def _deleteunreachable(repo, ctx):
    """Deletes all ancestor and descendant commits of the given revision that
    aren't reachable from another bookmark.
    """
    keepheads = "bookmark() + ."
    try:
        extensions.find('remotenames')
        keepheads += " + remotenames()"
    except KeyError:
        pass
    hiderevs = repo.revs('::%s - ::(%r)', ctx.rev(), keepheads)
    if hiderevs:
        lock = None
        try:
            lock = repo.lock()
            if _isobsstoreenabled(repo):
                markers = []
                for rev in hiderevs:
                    markers.append((repo[rev], ()))
                obsolete.createmarkers(repo, markers)
                repo.ui.status(_("%d changesets pruned\n") % len(hiderevs))
            else:
                repair.strip(repo.ui, repo,
                             [repo.changelog.node(r) for r in hiderevs])
        finally:
            lockmod.release(lock)

def strip(ui, repo, revs, update=True, backup=True, force=None, bookmarks=None):
    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()

        if update:
            checklocalchanges(repo, force=force)
            urev, p2 = repo.changelog.parents(revs[0])
            if (util.safehasattr(repo, 'mq') and
                p2 != nullid
                and p2 in [x.node for x in repo.mq.applied]):
                urev = p2
            hg.clean(repo, urev)
            repo.dirstate.write(repo.currenttransaction())

        repair.strip(ui, repo, revs, backup)

        repomarks = repo._bookmarks
        if bookmarks:
            tr = None
            try:
                tr = repo.transaction('strip')
                if repo._activebookmark in bookmarks:
                    bookmarksmod.deactivate(repo)
                for bookmark in bookmarks:
                    del repomarks[bookmark]
                repomarks.recordchange(tr)
                tr.close()
                for bookmark in sorted(bookmarks):
                    ui.write(_("bookmark '%s' deleted\n") % bookmark)
            finally:
                release(tr)
    finally:
        release(lock, wlock)

 def apply(self, repo, series, list=False, update_status=True,
           strict=False, patchdir=None, merge=None, all_files=None,
           tobackup=None, keepchanges=False):
     wlock = lock = tr = None
     try:
         wlock = repo.wlock()
         lock = repo.lock()
         tr = repo.transaction("qpush")
         try:
             ret = self._apply(repo, series, list, update_status,
                               strict, patchdir, merge, all_files=all_files,
                               tobackup=tobackup, keepchanges=keepchanges)
             tr.close()
             self.savedirty()
             return ret
         except AbortNoCleanup:
             tr.close()
             self.savedirty()
             return 2, repo.dirstate.p1()
         except: # re-raises
             try:
                 tr.abort()
             finally:
                 repo.invalidate()
                 repo.dirstate.invalidate()
                 self.invalidate()
             raise
     finally:
         release(tr, lock, wlock)
         self.removeundo(repo)

def histedit(ui, repo, *freeargs, **opts):
    """interactively edit changeset history

    This command edits changesets between ANCESTOR and the parent of
    the working directory.

    With --outgoing, this edits changesets not found in the
    destination repository. If URL of the destination is omitted, the
    'default-push' (or 'default') path will be used.

    For safety, this command is aborted, also if there are ambiguous
    outgoing revisions which may confuse users: for example, there are
    multiple branches containing outgoing revisions.

    Use "min(outgoing() and ::.)" or similar revset specification
    instead of --outgoing to specify edit target revision exactly in
    such ambiguous situation. See :hg:`help revsets` for detail about
    selecting revisions.

    Returns 0 on success, 1 if user intervention is required (not only
    for intentional "edit" command, but also for resolving unexpected
    conflicts).
    """
    state = histeditstate(repo)
    try:
        state.wlock = repo.wlock()
        state.lock = repo.lock()
        _histedit(ui, repo, state, *freeargs, **opts)
    finally:
        release(state.lock, state.wlock)

def _inhibitmarkers(repo, nodes):
    """add marker inhibitor for all obsolete revision under <nodes>

    Content of <nodes> and all mutable ancestors are considered. Marker for
    obsolete revision only are created.
    """
    if not _inhibitenabled(repo):
        return

    # we add (non public()) as a lower boundary to
    # - use the C code in 3.6 (no ancestors in C as this is written)
    # - restrict the search space. Otherwise, the ancestors can spend a lot of
    #   time iterating if you have a check very low in the repo. We do not need
    #   to iterate over tens of thousand of public revisions with higher
    #   revision number
    #
    # In addition, the revset logic could be made significantly smarter here.
    newinhibit = repo.revs('(not public())::%ln and obsolete()', nodes)
    if newinhibit:
        node = repo.changelog.node
        lock = tr = None
        try:
            lock = repo.lock()
            tr = repo.transaction('obsinhibit')
            repo._obsinhibit.update(node(r) for r in newinhibit)
            _schedulewrite(tr, _filterpublic(repo, repo._obsinhibit))
            repo.invalidatevolatilesets()
            tr.close()
        finally:
            lockmod.release(tr, lock)

def concludenode(repo, rev, p1, p2, commitmsg=None, editor=None, extrafn=None,
                 keepbranches=False):
    '''Commit the wd changes with parents p1 and p2. Reuse commit info from rev
    but also store useful information in extra.
    Return node of committed revision.'''
    dsguard = cmdutil.dirstateguard(repo, 'rebase')
    try:
        repo.setparents(repo[p1].node(), repo[p2].node())
        ctx = repo[rev]
        if commitmsg is None:
            commitmsg = ctx.description()
        keepbranch = keepbranches and repo[p1].branch() != ctx.branch()
        extra = {'rebase_source': ctx.hex()}
        if extrafn:
            extrafn(ctx, extra)

        backup = repo.ui.backupconfig('phases', 'new-commit')
        try:
            targetphase = max(ctx.phase(), phases.draft)
            repo.ui.setconfig('phases', 'new-commit', targetphase, 'rebase')
            if keepbranch:
                repo.ui.setconfig('ui', 'allowemptycommit', True)
            # Commit might fail if unresolved files exist
            newnode = repo.commit(text=commitmsg, user=ctx.user(),
                                  date=ctx.date(), extra=extra, editor=editor)
        finally:
            repo.ui.restoreconfig(backup)

        repo.dirstate.setbranch(repo[newnode].branch())
        dsguard.close()
        return newnode
    finally:
        release(dsguard)

        def run(self):
            state = self.state
            repo, ctxnode = state.repo, state.parentctxnode
            hg.update(repo, ctxnode)

            # release locks so the program can call hg and then relock.
            lock.release(state.lock, state.wlock)

            try:
                ctx = repo[ctxnode]
                shell = encoding.environ.get('SHELL', None)
                cmd = self.command
                if shell and self.repo.ui.config('fbhistedit',
                                                 'exec_in_user_shell'):
                    cmd = "%s -c -i %s" % (shell, quote(cmd))
                rc = repo.ui.system(cmd,  environ={'HGNODE': ctx.hex()},
                                    cwd=self.cwd, blockedtag='histedit_exec')
            except OSError as ose:
                raise error.InterventionRequired(
                    _("Cannot execute command '%s': %s") % (self.command, ose))
            finally:
                # relock the repository
                state.wlock = repo.wlock()
                state.lock = repo.lock()
                repo.invalidateall()

            if rc != 0:
                raise error.InterventionRequired(
                    _("Command '%s' failed with exit status %d") %
                    (self.command, rc))

            m, a, r, d = self.repo.status()[:4]
            if m or a or r or d:
                self.continuedirty()
            return self.continueclean()

        def kwcommitctx(self, ctx, error=False):
            wlock = lock = None
            try:
                wlock = self.wlock()
                lock = self.lock()
                # store and postpone commit hooks
                commithooks = {}
                for name, cmd in ui.configitems('hooks'):
                    if name.split('.', 1)[0] == 'commit':
                        commithooks[name] = cmd
                        ui.setconfig('hooks', name, None)
                if commithooks:
                    # store parents for commit hooks
                    p1, p2 = ctx.p1(), ctx.p2()
                    xp1, xp2 = p1.hex(), p2 and p2.hex() or ''

                n = super(kwrepo, self).commitctx(ctx, error)

                kwt.overwrite(n, True, None)
                if commithooks:
                    for name, cmd in commithooks.iteritems():
                        ui.setconfig('hooks', name, cmd)
                    self.hook('commit', node=n, parent1=xp1, parent2=xp2)
                return n
            finally:
                release(lock, wlock)

def concludenode(repo, rev, p1, p2, commitmsg=None, editor=None, extrafn=None):
    """Commit the wd changes with parents p1 and p2. Reuse commit info from rev
    but also store useful information in extra.
    Return node of committed revision."""
    dsguard = cmdutil.dirstateguard(repo, "rebase")
    try:
        repo.setparents(repo[p1].node(), repo[p2].node())
        ctx = repo[rev]
        if commitmsg is None:
            commitmsg = ctx.description()
        extra = {"rebase_source": ctx.hex()}
        if extrafn:
            extrafn(ctx, extra)

        backup = repo.ui.backupconfig("phases", "new-commit")
        try:
            targetphase = max(ctx.phase(), phases.draft)
            repo.ui.setconfig("phases", "new-commit", targetphase, "rebase")
            # Commit might fail if unresolved files exist
            newnode = repo.commit(text=commitmsg, user=ctx.user(), date=ctx.date(), extra=extra, editor=editor)
        finally:
            repo.ui.restoreconfig(backup)

        repo.dirstate.setbranch(repo[newnode].branch())
        dsguard.close()
        return newnode
    finally:
        release(dsguard)

def unshelveabort(ui, repo, state, opts):
    """subcommand that abort an in-progress unshelve"""
    wlock = repo.wlock()
    lock = None
    try:
        checkparents(repo, state)

        util.rename(repo.join('unshelverebasestate'),
                    repo.join('rebasestate'))
        try:
            rebase.rebase(ui, repo, **{
                'abort' : True
            })
        except Exception:
            util.rename(repo.join('rebasestate'),
                        repo.join('unshelverebasestate'))
            raise

        lock = repo.lock()

        mergefiles(ui, repo, state.wctx, state.pendingctx)

        repair.strip(ui, repo, state.stripnodes, backup='none', topic='shelve')
        shelvedstate.clear(repo)
        ui.warn(_("unshelve of '%s' aborted\n") % state.name)
    finally:
        lockmod.release(lock, wlock)

def cleanupnode(ui, repo, name, nodes):
    """strip a group of nodes from the repository

    The set of node to strip may contains unknown nodes."""
    ui.debug('should strip %s nodes %s\n' %
             (name, ', '.join([node.short(n) for n in nodes])))
    lock = None
    try:
        lock = repo.lock()
        # do not let filtering get in the way of the cleanse
        # we should probably get rid of obsolescence marker created during the
        # histedit, but we currently do not have such information.
        repo = repo.unfiltered()
        # Find all nodes that need to be stripped
        # (we use %lr instead of %ln to silently ignore unknown items)
        nm = repo.changelog.nodemap
        nodes = sorted(n for n in nodes if n in nm)
        roots = [c.node() for c in repo.set("roots(%ln)", nodes)]
        for c in roots:
            # We should process node in reverse order to strip tip most first.
            # but this trigger a bug in changegroup hook.
            # This would reduce bundle overhead
            repair.strip(ui, repo, c)
    finally:
        release(lock)

def unshelveabort(ui, repo, state, opts):
    """subcommand that abort an in-progress unshelve"""
    wlock = repo.wlock()
    lock = None
    try:
        checkparents(repo, state)
        lock = repo.lock()
        merge.mergestate(repo).reset()
        if opts['keep']:
            repo.setparents(repo.dirstate.parents()[0])
        else:
            revertfiles = readshelvedfiles(repo, state.name)
            wctx = repo.parents()[0]
            cmdutil.revert(ui, repo, wctx, [wctx.node(), nullid],
                           *revertfiles, **{'no_backup': True})
            # fix up the weird dirstate states the merge left behind
            mf = wctx.manifest()
            dirstate = repo.dirstate
            for f in revertfiles:
                if f in mf:
                    dirstate.normallookup(f)
                else:
                    dirstate.drop(f)
            dirstate._pl = (wctx.node(), nullid)
            dirstate._dirty = True
        repair.strip(ui, repo, state.stripnodes, backup='none', topic='shelve')
        shelvedstate.clear(repo)
        ui.warn(_("unshelve of '%s' aborted\n") % state.name)
    finally:
        lockmod.release(lock, wlock)

def strip(ui, repo, revs, update=True, backup=True, force=None, bookmark=None):
    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()

        if update:
            checklocalchanges(repo, force=force)
            urev, p2 = repo.changelog.parents(revs[0])
            if (util.safehasattr(repo, 'mq') and
                p2 != nullid
                and p2 in [x.node for x in repo.mq.applied]):
                urev = p2
            hg.clean(repo, urev)
            repo.dirstate.write()

        repair.strip(ui, repo, revs, backup)

        marks = repo._bookmarks
        if bookmark:
            if bookmark == repo._bookmarkcurrent:
                bookmarks.unsetcurrent(repo)
            del marks[bookmark]
            marks.write()
            ui.write(_("bookmark '%s' deleted\n") % bookmark)
    finally:
        release(lock, wlock)

 def testlock(self):
     state = teststate(self, tempfile.mkdtemp(dir=os.getcwd()))
     lock = state.makelock()
     state.assertacquirecalled(True)
     lock.release()
     state.assertreleasecalled(True)
     state.assertpostreleasecalled(True)
     state.assertlockexists(False)

def createcmd(ui, repo, pats, opts):
    """subcommand that creates a new shelve"""
    wlock = repo.wlock()
    try:
        cmdutil.checkunfinished(repo)
        return _docreatecmd(ui, repo, pats, opts)
    finally:
        lockmod.release(wlock)

def censor(ui, repo, path, rev='', tombstone='', **opts):
    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()
        return _docensor(ui, repo, path, rev, tombstone, **opts)
    finally:
        lockmod.release(lock, wlock)

def transplant(ui, repo, *revs, **opts):
    '''transplant changesets from another branch

    Selected changesets will be applied on top of the current working
    directory with the log of the original changeset. The changesets
    are copied and will thus appear twice in the history with different
    identities.

    Consider using the graft command if everything is inside the same
    repository - it will use merges and will usually give a better result.
    Use the rebase extension if the changesets are unpublished and you want
    to move them instead of copying them.

    If --log is specified, log messages will have a comment appended
    of the form::

      (transplanted from CHANGESETHASH)

    You can rewrite the changelog message with the --filter option.
    Its argument will be invoked with the current changelog message as
    $1 and the patch as $2.

    --source/-s specifies another repository to use for selecting changesets,
    just as if it temporarily had been pulled.
    If --branch/-b is specified, these revisions will be used as
    heads when deciding which changesets to transplant, just as if only
    these revisions had been pulled.
    If --all/-a is specified, all the revisions up to the heads specified
    with --branch will be transplanted.

    Example:

    - transplant all changes up to REV on top of your current revision::

        hg transplant --branch REV --all

    You can optionally mark selected transplanted changesets as merge
    changesets. You will not be prompted to transplant any ancestors
    of a merged transplant, and you can merge descendants of them
    normally instead of transplanting them.

    Merge changesets may be transplanted directly by specifying the
    proper parent changeset by calling :hg:`transplant --parent`.

    If no merges or revisions are provided, :hg:`transplant` will
    start an interactive changeset browser.

    If a changeset application fails, you can fix the merge by hand
    and then resume where you left off by calling :hg:`transplant
    --continue/-c`.
    '''
    wlock = None
    try:
        wlock = repo.wlock()
        return _dotransplant(ui, repo, *revs, **opts)
    finally:
        lockmod.release(wlock)

 def kwcommitctx(self, ctx, error=False):
     wlock = lock = None
     try:
         wlock = self.wlock()
         lock = self.lock()
         n = super(kwrepo, self).commitctx(ctx, error)
         kwt.overwrite(n, True, None)
         return n
     finally:
         release(lock, wlock)

def cleanupcmd(ui, repo):
    """subcommand that deletes all shelves"""

    wlock = None
    try:
        wlock = repo.wlock()
        for (name, _) in repo.vfs.readdir('shelved'):
            suffix = name.rsplit('.', 1)[-1]
            if suffix in ('hg', 'files', 'patch'):
                shelvedfile(repo, name).unlink()
    finally:
        lockmod.release(wlock)

def _createmarkers(orig, repo, relations, flag=0, date=None, metadata=None):
    """wrap markers create to make sure we de-inhibit target nodes"""
    # wrapping transactio to unify the one in each function
    lock = tr = None
    try:
        lock = repo.lock()
        tr = repo.transaction('add-obsolescence-marker')
        orig(repo, relations, flag, date, metadata)
        precs = (r[0].node() for r in relations)
        _deinhibitmarkers(repo, precs)
        tr.close()
    finally:
        lockmod.release(tr, lock)