updates[0].extend(h.node() for h in pushop.outdatedphases)
         phasedata = phases.binaryencode(updates)
         bundler.newpart(b'phase-heads', data=phasedata)
 
 
 def _pushb2phasespushkey(pushop, bundler):
     """push phase information through a bundle2 - pushkey part"""
     pushop.stepsdone.add(b'phases')
     part2node = []
 
     def handlefailure(pushop, exc):
         targetid = int(exc.partid)
         for partid, node in part2node:
             if partid == targetid:
                 raise error.Abort(_(b'updating %s to public failed') % node)
 
     enc = pushkey.encode
     for newremotehead in pushop.outdatedphases:
         part = bundler.newpart(b'pushkey')
         part.addparam(b'namespace', enc(b'phases'))
         part.addparam(b'key', enc(newremotehead.hex()))
         part.addparam(b'old', enc(b'%d' % phases.draft))
         part.addparam(b'new', enc(b'%d' % phases.public))
         part2node.append((part.id, newremotehead))
         pushop.pkfailcb[part.id] = handlefailure
 
     def handlereply(op):
         for partid, node in part2node:
             partrep = op.records.getreplies(partid)
             results = partrep[b'pushkey']
             assert len(results) <= 1
             msg = None
             if not results:
                 msg = _(b'server ignored update of %s to public!\n') % node
             elif not int(results[0][b'return']):
                 msg = _(b'updating %s to public failed!\n') % node
             if msg is not None:
                 pushop.ui.warn(msg)
 
     return handlereply
 
 
 @b2partsgenerator(b'obsmarkers')
 def _pushb2obsmarkers(pushop, bundler):
     if b'obsmarkers' in pushop.stepsdone:
         return
     remoteversions = bundle2.obsmarkersversion(bundler.capabilities)
     if obsolete.commonversion(remoteversions) is None:
         return
     pushop.stepsdone.add(b'obsmarkers')
     if pushop.outobsmarkers:
-        markers = _sortedmarkers(pushop.outobsmarkers)
+        markers = obsutil.sortedmarkers(pushop.outobsmarkers)
         bundle2.buildobsmarkerspart(bundler, markers)
 
 
 @b2partsgenerator(b'bookmarks')
 def _pushb2bookmarks(pushop, bundler):
     """handle bookmark push through bundle2"""
     if b'bookmarks' in pushop.stepsdone:
         return
     b2caps = bundle2.bundle2caps(pushop.remote)
 
     legacy = pushop.repo.ui.configlist(b'devel', b'legacy.exchange')
     legacybooks = b'bookmarks' in legacy
 
     if not legacybooks and b'bookmarks' in b2caps:
         return _pushb2bookmarkspart(pushop, bundler)
     elif b'pushkey' in b2caps:
         return _pushb2bookmarkspushkey(pushop, bundler)
 
 
 def _bmaction(old, new):
     """small utility for bookmark pushing"""
     if not old:
         return b'export'
     elif not new:
         return b'delete'
     return b'update'
 
 
 def _abortonsecretctx(pushop, node, b):
     """abort if a given bookmark points to a secret changeset"""
     if node and pushop.repo[node].phase() == phases.secret:
         raise error.Abort(
             _(b'cannot push bookmark %s as it points to a secret changeset') % b
         )
 
 
 def _pushb2bookmarkspart(pushop, bundler):
     pushop.stepsdone.add(b'bookmarks')
     if not pushop.outbookmarks:
         return
 
     allactions = []
     data = []
     for book, old, new in pushop.outbookmarks:
         _abortonsecretctx(pushop, new, book)
         data.append((book, new))
         allactions.append((book, _bmaction(old, new)))
     checkdata = bookmod.binaryencode(data)
     bundler.newpart(b'bookmarks', data=checkdata)
 
     def handlereply(op):
         ui = pushop.ui
         # if success
         for book, action in allactions:
             ui.status(bookmsgmap[action][0] % book)
 
     return handlereply
 
 
 def _pushb2bookmarkspushkey(pushop, bundler):
     pushop.stepsdone.add(b'bookmarks')
     part2book = []
     enc = pushkey.encode
 
     def handlefailure(pushop, exc):
         targetid = int(exc.partid)
         for partid, book, action in part2book:
             if partid == targetid:
                 raise error.Abort(bookmsgmap[action][1].rstrip() % book)
         # we should not be called for part we did not generated
         assert False
 
     for book, old, new in pushop.outbookmarks:
         _abortonsecretctx(pushop, new, book)
         part = bundler.newpart(b'pushkey')
         part.addparam(b'namespace', enc(b'bookmarks'))
         part.addparam(b'key', enc(book))
         part.addparam(b'old', enc(hex(old)))
         part.addparam(b'new', enc(hex(new)))
         action = b'update'
         if not old:
             action = b'export'
         elif not new:
             action = b'delete'
         part2book.append((part.id, book, action))
         pushop.pkfailcb[part.id] = handlefailure
 
     def handlereply(op):
         ui = pushop.ui
         for partid, book, action in part2book:
             partrep = op.records.getreplies(partid)
             results = partrep[b'pushkey']
             assert len(results) <= 1
             if not results:
                 pushop.ui.warn(_(b'server ignored bookmark %s update\n') % book)
             else:
                 ret = int(results[0][b'return'])
                 if ret:
                     ui.status(bookmsgmap[action][0] % book)
                 else:
                     ui.warn(bookmsgmap[action][1] % book)
                     if pushop.bkresult is not None:
                         pushop.bkresult = 1
 
     return handlereply
 
 
 @b2partsgenerator(b'pushvars', idx=0)
 def _getbundlesendvars(pushop, bundler):
     '''send shellvars via bundle2'''
     pushvars = pushop.pushvars
     if pushvars:
         shellvars = {}
         for raw in pushvars:
             if b'=' not in raw:
                 msg = (
                     b"unable to parse variable '%s', should follow "
                     b"'KEY=VALUE' or 'KEY=' format"
                 )
                 raise error.Abort(msg % raw)
             k, v = raw.split(b'=', 1)
             shellvars[k] = v
 
         part = bundler.newpart(b'pushvars')
 
         for key, value in pycompat.iteritems(shellvars):
             part.addparam(key, value, mandatory=False)
 
 
 def _pushbundle2(pushop):
     """push data to the remote using bundle2
 
     The only currently supported type of data is changegroup but this will
     evolve in the future."""
     bundler = bundle2.bundle20(pushop.ui, bundle2.bundle2caps(pushop.remote))
     pushback = pushop.trmanager and pushop.ui.configbool(
         b'experimental', b'bundle2.pushback'
     )
 
     # create reply capability
     capsblob = bundle2.encodecaps(
         bundle2.getrepocaps(pushop.repo, allowpushback=pushback, role=b'client')
     )
     bundler.newpart(b'replycaps', data=capsblob)
     replyhandlers = []
     for partgenname in b2partsgenorder:
         partgen = b2partsgenmapping[partgenname]
         ret = partgen(pushop, bundler)
         if callable(ret):
             replyhandlers.append(ret)
     # do not push if nothing to push
     if bundler.nbparts <= 1:
         return
     stream = util.chunkbuffer(bundler.getchunks())
     try:
         try:
             with pushop.remote.commandexecutor() as e:
                 reply = e.callcommand(
                     b'unbundle',
                     {
                         b'bundle': stream,
                         b'heads': [b'force'],
                         b'url': pushop.remote.url(),
                     },
                 ).result()
         except error.BundleValueError as exc:
             raise error.Abort(_(b'missing support for %s') % exc)
         try:
             trgetter = None
             if pushback:
                 trgetter = pushop.trmanager.transaction
             op = bundle2.processbundle(pushop.repo, reply, trgetter)
         except error.BundleValueError as exc:
             raise error.Abort(_(b'missing support for %s') % exc)
         except bundle2.AbortFromPart as exc:
             pushop.ui.status(_(b'remote: %s\n') % exc)
             if exc.hint is not None:
                 pushop.ui.status(_(b'remote: %s\n') % (b'(%s)' % exc.hint))
             raise error.Abort(_(b'push failed on remote'))
     except error.PushkeyFailed as exc:
         partid = int(exc.partid)
         if partid not in pushop.pkfailcb:
             raise
         pushop.pkfailcb[partid](pushop, exc)
     for rephand in replyhandlers:
         rephand(op)
 
 
 def _pushchangeset(pushop):
     """Make the actual push of changeset bundle to remote repo"""
     if b'changesets' in pushop.stepsdone:
         return
     pushop.stepsdone.add(b'changesets')
     if not _pushcheckoutgoing(pushop):
         return
 
     # Should have verified this in push().
     assert pushop.remote.capable(b'unbundle')
 
     pushop.repo.prepushoutgoinghooks(pushop)
     outgoing = pushop.outgoing
     # TODO: get bundlecaps from remote
     bundlecaps = None
     # create a changegroup from local
     if pushop.revs is None and not (
         outgoing.excluded or pushop.repo.changelog.filteredrevs
     ):
         # push everything,
         # use the fast path, no race possible on push
         cg = changegroup.makechangegroup(
             pushop.repo,
             outgoing,
             b'01',
             b'push',
             fastpath=True,
             bundlecaps=bundlecaps,
         )
     else:
         cg = changegroup.makechangegroup(
             pushop.repo, outgoing, b'01', b'push', bundlecaps=bundlecaps
         )
 
     # apply changegroup to remote
     # local repo finds heads on server, finds out what
     # revs it must push. once revs transferred, if server
     # finds it has different heads (someone else won
     # commit/push race), server aborts.
     if pushop.force:
         remoteheads = [b'force']
     else:
         remoteheads = pushop.remoteheads
     # ssh: return remote's addchangegroup()
     # http: return remote's addchangegroup() or 0 for error
     pushop.cgresult = pushop.remote.unbundle(cg, remoteheads, pushop.repo.url())
 
 
 def _pushsyncphase(pushop):
     """synchronise phase information locally and remotely"""
     cheads = pushop.commonheads
     # even when we don't push, exchanging phase data is useful
     remotephases = listkeys(pushop.remote, b'phases')
     if (
         pushop.ui.configbool(b'ui', b'_usedassubrepo')
         and remotephases  # server supports phases
         and pushop.cgresult is None  # nothing was pushed
         and remotephases.get(b'publishing', False)
     ):
         # When:
         # - this is a subrepo push
         # - and remote support phase
         # - and no changeset was pushed
         # - and remote is publishing
         # We may be in issue 3871 case!
         # We drop the possible phase synchronisation done by
         # courtesy to publish changesets possibly locally draft
         # on the remote.
         remotephases = {b'publishing': b'True'}
     if not remotephases:  # old server or public only reply from non-publishing
         _localphasemove(pushop, cheads)
         # don't push any phase data as there is nothing to push
     else:
         ana = phases.analyzeremotephases(pushop.repo, cheads, remotephases)
         pheads, droots = ana
         ### Apply remote phase on local
         if remotephases.get(b'publishing', False):
             _localphasemove(pushop, cheads)
         else:  # publish = False
             _localphasemove(pushop, pheads)
             _localphasemove(pushop, cheads, phases.draft)
         ### Apply local phase on remote
 
         if pushop.cgresult:
             if b'phases' in pushop.stepsdone:
                 # phases already pushed though bundle2
                 return
             outdated = pushop.outdatedphases
         else:
             outdated = pushop.fallbackoutdatedphases
 
         pushop.stepsdone.add(b'phases')
 
         # filter heads already turned public by the push
         outdated = [c for c in outdated if c.node() not in pheads]
         # fallback to independent pushkey command
         for newremotehead in outdated:
             with pushop.remote.commandexecutor() as e:
                 r = e.callcommand(
                     b'pushkey',
                     {
                         b'namespace': b'phases',
                         b'key': newremotehead.hex(),
                         b'old': b'%d' % phases.draft,
                         b'new': b'%d' % phases.public,
                     },
                 ).result()
 
             if not r:
                 pushop.ui.warn(
                     _(b'updating %s to public failed!\n') % newremotehead
                 )
 
 
 def _localphasemove(pushop, nodes, phase=phases.public):
     """move <nodes> to <phase> in the local source repo"""
     if pushop.trmanager:
         phases.advanceboundary(
             pushop.repo, pushop.trmanager.transaction(), phase, nodes
         )
     else:
         # repo is not locked, do not change any phases!
         # Informs the user that phases should have been moved when
         # applicable.
         actualmoves = [n for n in nodes if phase < pushop.repo[n].phase()]
         phasestr = phases.phasenames[phase]
         if actualmoves:
             pushop.ui.status(
                 _(
                     b'cannot lock source repo, skipping '
                     b'local %s phase update\n'
                 )
                 % phasestr
             )
 
 
 def _pushobsolete(pushop):
     """utility function to push obsolete markers to a remote"""
     if b'obsmarkers' in pushop.stepsdone:
         return
     repo = pushop.repo
     remote = pushop.remote
     pushop.stepsdone.add(b'obsmarkers')
     if pushop.outobsmarkers:
         pushop.ui.debug(b'try to push obsolete markers to remote\n')
         rslts = []
-        markers = _sortedmarkers(pushop.outobsmarkers)
+        markers = obsutil.sortedmarkers(pushop.outobsmarkers)
         remotedata = obsolete._pushkeyescape(markers)
         for key in sorted(remotedata, reverse=True):
             # reverse sort to ensure we end with dump0
             data = remotedata[key]
             rslts.append(remote.pushkey(b'obsolete', key, b'', data))
         if [r for r in rslts if not r]:
             msg = _(b'failed to push some obsolete markers!\n')
             repo.ui.warn(msg)
 
 
 def _pushbookmark(pushop):
     """Update bookmark position on remote"""
     if pushop.cgresult == 0 or b'bookmarks' in pushop.stepsdone:
         return
     pushop.stepsdone.add(b'bookmarks')
     ui = pushop.ui
     remote = pushop.remote
 
     for b, old, new in pushop.outbookmarks:
         action = b'update'
         if not old:
             action = b'export'
         elif not new:
             action = b'delete'
 
         with remote.commandexecutor() as e:
             r = e.callcommand(
                 b'pushkey',
                 {
                     b'namespace': b'bookmarks',
                     b'key': b,
                     b'old': hex(old),
                     b'new': hex(new),
                 },
             ).result()
 
         if r:
             ui.status(bookmsgmap[action][0] % b)
         else:
             ui.warn(bookmsgmap[action][1] % b)
             # discovery can have set the value form invalid entry
             if pushop.bkresult is not None:
                 pushop.bkresult = 1
 
 
 class pulloperation(object):
     """A object that represent a single pull operation
 
     It purpose is to carry pull related state and very common operation.
 
     A new should be created at the beginning of each pull and discarded
     afterward.
     """
 
     def __init__(
         self,
         repo,
         remote,
         heads=None,
         force=False,
         bookmarks=(),
         remotebookmarks=None,
         streamclonerequested=None,
         includepats=None,
         excludepats=None,
         depth=None,
     ):
         # repo we pull into
         self.repo = repo
         # repo we pull from
         self.remote = remote
         # revision we try to pull (None is "all")
         self.heads = heads
         # bookmark pulled explicitly
         self.explicitbookmarks = [
             repo._bookmarks.expandname(bookmark) for bookmark in bookmarks
         ]
         # do we force pull?
         self.force = force
         # whether a streaming clone was requested
         self.streamclonerequested = streamclonerequested
         # transaction manager
         self.trmanager = None
         # set of common changeset between local and remote before pull
         self.common = None
         # set of pulled head
         self.rheads = None
         # list of missing changeset to fetch remotely
         self.fetch = None
         # remote bookmarks data
         self.remotebookmarks = remotebookmarks
         # result of changegroup pulling (used as return code by pull)
         self.cgresult = None
         # list of step already done
         self.stepsdone = set()
         # Whether we attempted a clone from pre-generated bundles.
         self.clonebundleattempted = False
         # Set of file patterns to include.
         self.includepats = includepats
         # Set of file patterns to exclude.
         self.excludepats = excludepats
         # Number of ancestor changesets to pull from each pulled head.
         self.depth = depth
 
     @util.propertycache
     def pulledsubset(self):
         """heads of the set of changeset target by the pull"""
         # compute target subset
         if self.heads is None:
             # We pulled every thing possible
             # sync on everything common
             c = set(self.common)
             ret = list(self.common)
             for n in self.rheads:
                 if n not in c:
                     ret.append(n)
             return ret
         else:
             # We pulled a specific subset
             # sync on this subset
             return self.heads
 
     @util.propertycache
     def canusebundle2(self):
         return not _forcebundle1(self)
 
     @util.propertycache
     def remotebundle2caps(self):
         return bundle2.bundle2caps(self.remote)
 
     def gettransaction(self):
         # deprecated; talk to trmanager directly
         return self.trmanager.transaction()
 
 
 class transactionmanager(util.transactional):
     """An object to manage the life cycle of a transaction
 
     It creates the transaction on demand and calls the appropriate hooks when
     closing the transaction."""
 
     def __init__(self, repo, source, url):
         self.repo = repo
         self.source = source
         self.url = url
         self._tr = None
 
     def transaction(self):
         """Return an open transaction object, constructing if necessary"""
         if not self._tr:
             trname = b'%s\n%s' % (self.source, util.hidepassword(self.url))
             self._tr = self.repo.transaction(trname)
             self._tr.hookargs[b'source'] = self.source
             self._tr.hookargs[b'url'] = self.url
         return self._tr
 
     def close(self):
         """close transaction if created"""
         if self._tr is not None:
             self._tr.close()
 
     def release(self):
         """release transaction if created"""
         if self._tr is not None:
             self._tr.release()
 
 
 def listkeys(remote, namespace):
     with remote.commandexecutor() as e:
         return e.callcommand(b'listkeys', {b'namespace': namespace}).result()
 
 
 def _fullpullbundle2(repo, pullop):
     # The server may send a partial reply, i.e. when inlining
     # pre-computed bundles. In that case, update the common
     # set based on the results and pull another bundle.
     #
     # There are two indicators that the process is finished:
     # - no changeset has been added, or
     # - all remote heads are known locally.
     # The head check must use the unfiltered view as obsoletion
     # markers can hide heads.
     unfi = repo.unfiltered()
     unficl = unfi.changelog
 
     def headsofdiff(h1, h2):
         """Returns heads(h1 % h2)"""
         res = unfi.set(b'heads(%ln %% %ln)', h1, h2)
         return set(ctx.node() for ctx in res)
 
     def headsofunion(h1, h2):
         """Returns heads((h1 + h2) - null)"""
         res = unfi.set(b'heads((%ln + %ln - null))', h1, h2)
         return set(ctx.node() for ctx in res)
 
     while True:
         old_heads = unficl.heads()
         clstart = len(unficl)
         _pullbundle2(pullop)
         if repository.NARROW_REQUIREMENT in repo.requirements:
             # XXX narrow clones filter the heads on the server side during
             # XXX getbundle and result in partial replies as well.
             # XXX Disable pull bundles in this case as band aid to avoid
             # XXX extra round trips.
             break
         if clstart == len(unficl):
             break
         if all(unficl.hasnode(n) for n in pullop.rheads):
             break
         new_heads = headsofdiff(unficl.heads(), old_heads)
         pullop.common = headsofunion(new_heads, pullop.common)
         pullop.rheads = set(pullop.rheads) - pullop.common
 
 
 def pull(
     repo,
     remote,
     heads=None,
     force=False,
     bookmarks=(),
     opargs=None,
     streamclonerequested=None,
     includepats=None,
     excludepats=None,
     depth=None,
 ):
     """Fetch repository data from a remote.
 
     This is the main function used to retrieve data from a remote repository.
 
     ``repo`` is the local repository to clone into.
     ``remote`` is a peer instance.
     ``heads`` is an iterable of revisions we want to pull. ``None`` (the
     default) means to pull everything from the remote.
     ``bookmarks`` is an iterable of bookmarks requesting to be pulled. By
     default, all remote bookmarks are pulled.
     ``opargs`` are additional keyword arguments to pass to ``pulloperation``
     initialization.
     ``streamclonerequested`` is a boolean indicating whether a "streaming
     clone" is requested. A "streaming clone" is essentially a raw file copy
     of revlogs from the server. This only works when the local repository is
     empty. The default value of ``None`` means to respect the server
     configuration for preferring stream clones.
     ``includepats`` and ``excludepats`` define explicit file patterns to
     include and exclude in storage, respectively. If not defined, narrow
     patterns from the repo instance are used, if available.
     ``depth`` is an integer indicating the DAG depth of history we're
     interested in. If defined, for each revision specified in ``heads``, we
     will fetch up to this many of its ancestors and data associated with them.
 
     Returns the ``pulloperation`` created for this pull.
     """
     if opargs is None:
         opargs = {}
 
     # We allow the narrow patterns to be passed in explicitly to provide more
     # flexibility for API consumers.
     if includepats or excludepats:
         includepats = includepats or set()
         excludepats = excludepats or set()
     else:
         includepats, excludepats = repo.narrowpats
 
     narrowspec.validatepatterns(includepats)
     narrowspec.validatepatterns(excludepats)
 
     pullop = pulloperation(
         repo,
         remote,
         heads,
         force,
         bookmarks=bookmarks,
         streamclonerequested=streamclonerequested,
         includepats=includepats,
         excludepats=excludepats,
         depth=depth,
         **pycompat.strkwargs(opargs)
     )
 
     peerlocal = pullop.remote.local()
     if peerlocal:
         missing = set(peerlocal.requirements) - pullop.repo.supported
         if missing:
             msg = _(
                 b"required features are not"
                 b" supported in the destination:"
                 b" %s"
             ) % (b', '.join(sorted(missing)))
             raise error.Abort(msg)
 
     pullop.trmanager = transactionmanager(repo, b'pull', remote.url())
     wlock = util.nullcontextmanager()
     if not bookmod.bookmarksinstore(repo):
         wlock = repo.wlock()
     with wlock, repo.lock(), pullop.trmanager:
         # Use the modern wire protocol, if available.
         if remote.capable(b'command-changesetdata'):
             exchangev2.pull(pullop)
         else:
             # This should ideally be in _pullbundle2(). However, it needs to run
             # before discovery to avoid extra work.
             _maybeapplyclonebundle(pullop)
             streamclone.maybeperformlegacystreamclone(pullop)
             _pulldiscovery(pullop)
             if pullop.canusebundle2:
                 _fullpullbundle2(repo, pullop)
             _pullchangeset(pullop)
             _pullphase(pullop)
             _pullbookmarks(pullop)
             _pullobsolete(pullop)
 
     # storing remotenames
     if repo.ui.configbool(b'experimental', b'remotenames'):
         logexchange.pullremotenames(repo, remote)
 
     return pullop
 
 
 # list of steps to perform discovery before pull
 pulldiscoveryorder = []
 
 # Mapping between step name and function
 #
 # This exists to help extensions wrap steps if necessary
 pulldiscoverymapping = {}
 
 
 def pulldiscovery(stepname):
     """decorator for function performing discovery before pull
 
     The function is added to the step -> function mapping and appended to the
     list of steps.  Beware that decorated function will be added in order (this
     may matter).
 
     You can only use this decorator for a new step, if you want to wrap a step
     from an extension, change the pulldiscovery dictionary directly."""
 
     def dec(func):
         assert stepname not in pulldiscoverymapping
         pulldiscoverymapping[stepname] = func
         pulldiscoveryorder.append(stepname)
         return func
 
     return dec
 
 
 def _pulldiscovery(pullop):
     """Run all discovery steps"""
     for stepname in pulldiscoveryorder:
         step = pulldiscoverymapping[stepname]
         step(pullop)
 
 
 @pulldiscovery(b'b1:bookmarks')
 def _pullbookmarkbundle1(pullop):
     """fetch bookmark data in bundle1 case
 
     If not using bundle2, we have to fetch bookmarks before changeset
     discovery to reduce the chance and impact of race conditions."""
     if pullop.remotebookmarks is not None:
         return
     if pullop.canusebundle2 and b'listkeys' in pullop.remotebundle2caps:
         # all known bundle2 servers now support listkeys, but lets be nice with
         # new implementation.
         return
     books = listkeys(pullop.remote, b'bookmarks')
     pullop.remotebookmarks = bookmod.unhexlifybookmarks(books)
 
 
 @pulldiscovery(b'changegroup')
 def _pulldiscoverychangegroup(pullop):
     """discovery phase for the pull
 
     Current handle changeset discovery only, will change handle all discovery
     at some point."""
     tmp = discovery.findcommonincoming(
         pullop.repo, pullop.remote, heads=pullop.heads, force=pullop.force
     )
     common, fetch, rheads = tmp
     nm = pullop.repo.unfiltered().changelog.nodemap
     if fetch and rheads:
         # If a remote heads is filtered locally, put in back in common.
         #
         # This is a hackish solution to catch most of "common but locally
         # hidden situation".  We do not performs discovery on unfiltered
         # repository because it end up doing a pathological amount of round
         # trip for w huge amount of changeset we do not care about.
         #
         # If a set of such "common but filtered" changeset exist on the server
         # but are not including a remote heads, we'll not be able to detect it,
         scommon = set(common)
         for n in rheads:
             if n in nm:
                 if n not in scommon:
                     common.append(n)
         if set(rheads).issubset(set(common)):
             fetch = []
     pullop.common = common
     pullop.fetch = fetch
     pullop.rheads = rheads
 
 
 def _pullbundle2(pullop):
     """pull data using bundle2
 
     For now, the only supported data are changegroup."""
     kwargs = {b'bundlecaps': caps20to10(pullop.repo, role=b'client')}
 
     # make ui easier to access
     ui = pullop.repo.ui
 
     # At the moment we don't do stream clones over bundle2. If that is
     # implemented then here's where the check for that will go.
     streaming = streamclone.canperformstreamclone(pullop, bundle2=True)[0]
 
     # declare pull perimeters
     kwargs[b'common'] = pullop.common
     kwargs[b'heads'] = pullop.heads or pullop.rheads
 
     # check server supports narrow and then adding includepats and excludepats
     servernarrow = pullop.remote.capable(wireprototypes.NARROWCAP)
     if servernarrow and pullop.includepats:
         kwargs[b'includepats'] = pullop.includepats
     if servernarrow and pullop.excludepats:
         kwargs[b'excludepats'] = pullop.excludepats
 
     if streaming:
         kwargs[b'cg'] = False
         kwargs[b'stream'] = True
         pullop.stepsdone.add(b'changegroup')
         pullop.stepsdone.add(b'phases')
 
     else:
         # pulling changegroup
         pullop.stepsdone.add(b'changegroup')
 
         kwargs[b'cg'] = pullop.fetch
 
         legacyphase = b'phases' in ui.configlist(b'devel', b'legacy.exchange')
         hasbinaryphase = b'heads' in pullop.remotebundle2caps.get(b'phases', ())
         if not legacyphase and hasbinaryphase:
             kwargs[b'phases'] = True
             pullop.stepsdone.add(b'phases')
 
         if b'listkeys' in pullop.remotebundle2caps:
             if b'phases' not in pullop.stepsdone:
                 kwargs[b'listkeys'] = [b'phases']
 
     bookmarksrequested = False
     legacybookmark = b'bookmarks' in ui.configlist(b'devel', b'legacy.exchange')
     hasbinarybook = b'bookmarks' in pullop.remotebundle2caps
 
     if pullop.remotebookmarks is not None:
         pullop.stepsdone.add(b'request-bookmarks')
 
     if (
         b'request-bookmarks' not in pullop.stepsdone
         and pullop.remotebookmarks is None
         and not legacybookmark
         and hasbinarybook
     ):
         kwargs[b'bookmarks'] = True
         bookmarksrequested = True
 
     if b'listkeys' in pullop.remotebundle2caps:
         if b'request-bookmarks' not in pullop.stepsdone:
             # make sure to always includes bookmark data when migrating
             # `hg incoming --bundle` to using this function.
             pullop.stepsdone.add(b'request-bookmarks')
             kwargs.setdefault(b'listkeys', []).append(b'bookmarks')
 
     # If this is a full pull / clone and the server supports the clone bundles
     # feature, tell the server whether we attempted a clone bundle. The
     # presence of this flag indicates the client supports clone bundles. This
     # will enable the server to treat clients that support clone bundles
     # differently from those that don't.
     if (
         pullop.remote.capable(b'clonebundles')
         and pullop.heads is None
         and list(pullop.common) == [nullid]
     ):
         kwargs[b'cbattempted'] = pullop.clonebundleattempted
 
     if streaming:
         pullop.repo.ui.status(_(b'streaming all changes\n'))
     elif not pullop.fetch:
         pullop.repo.ui.status(_(b"no changes found\n"))
         pullop.cgresult = 0
     else:
         if pullop.heads is None and list(pullop.common) == [nullid]:
             pullop.repo.ui.status(_(b"requesting all changes\n"))
     if obsolete.isenabled(pullop.repo, obsolete.exchangeopt):
         remoteversions = bundle2.obsmarkersversion(pullop.remotebundle2caps)
         if obsolete.commonversion(remoteversions) is not None:
             kwargs[b'obsmarkers'] = True
             pullop.stepsdone.add(b'obsmarkers')
     _pullbundle2extraprepare(pullop, kwargs)
 
     with pullop.remote.commandexecutor() as e:
         args = dict(kwargs)
         args[b'source'] = b'pull'
         bundle = e.callcommand(b'getbundle', args).result()
 
         try:
             op = bundle2.bundleoperation(
                 pullop.repo, pullop.gettransaction, source=b'pull'
             )
             op.modes[b'bookmarks'] = b'records'
             bundle2.processbundle(pullop.repo, bundle, op=op)
         except bundle2.AbortFromPart as exc:
             pullop.repo.ui.status(_(b'remote: abort: %s\n') % exc)
             raise error.Abort(_(b'pull failed on remote'), hint=exc.hint)
         except error.BundleValueError as exc:
             raise error.Abort(_(b'missing support for %s') % exc)
 
     if pullop.fetch:
         pullop.cgresult = bundle2.combinechangegroupresults(op)
 
     # processing phases change
     for namespace, value in op.records[b'listkeys']:
         if namespace == b'phases':
             _pullapplyphases(pullop, value)
 
     # processing bookmark update
     if bookmarksrequested:
         books = {}
         for record in op.records[b'bookmarks']:
             books[record[b'bookmark']] = record[b"node"]
         pullop.remotebookmarks = books
     else:
         for namespace, value in op.records[b'listkeys']:
             if namespace == b'bookmarks':
                 pullop.remotebookmarks = bookmod.unhexlifybookmarks(value)
 
     # bookmark data were either already there or pulled in the bundle
     if pullop.remotebookmarks is not None:
         _pullbookmarks(pullop)
 
 
 def _pullbundle2extraprepare(pullop, kwargs):
     """hook function so that extensions can extend the getbundle call"""
 
 
 def _pullchangeset(pullop):
     """pull changeset from unbundle into the local repo"""
     # We delay the open of the transaction as late as possible so we
     # don't open transaction for nothing or you break future useful
     # rollback call
     if b'changegroup' in pullop.stepsdone:
         return
     pullop.stepsdone.add(b'changegroup')
     if not pullop.fetch:
         pullop.repo.ui.status(_(b"no changes found\n"))
         pullop.cgresult = 0
         return
     tr = pullop.gettransaction()
     if pullop.heads is None and list(pullop.common) == [nullid]:
         pullop.repo.ui.status(_(b"requesting all changes\n"))
     elif pullop.heads is None and pullop.remote.capable(b'changegroupsubset'):
         # issue1320, avoid a race if remote changed after discovery
         pullop.heads = pullop.rheads
 
     if pullop.remote.capable(b'getbundle'):
         # TODO: get bundlecaps from remote
         cg = pullop.remote.getbundle(
             b'pull', common=pullop.common, heads=pullop.heads or pullop.rheads
         )
     elif pullop.heads is None:
         with pullop.remote.commandexecutor() as e:
             cg = e.callcommand(
                 b'changegroup', {b'nodes': pullop.fetch, b'source': b'pull',}
             ).result()
 
     elif not pullop.remote.capable(b'changegroupsubset'):
         raise error.Abort(
             _(
                 b"partial pull cannot be done because "
                 b"other repository doesn't support "
                 b"changegroupsubset."
             )
         )
     else:
         with pullop.remote.commandexecutor() as e:
             cg = e.callcommand(
                 b'changegroupsubset',
                 {
                     b'bases': pullop.fetch,
                     b'heads': pullop.heads,
                     b'source': b'pull',
                 },
             ).result()
 
     bundleop = bundle2.applybundle(
         pullop.repo, cg, tr, b'pull', pullop.remote.url()
     )
     pullop.cgresult = bundle2.combinechangegroupresults(bundleop)
 
 
 def _pullphase(pullop):
     # Get remote phases data from remote
     if b'phases' in pullop.stepsdone:
         return
     remotephases = listkeys(pullop.remote, b'phases')
     _pullapplyphases(pullop, remotephases)
 
 
 def _pullapplyphases(pullop, remotephases):
     """apply phase movement from observed remote state"""
     if b'phases' in pullop.stepsdone:
         return
     pullop.stepsdone.add(b'phases')
     publishing = bool(remotephases.get(b'publishing', False))
     if remotephases and not publishing:
         # remote is new and non-publishing
         pheads, _dr = phases.analyzeremotephases(
             pullop.repo, pullop.pulledsubset, remotephases
         )
         dheads = pullop.pulledsubset
     else:
         # Remote is old or publishing all common changesets
         # should be seen as public
         pheads = pullop.pulledsubset
         dheads = []
     unfi = pullop.repo.unfiltered()
     phase = unfi._phasecache.phase
     rev = unfi.changelog.nodemap.get
     public = phases.public
     draft = phases.draft
 
     # exclude changesets already public locally and update the others
     pheads = [pn for pn in pheads if phase(unfi, rev(pn)) > public]
     if pheads:
         tr = pullop.gettransaction()
         phases.advanceboundary(pullop.repo, tr, public, pheads)
 
     # exclude changesets already draft locally and update the others
     dheads = [pn for pn in dheads if phase(unfi, rev(pn)) > draft]
     if dheads:
         tr = pullop.gettransaction()
         phases.advanceboundary(pullop.repo, tr, draft, dheads)
 
 
 def _pullbookmarks(pullop):
     """process the remote bookmark information to update the local one"""
     if b'bookmarks' in pullop.stepsdone:
         return
     pullop.stepsdone.add(b'bookmarks')
     repo = pullop.repo
     remotebookmarks = pullop.remotebookmarks
     bookmod.updatefromremote(
         repo.ui,
         repo,
         remotebookmarks,
         pullop.remote.url(),
         pullop.gettransaction,
         explicit=pullop.explicitbookmarks,
     )
 
 
 def _pullobsolete(pullop):
     """utility function to pull obsolete markers from a remote
 
     The `gettransaction` is function that return the pull transaction, creating
     one if necessary. We return the transaction to inform the calling code that
     a new transaction have been created (when applicable).
 
     Exists mostly to allow overriding for experimentation purpose"""
     if b'obsmarkers' in pullop.stepsdone:
         return
     pullop.stepsdone.add(b'obsmarkers')
     tr = None
     if obsolete.isenabled(pullop.repo, obsolete.exchangeopt):
         pullop.repo.ui.debug(b'fetching remote obsolete markers\n')
         remoteobs = listkeys(pullop.remote, b'obsolete')
         if b'dump0' in remoteobs:
             tr = pullop.gettransaction()
             markers = []
             for key in sorted(remoteobs, reverse=True):
                 if key.startswith(b'dump'):
                     data = util.b85decode(remoteobs[key])
                     version, newmarks = obsolete._readmarkers(data)
                     markers += newmarks
             if markers:
                 pullop.repo.obsstore.add(tr, markers)
             pullop.repo.invalidatevolatilesets()
     return tr
 
 
 def applynarrowacl(repo, kwargs):
     """Apply narrow fetch access control.
 
     This massages the named arguments for getbundle wire protocol commands
     so requested data is filtered through access control rules.
     """
     ui = repo.ui
     # TODO this assumes existence of HTTP and is a layering violation.
     username = ui.shortuser(ui.environ.get(b'REMOTE_USER') or ui.username())
     user_includes = ui.configlist(
         _NARROWACL_SECTION,
         username + b'.includes',
         ui.configlist(_NARROWACL_SECTION, b'default.includes'),
     )
     user_excludes = ui.configlist(
         _NARROWACL_SECTION,
         username + b'.excludes',
         ui.configlist(_NARROWACL_SECTION, b'default.excludes'),
     )
     if not user_includes:
         raise error.Abort(
             _(b"{} configuration for user {} is empty").format(
                 _NARROWACL_SECTION, username
             )
         )
 
     user_includes = [
         b'path:.' if p == b'*' else b'path:' + p for p in user_includes
     ]
     user_excludes = [
         b'path:.' if p == b'*' else b'path:' + p for p in user_excludes
     ]
 
     req_includes = set(kwargs.get(r'includepats', []))
     req_excludes = set(kwargs.get(r'excludepats', []))
 
     req_includes, req_excludes, invalid_includes = narrowspec.restrictpatterns(
         req_includes, req_excludes, user_includes, user_excludes
     )
 
     if invalid_includes:
         raise error.Abort(
             _(b"The following includes are not accessible for {}: {}").format(
                 username, invalid_includes
             )
         )
 
     new_args = {}
     new_args.update(kwargs)
     new_args[r'narrow'] = True
     new_args[r'narrow_acl'] = True
     new_args[r'includepats'] = req_includes
     if req_excludes:
         new_args[r'excludepats'] = req_excludes
 
     return new_args
 
 
 def _computeellipsis(repo, common, heads, known, match, depth=None):
     """Compute the shape of a narrowed DAG.
 
     Args:
       repo: The repository we're transferring.
       common: The roots of the DAG range we're transferring.
               May be just [nullid], which means all ancestors of heads.
       heads: The heads of the DAG range we're transferring.
       match: The narrowmatcher that allows us to identify relevant changes.
       depth: If not None, only consider nodes to be full nodes if they are at
              most depth changesets away from one of heads.
 
     Returns:
       A tuple of (visitnodes, relevant_nodes, ellipsisroots) where:
 
         visitnodes: The list of nodes (either full or ellipsis) which
                     need to be sent to the client.
         relevant_nodes: The set of changelog nodes which change a file inside
                  the narrowspec. The client needs these as non-ellipsis nodes.
         ellipsisroots: A dict of {rev: parents} that is used in
                        narrowchangegroup to produce ellipsis nodes with the
                        correct parents.
     """
     cl = repo.changelog
     mfl = repo.manifestlog
 
     clrev = cl.rev
 
     commonrevs = {clrev(n) for n in common} | {nullrev}
     headsrevs = {clrev(n) for n in heads}
 
     if depth:
         revdepth = {h: 0 for h in headsrevs}
 
     ellipsisheads = collections.defaultdict(set)
     ellipsisroots = collections.defaultdict(set)
 
     def addroot(head, curchange):
         """Add a root to an ellipsis head, splitting heads with 3 roots."""
         ellipsisroots[head].add(curchange)
         # Recursively split ellipsis heads with 3 roots by finding the
         # roots' youngest common descendant which is an elided merge commit.
         # That descendant takes 2 of the 3 roots as its own, and becomes a
         # root of the head.
         while len(ellipsisroots[head]) > 2:
             child, roots = splithead(head)
             splitroots(head, child, roots)
             head = child  # Recurse in case we just added a 3rd root
 
     def splitroots(head, child, roots):
         ellipsisroots[head].difference_update(roots)
         ellipsisroots[head].add(child)
         ellipsisroots[child].update(roots)
         ellipsisroots[child].discard(child)
 
     def splithead(head):
         r1, r2, r3 = sorted(ellipsisroots[head])
         for nr1, nr2 in ((r2, r3), (r1, r3), (r1, r2)):
             mid = repo.revs(
                 b'sort(merge() & %d::%d & %d::%d, -rev)', nr1, head, nr2, head
             )
             for j in mid:
                 if j == nr2:
                     return nr2, (nr1, nr2)
                 if j not in ellipsisroots or len(ellipsisroots[j]) < 2:
                     return j, (nr1, nr2)
         raise error.Abort(
             _(
                 b'Failed to split up ellipsis node! head: %d, '
                 b'roots: %d %d %d'
             )
             % (head, r1, r2, r3)
         )
 
     missing = list(cl.findmissingrevs(common=commonrevs, heads=headsrevs))
     visit = reversed(missing)
     relevant_nodes = set()
     visitnodes = [cl.node(m) for m in missing]
     required = set(headsrevs) | known
     for rev in visit:
         clrev = cl.changelogrevision(rev)
         ps = [prev for prev in cl.parentrevs(rev) if prev != nullrev]
         if depth is not None:
             curdepth = revdepth[rev]
             for p in ps:
                 revdepth[p] = min(curdepth + 1, revdepth.get(p, depth + 1))
         needed = False
         shallow_enough = depth is None or revdepth[rev] <= depth
         if shallow_enough:
             curmf = mfl[clrev.manifest].read()
             if ps:
                 # We choose to not trust the changed files list in
                 # changesets because it's not always correct. TODO: could
                 # we trust it for the non-merge case?
                 p1mf = mfl[cl.changelogrevision(ps[0]).manifest].read()
                 needed = bool(curmf.diff(p1mf, match))
                 if not needed and len(ps) > 1:
                     # For merge changes, the list of changed files is not
                     # helpful, since we need to emit the merge if a file
                     # in the narrow spec has changed on either side of the
                     # merge. As a result, we do a manifest diff to check.
                     p2mf = mfl[cl.changelogrevision(ps[1]).manifest].read()
                     needed = bool(curmf.diff(p2mf, match))
             else:
                 # For a root node, we need to include the node if any
                 # files in the node match the narrowspec.
                 needed = any(curmf.walk(match))
 
         if needed:
             for head in ellipsisheads[rev]:
                 addroot(head, rev)
             for p in ps:
                 required.add(p)
             relevant_nodes.add(cl.node(rev))
         else:
             if not ps:
                 ps = [nullrev]
             if rev in required:
                 for head in ellipsisheads[rev]:
                     addroot(head, rev)
                 for p in ps:
                     ellipsisheads[p].add(rev)
             else:
                 for p in ps:
                     ellipsisheads[p] |= ellipsisheads[rev]
 
     # add common changesets as roots of their reachable ellipsis heads
     for c in commonrevs:
         for head in ellipsisheads[c]:
             addroot(head, c)
     return visitnodes, relevant_nodes, ellipsisroots
 
 
 def caps20to10(repo, role):
     """return a set with appropriate options to use bundle20 during getbundle"""
     caps = {b'HG20'}
     capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo, role=role))
     caps.add(b'bundle2=' + urlreq.quote(capsblob))
     return caps
 
 
 # List of names of steps to perform for a bundle2 for getbundle, order matters.
 getbundle2partsorder = []
 
 # Mapping between step name and function
 #
 # This exists to help extensions wrap steps if necessary
 getbundle2partsmapping = {}
 
 
 def getbundle2partsgenerator(stepname, idx=None):
     """decorator for function generating bundle2 part for getbundle
 
     The function is added to the step -> function mapping and appended to the
     list of steps.  Beware that decorated functions will be added in order
     (this may matter).
 
     You can only use this decorator for new steps, if you want to wrap a step
     from an extension, attack the getbundle2partsmapping dictionary directly."""
 
     def dec(func):
         assert stepname not in getbundle2partsmapping
         getbundle2partsmapping[stepname] = func
         if idx is None:
             getbundle2partsorder.append(stepname)
         else:
             getbundle2partsorder.insert(idx, stepname)
         return func
 
     return dec
 
 
 def bundle2requested(bundlecaps):
     if bundlecaps is not None:
         return any(cap.startswith(b'HG2') for cap in bundlecaps)
     return False
 
 
 def getbundlechunks(
     repo, source, heads=None, common=None, bundlecaps=None, **kwargs
 ):
     """Return chunks constituting a bundle's raw data.
 
     Could be a bundle HG10 or a bundle HG20 depending on bundlecaps
     passed.
 
     Returns a 2-tuple of a dict with metadata about the generated bundle
     and an iterator over raw chunks (of varying sizes).
     """
     kwargs = pycompat.byteskwargs(kwargs)
     info = {}
     usebundle2 = bundle2requested(bundlecaps)
     # bundle10 case
     if not usebundle2:
         if bundlecaps and not kwargs.get(b'cg', True):
             raise ValueError(
                 _(b'request for bundle10 must include changegroup')
             )
 
         if kwargs:
             raise ValueError(
                 _(b'unsupported getbundle arguments: %s')
                 % b', '.join(sorted(kwargs.keys()))
             )
         outgoing = _computeoutgoing(repo, heads, common)
         info[b'bundleversion'] = 1
         return (
             info,
             changegroup.makestream(
                 repo, outgoing, b'01', source, bundlecaps=bundlecaps
             ),
         )
 
     # bundle20 case
     info[b'bundleversion'] = 2
     b2caps = {}
     for bcaps in bundlecaps:
         if bcaps.startswith(b'bundle2='):
             blob = urlreq.unquote(bcaps[len(b'bundle2=') :])
             b2caps.update(bundle2.decodecaps(blob))
     bundler = bundle2.bundle20(repo.ui, b2caps)
 
     kwargs[b'heads'] = heads
     kwargs[b'common'] = common
 
     for name in getbundle2partsorder:
         func = getbundle2partsmapping[name]
         func(
             bundler,
             repo,
             source,
             bundlecaps=bundlecaps,
             b2caps=b2caps,
             **pycompat.strkwargs(kwargs)
         )
 
     info[b'prefercompressed'] = bundler.prefercompressed
 
     return info, bundler.getchunks()
 
 
 @getbundle2partsgenerator(b'stream2')
 def _getbundlestream2(bundler, repo, *args, **kwargs):
     return bundle2.addpartbundlestream2(bundler, repo, **kwargs)
 
 
 @getbundle2partsgenerator(b'changegroup')
 def _getbundlechangegrouppart(
     bundler,
     repo,
     source,
     bundlecaps=None,
     b2caps=None,
     heads=None,
     common=None,
     **kwargs
 ):
     """add a changegroup part to the requested bundle"""
     if not kwargs.get(r'cg', True):
         return
 
     version = b'01'
     cgversions = b2caps.get(b'changegroup')
     if cgversions:  # 3.1 and 3.2 ship with an empty value
         cgversions = [
             v
             for v in cgversions
             if v in changegroup.supportedoutgoingversions(repo)
         ]
         if not cgversions:
             raise error.Abort(_(b'no common changegroup version'))
         version = max(cgversions)
 
     outgoing = _computeoutgoing(repo, heads, common)
     if not outgoing.missing:
         return
 
     if kwargs.get(r'narrow', False):
         include = sorted(filter(bool, kwargs.get(r'includepats', [])))
         exclude = sorted(filter(bool, kwargs.get(r'excludepats', [])))
         matcher = narrowspec.match(repo.root, include=include, exclude=exclude)
     else:
         matcher = None
 
     cgstream = changegroup.makestream(
         repo, outgoing, version, source, bundlecaps=bundlecaps, matcher=matcher
     )
 
     part = bundler.newpart(b'changegroup', data=cgstream)
     if cgversions:
         part.addparam(b'version', version)
 
     part.addparam(b'nbchanges', b'%d' % len(outgoing.missing), mandatory=False)
 
     if b'treemanifest' in repo.requirements:
         part.addparam(b'treemanifest', b'1')
 
     if b'exp-sidedata-flag' in repo.requirements:
         part.addparam(b'exp-sidedata', b'1')
 
     if (
         kwargs.get(r'narrow', False)
         and kwargs.get(r'narrow_acl', False)
         and (include or exclude)
     ):
         # this is mandatory because otherwise ACL clients won't work
         narrowspecpart = bundler.newpart(b'Narrow:responsespec')
         narrowspecpart.data = b'%s\0%s' % (
             b'\n'.join(include),
             b'\n'.join(exclude),
         )
 
 
 @getbundle2partsgenerator(b'bookmarks')
 def _getbundlebookmarkpart(
     bundler, repo, source, bundlecaps=None, b2caps=None, **kwargs
 ):
     """add a bookmark part to the requested bundle"""
     if not kwargs.get(r'bookmarks', False):
         return
     if b'bookmarks' not in b2caps:
         raise error.Abort(_(b'no common bookmarks exchange method'))
     books = bookmod.listbinbookmarks(repo)
     data = bookmod.binaryencode(books)
     if data:
         bundler.newpart(b'bookmarks', data=data)
 
 
 @getbundle2partsgenerator(b'listkeys')
 def _getbundlelistkeysparts(
     bundler, repo, source, bundlecaps=None, b2caps=None, **kwargs
 ):
     """add parts containing listkeys namespaces to the requested bundle"""
     listkeys = kwargs.get(r'listkeys', ())
     for namespace in listkeys:
         part = bundler.newpart(b'listkeys')
         part.addparam(b'namespace', namespace)
         keys = repo.listkeys(namespace).items()
         part.data = pushkey.encodekeys(keys)
 
 
 @getbundle2partsgenerator(b'obsmarkers')
 def _getbundleobsmarkerpart(
     bundler, repo, source, bundlecaps=None, b2caps=None, heads=None, **kwargs
 ):
     """add an obsolescence markers part to the requested bundle"""
     if kwargs.get(r'obsmarkers', False):
         if heads is None:
             heads = repo.heads()
         subset = [c.node() for c in repo.set(b'::%ln', heads)]
         markers = repo.obsstore.relevantmarkers(subset)
-        markers = _sortedmarkers(markers)
+        markers = obsutil.sortedmarkers(markers)
         bundle2.buildobsmarkerspart(bundler, markers)
 
 
 @getbundle2partsgenerator(b'phases')
 def _getbundlephasespart(
     bundler, repo, source, bundlecaps=None, b2caps=None, heads=None, **kwargs
 ):
     """add phase heads part to the requested bundle"""
     if kwargs.get(r'phases', False):
         if not b'heads' in b2caps.get(b'phases'):
             raise error.Abort(_(b'no common phases exchange method'))
         if heads is None:
             heads = repo.heads()
 
         headsbyphase = collections.defaultdict(set)
         if repo.publishing():
             headsbyphase[phases.public] = heads
         else:
             # find the appropriate heads to move
 
             phase = repo._phasecache.phase
             node = repo.changelog.node
             rev = repo.changelog.rev
             for h in heads:
                 headsbyphase[phase(repo, rev(h))].add(h)
             seenphases = list(headsbyphase.keys())
 
             # We do not handle anything but public and draft phase for now)
             if seenphases:
                 assert max(seenphases) <= phases.draft
 
             # if client is pulling non-public changesets, we need to find
             # intermediate public heads.
             draftheads = headsbyphase.get(phases.draft, set())
             if draftheads:
                 publicheads = headsbyphase.get(phases.public, set())
 
                 revset = b'heads(only(%ln, %ln) and public())'
                 extraheads = repo.revs(revset, draftheads, publicheads)
                 for r in extraheads:
                     headsbyphase[phases.public].add(node(r))
 
         # transform data in a format used by the encoding function
         phasemapping = []
         for phase in phases.allphases:
             phasemapping.append(sorted(headsbyphase[phase]))
 
         # generate the actual part
         phasedata = phases.binaryencode(phasemapping)
         bundler.newpart(b'phase-heads', data=phasedata)
 
 
 @getbundle2partsgenerator(b'hgtagsfnodes')
 def _getbundletagsfnodes(
     bundler,
     repo,
     source,
     bundlecaps=None,
     b2caps=None,
     heads=None,
     common=None,
     **kwargs
 ):
     """Transfer the .hgtags filenodes mapping.
 
     Only values for heads in this bundle will be transferred.
 
     The part data consists of pairs of 20 byte changeset node and .hgtags
     filenodes raw values.
     """
     # Don't send unless:
     # - changeset are being exchanged,
     # - the client supports it.
     if not (kwargs.get(r'cg', True) and b'hgtagsfnodes' in b2caps):
         return
 
     outgoing = _computeoutgoing(repo, heads, common)
     bundle2.addparttagsfnodescache(repo, bundler, outgoing)
 
 
 @getbundle2partsgenerator(b'cache:rev-branch-cache')
 def _getbundlerevbranchcache(
     bundler,
     repo,
     source,
     bundlecaps=None,
     b2caps=None,
     heads=None,
     common=None,
     **kwargs
 ):
     """Transfer the rev-branch-cache mapping
 
     The payload is a series of data related to each branch
 
     1) branch name length
     2) number of open heads
     3) number of closed heads
     4) open heads nodes
     5) closed heads nodes
     """
     # Don't send unless:
     # - changeset are being exchanged,
     # - the client supports it.
     # - narrow bundle isn't in play (not currently compatible).
     if (
         not kwargs.get(r'cg', True)
         or b'rev-branch-cache' not in b2caps
         or kwargs.get(r'narrow', False)
         or repo.ui.has_section(_NARROWACL_SECTION)
     ):
         return
 
     outgoing = _computeoutgoing(repo, heads, common)
     bundle2.addpartrevbranchcache(repo, bundler, outgoing)
 
 
 def check_heads(repo, their_heads, context):
     """check if the heads of a repo have been modified
 
     Used by peer for unbundling.
     """
     heads = repo.heads()
     heads_hash = hashlib.sha1(b''.join(sorted(heads))).digest()
     if not (
         their_heads == [b'force']
         or their_heads == heads
         or their_heads == [b'hashed', heads_hash]
     ):
         # someone else committed/pushed/unbundled while we
         # were transferring data
         raise error.PushRaced(
             b'repository changed while %s - please try again' % context
         )
 
 
 def unbundle(repo, cg, heads, source, url):
     """Apply a bundle to a repo.
 
     this function makes sure the repo is locked during the application and have
     mechanism to check that no push race occurred between the creation of the
     bundle and its application.
 
     If the push was raced as PushRaced exception is raised."""
     r = 0
     # need a transaction when processing a bundle2 stream
     # [wlock, lock, tr] - needs to be an array so nested functions can modify it
     lockandtr = [None, None, None]
     recordout = None
     # quick fix for output mismatch with bundle2 in 3.4
     captureoutput = repo.ui.configbool(
         b'experimental', b'bundle2-output-capture'
     )
     if url.startswith(b'remote:http:') or url.startswith(b'remote:https:'):
         captureoutput = True
     try:
         # note: outside bundle1, 'heads' is expected to be empty and this
         # 'check_heads' call wil be a no-op
         check_heads(repo, heads, b'uploading changes')
         # push can proceed
         if not isinstance(cg, bundle2.unbundle20):
             # legacy case: bundle1 (changegroup 01)
             txnname = b"\n".join([source, util.hidepassword(url)])
             with repo.lock(), repo.transaction(txnname) as tr:
                 op = bundle2.applybundle(repo, cg, tr, source, url)
                 r = bundle2.combinechangegroupresults(op)
         else:
             r = None
             try:
 
                 def gettransaction():
                     if not lockandtr[2]:
                         if not bookmod.bookmarksinstore(repo):
                             lockandtr[0] = repo.wlock()
                         lockandtr[1] = repo.lock()
                         lockandtr[2] = repo.transaction(source)
                         lockandtr[2].hookargs[b'source'] = source
                         lockandtr[2].hookargs[b'url'] = url
                         lockandtr[2].hookargs[b'bundle2'] = b'1'
                     return lockandtr[2]
 
                 # Do greedy locking by default until we're satisfied with lazy
                 # locking.
                 if not repo.ui.configbool(
                     b'experimental', b'bundle2lazylocking'
                 ):
                     gettransaction()
 
                 op = bundle2.bundleoperation(
                     repo,
                     gettransaction,
                     captureoutput=captureoutput,
                     source=b'push',
                 )
                 try:
                     op = bundle2.processbundle(repo, cg, op=op)
                 finally:
                     r = op.reply
                     if captureoutput and r is not None:
                         repo.ui.pushbuffer(error=True, subproc=True)
 
                         def recordout(output):
                             r.newpart(b'output', data=output, mandatory=False)
 
                 if lockandtr[2] is not None:
                     lockandtr[2].close()
             except BaseException as exc:
                 exc.duringunbundle2 = True
                 if captureoutput and r is not None:
                     parts = exc._bundle2salvagedoutput = r.salvageoutput()
 
                     def recordout(output):
                         part = bundle2.bundlepart(
                             b'output', data=output, mandatory=False
                         )
                         parts.append(part)
 
                 raise
     finally:
         lockmod.release(lockandtr[2], lockandtr[1], lockandtr[0])
         if recordout is not None:
             recordout(repo.ui.popbuffer())
     return r
 
 
 def _maybeapplyclonebundle(pullop):
     """Apply a clone bundle from a remote, if possible."""
 
     repo = pullop.repo
     remote = pullop.remote
 
     if not repo.ui.configbool(b'ui', b'clonebundles'):
         return
 
     # Only run if local repo is empty.
     if len(repo):
         return
 
     if pullop.heads:
         return
 
     if not remote.capable(b'clonebundles'):
         return
 
     with remote.commandexecutor() as e:
         res = e.callcommand(b'clonebundles', {}).result()
 
     # If we call the wire protocol command, that's good enough to record the
     # attempt.
     pullop.clonebundleattempted = True
 
     entries = parseclonebundlesmanifest(repo, res)
     if not entries:
         repo.ui.note(
             _(
                 b'no clone bundles available on remote; '
                 b'falling back to regular clone\n'
             )
         )
         return
 
     entries = filterclonebundleentries(
         repo, entries, streamclonerequested=pullop.streamclonerequested
     )
 
     if not entries:
         # There is a thundering herd concern here. However, if a server
         # operator doesn't advertise bundles appropriate for its clients,
         # they deserve what's coming. Furthermore, from a client's
         # perspective, no automatic fallback would mean not being able to
         # clone!
         repo.ui.warn(
             _(
                 b'no compatible clone bundles available on server; '
                 b'falling back to regular clone\n'
             )
         )
         repo.ui.warn(
             _(b'(you may want to report this to the server operator)\n')
         )
         return
 
     entries = sortclonebundleentries(repo.ui, entries)
 
     url = entries[0][b'URL']
     repo.ui.status(_(b'applying clone bundle from %s\n') % url)
     if trypullbundlefromurl(repo.ui, repo, url):
         repo.ui.status(_(b'finished applying clone bundle\n'))
     # Bundle failed.
     #
     # We abort by default to avoid the thundering herd of
     # clients flooding a server that was expecting expensive
     # clone load to be offloaded.
     elif repo.ui.configbool(b'ui', b'clonebundlefallback'):
         repo.ui.warn(_(b'falling back to normal clone\n'))
     else:
         raise error.Abort(
             _(b'error applying bundle'),
             hint=_(
                 b'if this error persists, consider contacting '
                 b'the server operator or disable clone '
                 b'bundles via '
                 b'"--config ui.clonebundles=false"'
             ),
         )
 
 
 def parseclonebundlesmanifest(repo, s):
     """Parses the raw text of a clone bundles manifest.
 
     Returns a list of dicts. The dicts have a ``URL`` key corresponding
     to the URL and other keys are the attributes for the entry.
     """
     m = []
     for line in s.splitlines():
         fields = line.split()
         if not fields:
             continue
         attrs = {b'URL': fields[0]}
         for rawattr in fields[1:]:
             key, value = rawattr.split(b'=', 1)
             key = urlreq.unquote(key)
             value = urlreq.unquote(value)
             attrs[key] = value
 
             # Parse BUNDLESPEC into components. This makes client-side
             # preferences easier to specify since you can prefer a single
             # component of the BUNDLESPEC.
             if key == b'BUNDLESPEC':
                 try:
                     bundlespec = parsebundlespec(repo, value)
                     attrs[b'COMPRESSION'] = bundlespec.compression
                     attrs[b'VERSION'] = bundlespec.version
                 except error.InvalidBundleSpecification:
                     pass
                 except error.UnsupportedBundleSpecification:
                     pass
 
         m.append(attrs)
 
     return m
 
 
 def isstreamclonespec(bundlespec):
     # Stream clone v1
     if bundlespec.wirecompression == b'UN' and bundlespec.wireversion == b's1':
         return True
 
     # Stream clone v2
     if (
         bundlespec.wirecompression == b'UN'
         and bundlespec.wireversion == b'02'
         and bundlespec.contentopts.get(b'streamv2')
     ):
         return True
 
     return False
 
 
 def filterclonebundleentries(repo, entries, streamclonerequested=False):
     """Remove incompatible clone bundle manifest entries.
 
     Accepts a list of entries parsed with ``parseclonebundlesmanifest``
     and returns a new list consisting of only the entries that this client
     should be able to apply.
 
     There is no guarantee we'll be able to apply all returned entries because
     the metadata we use to filter on may be missing or wrong.
     """
     newentries = []
     for entry in entries:
         spec = entry.get(b'BUNDLESPEC')
         if spec:
             try:
                 bundlespec = parsebundlespec(repo, spec, strict=True)
 
                 # If a stream clone was requested, filter out non-streamclone
                 # entries.
                 if streamclonerequested and not isstreamclonespec(bundlespec):
                     repo.ui.debug(
                         b'filtering %s because not a stream clone\n'
                         % entry[b'URL']
                     )
                     continue
 
             except error.InvalidBundleSpecification as e:
                 repo.ui.debug(stringutil.forcebytestr(e) + b'\n')
                 continue
             except error.UnsupportedBundleSpecification as e:
                 repo.ui.debug(
                     b'filtering %s because unsupported bundle '
                     b'spec: %s\n' % (entry[b'URL'], stringutil.forcebytestr(e))
                 )
                 continue
         # If we don't have a spec and requested a stream clone, we don't know
         # what the entry is so don't attempt to apply it.
         elif streamclonerequested:
             repo.ui.debug(
                 b'filtering %s because cannot determine if a stream '
                 b'clone bundle\n' % entry[b'URL']
             )
             continue
 
         if b'REQUIRESNI' in entry and not sslutil.hassni:
             repo.ui.debug(
                 b'filtering %s because SNI not supported\n' % entry[b'URL']
             )
             continue
 
         newentries.append(entry)
 
     return newentries
 
 
 class clonebundleentry(object):
     """Represents an item in a clone bundles manifest.
 
     This rich class is needed to support sorting since sorted() in Python 3
     doesn't support ``cmp`` and our comparison is complex enough that ``key=``
     won't work.
     """
 
     def __init__(self, value, prefers):
         self.value = value
         self.prefers = prefers
 
     def _cmp(self, other):
         for prefkey, prefvalue in self.prefers:
             avalue = self.value.get(prefkey)
             bvalue = other.value.get(prefkey)
 
             # Special case for b missing attribute and a matches exactly.
             if avalue is not None and bvalue is None and avalue == prefvalue:
                 return -1
 
             # Special case for a missing attribute and b matches exactly.
             if bvalue is not None and avalue is None and bvalue == prefvalue:
                 return 1
 
             # We can't compare unless attribute present on both.
             if avalue is None or bvalue is None:
                 continue
 
             # Same values should fall back to next attribute.
             if avalue == bvalue:
                 continue
 
             # Exact matches come first.
             if avalue == prefvalue:
                 return -1
             if bvalue == prefvalue:
                 return 1
 
             # Fall back to next attribute.
             continue
 
         # If we got here we couldn't sort by attributes and prefers. Fall
         # back to index order.
         return 0
 
     def __lt__(self, other):
         return self._cmp(other) < 0
 
     def __gt__(self, other):
         return self._cmp(other) > 0
 
     def __eq__(self, other):
         return self._cmp(other) == 0
 
     def __le__(self, other):
         return self._cmp(other) <= 0
 
     def __ge__(self, other):
         return self._cmp(other) >= 0
 
     def __ne__(self, other):
         return self._cmp(other) != 0
 
 
 def sortclonebundleentries(ui, entries):
     prefers = ui.configlist(b'ui', b'clonebundleprefers')
     if not prefers:
         return list(entries)
 
     prefers = [p.split(b'=', 1) for p in prefers]
 
     items = sorted(clonebundleentry(v, prefers) for v in entries)
     return [i.value for i in items]
 
 
 def trypullbundlefromurl(ui, repo, url):
     """Attempt to apply a bundle from a URL."""
     with repo.lock(), repo.transaction(b'bundleurl') as tr:
         try:
             fh = urlmod.open(ui, url)
             cg = readbundle(ui, fh, b'stream')
 
             if isinstance(cg, streamclone.streamcloneapplier):
                 cg.apply(repo)
             else:
                 bundle2.applybundle(repo, cg, tr, b'clonebundles', url)
             return True
         except urlerr.httperror as e:
             ui.warn(
                 _(b'HTTP error fetching bundle: %s\n')
                 % stringutil.forcebytestr(e)
             )
         except urlerr.urlerror as e:
             ui.warn(
                 _(b'error fetching bundle: %s\n')
                 % stringutil.forcebytestr(e.reason)
             )
 
         return False

mercurial/obsutil.py

@@ -1,1035 +1,1040 b''
 # obsutil.py - utility functions for obsolescence
 #
 # Copyright 2017 Boris Feld <[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 re
 
 from .i18n import _
 from . import (
     diffutil,
     encoding,
     node as nodemod,
     phases,
     pycompat,
     util,
 )
 from .utils import dateutil
 
 ### obsolescence marker flag
 
 ## bumpedfix flag
 #
 # When a changeset A' succeed to a changeset A which became public, we call A'
 # "bumped" because it's a successors of a public changesets
 #
 # o    A' (bumped)
 # |`:
 # | o  A
 # |/
 # o    Z
 #
 # The way to solve this situation is to create a new changeset Ad as children
 # of A. This changeset have the same content than A'. So the diff from A to A'
 # is the same than the diff from A to Ad. Ad is marked as a successors of A'
 #
 # o   Ad
 # |`:
 # | x A'
 # |'|
 # o | A
 # |/
 # o Z
 #
 # But by transitivity Ad is also a successors of A. To avoid having Ad marked
 # as bumped too, we add the `bumpedfix` flag to the marker. <A', (Ad,)>.
 # This flag mean that the successors express the changes between the public and
 # bumped version and fix the situation, breaking the transitivity of
 # "bumped" here.
 bumpedfix = 1
 usingsha256 = 2
 
 
 class marker(object):
     """Wrap obsolete marker raw data"""
 
     def __init__(self, repo, data):
         # the repo argument will be used to create changectx in later version
         self._repo = repo
         self._data = data
         self._decodedmeta = None
 
     def __hash__(self):
         return hash(self._data)
 
     def __eq__(self, other):
         if type(other) != type(self):
             return False
         return self._data == other._data
 
     def prednode(self):
         """Predecessor changeset node identifier"""
         return self._data[0]
 
     def succnodes(self):
         """List of successor changesets node identifiers"""
         return self._data[1]
 
     def parentnodes(self):
         """Parents of the predecessors (None if not recorded)"""
         return self._data[5]
 
     def metadata(self):
         """Decoded metadata dictionary"""
         return dict(self._data[3])
 
     def date(self):
         """Creation date as (unixtime, offset)"""
         return self._data[4]
 
     def flags(self):
         """The flags field of the marker"""
         return self._data[2]
 
 
 def getmarkers(repo, nodes=None, exclusive=False):
     """returns markers known in a repository
 
     If <nodes> is specified, only markers "relevant" to those nodes are are
     returned"""
     if nodes is None:
         rawmarkers = repo.obsstore
     elif exclusive:
         rawmarkers = exclusivemarkers(repo, nodes)
     else:
         rawmarkers = repo.obsstore.relevantmarkers(nodes)
 
     for markerdata in rawmarkers:
         yield marker(repo, markerdata)
 
 
+def sortedmarkers(markers):
+    # last item of marker tuple ('parents') may be None or a tuple
+    return sorted(markers, key=lambda m: m[:-1] + (m[-1] or (),))
+
+
 def closestpredecessors(repo, nodeid):
     """yield the list of next predecessors pointing on visible changectx nodes
 
     This function respect the repoview filtering, filtered revision will be
     considered missing.
     """
 
     precursors = repo.obsstore.predecessors
     stack = [nodeid]
     seen = set(stack)
 
     while stack:
         current = stack.pop()
         currentpreccs = precursors.get(current, ())
 
         for prec in currentpreccs:
             precnodeid = prec[0]
 
             # Basic cycle protection
             if precnodeid in seen:
                 continue
             seen.add(precnodeid)
 
             if precnodeid in repo:
                 yield precnodeid
             else:
                 stack.append(precnodeid)
 
 
 def allpredecessors(obsstore, nodes, ignoreflags=0):
     """Yield node for every precursors of <nodes>.
 
     Some precursors may be unknown locally.
 
     This is a linear yield unsuited to detecting folded changesets. It includes
     initial nodes too."""
 
     remaining = set(nodes)
     seen = set(remaining)
     prec = obsstore.predecessors.get
     while remaining:
         current = remaining.pop()
         yield current
         for mark in prec(current, ()):
             # ignore marker flagged with specified flag
             if mark[2] & ignoreflags:
                 continue
             suc = mark[0]
             if suc not in seen:
                 seen.add(suc)
                 remaining.add(suc)
 
 
 def allsuccessors(obsstore, nodes, ignoreflags=0):
     """Yield node for every successor of <nodes>.
 
     Some successors may be unknown locally.
 
     This is a linear yield unsuited to detecting split changesets. It includes
     initial nodes too."""
     remaining = set(nodes)
     seen = set(remaining)
     while remaining:
         current = remaining.pop()
         yield current
         for mark in obsstore.successors.get(current, ()):
             # ignore marker flagged with specified flag
             if mark[2] & ignoreflags:
                 continue
             for suc in mark[1]:
                 if suc not in seen:
                     seen.add(suc)
                     remaining.add(suc)
 
 
 def _filterprunes(markers):
     """return a set with no prune markers"""
     return set(m for m in markers if m[1])
 
 
 def exclusivemarkers(repo, nodes):
     """set of markers relevant to "nodes" but no other locally-known nodes
 
     This function compute the set of markers "exclusive" to a locally-known
     node. This means we walk the markers starting from <nodes> until we reach a
     locally-known precursors outside of <nodes>. Element of <nodes> with
     locally-known successors outside of <nodes> are ignored (since their
     precursors markers are also relevant to these successors).
 
     For example:
 
         # (A0 rewritten as A1)
         #
         # A0 <-1- A1 # Marker "1" is exclusive to A1
 
         or
 
         # (A0 rewritten as AX; AX rewritten as A1; AX is unkown locally)
         #
         # <-1- A0 <-2- AX <-3- A1 # Marker "2,3" are exclusive to A1
 
         or
 
         # (A0 has unknown precursors, A0 rewritten as A1 and A2 (divergence))
         #
         #          <-2- A1 # Marker "2" is exclusive to A0,A1
         #        /
         # <-1- A0
         #        \
         #         <-3- A2 # Marker "3" is exclusive to A0,A2
         #
         # in addition:
         #
         #  Markers "2,3" are exclusive to A1,A2
         #  Markers "1,2,3" are exclusive to A0,A1,A2
 
         See test/test-obsolete-bundle-strip.t for more examples.
 
     An example usage is strip. When stripping a changeset, we also want to
     strip the markers exclusive to this changeset. Otherwise we would have
     "dangling"" obsolescence markers from its precursors: Obsolescence markers
     marking a node as obsolete without any successors available locally.
 
     As for relevant markers, the prune markers for children will be followed.
     Of course, they will only be followed if the pruned children is
     locally-known. Since the prune markers are relevant to the pruned node.
     However, while prune markers are considered relevant to the parent of the
     pruned changesets, prune markers for locally-known changeset (with no
     successors) are considered exclusive to the pruned nodes. This allows
     to strip the prune markers (with the rest of the exclusive chain) alongside
     the pruned changesets.
     """
     # running on a filtered repository would be dangerous as markers could be
     # reported as exclusive when they are relevant for other filtered nodes.
     unfi = repo.unfiltered()
 
     # shortcut to various useful item
     nm = unfi.changelog.nodemap
     precursorsmarkers = unfi.obsstore.predecessors
     successormarkers = unfi.obsstore.successors
     childrenmarkers = unfi.obsstore.children
 
     # exclusive markers (return of the function)
     exclmarkers = set()
     # we need fast membership testing
     nodes = set(nodes)
     # looking for head in the obshistory
     #
     # XXX we are ignoring all issues in regard with cycle for now.
     stack = [n for n in nodes if not _filterprunes(successormarkers.get(n, ()))]
     stack.sort()
     # nodes already stacked
     seennodes = set(stack)
     while stack:
         current = stack.pop()
         # fetch precursors markers
         markers = list(precursorsmarkers.get(current, ()))
         # extend the list with prune markers
         for mark in successormarkers.get(current, ()):
             if not mark[1]:
                 markers.append(mark)
         # and markers from children (looking for prune)
         for mark in childrenmarkers.get(current, ()):
             if not mark[1]:
                 markers.append(mark)
         # traverse the markers
         for mark in markers:
             if mark in exclmarkers:
                 # markers already selected
                 continue
 
             # If the markers is about the current node, select it
             #
             # (this delay the addition of markers from children)
             if mark[1] or mark[0] == current:
                 exclmarkers.add(mark)
 
             # should we keep traversing through the precursors?
             prec = mark[0]
 
             # nodes in the stack or already processed
             if prec in seennodes:
                 continue
 
             # is this a locally known node ?
             known = prec in nm
             # if locally-known and not in the <nodes> set the traversal
             # stop here.
             if known and prec not in nodes:
                 continue
 
             # do not keep going if there are unselected markers pointing to this
             # nodes. If we end up traversing these unselected markers later the
             # node will be taken care of at that point.
             precmarkers = _filterprunes(successormarkers.get(prec))
             if precmarkers.issubset(exclmarkers):
                 seennodes.add(prec)
                 stack.append(prec)
 
     return exclmarkers
 
 
 def foreground(repo, nodes):
     """return all nodes in the "foreground" of other node
 
     The foreground of a revision is anything reachable using parent -> children
     or precursor -> successor relation. It is very similar to "descendant" but
     augmented with obsolescence information.
 
     Beware that possible obsolescence cycle may result if complex situation.
     """
     repo = repo.unfiltered()
     foreground = set(repo.set(b'%ln::', nodes))
     if repo.obsstore:
         # We only need this complicated logic if there is obsolescence
         # XXX will probably deserve an optimised revset.
         nm = repo.changelog.nodemap
         plen = -1
         # compute the whole set of successors or descendants
         while len(foreground) != plen:
             plen = len(foreground)
             succs = set(c.node() for c in foreground)
             mutable = [c.node() for c in foreground if c.mutable()]
             succs.update(allsuccessors(repo.obsstore, mutable))
             known = (n for n in succs if n in nm)
             foreground = set(repo.set(b'%ln::', known))
     return set(c.node() for c in foreground)
 
 
 # effectflag field
 #
 # Effect-flag is a 1-byte bit field used to store what changed between a
 # changeset and its successor(s).
 #
 # The effect flag is stored in obs-markers metadata while we iterate on the
 # information design. That's why we have the EFFECTFLAGFIELD. If we come up
 # with an incompatible design for effect flag, we can store a new design under
 # another field name so we don't break readers. We plan to extend the existing
 # obsmarkers bit-field when the effect flag design will be stabilized.
 #
 # The effect-flag is placed behind an experimental flag
 # `effect-flags` set to off by default.
 #
 
 EFFECTFLAGFIELD = b"ef1"
 
 DESCCHANGED = 1 << 0  # action changed the description
 METACHANGED = 1 << 1  # action change the meta
 DIFFCHANGED = 1 << 3  # action change diff introduced by the changeset
 PARENTCHANGED = 1 << 2  # action change the parent
 USERCHANGED = 1 << 4  # the user changed
 DATECHANGED = 1 << 5  # the date changed
 BRANCHCHANGED = 1 << 6  # the branch changed
 
 METABLACKLIST = [
     re.compile(b'^branch$'),
     re.compile(b'^.*-source$'),
     re.compile(b'^.*_source$'),
     re.compile(b'^source$'),
 ]
 
 
 def metanotblacklisted(metaitem):
     """ Check that the key of a meta item (extrakey, extravalue) does not
     match at least one of the blacklist pattern
     """
     metakey = metaitem[0]
 
     return not any(pattern.match(metakey) for pattern in METABLACKLIST)
 
 
 def _prepare_hunk(hunk):
     """Drop all information but the username and patch"""
     cleanhunk = []
     for line in hunk.splitlines():
         if line.startswith(b'# User') or not line.startswith(b'#'):
             if line.startswith(b'@@'):
                 line = b'@@\n'
             cleanhunk.append(line)
     return cleanhunk
 
 
 def _getdifflines(iterdiff):
     """return a cleaned up lines"""
     lines = next(iterdiff, None)
 
     if lines is None:
         return lines
 
     return _prepare_hunk(lines)
 
 
 def _cmpdiff(leftctx, rightctx):
     """return True if both ctx introduce the "same diff"
 
     This is a first and basic implementation, with many shortcoming.
     """
     diffopts = diffutil.diffallopts(leftctx.repo().ui, {b'git': True})
 
     # Leftctx or right ctx might be filtered, so we need to use the contexts
     # with an unfiltered repository to safely compute the diff
 
     # leftctx and rightctx can be from different repository views in case of
     # hgsubversion, do don't try to access them from same repository
     # rightctx.repo() and leftctx.repo() are not always the same
     leftunfi = leftctx._repo.unfiltered()[leftctx.rev()]
     leftdiff = leftunfi.diff(opts=diffopts)
     rightunfi = rightctx._repo.unfiltered()[rightctx.rev()]
     rightdiff = rightunfi.diff(opts=diffopts)
 
     left, right = (0, 0)
     while None not in (left, right):
         left = _getdifflines(leftdiff)
         right = _getdifflines(rightdiff)
 
         if left != right:
             return False
     return True
 
 
 def geteffectflag(source, successors):
     """ From an obs-marker relation, compute what changed between the
     predecessor and the successor.
     """
     effects = 0
 
     for changectx in successors:
         # Check if description has changed
         if changectx.description() != source.description():
             effects |= DESCCHANGED
 
         # Check if user has changed
         if changectx.user() != source.user():
             effects |= USERCHANGED
 
         # Check if date has changed
         if changectx.date() != source.date():
             effects |= DATECHANGED
 
         # Check if branch has changed
         if changectx.branch() != source.branch():
             effects |= BRANCHCHANGED
 
         # Check if at least one of the parent has changed
         if changectx.parents() != source.parents():
             effects |= PARENTCHANGED
 
         # Check if other meta has changed
         changeextra = changectx.extra().items()
         ctxmeta = list(filter(metanotblacklisted, changeextra))
 
         sourceextra = source.extra().items()
         srcmeta = list(filter(metanotblacklisted, sourceextra))
 
         if ctxmeta != srcmeta:
             effects |= METACHANGED
 
         # Check if the diff has changed
         if not _cmpdiff(source, changectx):
             effects |= DIFFCHANGED
 
     return effects
 
 
 def getobsoleted(repo, tr):
     """return the set of pre-existing revisions obsoleted by a transaction"""
     torev = repo.unfiltered().changelog.nodemap.get
     phase = repo._phasecache.phase
     succsmarkers = repo.obsstore.successors.get
     public = phases.public
     addedmarkers = tr.changes[b'obsmarkers']
     origrepolen = tr.changes[b'origrepolen']
     seenrevs = set()
     obsoleted = set()
     for mark in addedmarkers:
         node = mark[0]
         rev = torev(node)
         if rev is None or rev in seenrevs or rev >= origrepolen:
             continue
         seenrevs.add(rev)
         if phase(repo, rev) == public:
             continue
         if set(succsmarkers(node) or []).issubset(addedmarkers):
             obsoleted.add(rev)
     return obsoleted
 
 
 class _succs(list):
     """small class to represent a successors with some metadata about it"""
 
     def __init__(self, *args, **kwargs):
         super(_succs, self).__init__(*args, **kwargs)
         self.markers = set()
 
     def copy(self):
         new = _succs(self)
         new.markers = self.markers.copy()
         return new
 
     @util.propertycache
     def _set(self):
         # immutable
         return set(self)
 
     def canmerge(self, other):
         return self._set.issubset(other._set)
 
 
 def successorssets(repo, initialnode, closest=False, cache=None):
     """Return set of all latest successors of initial nodes
 
     The successors set of a changeset A are the group of revisions that succeed
     A. It succeeds A as a consistent whole, each revision being only a partial
     replacement. By default, the successors set contains non-obsolete
     changesets only, walking the obsolescence graph until reaching a leaf. If
     'closest' is set to True, closest successors-sets are return (the
     obsolescence walk stops on known changesets).
 
     This function returns the full list of successor sets which is why it
     returns a list of tuples and not just a single tuple. Each tuple is a valid
     successors set. Note that (A,) may be a valid successors set for changeset A
     (see below).
 
     In most cases, a changeset A will have a single element (e.g. the changeset
     A is replaced by A') in its successors set. Though, it is also common for a
     changeset A to have no elements in its successor set (e.g. the changeset
     has been pruned). Therefore, the returned list of successors sets will be
     [(A',)] or [], respectively.
 
     When a changeset A is split into A' and B', however, it will result in a
     successors set containing more than a single element, i.e. [(A',B')].
     Divergent changesets will result in multiple successors sets, i.e. [(A',),
     (A'')].
 
     If a changeset A is not obsolete, then it will conceptually have no
     successors set. To distinguish this from a pruned changeset, the successor
     set will contain itself only, i.e. [(A,)].
 
     Finally, final successors unknown locally are considered to be pruned
     (pruned: obsoleted without any successors). (Final: successors not affected
     by markers).
 
     The 'closest' mode respect the repoview filtering. For example, without
     filter it will stop at the first locally known changeset, with 'visible'
     filter it will stop on visible changesets).
 
     The optional `cache` parameter is a dictionary that may contains
     precomputed successors sets. It is meant to reuse the computation of a
     previous call to `successorssets` when multiple calls are made at the same
     time. The cache dictionary is updated in place. The caller is responsible
     for its life span. Code that makes multiple calls to `successorssets`
     *should* use this cache mechanism or risk a performance hit.
 
     Since results are different depending of the 'closest' most, the same cache
     cannot be reused for both mode.
     """
 
     succmarkers = repo.obsstore.successors
 
     # Stack of nodes we search successors sets for
     toproceed = [initialnode]
     # set version of above list for fast loop detection
     # element added to "toproceed" must be added here
     stackedset = set(toproceed)
     if cache is None:
         cache = {}
 
     # This while loop is the flattened version of a recursive search for
     # successors sets
     #
     # def successorssets(x):
     #    successors = directsuccessors(x)
     #    ss = [[]]
     #    for succ in directsuccessors(x):
     #        # product as in itertools cartesian product
     #        ss = product(ss, successorssets(succ))
     #    return ss
     #
     # But we can not use plain recursive calls here:
     # - that would blow the python call stack
     # - obsolescence markers may have cycles, we need to handle them.
     #
     # The `toproceed` list act as our call stack. Every node we search
     # successors set for are stacked there.
     #
     # The `stackedset` is set version of this stack used to check if a node is
     # already stacked. This check is used to detect cycles and prevent infinite
     # loop.
     #
     # successors set of all nodes are stored in the `cache` dictionary.
     #
     # After this while loop ends we use the cache to return the successors sets
     # for the node requested by the caller.
     while toproceed:
         # Every iteration tries to compute the successors sets of the topmost
         # node of the stack: CURRENT.
         #
         # There are four possible outcomes:
         #
         # 1) We already know the successors sets of CURRENT:
         #    -> mission accomplished, pop it from the stack.
         # 2) Stop the walk:
         #    default case: Node is not obsolete
         #    closest case: Node is known at this repo filter level
         #      -> the node is its own successors sets. Add it to the cache.
         # 3) We do not know successors set of direct successors of CURRENT:
         #    -> We add those successors to the stack.
         # 4) We know successors sets of all direct successors of CURRENT:
         #    -> We can compute CURRENT successors set and add it to the
         #       cache.
         #
         current = toproceed[-1]
 
         # case 2 condition is a bit hairy because of closest,
         # we compute it on its own
         case2condition = (current not in succmarkers) or (
             closest and current != initialnode and current in repo
         )
 
         if current in cache:
             # case (1): We already know the successors sets
             stackedset.remove(toproceed.pop())
         elif case2condition:
             # case (2): end of walk.
             if current in repo:
                 # We have a valid successors.
                 cache[current] = [_succs((current,))]
             else:
                 # Final obsolete version is unknown locally.
                 # Do not count that as a valid successors
                 cache[current] = []
         else:
             # cases (3) and (4)
             #
             # We proceed in two phases. Phase 1 aims to distinguish case (3)
             # from case (4):
             #
             #     For each direct successors of CURRENT, we check whether its
             #     successors sets are known. If they are not, we stack the
             #     unknown node and proceed to the next iteration of the while
             #     loop. (case 3)
             #
             #     During this step, we may detect obsolescence cycles: a node
             #     with unknown successors sets but already in the call stack.
             #     In such a situation, we arbitrary set the successors sets of
             #     the node to nothing (node pruned) to break the cycle.
             #
             #     If no break was encountered we proceed to phase 2.
             #
             # Phase 2 computes successors sets of CURRENT (case 4); see details
             # in phase 2 itself.
             #
             # Note the two levels of iteration in each phase.
             # - The first one handles obsolescence markers using CURRENT as
             #   precursor (successors markers of CURRENT).
             #
             #   Having multiple entry here means divergence.
             #
             # - The second one handles successors defined in each marker.
             #
             #   Having none means pruned node, multiple successors means split,
             #   single successors are standard replacement.
             #
-            for mark in sorted(succmarkers[current]):
+            for mark in sortedmarkers(succmarkers[current]):
                 for suc in mark[1]:
                     if suc not in cache:
                         if suc in stackedset:
                             # cycle breaking
                             cache[suc] = []
                         else:
                             # case (3) If we have not computed successors sets
                             # of one of those successors we add it to the
                             # `toproceed` stack and stop all work for this
                             # iteration.
                             toproceed.append(suc)
                             stackedset.add(suc)
                             break
                 else:
                     continue
                 break
             else:
                 # case (4): we know all successors sets of all direct
                 # successors
                 #
                 # Successors set contributed by each marker depends on the
                 # successors sets of all its "successors" node.
                 #
                 # Each different marker is a divergence in the obsolescence
                 # history. It contributes successors sets distinct from other
                 # markers.
                 #
                 # Within a marker, a successor may have divergent successors
                 # sets. In such a case, the marker will contribute multiple
                 # divergent successors sets. If multiple successors have
                 # divergent successors sets, a Cartesian product is used.
                 #
                 # At the end we post-process successors sets to remove
                 # duplicated entry and successors set that are strict subset of
                 # another one.
                 succssets = []
-                for mark in sorted(succmarkers[current]):
+                for mark in sortedmarkers(succmarkers[current]):
                     # successors sets contributed by this marker
                     base = _succs()
                     base.markers.add(mark)
                     markss = [base]
                     for suc in mark[1]:
                         # cardinal product with previous successors
                         productresult = []
                         for prefix in markss:
                             for suffix in cache[suc]:
                                 newss = prefix.copy()
                                 newss.markers.update(suffix.markers)
                                 for part in suffix:
                                     # do not duplicated entry in successors set
                                     # first entry wins.
                                     if part not in newss:
                                         newss.append(part)
                                 productresult.append(newss)
                         if productresult:
                             markss = productresult
                     succssets.extend(markss)
                 # remove duplicated and subset
                 seen = []
                 final = []
                 candidates = sorted(
                     (s for s in succssets if s), key=len, reverse=True
                 )
                 for cand in candidates:
                     for seensuccs in seen:
                         if cand.canmerge(seensuccs):
                             seensuccs.markers.update(cand.markers)
                             break
                     else:
                         final.append(cand)
                         seen.append(cand)
                 final.reverse()  # put small successors set first
                 cache[current] = final
     return cache[initialnode]
 
 
 def successorsandmarkers(repo, ctx):
     """compute the raw data needed for computing obsfate
     Returns a list of dict, one dict per successors set
     """
     if not ctx.obsolete():
         return None
 
     ssets = successorssets(repo, ctx.node(), closest=True)
 
     # closestsuccessors returns an empty list for pruned revisions, remap it
     # into a list containing an empty list for future processing
     if ssets == []:
         ssets = [[]]
 
     # Try to recover pruned markers
     succsmap = repo.obsstore.successors
     fullsuccessorsets = []  # successor set + markers
     for sset in ssets:
         if sset:
             fullsuccessorsets.append(sset)
         else:
             # successorsset return an empty set() when ctx or one of its
             # successors is pruned.
             # In this case, walk the obs-markers tree again starting with ctx
             # and find the relevant pruning obs-makers, the ones without
             # successors.
             # Having these markers allow us to compute some information about
             # its fate, like who pruned this changeset and when.
 
             # XXX we do not catch all prune markers (eg rewritten then pruned)
             # (fix me later)
             foundany = False
             for mark in succsmap.get(ctx.node(), ()):
                 if not mark[1]:
                     foundany = True
                     sset = _succs()
                     sset.markers.add(mark)
                     fullsuccessorsets.append(sset)
             if not foundany:
                 fullsuccessorsets.append(_succs())
 
     values = []
     for sset in fullsuccessorsets:
         values.append({b'successors': sset, b'markers': sset.markers})
 
     return values
 
 
 def _getobsfate(successorssets):
     """ Compute a changeset obsolescence fate based on its successorssets.
     Successors can be the tipmost ones or the immediate ones. This function
     return values are not meant to be shown directly to users, it is meant to
     be used by internal functions only.
     Returns one fate from the following values:
     - pruned
     - diverged
     - superseded
     - superseded_split
     """
 
     if len(successorssets) == 0:
         # The commit has been pruned
         return b'pruned'
     elif len(successorssets) > 1:
         return b'diverged'
     else:
         # No divergence, only one set of successors
         successors = successorssets[0]
 
         if len(successors) == 1:
             return b'superseded'
         else:
             return b'superseded_split'
 
 
 def obsfateverb(successorset, markers):
     """ Return the verb summarizing the successorset and potentially using
     information from the markers
     """
     if not successorset:
         verb = b'pruned'
     elif len(successorset) == 1:
         verb = b'rewritten'
     else:
         verb = b'split'
     return verb
 
 
 def markersdates(markers):
     """returns the list of dates for a list of markers
     """
     return [m[4] for m in markers]
 
 
 def markersusers(markers):
     """ Returns a sorted list of markers users without duplicates
     """
     markersmeta = [dict(m[3]) for m in markers]
     users = set(
         encoding.tolocal(meta[b'user'])
         for meta in markersmeta
         if meta.get(b'user')
     )
 
     return sorted(users)
 
 
 def markersoperations(markers):
     """ Returns a sorted list of markers operations without duplicates
     """
     markersmeta = [dict(m[3]) for m in markers]
     operations = set(
         meta.get(b'operation') for meta in markersmeta if meta.get(b'operation')
     )
 
     return sorted(operations)
 
 
 def obsfateprinter(ui, repo, successors, markers, formatctx):
     """ Build a obsfate string for a single successorset using all obsfate
     related function defined in obsutil
     """
     quiet = ui.quiet
     verbose = ui.verbose
     normal = not verbose and not quiet
 
     line = []
 
     # Verb
     line.append(obsfateverb(successors, markers))
 
     # Operations
     operations = markersoperations(markers)
     if operations:
         line.append(b" using %s" % b", ".join(operations))
 
     # Successors
     if successors:
         fmtsuccessors = [formatctx(repo[succ]) for succ in successors]
         line.append(b" as %s" % b", ".join(fmtsuccessors))
 
     # Users
     users = markersusers(markers)
     # Filter out current user in not verbose mode to reduce amount of
     # information
     if not verbose:
         currentuser = ui.username(acceptempty=True)
         if len(users) == 1 and currentuser in users:
             users = None
 
     if (verbose or normal) and users:
         line.append(b" by %s" % b", ".join(users))
 
     # Date
     dates = markersdates(markers)
 
     if dates and verbose:
         min_date = min(dates)
         max_date = max(dates)
 
         if min_date == max_date:
             fmtmin_date = dateutil.datestr(min_date, b'%Y-%m-%d %H:%M %1%2')
             line.append(b" (at %s)" % fmtmin_date)
         else:
             fmtmin_date = dateutil.datestr(min_date, b'%Y-%m-%d %H:%M %1%2')
             fmtmax_date = dateutil.datestr(max_date, b'%Y-%m-%d %H:%M %1%2')
             line.append(b" (between %s and %s)" % (fmtmin_date, fmtmax_date))
 
     return b"".join(line)
 
 
 filteredmsgtable = {
     b"pruned": _(b"hidden revision '%s' is pruned"),
     b"diverged": _(b"hidden revision '%s' has diverged"),
     b"superseded": _(b"hidden revision '%s' was rewritten as: %s"),
     b"superseded_split": _(b"hidden revision '%s' was split as: %s"),
     b"superseded_split_several": _(
         b"hidden revision '%s' was split as: %s and %d more"
     ),
 }
 
 
 def _getfilteredreason(repo, changeid, ctx):
     """return a human-friendly string on why a obsolete changeset is hidden
     """
     successors = successorssets(repo, ctx.node())
     fate = _getobsfate(successors)
 
     # Be more precise in case the revision is superseded
     if fate == b'pruned':
         return filteredmsgtable[b'pruned'] % changeid
     elif fate == b'diverged':
         return filteredmsgtable[b'diverged'] % changeid
     elif fate == b'superseded':
         single_successor = nodemod.short(successors[0][0])
         return filteredmsgtable[b'superseded'] % (changeid, single_successor)
     elif fate == b'superseded_split':
 
         succs = []
         for node_id in successors[0]:
             succs.append(nodemod.short(node_id))
 
         if len(succs) <= 2:
             fmtsuccs = b', '.join(succs)
             return filteredmsgtable[b'superseded_split'] % (changeid, fmtsuccs)
         else:
             firstsuccessors = b', '.join(succs[:2])
             remainingnumber = len(succs) - 2
 
             args = (changeid, firstsuccessors, remainingnumber)
             return filteredmsgtable[b'superseded_split_several'] % args
 
 
 def divergentsets(repo, ctx):
     """Compute sets of commits divergent with a given one"""
     cache = {}
     base = {}
     for n in allpredecessors(repo.obsstore, [ctx.node()]):
         if n == ctx.node():
             # a node can't be a base for divergence with itself
             continue
         nsuccsets = successorssets(repo, n, cache)
         for nsuccset in nsuccsets:
             if ctx.node() in nsuccset:
                 # we are only interested in *other* successor sets
                 continue
             if tuple(nsuccset) in base:
                 # we already know the latest base for this divergency
                 continue
             base[tuple(nsuccset)] = n
     return [
         {b'divergentnodes': divset, b'commonpredecessor': b}
         for divset, b in pycompat.iteritems(base)
     ]
 
 
 def whyunstable(repo, ctx):
     result = []
     if ctx.orphan():
         for parent in ctx.parents():
             kind = None
             if parent.orphan():
                 kind = b'orphan'
             elif parent.obsolete():
                 kind = b'obsolete'
             if kind is not None:
                 result.append(
                     {
                         b'instability': b'orphan',
                         b'reason': b'%s parent' % kind,
                         b'node': parent.hex(),
                     }
                 )
     if ctx.phasedivergent():
         predecessors = allpredecessors(
             repo.obsstore, [ctx.node()], ignoreflags=bumpedfix
         )
         immutable = [
             repo[p] for p in predecessors if p in repo and not repo[p].mutable()
         ]
         for predecessor in immutable:
             result.append(
                 {
                     b'instability': b'phase-divergent',
                     b'reason': b'immutable predecessor',
                     b'node': predecessor.hex(),
                 }
             )
     if ctx.contentdivergent():
         dsets = divergentsets(repo, ctx)
         for dset in dsets:
             divnodes = [repo[n] for n in dset[b'divergentnodes']]
             result.append(
                 {
                     b'instability': b'content-divergent',
                     b'divergentnodes': divnodes,
                     b'reason': b'predecessor',
                     b'node': nodemod.hex(dset[b'commonpredecessor']),
                 }
             )
     return result