localrepo: execute appropriate actions for dirstate at releasing transaction

Before this patch, in-memory dirstate changes are still kept over a
transaction scope boundary regardless of the result of it.

For "all or nothing" policy of the transaction, in-memory dirstate
changes should be:

  - written out at successful closing a transaction, because
    subsequent 'dirstate.invalidate()' can lose them

  - discarded at failure of a transaction, because outer
    'wlock.release()' or so may write them out

To discard all changes in a transaction completely, this patch also
restores '.hg/dirstate' by '.hg/journal.dirstate' at failure, because
'transaction' itself does nothing for files related to '.hg/journal.*'
in such case (therefore, renaming in this patch is safe enough).

This is a part of preparations for "transactional dirstate". See also
the wiki page below for detail about it.

    https://mercurial.selenic.com/wiki/DirstateTransactionPlan

This patch also removes redundant 'dirstate.invalidate()' just before
aborting a transaction for shelve/unshelve.

hgext/shelve.py

@@ -1,836 +1,833 b''
 # shelve.py - save/restore working directory state
 #
 # Copyright 2013 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """save and restore changes to the working directory
 
 The "hg shelve" command saves changes made to the working directory
 and reverts those changes, resetting the working directory to a clean
 state.
 
 Later on, the "hg unshelve" command restores the changes saved by "hg
 shelve". Changes can be restored even after updating to a different
 parent, in which case Mercurial's merge machinery will resolve any
 conflicts if necessary.
 
 You can have more than one shelved change outstanding at a time; each
 shelved change has a distinct name. For details, see the help for "hg
 shelve".
 """
 
 import collections
 import itertools
 from mercurial.i18n import _
 from mercurial.node import nullid, nullrev, bin, hex
 from mercurial import changegroup, cmdutil, scmutil, phases, commands
 from mercurial import error, hg, mdiff, merge, patch, repair, util
 from mercurial import templatefilters, exchange, bundlerepo
 from mercurial import lock as lockmod
 from hgext import rebase
 import errno
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 # Note for extension authors: ONLY specify testedwith = 'internal' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'internal'
 
 backupdir = 'shelve-backup'
 
 class shelvedfile(object):
     """Helper for the file storing a single shelve
 
     Handles common functions on shelve files (.hg/.patch) using
     the vfs layer"""
     def __init__(self, repo, name, filetype=None):
         self.repo = repo
         self.name = name
         self.vfs = scmutil.vfs(repo.join('shelved'))
         self.backupvfs = scmutil.vfs(repo.join(backupdir))
         self.ui = self.repo.ui
         if filetype:
             self.fname = name + '.' + filetype
         else:
             self.fname = name
 
     def exists(self):
         return self.vfs.exists(self.fname)
 
     def filename(self):
         return self.vfs.join(self.fname)
 
     def backupfilename(self):
         def gennames(base):
             yield base
             base, ext = base.rsplit('.', 1)
             for i in itertools.count(1):
                 yield '%s-%d.%s' % (base, i, ext)
 
         name = self.backupvfs.join(self.fname)
         for n in gennames(name):
             if not self.backupvfs.exists(n):
                 return n
 
     def movetobackup(self):
         if not self.backupvfs.isdir():
             self.backupvfs.makedir()
         util.rename(self.filename(), self.backupfilename())
 
     def stat(self):
         return self.vfs.stat(self.fname)
 
     def opener(self, mode='rb'):
         try:
             return self.vfs(self.fname, mode)
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
             raise util.Abort(_("shelved change '%s' not found") % self.name)
 
     def applybundle(self):
         fp = self.opener()
         try:
             gen = exchange.readbundle(self.repo.ui, fp, self.fname, self.vfs)
             changegroup.addchangegroup(self.repo, gen, 'unshelve',
                                        'bundle:' + self.vfs.join(self.fname),
                                        targetphase=phases.secret)
         finally:
             fp.close()
 
     def bundlerepo(self):
         return bundlerepo.bundlerepository(self.repo.baseui, self.repo.root,
                                            self.vfs.join(self.fname))
     def writebundle(self, bases, node):
         btype = 'HG10BZ'
         cgversion = '01'
         compression = None
         if 'generaldelta' in self.repo.requirements:
             btype = 'HG20'
             cgversion = '02'
             compression = 'BZ'
 
         cg = changegroup.changegroupsubset(self.repo, bases, [node], 'shelve',
                                            version=cgversion)
         changegroup.writebundle(self.ui, cg, self.fname, btype, self.vfs,
                                 compression=compression)
 
 class shelvedstate(object):
     """Handle persistence during unshelving operations.
 
     Handles saving and restoring a shelved state. Ensures that different
     versions of a shelved state are possible and handles them appropriately.
     """
     _version = 1
     _filename = 'shelvedstate'
 
     @classmethod
     def load(cls, repo):
         fp = repo.vfs(cls._filename)
         try:
             version = int(fp.readline().strip())
 
             if version != cls._version:
                 raise util.Abort(_('this version of shelve is incompatible '
                                    'with the version used in this repo'))
             name = fp.readline().strip()
             wctx = fp.readline().strip()
             pendingctx = fp.readline().strip()
             parents = [bin(h) for h in fp.readline().split()]
             stripnodes = [bin(h) for h in fp.readline().split()]
         finally:
             fp.close()
 
         obj = cls()
         obj.name = name
         obj.wctx = repo[bin(wctx)]
         obj.pendingctx = repo[bin(pendingctx)]
         obj.parents = parents
         obj.stripnodes = stripnodes
 
         return obj
 
     @classmethod
     def save(cls, repo, name, originalwctx, pendingctx, stripnodes):
         fp = repo.vfs(cls._filename, 'wb')
         fp.write('%i\n' % cls._version)
         fp.write('%s\n' % name)
         fp.write('%s\n' % hex(originalwctx.node()))
         fp.write('%s\n' % hex(pendingctx.node()))
         fp.write('%s\n' % ' '.join([hex(p) for p in repo.dirstate.parents()]))
         fp.write('%s\n' % ' '.join([hex(n) for n in stripnodes]))
         fp.close()
 
     @classmethod
     def clear(cls, repo):
         util.unlinkpath(repo.join(cls._filename), ignoremissing=True)
 
 def cleanupoldbackups(repo):
     vfs = scmutil.vfs(repo.join(backupdir))
     maxbackups = repo.ui.configint('shelve', 'maxbackups', 10)
     hgfiles = [f for f in vfs.listdir() if f.endswith('.hg')]
     hgfiles = sorted([(vfs.stat(f).st_mtime, f) for f in hgfiles])
     if 0 < maxbackups and maxbackups < len(hgfiles):
         bordermtime = hgfiles[-maxbackups][0]
     else:
         bordermtime = None
     for mtime, f in hgfiles[:len(hgfiles) - maxbackups]:
         if mtime == bordermtime:
             # keep it, because timestamp can't decide exact order of backups
             continue
         base = f[:-3]
         for ext in 'hg patch'.split():
             try:
                 vfs.unlink(base + '.' + ext)
             except OSError as err:
                 if err.errno != errno.ENOENT:
                     raise
 
 def _aborttransaction(repo):
     '''Abort current transaction for shelve/unshelve, but keep dirstate
     '''
     backupname = 'dirstate.shelve'
     dirstatebackup = None
     try:
         # create backup of (un)shelved dirstate, because aborting transaction
         # should restore dirstate to one at the beginning of the
         # transaction, which doesn't include the result of (un)shelving
         fp = repo.vfs.open(backupname, "w")
         dirstatebackup = backupname
         # clearing _dirty/_dirtypl of dirstate by _writedirstate below
         # is unintentional. but it doesn't cause problem in this case,
         # because no code path refers them until transaction is aborted.
         repo.dirstate._writedirstate(fp) # write in-memory changes forcibly
 
         tr = repo.currenttransaction()
         tr.abort()
 
-        # TODO: this should be done via transaction.abort()
-        repo.dirstate.invalidate() # prevent wlock from writing changes out
-
         # restore to backuped dirstate
         repo.vfs.rename(dirstatebackup, 'dirstate')
         dirstatebackup = None
     finally:
         if dirstatebackup:
             repo.vfs.unlink(dirstatebackup)
 
 def createcmd(ui, repo, pats, opts):
     """subcommand that creates a new shelve"""
 
     def publicancestors(ctx):
         """Compute the public ancestors of a commit.
 
         Much faster than the revset ancestors(ctx) & draft()"""
         seen = set([nullrev])
         visit = collections.deque()
         visit.append(ctx)
         while visit:
             ctx = visit.popleft()
             yield ctx.node()
             for parent in ctx.parents():
                 rev = parent.rev()
                 if rev not in seen:
                     seen.add(rev)
                     if parent.mutable():
                         visit.append(parent)
 
     wctx = repo[None]
     parents = wctx.parents()
     if len(parents) > 1:
         raise util.Abort(_('cannot shelve while merging'))
     parent = parents[0]
 
     # we never need the user, so we use a generic user for all shelve operations
     user = 'shelve@localhost'
     label = repo._activebookmark or parent.branch() or 'default'
 
     # slashes aren't allowed in filenames, therefore we rename it
     label = label.replace('/', '_')
 
     def gennames():
         yield label
         for i in xrange(1, 100):
             yield '%s-%02d' % (label, i)
 
     def commitfunc(ui, repo, message, match, opts):
         hasmq = util.safehasattr(repo, 'mq')
         if hasmq:
             saved, repo.mq.checkapplied = repo.mq.checkapplied, False
         backup = repo.ui.backupconfig('phases', 'new-commit')
         try:
             repo.ui. setconfig('phases', 'new-commit', phases.secret)
             editor = cmdutil.getcommiteditor(editform='shelve.shelve', **opts)
             return repo.commit(message, user, opts.get('date'), match,
                                editor=editor)
         finally:
             repo.ui.restoreconfig(backup)
             if hasmq:
                 repo.mq.checkapplied = saved
 
     if parent.node() != nullid:
         desc = "changes to '%s'" % parent.description().split('\n', 1)[0]
     else:
         desc = '(changes in empty repository)'
 
     if not opts['message']:
         opts['message'] = desc
 
     name = opts['name']
 
     wlock = lock = tr = None
     try:
         wlock = repo.wlock()
         lock = repo.lock()
 
         # use an uncommitted transaction to generate the bundle to avoid
         # pull races. ensure we don't print the abort message to stderr.
         tr = repo.transaction('commit', report=lambda x: None)
 
         if name:
             if shelvedfile(repo, name, 'hg').exists():
                 raise util.Abort(_("a shelved change named '%s' already exists")
                                  % name)
         else:
             for n in gennames():
                 if not shelvedfile(repo, n, 'hg').exists():
                     name = n
                     break
             else:
                 raise util.Abort(_("too many shelved changes named '%s'") %
                                  label)
 
         # ensure we are not creating a subdirectory or a hidden file
         if '/' in name or '\\' in name:
             raise util.Abort(_('shelved change names may not contain slashes'))
         if name.startswith('.'):
             raise util.Abort(_("shelved change names may not start with '.'"))
         interactive = opts.get('interactive', False)
 
         def interactivecommitfunc(ui, repo, *pats, **opts):
             match = scmutil.match(repo['.'], pats, {})
             message = opts['message']
             return commitfunc(ui, repo, message, match, opts)
         if not interactive:
             node = cmdutil.commit(ui, repo, commitfunc, pats, opts)
         else:
             node = cmdutil.dorecord(ui, repo, interactivecommitfunc, None,
                                     False, cmdutil.recordfilter, *pats, **opts)
         if not node:
             stat = repo.status(match=scmutil.match(repo[None], pats, opts))
             if stat.deleted:
                 ui.status(_("nothing changed (%d missing files, see "
                             "'hg status')\n") % len(stat.deleted))
             else:
                 ui.status(_("nothing changed\n"))
             return 1
 
         bases = list(publicancestors(repo[node]))
         shelvedfile(repo, name, 'hg').writebundle(bases, node)
         cmdutil.export(repo, [node],
                        fp=shelvedfile(repo, name, 'patch').opener('wb'),
                        opts=mdiff.diffopts(git=True))
 
 
         if ui.formatted():
             desc = util.ellipsis(desc, ui.termwidth())
         ui.status(_('shelved as %s\n') % name)
         hg.update(repo, parent.node())
 
         _aborttransaction(repo)
     finally:
         lockmod.release(tr, lock, wlock)
 
 def cleanupcmd(ui, repo):
     """subcommand that deletes all shelves"""
 
     wlock = None
     try:
         wlock = repo.wlock()
         for (name, _type) in repo.vfs.readdir('shelved'):
             suffix = name.rsplit('.', 1)[-1]
             if suffix in ('hg', 'patch'):
                 shelvedfile(repo, name).movetobackup()
             cleanupoldbackups(repo)
     finally:
         lockmod.release(wlock)
 
 def deletecmd(ui, repo, pats):
     """subcommand that deletes a specific shelve"""
     if not pats:
         raise util.Abort(_('no shelved changes specified!'))
     wlock = repo.wlock()
     try:
         for name in pats:
             for suffix in 'hg patch'.split():
                 shelvedfile(repo, name, suffix).movetobackup()
         cleanupoldbackups(repo)
     except OSError as err:
         if err.errno != errno.ENOENT:
             raise
         raise util.Abort(_("shelved change '%s' not found") % name)
     finally:
         lockmod.release(wlock)
 
 def listshelves(repo):
     """return all shelves in repo as list of (time, filename)"""
     try:
         names = repo.vfs.readdir('shelved')
     except OSError as err:
         if err.errno != errno.ENOENT:
             raise
         return []
     info = []
     for (name, _type) in names:
         pfx, sfx = name.rsplit('.', 1)
         if not pfx or sfx != 'patch':
             continue
         st = shelvedfile(repo, name).stat()
         info.append((st.st_mtime, shelvedfile(repo, pfx).filename()))
     return sorted(info, reverse=True)
 
 def listcmd(ui, repo, pats, opts):
     """subcommand that displays the list of shelves"""
     pats = set(pats)
     width = 80
     if not ui.plain():
         width = ui.termwidth()
     namelabel = 'shelve.newest'
     for mtime, name in listshelves(repo):
         sname = util.split(name)[1]
         if pats and sname not in pats:
             continue
         ui.write(sname, label=namelabel)
         namelabel = 'shelve.name'
         if ui.quiet:
             ui.write('\n')
             continue
         ui.write(' ' * (16 - len(sname)))
         used = 16
         age = '(%s)' % templatefilters.age(util.makedate(mtime), abbrev=True)
         ui.write(age, label='shelve.age')
         ui.write(' ' * (12 - len(age)))
         used += 12
         fp = open(name + '.patch', 'rb')
         try:
             while True:
                 line = fp.readline()
                 if not line:
                     break
                 if not line.startswith('#'):
                     desc = line.rstrip()
                     if ui.formatted():
                         desc = util.ellipsis(desc, width - used)
                     ui.write(desc)
                     break
             ui.write('\n')
             if not (opts['patch'] or opts['stat']):
                 continue
             difflines = fp.readlines()
             if opts['patch']:
                 for chunk, label in patch.difflabel(iter, difflines):
                     ui.write(chunk, label=label)
             if opts['stat']:
                 for chunk, label in patch.diffstatui(difflines, width=width,
                                                      git=True):
                     ui.write(chunk, label=label)
         finally:
             fp.close()
 
 def singlepatchcmds(ui, repo, pats, opts, subcommand):
     """subcommand that displays a single shelf"""
     if len(pats) != 1:
         raise util.Abort(_("--%s expects a single shelf") % subcommand)
     shelfname = pats[0]
 
     if not shelvedfile(repo, shelfname, 'patch').exists():
         raise util.Abort(_("cannot find shelf %s") % shelfname)
 
     listcmd(ui, repo, pats, opts)
 
 def checkparents(repo, state):
     """check parent while resuming an unshelve"""
     if state.parents != repo.dirstate.parents():
         raise util.Abort(_('working directory parents do not match unshelve '
                            'state'))
 
 def pathtofiles(repo, files):
     cwd = repo.getcwd()
     return [repo.pathto(f, cwd) for f in files]
 
 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=False, topic='shelve')
         shelvedstate.clear(repo)
         ui.warn(_("unshelve of '%s' aborted\n") % state.name)
     finally:
         lockmod.release(lock, wlock)
 
 def mergefiles(ui, repo, wctx, shelvectx):
     """updates to wctx and merges the changes from shelvectx into the
     dirstate."""
     oldquiet = ui.quiet
     try:
         ui.quiet = True
         hg.update(repo, wctx.node())
         files = []
         files.extend(shelvectx.files())
         files.extend(shelvectx.parents()[0].files())
 
         # revert will overwrite unknown files, so move them out of the way
         for file in repo.status(unknown=True).unknown:
             if file in files:
                 util.rename(file, file + ".orig")
         ui.pushbuffer(True)
         cmdutil.revert(ui, repo, shelvectx, repo.dirstate.parents(),
                        *pathtofiles(repo, files),
                        **{'no_backup': True})
         ui.popbuffer()
     finally:
         ui.quiet = oldquiet
 
 def unshelvecleanup(ui, repo, name, opts):
     """remove related files after an unshelve"""
     if not opts['keep']:
         for filetype in 'hg patch'.split():
             shelvedfile(repo, name, filetype).movetobackup()
         cleanupoldbackups(repo)
 
 def unshelvecontinue(ui, repo, state, opts):
     """subcommand to continue an in-progress unshelve"""
     # We're finishing off a merge. First parent is our original
     # parent, second is the temporary "fake" commit we're unshelving.
     wlock = repo.wlock()
     lock = None
     try:
         checkparents(repo, state)
         ms = merge.mergestate(repo)
         if [f for f in ms if ms[f] == 'u']:
             raise util.Abort(
                 _("unresolved conflicts, can't continue"),
                 hint=_("see 'hg resolve', then 'hg unshelve --continue'"))
 
         lock = repo.lock()
 
         util.rename(repo.join('unshelverebasestate'),
                     repo.join('rebasestate'))
         try:
             rebase.rebase(ui, repo, **{
                 'continue' : True
             })
         except Exception:
             util.rename(repo.join('rebasestate'),
                         repo.join('unshelverebasestate'))
             raise
 
         shelvectx = repo['tip']
         if not shelvectx in state.pendingctx.children():
             # rebase was a no-op, so it produced no child commit
             shelvectx = state.pendingctx
         else:
             # only strip the shelvectx if the rebase produced it
             state.stripnodes.append(shelvectx.node())
 
         mergefiles(ui, repo, state.wctx, shelvectx)
 
         repair.strip(ui, repo, state.stripnodes, backup=False, topic='shelve')
         shelvedstate.clear(repo)
         unshelvecleanup(ui, repo, state.name, opts)
         ui.status(_("unshelve of '%s' complete\n") % state.name)
     finally:
         lockmod.release(lock, wlock)
 
 @command('unshelve',
          [('a', 'abort', None,
            _('abort an incomplete unshelve operation')),
           ('c', 'continue', None,
            _('continue an incomplete unshelve operation')),
           ('', 'keep', None,
            _('keep shelve after unshelving')),
           ('', 'date', '',
            _('set date for temporary commits (DEPRECATED)'), _('DATE'))],
          _('hg unshelve [SHELVED]'))
 def unshelve(ui, repo, *shelved, **opts):
     """restore a shelved change to the working directory
 
     This command accepts an optional name of a shelved change to
     restore. If none is given, the most recent shelved change is used.
 
     If a shelved change is applied successfully, the bundle that
     contains the shelved changes is moved to a backup location
     (.hg/shelve-backup).
 
     Since you can restore a shelved change on top of an arbitrary
     commit, it is possible that unshelving will result in a conflict
     between your changes and the commits you are unshelving onto. If
     this occurs, you must resolve the conflict, then use
     ``--continue`` to complete the unshelve operation. (The bundle
     will not be moved until you successfully complete the unshelve.)
 
     (Alternatively, you can use ``--abort`` to abandon an unshelve
     that causes a conflict. This reverts the unshelved changes, and
     leaves the bundle in place.)
 
     After a successful unshelve, the shelved changes are stored in a
     backup directory. Only the N most recent backups are kept. N
     defaults to 10 but can be overridden using the ``shelve.maxbackups``
     configuration option.
 
     .. container:: verbose
 
        Timestamp in seconds is used to decide order of backups. More
        than ``maxbackups`` backups are kept, if same timestamp
        prevents from deciding exact order of them, for safety.
     """
     abortf = opts['abort']
     continuef = opts['continue']
     if not abortf and not continuef:
         cmdutil.checkunfinished(repo)
 
     if abortf or continuef:
         if abortf and continuef:
             raise util.Abort(_('cannot use both abort and continue'))
         if shelved:
             raise util.Abort(_('cannot combine abort/continue with '
                                'naming a shelved change'))
 
         try:
             state = shelvedstate.load(repo)
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
             raise util.Abort(_('no unshelve operation underway'))
 
         if abortf:
             return unshelveabort(ui, repo, state, opts)
         elif continuef:
             return unshelvecontinue(ui, repo, state, opts)
     elif len(shelved) > 1:
         raise util.Abort(_('can only unshelve one change at a time'))
     elif not shelved:
         shelved = listshelves(repo)
         if not shelved:
             raise util.Abort(_('no shelved changes to apply!'))
         basename = util.split(shelved[0][1])[1]
         ui.status(_("unshelving change '%s'\n") % basename)
     else:
         basename = shelved[0]
 
     if not shelvedfile(repo, basename, 'patch').exists():
         raise util.Abort(_("shelved change '%s' not found") % basename)
 
     oldquiet = ui.quiet
     wlock = lock = tr = None
     try:
         wlock = repo.wlock()
         lock = repo.lock()
 
         tr = repo.transaction('unshelve', report=lambda x: None)
         oldtiprev = len(repo)
 
         pctx = repo['.']
         tmpwctx = pctx
         # The goal is to have a commit structure like so:
         # ...-> pctx -> tmpwctx -> shelvectx
         # where tmpwctx is an optional commit with the user's pending changes
         # and shelvectx is the unshelved changes. Then we merge it all down
         # to the original pctx.
 
         # Store pending changes in a commit
         s = repo.status()
         if s.modified or s.added or s.removed or s.deleted:
             ui.status(_("temporarily committing pending changes "
                         "(restore with 'hg unshelve --abort')\n"))
             def commitfunc(ui, repo, message, match, opts):
                 hasmq = util.safehasattr(repo, 'mq')
                 if hasmq:
                     saved, repo.mq.checkapplied = repo.mq.checkapplied, False
 
                 backup = repo.ui.backupconfig('phases', 'new-commit')
                 try:
                     repo.ui. setconfig('phases', 'new-commit', phases.secret)
                     return repo.commit(message, 'shelve@localhost',
                                        opts.get('date'), match)
                 finally:
                     repo.ui.restoreconfig(backup)
                     if hasmq:
                         repo.mq.checkapplied = saved
 
             tempopts = {}
             tempopts['message'] = "pending changes temporary commit"
             tempopts['date'] = opts.get('date')
             ui.quiet = True
             node = cmdutil.commit(ui, repo, commitfunc, [], tempopts)
             tmpwctx = repo[node]
 
         ui.quiet = True
         shelvedfile(repo, basename, 'hg').applybundle()
 
         ui.quiet = oldquiet
 
         shelvectx = repo['tip']
 
         # If the shelve is not immediately on top of the commit
         # we'll be merging with, rebase it to be on top.
         if tmpwctx.node() != shelvectx.parents()[0].node():
             ui.status(_('rebasing shelved changes\n'))
             try:
                 rebase.rebase(ui, repo, **{
                     'rev' : [shelvectx.rev()],
                     'dest' : str(tmpwctx.rev()),
                     'keep' : True,
                 })
             except error.InterventionRequired:
                 tr.close()
 
                 stripnodes = [repo.changelog.node(rev)
                               for rev in xrange(oldtiprev, len(repo))]
                 shelvedstate.save(repo, basename, pctx, tmpwctx, stripnodes)
 
                 util.rename(repo.join('rebasestate'),
                             repo.join('unshelverebasestate'))
                 raise error.InterventionRequired(
                     _("unresolved conflicts (see 'hg resolve', then "
                       "'hg unshelve --continue')"))
 
             # refresh ctx after rebase completes
             shelvectx = repo['tip']
 
             if not shelvectx in tmpwctx.children():
                 # rebase was a no-op, so it produced no child commit
                 shelvectx = tmpwctx
 
         mergefiles(ui, repo, pctx, shelvectx)
         shelvedstate.clear(repo)
 
         # The transaction aborting will strip all the commits for us,
         # but it doesn't update the inmemory structures, so addchangegroup
         # hooks still fire and try to operate on the missing commits.
         # Clean up manually to prevent this.
         repo.unfiltered().changelog.strip(oldtiprev, tr)
 
         unshelvecleanup(ui, repo, basename, opts)
 
         _aborttransaction(repo)
     finally:
         ui.quiet = oldquiet
         if tr:
             tr.release()
         lockmod.release(lock, wlock)
 
 @command('shelve',
          [('A', 'addremove', None,
            _('mark new/missing files as added/removed before shelving')),
           ('', 'cleanup', None,
            _('delete all shelved changes')),
           ('', 'date', '',
            _('shelve with the specified commit date'), _('DATE')),
           ('d', 'delete', None,
            _('delete the named shelved change(s)')),
           ('e', 'edit', False,
            _('invoke editor on commit messages')),
           ('l', 'list', None,
            _('list current shelves')),
           ('m', 'message', '',
            _('use text as shelve message'), _('TEXT')),
           ('n', 'name', '',
            _('use the given name for the shelved commit'), _('NAME')),
           ('p', 'patch', None,
            _('show patch')),
           ('i', 'interactive', None,
            _('interactive mode, only works while creating a shelve')),
           ('', 'stat', None,
            _('output diffstat-style summary of changes'))] + commands.walkopts,
          _('hg shelve [OPTION]... [FILE]...'))
 def shelvecmd(ui, repo, *pats, **opts):
     '''save and set aside changes from the working directory
 
     Shelving takes files that "hg status" reports as not clean, saves
     the modifications to a bundle (a shelved change), and reverts the
     files so that their state in the working directory becomes clean.
 
     To restore these changes to the working directory, using "hg
     unshelve"; this will work even if you switch to a different
     commit.
 
     When no files are specified, "hg shelve" saves all not-clean
     files. If specific files or directories are named, only changes to
     those files are shelved.
 
     Each shelved change has a name that makes it easier to find later.
     The name of a shelved change defaults to being based on the active
     bookmark, or if there is no active bookmark, the current named
     branch.  To specify a different name, use ``--name``.
 
     To see a list of existing shelved changes, use the ``--list``
     option. For each shelved change, this will print its name, age,
     and description; use ``--patch`` or ``--stat`` for more details.
 
     To delete specific shelved changes, use ``--delete``. To delete
     all shelved changes, use ``--cleanup``.
     '''
     cmdutil.checkunfinished(repo)
 
     allowables = [
         ('addremove', set(['create'])), # 'create' is pseudo action
         ('cleanup', set(['cleanup'])),
 #       ('date', set(['create'])), # ignored for passing '--date "0 0"' in tests
         ('delete', set(['delete'])),
         ('edit', set(['create'])),
         ('list', set(['list'])),
         ('message', set(['create'])),
         ('name', set(['create'])),
         ('patch', set(['patch', 'list'])),
         ('stat', set(['stat', 'list'])),
     ]
     def checkopt(opt):
         if opts[opt]:
             for i, allowable in allowables:
                 if opts[i] and opt not in allowable:
                     raise util.Abort(_("options '--%s' and '--%s' may not be "
                                        "used together") % (opt, i))
             return True
     if checkopt('cleanup'):
         if pats:
             raise util.Abort(_("cannot specify names when using '--cleanup'"))
         return cleanupcmd(ui, repo)
     elif checkopt('delete'):
         return deletecmd(ui, repo, pats)
     elif checkopt('list'):
         return listcmd(ui, repo, pats, opts)
     elif checkopt('patch'):
         return singlepatchcmds(ui, repo, pats, opts, subcommand='patch')
     elif checkopt('stat'):
         return singlepatchcmds(ui, repo, pats, opts, subcommand='stat')
     else:
         return createcmd(ui, repo, pats, opts)
 
 def extsetup(ui):
     cmdutil.unfinishedstates.append(
         [shelvedstate._filename, False, False,
          _('unshelve already in progress'),
          _("use 'hg unshelve --continue' or 'hg unshelve --abort'")])

mercurial/localrepo.py

@@ -1,1894 +1,1907 b''
 # localrepo.py - read/write repository class for mercurial
 #
 # 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 node import hex, nullid, wdirrev, short
 from i18n import _
 import urllib
 import peer, changegroup, subrepo, pushkey, obsolete, repoview
 import changelog, dirstate, filelog, manifest, context, bookmarks, phases
 import lock as lockmod
 import transaction, store, encoding, exchange, bundle2
 import scmutil, util, extensions, hook, error, revset
 import match as matchmod
 import merge as mergemod
 import tags as tagsmod
 from lock import release
 import weakref, errno, os, time, inspect, random
 import branchmap, pathutil
 import namespaces
 propertycache = util.propertycache
 filecache = scmutil.filecache
 
 class repofilecache(filecache):
     """All filecache usage on repo are done for logic that should be unfiltered
     """
 
     def __get__(self, repo, type=None):
         return super(repofilecache, self).__get__(repo.unfiltered(), type)
     def __set__(self, repo, value):
         return super(repofilecache, self).__set__(repo.unfiltered(), value)
     def __delete__(self, repo):
         return super(repofilecache, self).__delete__(repo.unfiltered())
 
 class storecache(repofilecache):
     """filecache for files in the store"""
     def join(self, obj, fname):
         return obj.sjoin(fname)
 
 class unfilteredpropertycache(propertycache):
     """propertycache that apply to unfiltered repo only"""
 
     def __get__(self, repo, type=None):
         unfi = repo.unfiltered()
         if unfi is repo:
             return super(unfilteredpropertycache, self).__get__(unfi)
         return getattr(unfi, self.name)
 
 class filteredpropertycache(propertycache):
     """propertycache that must take filtering in account"""
 
     def cachevalue(self, obj, value):
         object.__setattr__(obj, self.name, value)
 
 
 def hasunfilteredcache(repo, name):
     """check if a repo has an unfilteredpropertycache value for <name>"""
     return name in vars(repo.unfiltered())
 
 def unfilteredmethod(orig):
     """decorate method that always need to be run on unfiltered version"""
     def wrapper(repo, *args, **kwargs):
         return orig(repo.unfiltered(), *args, **kwargs)
     return wrapper
 
 moderncaps = set(('lookup', 'branchmap', 'pushkey', 'known', 'getbundle',
                   'unbundle'))
 legacycaps = moderncaps.union(set(['changegroupsubset']))
 
 class localpeer(peer.peerrepository):
     '''peer for a local repo; reflects only the most recent API'''
 
     def __init__(self, repo, caps=moderncaps):
         peer.peerrepository.__init__(self)
         self._repo = repo.filtered('served')
         self.ui = repo.ui
         self._caps = repo._restrictcapabilities(caps)
         self.requirements = repo.requirements
         self.supportedformats = repo.supportedformats
 
     def close(self):
         self._repo.close()
 
     def _capabilities(self):
         return self._caps
 
     def local(self):
         return self._repo
 
     def canpush(self):
         return True
 
     def url(self):
         return self._repo.url()
 
     def lookup(self, key):
         return self._repo.lookup(key)
 
     def branchmap(self):
         return self._repo.branchmap()
 
     def heads(self):
         return self._repo.heads()
 
     def known(self, nodes):
         return self._repo.known(nodes)
 
     def getbundle(self, source, heads=None, common=None, bundlecaps=None,
                   **kwargs):
         cg = exchange.getbundle(self._repo, source, heads=heads,
                                 common=common, bundlecaps=bundlecaps, **kwargs)
         if bundlecaps is not None and 'HG20' in bundlecaps:
             # When requesting a bundle2, getbundle returns a stream to make the
             # wire level function happier. We need to build a proper object
             # from it in local peer.
             cg = bundle2.getunbundler(self.ui, cg)
         return cg
 
     # TODO We might want to move the next two calls into legacypeer and add
     # unbundle instead.
 
     def unbundle(self, cg, heads, url):
         """apply a bundle on a repo
 
         This function handles the repo locking itself."""
         try:
             try:
                 cg = exchange.readbundle(self.ui, cg, None)
                 ret = exchange.unbundle(self._repo, cg, heads, 'push', url)
                 if util.safehasattr(ret, 'getchunks'):
                     # This is a bundle20 object, turn it into an unbundler.
                     # This little dance should be dropped eventually when the
                     # API is finally improved.
                     stream = util.chunkbuffer(ret.getchunks())
                     ret = bundle2.getunbundler(self.ui, stream)
                 return ret
             except Exception as exc:
                 # If the exception contains output salvaged from a bundle2
                 # reply, we need to make sure it is printed before continuing
                 # to fail. So we build a bundle2 with such output and consume
                 # it directly.
                 #
                 # This is not very elegant but allows a "simple" solution for
                 # issue4594
                 output = getattr(exc, '_bundle2salvagedoutput', ())
                 if output:
                     bundler = bundle2.bundle20(self._repo.ui)
                     for out in output:
                         bundler.addpart(out)
                     stream = util.chunkbuffer(bundler.getchunks())
                     b = bundle2.getunbundler(self.ui, stream)
                     bundle2.processbundle(self._repo, b)
                 raise
         except error.PushRaced as exc:
             raise error.ResponseError(_('push failed:'), str(exc))
 
     def lock(self):
         return self._repo.lock()
 
     def addchangegroup(self, cg, source, url):
         return changegroup.addchangegroup(self._repo, cg, source, url)
 
     def pushkey(self, namespace, key, old, new):
         return self._repo.pushkey(namespace, key, old, new)
 
     def listkeys(self, namespace):
         return self._repo.listkeys(namespace)
 
     def debugwireargs(self, one, two, three=None, four=None, five=None):
         '''used to test argument passing over the wire'''
         return "%s %s %s %s %s" % (one, two, three, four, five)
 
 class locallegacypeer(localpeer):
     '''peer extension which implements legacy methods too; used for tests with
     restricted capabilities'''
 
     def __init__(self, repo):
         localpeer.__init__(self, repo, caps=legacycaps)
 
     def branches(self, nodes):
         return self._repo.branches(nodes)
 
     def between(self, pairs):
         return self._repo.between(pairs)
 
     def changegroup(self, basenodes, source):
         return changegroup.changegroup(self._repo, basenodes, source)
 
     def changegroupsubset(self, bases, heads, source):
         return changegroup.changegroupsubset(self._repo, bases, heads, source)
 
 class localrepository(object):
 
     supportedformats = set(('revlogv1', 'generaldelta', 'treemanifest',
                             'manifestv2'))
     _basesupported = supportedformats | set(('store', 'fncache', 'shared',
                                              'dotencode'))
     openerreqs = set(('revlogv1', 'generaldelta', 'treemanifest', 'manifestv2'))
     filtername = None
 
     # a list of (ui, featureset) functions.
     # only functions defined in module of enabled extensions are invoked
     featuresetupfuncs = set()
 
     def _baserequirements(self, create):
         return ['revlogv1']
 
     def __init__(self, baseui, path=None, create=False):
         self.requirements = set()
         self.wvfs = scmutil.vfs(path, expandpath=True, realpath=True)
         self.wopener = self.wvfs
         self.root = self.wvfs.base
         self.path = self.wvfs.join(".hg")
         self.origroot = path
         self.auditor = pathutil.pathauditor(self.root, self._checknested)
         self.vfs = scmutil.vfs(self.path)
         self.opener = self.vfs
         self.baseui = baseui
         self.ui = baseui.copy()
         self.ui.copy = baseui.copy # prevent copying repo configuration
         # A list of callback to shape the phase if no data were found.
         # Callback are in the form: func(repo, roots) --> processed root.
         # This list it to be filled by extension during repo setup
         self._phasedefaults = []
         try:
             self.ui.readconfig(self.join("hgrc"), self.root)
             extensions.loadall(self.ui)
         except IOError:
             pass
 
         if self.featuresetupfuncs:
             self.supported = set(self._basesupported) # use private copy
             extmods = set(m.__name__ for n, m
                           in extensions.extensions(self.ui))
             for setupfunc in self.featuresetupfuncs:
                 if setupfunc.__module__ in extmods:
                     setupfunc(self.ui, self.supported)
         else:
             self.supported = self._basesupported
 
         if not self.vfs.isdir():
             if create:
                 if not self.wvfs.exists():
                     self.wvfs.makedirs()
                 self.vfs.makedir(notindexed=True)
                 self.requirements.update(self._baserequirements(create))
                 if self.ui.configbool('format', 'usestore', True):
                     self.vfs.mkdir("store")
                     self.requirements.add("store")
                     if self.ui.configbool('format', 'usefncache', True):
                         self.requirements.add("fncache")
                         if self.ui.configbool('format', 'dotencode', True):
                             self.requirements.add('dotencode')
                     # create an invalid changelog
                     self.vfs.append(
                         "00changelog.i",
                         '\0\0\0\2' # represents revlogv2
                         ' dummy changelog to prevent using the old repo layout'
                     )
                 # experimental config: format.generaldelta
                 if self.ui.configbool('format', 'generaldelta', False):
                     self.requirements.add("generaldelta")
                 if self.ui.configbool('experimental', 'treemanifest', False):
                     self.requirements.add("treemanifest")
                 if self.ui.configbool('experimental', 'manifestv2', False):
                     self.requirements.add("manifestv2")
             else:
                 raise error.RepoError(_("repository %s not found") % path)
         elif create:
             raise error.RepoError(_("repository %s already exists") % path)
         else:
             try:
                 self.requirements = scmutil.readrequires(
                         self.vfs, self.supported)
             except IOError as inst:
                 if inst.errno != errno.ENOENT:
                     raise
 
         self.sharedpath = self.path
         try:
             vfs = scmutil.vfs(self.vfs.read("sharedpath").rstrip('\n'),
                               realpath=True)
             s = vfs.base
             if not vfs.exists():
                 raise error.RepoError(
                     _('.hg/sharedpath points to nonexistent directory %s') % s)
             self.sharedpath = s
         except IOError as inst:
             if inst.errno != errno.ENOENT:
                 raise
 
         self.store = store.store(
                 self.requirements, self.sharedpath, scmutil.vfs)
         self.spath = self.store.path
         self.svfs = self.store.vfs
         self.sjoin = self.store.join
         self.vfs.createmode = self.store.createmode
         self._applyopenerreqs()
         if create:
             self._writerequirements()
 
         self._dirstatevalidatewarned = False
 
         self._branchcaches = {}
         self._revbranchcache = None
         self.filterpats = {}
         self._datafilters = {}
         self._transref = self._lockref = self._wlockref = None
 
         # A cache for various files under .hg/ that tracks file changes,
         # (used by the filecache decorator)
         #
         # Maps a property name to its util.filecacheentry
         self._filecache = {}
 
         # hold sets of revision to be filtered
         # should be cleared when something might have changed the filter value:
         # - new changesets,
         # - phase change,
         # - new obsolescence marker,
         # - working directory parent change,
         # - bookmark changes
         self.filteredrevcache = {}
 
         # generic mapping between names and nodes
         self.names = namespaces.namespaces()
 
     def close(self):
         self._writecaches()
 
     def _writecaches(self):
         if self._revbranchcache:
             self._revbranchcache.write()
 
     def _restrictcapabilities(self, caps):
         if self.ui.configbool('experimental', 'bundle2-advertise', True):
             caps = set(caps)
             capsblob = bundle2.encodecaps(bundle2.getrepocaps(self))
             caps.add('bundle2=' + urllib.quote(capsblob))
         return caps
 
     def _applyopenerreqs(self):
         self.svfs.options = dict((r, 1) for r in self.requirements
                                            if r in self.openerreqs)
         # experimental config: format.chunkcachesize
         chunkcachesize = self.ui.configint('format', 'chunkcachesize')
         if chunkcachesize is not None:
             self.svfs.options['chunkcachesize'] = chunkcachesize
         # experimental config: format.maxchainlen
         maxchainlen = self.ui.configint('format', 'maxchainlen')
         if maxchainlen is not None:
             self.svfs.options['maxchainlen'] = maxchainlen
         # experimental config: format.manifestcachesize
         manifestcachesize = self.ui.configint('format', 'manifestcachesize')
         if manifestcachesize is not None:
             self.svfs.options['manifestcachesize'] = manifestcachesize
         # experimental config: format.aggressivemergedeltas
         aggressivemergedeltas = self.ui.configbool('format',
             'aggressivemergedeltas', False)
         self.svfs.options['aggressivemergedeltas'] = aggressivemergedeltas
 
     def _writerequirements(self):
         scmutil.writerequires(self.vfs, self.requirements)
 
     def _checknested(self, path):
         """Determine if path is a legal nested repository."""
         if not path.startswith(self.root):
             return False
         subpath = path[len(self.root) + 1:]
         normsubpath = util.pconvert(subpath)
 
         # XXX: Checking against the current working copy is wrong in
         # the sense that it can reject things like
         #
         #   $ hg cat -r 10 sub/x.txt
         #
         # if sub/ is no longer a subrepository in the working copy
         # parent revision.
         #
         # However, it can of course also allow things that would have
         # been rejected before, such as the above cat command if sub/
         # is a subrepository now, but was a normal directory before.
         # The old path auditor would have rejected by mistake since it
         # panics when it sees sub/.hg/.
         #
         # All in all, checking against the working copy seems sensible
         # since we want to prevent access to nested repositories on
         # the filesystem *now*.
         ctx = self[None]
         parts = util.splitpath(subpath)
         while parts:
             prefix = '/'.join(parts)
             if prefix in ctx.substate:
                 if prefix == normsubpath:
                     return True
                 else:
                     sub = ctx.sub(prefix)
                     return sub.checknested(subpath[len(prefix) + 1:])
             else:
                 parts.pop()
         return False
 
     def peer(self):
         return localpeer(self) # not cached to avoid reference cycle
 
     def unfiltered(self):
         """Return unfiltered version of the repository
 
         Intended to be overwritten by filtered repo."""
         return self
 
     def filtered(self, name):
         """Return a filtered version of a repository"""
         # build a new class with the mixin and the current class
         # (possibly subclass of the repo)
         class proxycls(repoview.repoview, self.unfiltered().__class__):
             pass
         return proxycls(self, name)
 
     @repofilecache('bookmarks')
     def _bookmarks(self):
         return bookmarks.bmstore(self)
 
     @repofilecache('bookmarks.current')
     def _activebookmark(self):
         return bookmarks.readactive(self)
 
     def bookmarkheads(self, bookmark):
         name = bookmark.split('@', 1)[0]
         heads = []
         for mark, n in self._bookmarks.iteritems():
             if mark.split('@', 1)[0] == name:
                 heads.append(n)
         return heads
 
     # _phaserevs and _phasesets depend on changelog. what we need is to
     # call _phasecache.invalidate() if '00changelog.i' was changed, but it
     # can't be easily expressed in filecache mechanism.
     @storecache('phaseroots', '00changelog.i')
     def _phasecache(self):
         return phases.phasecache(self, self._phasedefaults)
 
     @storecache('obsstore')
     def obsstore(self):
         # read default format for new obsstore.
         # developer config: format.obsstore-version
         defaultformat = self.ui.configint('format', 'obsstore-version', None)
         # rely on obsstore class default when possible.
         kwargs = {}
         if defaultformat is not None:
             kwargs['defaultformat'] = defaultformat
         readonly = not obsolete.isenabled(self, obsolete.createmarkersopt)
         store = obsolete.obsstore(self.svfs, readonly=readonly,
                                   **kwargs)
         if store and readonly:
             self.ui.warn(
                 _('obsolete feature not enabled but %i markers found!\n')
                 % len(list(store)))
         return store
 
     @storecache('00changelog.i')
     def changelog(self):
         c = changelog.changelog(self.svfs)
         if 'HG_PENDING' in os.environ:
             p = os.environ['HG_PENDING']
             if p.startswith(self.root):
                 c.readpending('00changelog.i.a')
         return c
 
     @storecache('00manifest.i')
     def manifest(self):
         return manifest.manifest(self.svfs)
 
     def dirlog(self, dir):
         return self.manifest.dirlog(dir)
 
     @repofilecache('dirstate')
     def dirstate(self):
         return dirstate.dirstate(self.vfs, self.ui, self.root,
                                  self._dirstatevalidate)
 
     def _dirstatevalidate(self, node):
         try:
             self.changelog.rev(node)
             return node
         except error.LookupError:
             if not self._dirstatevalidatewarned:
                 self._dirstatevalidatewarned = True
                 self.ui.warn(_("warning: ignoring unknown"
                                " working parent %s!\n") % short(node))
             return nullid
 
     def __getitem__(self, changeid):
         if changeid is None or changeid == wdirrev:
             return context.workingctx(self)
         if isinstance(changeid, slice):
             return [context.changectx(self, i)
                     for i in xrange(*changeid.indices(len(self)))
                     if i not in self.changelog.filteredrevs]
         return context.changectx(self, changeid)
 
     def __contains__(self, changeid):
         try:
             self[changeid]
             return True
         except error.RepoLookupError:
             return False
 
     def __nonzero__(self):
         return True
 
     def __len__(self):
         return len(self.changelog)
 
     def __iter__(self):
         return iter(self.changelog)
 
     def revs(self, expr, *args):
         '''Return a list of revisions matching the given revset'''
         expr = revset.formatspec(expr, *args)
         m = revset.match(None, expr)
         return m(self)
 
     def set(self, expr, *args):
         '''
         Yield a context for each matching revision, after doing arg
         replacement via revset.formatspec
         '''
         for r in self.revs(expr, *args):
             yield self[r]
 
     def url(self):
         return 'file:' + self.root
 
     def hook(self, name, throw=False, **args):
         """Call a hook, passing this repo instance.
 
         This a convenience method to aid invoking hooks. Extensions likely
         won't call this unless they have registered a custom hook or are
         replacing code that is expected to call a hook.
         """
         return hook.hook(self.ui, self, name, throw, **args)
 
     @unfilteredmethod
     def _tag(self, names, node, message, local, user, date, extra=None,
              editor=False):
         if isinstance(names, str):
             names = (names,)
 
         branches = self.branchmap()
         for name in names:
             self.hook('pretag', throw=True, node=hex(node), tag=name,
                       local=local)
             if name in branches:
                 self.ui.warn(_("warning: tag %s conflicts with existing"
                 " branch name\n") % name)
 
         def writetags(fp, names, munge, prevtags):
             fp.seek(0, 2)
             if prevtags and prevtags[-1] != '\n':
                 fp.write('\n')
             for name in names:
                 if munge:
                     m = munge(name)
                 else:
                     m = name
 
                 if (self._tagscache.tagtypes and
                     name in self._tagscache.tagtypes):
                     old = self.tags().get(name, nullid)
                     fp.write('%s %s\n' % (hex(old), m))
                 fp.write('%s %s\n' % (hex(node), m))
             fp.close()
 
         prevtags = ''
         if local:
             try:
                 fp = self.vfs('localtags', 'r+')
             except IOError:
                 fp = self.vfs('localtags', 'a')
             else:
                 prevtags = fp.read()
 
             # local tags are stored in the current charset
             writetags(fp, names, None, prevtags)
             for name in names:
                 self.hook('tag', node=hex(node), tag=name, local=local)
             return
 
         try:
             fp = self.wfile('.hgtags', 'rb+')
         except IOError as e:
             if e.errno != errno.ENOENT:
                 raise
             fp = self.wfile('.hgtags', 'ab')
         else:
             prevtags = fp.read()
 
         # committed tags are stored in UTF-8
         writetags(fp, names, encoding.fromlocal, prevtags)
 
         fp.close()
 
         self.invalidatecaches()
 
         if '.hgtags' not in self.dirstate:
             self[None].add(['.hgtags'])
 
         m = matchmod.exact(self.root, '', ['.hgtags'])
         tagnode = self.commit(message, user, date, extra=extra, match=m,
                               editor=editor)
 
         for name in names:
             self.hook('tag', node=hex(node), tag=name, local=local)
 
         return tagnode
 
     def tag(self, names, node, message, local, user, date, editor=False):
         '''tag a revision with one or more symbolic names.
 
         names is a list of strings or, when adding a single tag, names may be a
         string.
 
         if local is True, the tags are stored in a per-repository file.
         otherwise, they are stored in the .hgtags file, and a new
         changeset is committed with the change.
 
         keyword arguments:
 
         local: whether to store tags in non-version-controlled file
         (default False)
 
         message: commit message to use if committing
 
         user: name of user to use if committing
 
         date: date tuple to use if committing'''
 
         if not local:
             m = matchmod.exact(self.root, '', ['.hgtags'])
             if any(self.status(match=m, unknown=True, ignored=True)):
                 raise util.Abort(_('working copy of .hgtags is changed'),
                                  hint=_('please commit .hgtags manually'))
 
         self.tags() # instantiate the cache
         self._tag(names, node, message, local, user, date, editor=editor)
 
     @filteredpropertycache
     def _tagscache(self):
         '''Returns a tagscache object that contains various tags related
         caches.'''
 
         # This simplifies its cache management by having one decorated
         # function (this one) and the rest simply fetch things from it.
         class tagscache(object):
             def __init__(self):
                 # These two define the set of tags for this repository. tags
                 # maps tag name to node; tagtypes maps tag name to 'global' or
                 # 'local'. (Global tags are defined by .hgtags across all
                 # heads, and local tags are defined in .hg/localtags.)
                 # They constitute the in-memory cache of tags.
                 self.tags = self.tagtypes = None
 
                 self.nodetagscache = self.tagslist = None
 
         cache = tagscache()
         cache.tags, cache.tagtypes = self._findtags()
 
         return cache
 
     def tags(self):
         '''return a mapping of tag to node'''
         t = {}
         if self.changelog.filteredrevs:
             tags, tt = self._findtags()
         else:
             tags = self._tagscache.tags
         for k, v in tags.iteritems():
             try:
                 # ignore tags to unknown nodes
                 self.changelog.rev(v)
                 t[k] = v
             except (error.LookupError, ValueError):
                 pass
         return t
 
     def _findtags(self):
         '''Do the hard work of finding tags.  Return a pair of dicts
         (tags, tagtypes) where tags maps tag name to node, and tagtypes
         maps tag name to a string like \'global\' or \'local\'.
         Subclasses or extensions are free to add their own tags, but
         should be aware that the returned dicts will be retained for the
         duration of the localrepo object.'''
 
         # XXX what tagtype should subclasses/extensions use?  Currently
         # mq and bookmarks add tags, but do not set the tagtype at all.
         # Should each extension invent its own tag type?  Should there
         # be one tagtype for all such "virtual" tags?  Or is the status
         # quo fine?
 
         alltags = {}                    # map tag name to (node, hist)
         tagtypes = {}
 
         tagsmod.findglobaltags(self.ui, self, alltags, tagtypes)
         tagsmod.readlocaltags(self.ui, self, alltags, tagtypes)
 
         # Build the return dicts.  Have to re-encode tag names because
         # the tags module always uses UTF-8 (in order not to lose info
         # writing to the cache), but the rest of Mercurial wants them in
         # local encoding.
         tags = {}
         for (name, (node, hist)) in alltags.iteritems():
             if node != nullid:
                 tags[encoding.tolocal(name)] = node
         tags['tip'] = self.changelog.tip()
         tagtypes = dict([(encoding.tolocal(name), value)
                          for (name, value) in tagtypes.iteritems()])
         return (tags, tagtypes)
 
     def tagtype(self, tagname):
         '''
         return the type of the given tag. result can be:
 
         'local'  : a local tag
         'global' : a global tag
         None     : tag does not exist
         '''
 
         return self._tagscache.tagtypes.get(tagname)
 
     def tagslist(self):
         '''return a list of tags ordered by revision'''
         if not self._tagscache.tagslist:
             l = []
             for t, n in self.tags().iteritems():
                 l.append((self.changelog.rev(n), t, n))
             self._tagscache.tagslist = [(t, n) for r, t, n in sorted(l)]
 
         return self._tagscache.tagslist
 
     def nodetags(self, node):
         '''return the tags associated with a node'''
         if not self._tagscache.nodetagscache:
             nodetagscache = {}
             for t, n in self._tagscache.tags.iteritems():
                 nodetagscache.setdefault(n, []).append(t)
             for tags in nodetagscache.itervalues():
                 tags.sort()
             self._tagscache.nodetagscache = nodetagscache
         return self._tagscache.nodetagscache.get(node, [])
 
     def nodebookmarks(self, node):
         marks = []
         for bookmark, n in self._bookmarks.iteritems():
             if n == node:
                 marks.append(bookmark)
         return sorted(marks)
 
     def branchmap(self):
         '''returns a dictionary {branch: [branchheads]} with branchheads
         ordered by increasing revision number'''
         branchmap.updatecache(self)
         return self._branchcaches[self.filtername]
 
     @unfilteredmethod
     def revbranchcache(self):
         if not self._revbranchcache:
             self._revbranchcache = branchmap.revbranchcache(self.unfiltered())
         return self._revbranchcache
 
     def branchtip(self, branch, ignoremissing=False):
         '''return the tip node for a given branch
 
         If ignoremissing is True, then this method will not raise an error.
         This is helpful for callers that only expect None for a missing branch
         (e.g. namespace).
 
         '''
         try:
             return self.branchmap().branchtip(branch)
         except KeyError:
             if not ignoremissing:
                 raise error.RepoLookupError(_("unknown branch '%s'") % branch)
             else:
                 pass
 
     def lookup(self, key):
         return self[key].node()
 
     def lookupbranch(self, key, remote=None):
         repo = remote or self
         if key in repo.branchmap():
             return key
 
         repo = (remote and remote.local()) and remote or self
         return repo[key].branch()
 
     def known(self, nodes):
         nm = self.changelog.nodemap
         pc = self._phasecache
         result = []
         for n in nodes:
             r = nm.get(n)
             resp = not (r is None or pc.phase(self, r) >= phases.secret)
             result.append(resp)
         return result
 
     def local(self):
         return self
 
     def publishing(self):
         # it's safe (and desirable) to trust the publish flag unconditionally
         # so that we don't finalize changes shared between users via ssh or nfs
         return self.ui.configbool('phases', 'publish', True, untrusted=True)
 
     def cancopy(self):
         # so statichttprepo's override of local() works
         if not self.local():
             return False
         if not self.publishing():
             return True
         # if publishing we can't copy if there is filtered content
         return not self.filtered('visible').changelog.filteredrevs
 
     def shared(self):
         '''the type of shared repository (None if not shared)'''
         if self.sharedpath != self.path:
             return 'store'
         return None
 
     def join(self, f, *insidef):
         return self.vfs.join(os.path.join(f, *insidef))
 
     def wjoin(self, f, *insidef):
         return self.vfs.reljoin(self.root, f, *insidef)
 
     def file(self, f):
         if f[0] == '/':
             f = f[1:]
         return filelog.filelog(self.svfs, f)
 
     def changectx(self, changeid):
         return self[changeid]
 
     def parents(self, changeid=None):
         '''get list of changectxs for parents of changeid'''
         return self[changeid].parents()
 
     def setparents(self, p1, p2=nullid):
         self.dirstate.beginparentchange()
         copies = self.dirstate.setparents(p1, p2)
         pctx = self[p1]
         if copies:
             # Adjust copy records, the dirstate cannot do it, it
             # requires access to parents manifests. Preserve them
             # only for entries added to first parent.
             for f in copies:
                 if f not in pctx and copies[f] in pctx:
                     self.dirstate.copy(copies[f], f)
         if p2 == nullid:
             for f, s in sorted(self.dirstate.copies().items()):
                 if f not in pctx and s not in pctx:
                     self.dirstate.copy(None, f)
         self.dirstate.endparentchange()
 
     def filectx(self, path, changeid=None, fileid=None):
         """changeid can be a changeset revision, node, or tag.
            fileid can be a file revision or node."""
         return context.filectx(self, path, changeid, fileid)
 
     def getcwd(self):
         return self.dirstate.getcwd()
 
     def pathto(self, f, cwd=None):
         return self.dirstate.pathto(f, cwd)
 
     def wfile(self, f, mode='r'):
         return self.wvfs(f, mode)
 
     def _link(self, f):
         return self.wvfs.islink(f)
 
     def _loadfilter(self, filter):
         if filter not in self.filterpats:
             l = []
             for pat, cmd in self.ui.configitems(filter):
                 if cmd == '!':
                     continue
                 mf = matchmod.match(self.root, '', [pat])
                 fn = None
                 params = cmd
                 for name, filterfn in self._datafilters.iteritems():
                     if cmd.startswith(name):
                         fn = filterfn
                         params = cmd[len(name):].lstrip()
                         break
                 if not fn:
                     fn = lambda s, c, **kwargs: util.filter(s, c)
                 # Wrap old filters not supporting keyword arguments
                 if not inspect.getargspec(fn)[2]:
                     oldfn = fn
                     fn = lambda s, c, **kwargs: oldfn(s, c)
                 l.append((mf, fn, params))
             self.filterpats[filter] = l
         return self.filterpats[filter]
 
     def _filter(self, filterpats, filename, data):
         for mf, fn, cmd in filterpats:
             if mf(filename):
                 self.ui.debug("filtering %s through %s\n" % (filename, cmd))
                 data = fn(data, cmd, ui=self.ui, repo=self, filename=filename)
                 break
 
         return data
 
     @unfilteredpropertycache
     def _encodefilterpats(self):
         return self._loadfilter('encode')
 
     @unfilteredpropertycache
     def _decodefilterpats(self):
         return self._loadfilter('decode')
 
     def adddatafilter(self, name, filter):
         self._datafilters[name] = filter
 
     def wread(self, filename):
         if self._link(filename):
             data = self.wvfs.readlink(filename)
         else:
             data = self.wvfs.read(filename)
         return self._filter(self._encodefilterpats, filename, data)
 
     def wwrite(self, filename, data, flags):
         """write ``data`` into ``filename`` in the working directory
 
         This returns length of written (maybe decoded) data.
         """
         data = self._filter(self._decodefilterpats, filename, data)
         if 'l' in flags:
             self.wvfs.symlink(data, filename)
         else:
             self.wvfs.write(filename, data)
             if 'x' in flags:
                 self.wvfs.setflags(filename, False, True)
         return len(data)
 
     def wwritedata(self, filename, data):
         return self._filter(self._decodefilterpats, filename, data)
 
     def currenttransaction(self):
         """return the current transaction or None if non exists"""
         if self._transref:
             tr = self._transref()
         else:
             tr = None
 
         if tr and tr.running():
             return tr
         return None
 
     def transaction(self, desc, report=None):
         if (self.ui.configbool('devel', 'all-warnings')
                 or self.ui.configbool('devel', 'check-locks')):
             l = self._lockref and self._lockref()
             if l is None or not l.held:
                 self.ui.develwarn('transaction with no lock')
         tr = self.currenttransaction()
         if tr is not None:
             return tr.nest()
 
         # abort here if the journal already exists
         if self.svfs.exists("journal"):
             raise error.RepoError(
                 _("abandoned transaction found"),
                 hint=_("run 'hg recover' to clean up transaction"))
 
         # make journal.dirstate contain in-memory changes at this point
         self.dirstate.write()
 
         idbase = "%.40f#%f" % (random.random(), time.time())
         txnid = 'TXN:' + util.sha1(idbase).hexdigest()
         self.hook('pretxnopen', throw=True, txnname=desc, txnid=txnid)
 
         self._writejournal(desc)
         renames = [(vfs, x, undoname(x)) for vfs, x in self._journalfiles()]
         if report:
             rp = report
         else:
             rp = self.ui.warn
         vfsmap = {'plain': self.vfs} # root of .hg/
         # we must avoid cyclic reference between repo and transaction.
         reporef = weakref.ref(self)
         def validate(tr):
             """will run pre-closing hooks"""
             pending = lambda: tr.writepending() and self.root or ""
             reporef().hook('pretxnclose', throw=True, pending=pending,
                            txnname=desc, **tr.hookargs)
+        def releasefn(tr, success):
+            repo = reporef()
+            if success:
+                repo.dirstate.write()
+            else:
+                # prevent in-memory changes from being written out at
+                # the end of outer wlock scope or so
+                repo.dirstate.invalidate()
+
+                # discard all changes (including ones already written
+                # out) in this transaction
+                repo.vfs.rename('journal.dirstate', 'dirstate')
 
         tr = transaction.transaction(rp, self.svfs, vfsmap,
                                      "journal",
                                      "undo",
                                      aftertrans(renames),
                                      self.store.createmode,
-                                     validator=validate)
+                                     validator=validate,
+                                     releasefn=releasefn)
 
         tr.hookargs['txnid'] = txnid
         # note: writing the fncache only during finalize mean that the file is
         # outdated when running hooks. As fncache is used for streaming clone,
         # this is not expected to break anything that happen during the hooks.
         tr.addfinalize('flush-fncache', self.store.write)
         def txnclosehook(tr2):
             """To be run if transaction is successful, will schedule a hook run
             """
             def hook():
                 reporef().hook('txnclose', throw=False, txnname=desc,
                                **tr2.hookargs)
             reporef()._afterlock(hook)
         tr.addfinalize('txnclose-hook', txnclosehook)
         def txnaborthook(tr2):
             """To be run if transaction is aborted
             """
             reporef().hook('txnabort', throw=False, txnname=desc,
                            **tr2.hookargs)
         tr.addabort('txnabort-hook', txnaborthook)
         # avoid eager cache invalidation. in-memory data should be identical
         # to stored data if transaction has no error.
         tr.addpostclose('refresh-filecachestats', self._refreshfilecachestats)
         self._transref = weakref.ref(tr)
         return tr
 
     def _journalfiles(self):
         return ((self.svfs, 'journal'),
                 (self.vfs, 'journal.dirstate'),
                 (self.vfs, 'journal.branch'),
                 (self.vfs, 'journal.desc'),
                 (self.vfs, 'journal.bookmarks'),
                 (self.svfs, 'journal.phaseroots'))
 
     def undofiles(self):
         return [(vfs, undoname(x)) for vfs, x in self._journalfiles()]
 
     def _writejournal(self, desc):
         self.vfs.write("journal.dirstate",
                           self.vfs.tryread("dirstate"))
         self.vfs.write("journal.branch",
                           encoding.fromlocal(self.dirstate.branch()))
         self.vfs.write("journal.desc",
                           "%d\n%s\n" % (len(self), desc))
         self.vfs.write("journal.bookmarks",
                           self.vfs.tryread("bookmarks"))
         self.svfs.write("journal.phaseroots",
                            self.svfs.tryread("phaseroots"))
 
     def recover(self):
         lock = self.lock()
         try:
             if self.svfs.exists("journal"):
                 self.ui.status(_("rolling back interrupted transaction\n"))
                 vfsmap = {'': self.svfs,
                           'plain': self.vfs,}
                 transaction.rollback(self.svfs, vfsmap, "journal",
                                      self.ui.warn)
                 self.invalidate()
                 return True
             else:
                 self.ui.warn(_("no interrupted transaction available\n"))
                 return False
         finally:
             lock.release()
 
     def rollback(self, dryrun=False, force=False):
         wlock = lock = None
         try:
             wlock = self.wlock()
             lock = self.lock()
             if self.svfs.exists("undo"):
                 return self._rollback(dryrun, force)
             else:
                 self.ui.warn(_("no rollback information available\n"))
                 return 1
         finally:
             release(lock, wlock)
 
     @unfilteredmethod # Until we get smarter cache management
     def _rollback(self, dryrun, force):
         ui = self.ui
         try:
             args = self.vfs.read('undo.desc').splitlines()
             (oldlen, desc, detail) = (int(args[0]), args[1], None)
             if len(args) >= 3:
                 detail = args[2]
             oldtip = oldlen - 1
 
             if detail and ui.verbose:
                 msg = (_('repository tip rolled back to revision %s'
                          ' (undo %s: %s)\n')
                        % (oldtip, desc, detail))
             else:
                 msg = (_('repository tip rolled back to revision %s'
                          ' (undo %s)\n')
                        % (oldtip, desc))
         except IOError:
             msg = _('rolling back unknown transaction\n')
             desc = None
 
         if not force and self['.'] != self['tip'] and desc == 'commit':
             raise util.Abort(
                 _('rollback of last commit while not checked out '
                   'may lose data'), hint=_('use -f to force'))
 
         ui.status(msg)
         if dryrun:
             return 0
 
         parents = self.dirstate.parents()
         self.destroying()
         vfsmap = {'plain': self.vfs, '': self.svfs}
         transaction.rollback(self.svfs, vfsmap, 'undo', ui.warn)
         if self.vfs.exists('undo.bookmarks'):
             self.vfs.rename('undo.bookmarks', 'bookmarks')
         if self.svfs.exists('undo.phaseroots'):
             self.svfs.rename('undo.phaseroots', 'phaseroots')
         self.invalidate()
 
         parentgone = (parents[0] not in self.changelog.nodemap or
                       parents[1] not in self.changelog.nodemap)
         if parentgone:
             self.vfs.rename('undo.dirstate', 'dirstate')
             try:
                 branch = self.vfs.read('undo.branch')
                 self.dirstate.setbranch(encoding.tolocal(branch))
             except IOError:
                 ui.warn(_('named branch could not be reset: '
                           'current branch is still \'%s\'\n')
                         % self.dirstate.branch())
 
             self.dirstate.invalidate()
             parents = tuple([p.rev() for p in self.parents()])
             if len(parents) > 1:
                 ui.status(_('working directory now based on '
                             'revisions %d and %d\n') % parents)
             else:
                 ui.status(_('working directory now based on '
                             'revision %d\n') % parents)
             ms = mergemod.mergestate(self)
             ms.reset(self['.'].node())
 
         # TODO: if we know which new heads may result from this rollback, pass
         # them to destroy(), which will prevent the branchhead cache from being
         # invalidated.
         self.destroyed()
         return 0
 
     def invalidatecaches(self):
 
         if '_tagscache' in vars(self):
             # can't use delattr on proxy
             del self.__dict__['_tagscache']
 
         self.unfiltered()._branchcaches.clear()
         self.invalidatevolatilesets()
 
     def invalidatevolatilesets(self):
         self.filteredrevcache.clear()
         obsolete.clearobscaches(self)
 
     def invalidatedirstate(self):
         '''Invalidates the dirstate, causing the next call to dirstate
         to check if it was modified since the last time it was read,
         rereading it if it has.
 
         This is different to dirstate.invalidate() that it doesn't always
         rereads the dirstate. Use dirstate.invalidate() if you want to
         explicitly read the dirstate again (i.e. restoring it to a previous
         known good state).'''
         if hasunfilteredcache(self, 'dirstate'):
             for k in self.dirstate._filecache:
                 try:
                     delattr(self.dirstate, k)
                 except AttributeError:
                     pass
             delattr(self.unfiltered(), 'dirstate')
 
     def invalidate(self):
         unfiltered = self.unfiltered() # all file caches are stored unfiltered
         for k in self._filecache:
             # dirstate is invalidated separately in invalidatedirstate()
             if k == 'dirstate':
                 continue
 
             try:
                 delattr(unfiltered, k)
             except AttributeError:
                 pass
         self.invalidatecaches()
         self.store.invalidatecaches()
 
     def invalidateall(self):
         '''Fully invalidates both store and non-store parts, causing the
         subsequent operation to reread any outside changes.'''
         # extension should hook this to invalidate its caches
         self.invalidate()
         self.invalidatedirstate()
 
     def _refreshfilecachestats(self, tr):
         """Reload stats of cached files so that they are flagged as valid"""
         for k, ce in self._filecache.items():
             if k == 'dirstate' or k not in self.__dict__:
                 continue
             ce.refresh()
 
     def _lock(self, vfs, lockname, wait, releasefn, acquirefn, desc,
               inheritchecker=None, parentenvvar=None):
         parentlock = None
         # the contents of parentenvvar are used by the underlying lock to
         # determine whether it can be inherited
         if parentenvvar is not None:
             parentlock = os.environ.get(parentenvvar)
         try:
             l = lockmod.lock(vfs, lockname, 0, releasefn=releasefn,
                              acquirefn=acquirefn, desc=desc,
                              inheritchecker=inheritchecker,
                              parentlock=parentlock)
         except error.LockHeld as inst:
             if not wait:
                 raise
             self.ui.warn(_("waiting for lock on %s held by %r\n") %
                          (desc, inst.locker))
             # default to 600 seconds timeout
             l = lockmod.lock(vfs, lockname,
                              int(self.ui.config("ui", "timeout", "600")),
                              releasefn=releasefn, acquirefn=acquirefn,
                              desc=desc)
             self.ui.warn(_("got lock after %s seconds\n") % l.delay)
         return l
 
     def _afterlock(self, callback):
         """add a callback to be run when the repository is fully unlocked
 
         The callback will be executed when the outermost lock is released
         (with wlock being higher level than 'lock')."""
         for ref in (self._wlockref, self._lockref):
             l = ref and ref()
             if l and l.held:
                 l.postrelease.append(callback)
                 break
         else: # no lock have been found.
             callback()
 
     def lock(self, wait=True):
         '''Lock the repository store (.hg/store) and return a weak reference
         to the lock. Use this before modifying the store (e.g. committing or
         stripping). If you are opening a transaction, get a lock as well.)
 
         If both 'lock' and 'wlock' must be acquired, ensure you always acquires
         'wlock' first to avoid a dead-lock hazard.'''
         l = self._lockref and self._lockref()
         if l is not None and l.held:
             l.lock()
             return l
 
         l = self._lock(self.svfs, "lock", wait, None,
                        self.invalidate, _('repository %s') % self.origroot)
         self._lockref = weakref.ref(l)
         return l
 
     def _wlockchecktransaction(self):
         if self.currenttransaction() is not None:
             raise error.LockInheritanceContractViolation(
                 'wlock cannot be inherited in the middle of a transaction')
 
     def wlock(self, wait=True):
         '''Lock the non-store parts of the repository (everything under
         .hg except .hg/store) and return a weak reference to the lock.
 
         Use this before modifying files in .hg.
 
         If both 'lock' and 'wlock' must be acquired, ensure you always acquires
         'wlock' first to avoid a dead-lock hazard.'''
         l = self._wlockref and self._wlockref()
         if l is not None and l.held:
             l.lock()
             return l
 
         # We do not need to check for non-waiting lock aquisition.  Such
         # acquisition would not cause dead-lock as they would just fail.
         if wait and (self.ui.configbool('devel', 'all-warnings')
                      or self.ui.configbool('devel', 'check-locks')):
             l = self._lockref and self._lockref()
             if l is not None and l.held:
                 self.ui.develwarn('"wlock" acquired after "lock"')
 
         def unlock():
             if self.dirstate.pendingparentchange():
                 self.dirstate.invalidate()
             else:
                 self.dirstate.write()
 
             self._filecache['dirstate'].refresh()
 
         l = self._lock(self.vfs, "wlock", wait, unlock,
                        self.invalidatedirstate, _('working directory of %s') %
                        self.origroot,
                        inheritchecker=self._wlockchecktransaction,
                        parentenvvar='HG_WLOCK_LOCKER')
         self._wlockref = weakref.ref(l)
         return l
 
     def _currentlock(self, lockref):
         """Returns the lock if it's held, or None if it's not."""
         if lockref is None:
             return None
         l = lockref()
         if l is None or not l.held:
             return None
         return l
 
     def currentwlock(self):
         """Returns the wlock if it's held, or None if it's not."""
         return self._currentlock(self._wlockref)
 
     def _filecommit(self, fctx, manifest1, manifest2, linkrev, tr, changelist):
         """
         commit an individual file as part of a larger transaction
         """
 
         fname = fctx.path()
         fparent1 = manifest1.get(fname, nullid)
         fparent2 = manifest2.get(fname, nullid)
         if isinstance(fctx, context.filectx):
             node = fctx.filenode()
             if node in [fparent1, fparent2]:
                 self.ui.debug('reusing %s filelog entry\n' % fname)
                 return node
 
         flog = self.file(fname)
         meta = {}
         copy = fctx.renamed()
         if copy and copy[0] != fname:
             # Mark the new revision of this file as a copy of another
             # file.  This copy data will effectively act as a parent
             # of this new revision.  If this is a merge, the first
             # parent will be the nullid (meaning "look up the copy data")
             # and the second one will be the other parent.  For example:
             #
             # 0 --- 1 --- 3   rev1 changes file foo
             #   \       /     rev2 renames foo to bar and changes it
             #    \- 2 -/      rev3 should have bar with all changes and
             #                      should record that bar descends from
             #                      bar in rev2 and foo in rev1
             #
             # this allows this merge to succeed:
             #
             # 0 --- 1 --- 3   rev4 reverts the content change from rev2
             #   \       /     merging rev3 and rev4 should use bar@rev2
             #    \- 2 --- 4        as the merge base
             #
 
             cfname = copy[0]
             crev = manifest1.get(cfname)
             newfparent = fparent2
 
             if manifest2: # branch merge
                 if fparent2 == nullid or crev is None: # copied on remote side
                     if cfname in manifest2:
                         crev = manifest2[cfname]
                         newfparent = fparent1
 
             # Here, we used to search backwards through history to try to find
             # where the file copy came from if the source of a copy was not in
             # the parent directory. However, this doesn't actually make sense to
             # do (what does a copy from something not in your working copy even
             # mean?) and it causes bugs (eg, issue4476). Instead, we will warn
             # the user that copy information was dropped, so if they didn't
             # expect this outcome it can be fixed, but this is the correct
             # behavior in this circumstance.
 
             if crev:
                 self.ui.debug(" %s: copy %s:%s\n" % (fname, cfname, hex(crev)))
                 meta["copy"] = cfname
                 meta["copyrev"] = hex(crev)
                 fparent1, fparent2 = nullid, newfparent
             else:
                 self.ui.warn(_("warning: can't find ancestor for '%s' "
                                "copied from '%s'!\n") % (fname, cfname))
 
         elif fparent1 == nullid:
             fparent1, fparent2 = fparent2, nullid
         elif fparent2 != nullid:
             # is one parent an ancestor of the other?
             fparentancestors = flog.commonancestorsheads(fparent1, fparent2)
             if fparent1 in fparentancestors:
                 fparent1, fparent2 = fparent2, nullid
             elif fparent2 in fparentancestors:
                 fparent2 = nullid
 
         # is the file changed?
         text = fctx.data()
         if fparent2 != nullid or flog.cmp(fparent1, text) or meta:
             changelist.append(fname)
             return flog.add(text, meta, tr, linkrev, fparent1, fparent2)
         # are just the flags changed during merge?
         elif fname in manifest1 and manifest1.flags(fname) != fctx.flags():
             changelist.append(fname)
 
         return fparent1
 
     @unfilteredmethod
     def commit(self, text="", user=None, date=None, match=None, force=False,
                editor=False, extra=None):
         """Add a new revision to current repository.
 
         Revision information is gathered from the working directory,
         match can be used to filter the committed files. If editor is
         supplied, it is called to get a commit message.
         """
         if extra is None:
             extra = {}
 
         def fail(f, msg):
             raise util.Abort('%s: %s' % (f, msg))
 
         if not match:
             match = matchmod.always(self.root, '')
 
         if not force:
             vdirs = []
             match.explicitdir = vdirs.append
             match.bad = fail
 
         wlock = self.wlock()
         try:
             wctx = self[None]
             merge = len(wctx.parents()) > 1
 
             if not force and merge and match.ispartial():
                 raise util.Abort(_('cannot partially commit a merge '
                                    '(do not specify files or patterns)'))
 
             status = self.status(match=match, clean=force)
             if force:
                 status.modified.extend(status.clean) # mq may commit clean files
 
             # check subrepos
             subs = []
             commitsubs = set()
             newstate = wctx.substate.copy()
             # only manage subrepos and .hgsubstate if .hgsub is present
             if '.hgsub' in wctx:
                 # we'll decide whether to track this ourselves, thanks
                 for c in status.modified, status.added, status.removed:
                     if '.hgsubstate' in c:
                         c.remove('.hgsubstate')
 
                 # compare current state to last committed state
                 # build new substate based on last committed state
                 oldstate = wctx.p1().substate
                 for s in sorted(newstate.keys()):
                     if not match(s):
                         # ignore working copy, use old state if present
                         if s in oldstate:
                             newstate[s] = oldstate[s]
                             continue
                         if not force:
                             raise util.Abort(
                                 _("commit with new subrepo %s excluded") % s)
                     dirtyreason = wctx.sub(s).dirtyreason(True)
                     if dirtyreason:
                         if not self.ui.configbool('ui', 'commitsubrepos'):
                             raise util.Abort(dirtyreason,
                                 hint=_("use --subrepos for recursive commit"))
                         subs.append(s)
                         commitsubs.add(s)
                     else:
                         bs = wctx.sub(s).basestate()
                         newstate[s] = (newstate[s][0], bs, newstate[s][2])
                         if oldstate.get(s, (None, None, None))[1] != bs:
                             subs.append(s)
 
                 # check for removed subrepos
                 for p in wctx.parents():
                     r = [s for s in p.substate if s not in newstate]
                     subs += [s for s in r if match(s)]
                 if subs:
                     if (not match('.hgsub') and
                         '.hgsub' in (wctx.modified() + wctx.added())):
                         raise util.Abort(
                             _("can't commit subrepos without .hgsub"))
                     status.modified.insert(0, '.hgsubstate')
 
             elif '.hgsub' in status.removed:
                 # clean up .hgsubstate when .hgsub is removed
                 if ('.hgsubstate' in wctx and
                     '.hgsubstate' not in (status.modified + status.added +
                                           status.removed)):
                     status.removed.insert(0, '.hgsubstate')
 
             # make sure all explicit patterns are matched
             if not force and (match.isexact() or match.prefix()):
                 matched = set(status.modified + status.added + status.removed)
 
                 for f in match.files():
                     f = self.dirstate.normalize(f)
                     if f == '.' or f in matched or f in wctx.substate:
                         continue
                     if f in status.deleted:
                         fail(f, _('file not found!'))
                     if f in vdirs: # visited directory
                         d = f + '/'
                         for mf in matched:
                             if mf.startswith(d):
                                 break
                         else:
                             fail(f, _("no match under directory!"))
                     elif f not in self.dirstate:
                         fail(f, _("file not tracked!"))
 
             cctx = context.workingcommitctx(self, status,
                                             text, user, date, extra)
 
             # internal config: ui.allowemptycommit
             allowemptycommit = (wctx.branch() != wctx.p1().branch()
                                 or extra.get('close') or merge or cctx.files()
                                 or self.ui.configbool('ui', 'allowemptycommit'))
             if not allowemptycommit:
                 return None
 
             if merge and cctx.deleted():
                 raise util.Abort(_("cannot commit merge with missing files"))
 
             ms = mergemod.mergestate(self)
             for f in status.modified:
                 if f in ms and ms[f] == 'u':
                     raise util.Abort(_('unresolved merge conflicts '
                                        '(see "hg help resolve")'))
 
             if editor:
                 cctx._text = editor(self, cctx, subs)
             edited = (text != cctx._text)
 
             # Save commit message in case this transaction gets rolled back
             # (e.g. by a pretxncommit hook).  Leave the content alone on
             # the assumption that the user will use the same editor again.
             msgfn = self.savecommitmessage(cctx._text)
 
             # commit subs and write new state
             if subs:
                 for s in sorted(commitsubs):
                     sub = wctx.sub(s)
                     self.ui.status(_('committing subrepository %s\n') %
                         subrepo.subrelpath(sub))
                     sr = sub.commit(cctx._text, user, date)
                     newstate[s] = (newstate[s][0], sr)
                 subrepo.writestate(self, newstate)
 
             p1, p2 = self.dirstate.parents()
             hookp1, hookp2 = hex(p1), (p2 != nullid and hex(p2) or '')
             try:
                 self.hook("precommit", throw=True, parent1=hookp1,
                           parent2=hookp2)
                 ret = self.commitctx(cctx, True)
             except: # re-raises
                 if edited:
                     self.ui.write(
                         _('note: commit message saved in %s\n') % msgfn)
                 raise
 
             # update bookmarks, dirstate and mergestate
             bookmarks.update(self, [p1, p2], ret)
             cctx.markcommitted(ret)
             ms.reset()
         finally:
             wlock.release()
 
         def commithook(node=hex(ret), parent1=hookp1, parent2=hookp2):
             # hack for command that use a temporary commit (eg: histedit)
             # temporary commit got stripped before hook release
             if self.changelog.hasnode(ret):
                 self.hook("commit", node=node, parent1=parent1,
                           parent2=parent2)
         self._afterlock(commithook)
         return ret
 
     @unfilteredmethod
     def commitctx(self, ctx, error=False):
         """Add a new revision to current repository.
         Revision information is passed via the context argument.
         """
 
         tr = None
         p1, p2 = ctx.p1(), ctx.p2()
         user = ctx.user()
 
         lock = self.lock()
         try:
             tr = self.transaction("commit")
             trp = weakref.proxy(tr)
 
             if ctx.files():
                 m1 = p1.manifest()
                 m2 = p2.manifest()
                 m = m1.copy()
 
                 # check in files
                 added = []
                 changed = []
                 removed = list(ctx.removed())
                 linkrev = len(self)
                 self.ui.note(_("committing files:\n"))
                 for f in sorted(ctx.modified() + ctx.added()):
                     self.ui.note(f + "\n")
                     try:
                         fctx = ctx[f]
                         if fctx is None:
                             removed.append(f)
                         else:
                             added.append(f)
                             m[f] = self._filecommit(fctx, m1, m2, linkrev,
                                                     trp, changed)
                             m.setflag(f, fctx.flags())
                     except OSError as inst:
                         self.ui.warn(_("trouble committing %s!\n") % f)
                         raise
                     except IOError as inst:
                         errcode = getattr(inst, 'errno', errno.ENOENT)
                         if error or errcode and errcode != errno.ENOENT:
                             self.ui.warn(_("trouble committing %s!\n") % f)
                         raise
 
                 # update manifest
                 self.ui.note(_("committing manifest\n"))
                 removed = [f for f in sorted(removed) if f in m1 or f in m2]
                 drop = [f for f in removed if f in m]
                 for f in drop:
                     del m[f]
                 mn = self.manifest.add(m, trp, linkrev,
                                        p1.manifestnode(), p2.manifestnode(),
                                        added, drop)
                 files = changed + removed
             else:
                 mn = p1.manifestnode()
                 files = []
 
             # update changelog
             self.ui.note(_("committing changelog\n"))
             self.changelog.delayupdate(tr)
             n = self.changelog.add(mn, files, ctx.description(),
                                    trp, p1.node(), p2.node(),
                                    user, ctx.date(), ctx.extra().copy())
             p = lambda: tr.writepending() and self.root or ""
             xp1, xp2 = p1.hex(), p2 and p2.hex() or ''
             self.hook('pretxncommit', throw=True, node=hex(n), parent1=xp1,
                       parent2=xp2, pending=p)
             # set the new commit is proper phase
             targetphase = subrepo.newcommitphase(self.ui, ctx)
             if targetphase:
                 # retract boundary do not alter parent changeset.
                 # if a parent have higher the resulting phase will
                 # be compliant anyway
                 #
                 # if minimal phase was 0 we don't need to retract anything
                 phases.retractboundary(self, tr, targetphase, [n])
             tr.close()
             branchmap.updatecache(self.filtered('served'))
             return n
         finally:
             if tr:
                 tr.release()
             lock.release()
 
     @unfilteredmethod
     def destroying(self):
         '''Inform the repository that nodes are about to be destroyed.
         Intended for use by strip and rollback, so there's a common
         place for anything that has to be done before destroying history.
 
         This is mostly useful for saving state that is in memory and waiting
         to be flushed when the current lock is released. Because a call to
         destroyed is imminent, the repo will be invalidated causing those
         changes to stay in memory (waiting for the next unlock), or vanish
         completely.
         '''
         # When using the same lock to commit and strip, the phasecache is left
         # dirty after committing. Then when we strip, the repo is invalidated,
         # causing those changes to disappear.
         if '_phasecache' in vars(self):
             self._phasecache.write()
 
     @unfilteredmethod
     def destroyed(self):
         '''Inform the repository that nodes have been destroyed.
         Intended for use by strip and rollback, so there's a common
         place for anything that has to be done after destroying history.
         '''
         # When one tries to:
         # 1) destroy nodes thus calling this method (e.g. strip)
         # 2) use phasecache somewhere (e.g. commit)
         #
         # then 2) will fail because the phasecache contains nodes that were
         # removed. We can either remove phasecache from the filecache,
         # causing it to reload next time it is accessed, or simply filter
         # the removed nodes now and write the updated cache.
         self._phasecache.filterunknown(self)
         self._phasecache.write()
 
         # update the 'served' branch cache to help read only server process
         # Thanks to branchcache collaboration this is done from the nearest
         # filtered subset and it is expected to be fast.
         branchmap.updatecache(self.filtered('served'))
 
         # Ensure the persistent tag cache is updated.  Doing it now
         # means that the tag cache only has to worry about destroyed
         # heads immediately after a strip/rollback.  That in turn
         # guarantees that "cachetip == currenttip" (comparing both rev
         # and node) always means no nodes have been added or destroyed.
 
         # XXX this is suboptimal when qrefresh'ing: we strip the current
         # head, refresh the tag cache, then immediately add a new head.
         # But I think doing it this way is necessary for the "instant
         # tag cache retrieval" case to work.
         self.invalidate()
 
     def walk(self, match, node=None):
         '''
         walk recursively through the directory tree or a given
         changeset, finding all files matched by the match
         function
         '''
         return self[node].walk(match)
 
     def status(self, node1='.', node2=None, match=None,
                ignored=False, clean=False, unknown=False,
                listsubrepos=False):
         '''a convenience method that calls node1.status(node2)'''
         return self[node1].status(node2, match, ignored, clean, unknown,
                                   listsubrepos)
 
     def heads(self, start=None):
         heads = self.changelog.heads(start)
         # sort the output in rev descending order
         return sorted(heads, key=self.changelog.rev, reverse=True)
 
     def branchheads(self, branch=None, start=None, closed=False):
         '''return a (possibly filtered) list of heads for the given branch
 
         Heads are returned in topological order, from newest to oldest.
         If branch is None, use the dirstate branch.
         If start is not None, return only heads reachable from start.
         If closed is True, return heads that are marked as closed as well.
         '''
         if branch is None:
             branch = self[None].branch()
         branches = self.branchmap()
         if branch not in branches:
             return []
         # the cache returns heads ordered lowest to highest
         bheads = list(reversed(branches.branchheads(branch, closed=closed)))
         if start is not None:
             # filter out the heads that cannot be reached from startrev
             fbheads = set(self.changelog.nodesbetween([start], bheads)[2])
             bheads = [h for h in bheads if h in fbheads]
         return bheads
 
     def branches(self, nodes):
         if not nodes:
             nodes = [self.changelog.tip()]
         b = []
         for n in nodes:
             t = n
             while True:
                 p = self.changelog.parents(n)
                 if p[1] != nullid or p[0] == nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
         return b
 
     def between(self, pairs):
         r = []
 
         for top, bottom in pairs:
             n, l, i = top, [], 0
             f = 1
 
             while n != bottom and n != nullid:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
                     f = f * 2
                 n = p
                 i += 1
 
             r.append(l)
 
         return r
 
     def checkpush(self, pushop):
         """Extensions can override this function if additional checks have
         to be performed before pushing, or call it if they override push
         command.
         """
         pass
 
     @unfilteredpropertycache
     def prepushoutgoinghooks(self):
         """Return util.hooks consists of "(repo, remote, outgoing)"
         functions, which are called before pushing changesets.
         """
         return util.hooks()
 
     def clone(self, remote, heads=[], stream=None):
         '''clone remote repository.
 
         keyword arguments:
         heads: list of revs to clone (forces use of pull)
         stream: use streaming clone if possible'''
         # internal config: ui.quietbookmarkmove
         quiet = self.ui.backupconfig('ui', 'quietbookmarkmove')
         try:
             self.ui.setconfig('ui', 'quietbookmarkmove', True, 'clone')
             pullop = exchange.pull(self, remote, heads,
                                    streamclonerequested=stream)
             return pullop.cgresult
         finally:
             self.ui.restoreconfig(quiet)
 
     def pushkey(self, namespace, key, old, new):
         try:
             tr = self.currenttransaction()
             hookargs = {}
             if tr is not None:
                 hookargs.update(tr.hookargs)
                 pending = lambda: tr.writepending() and self.root or ""
                 hookargs['pending'] = pending
             hookargs['namespace'] = namespace
             hookargs['key'] = key
             hookargs['old'] = old
             hookargs['new'] = new
             self.hook('prepushkey', throw=True, **hookargs)
         except error.HookAbort as exc:
             self.ui.write_err(_("pushkey-abort: %s\n") % exc)
             if exc.hint:
                 self.ui.write_err(_("(%s)\n") % exc.hint)
             return False
         self.ui.debug('pushing key for "%s:%s"\n' % (namespace, key))
         ret = pushkey.push(self, namespace, key, old, new)
         def runhook():
             self.hook('pushkey', namespace=namespace, key=key, old=old, new=new,
                       ret=ret)
         self._afterlock(runhook)
         return ret
 
     def listkeys(self, namespace):
         self.hook('prelistkeys', throw=True, namespace=namespace)
         self.ui.debug('listing keys for "%s"\n' % namespace)
         values = pushkey.list(self, namespace)
         self.hook('listkeys', namespace=namespace, values=values)
         return values
 
     def debugwireargs(self, one, two, three=None, four=None, five=None):
         '''used to test argument passing over the wire'''
         return "%s %s %s %s %s" % (one, two, three, four, five)
 
     def savecommitmessage(self, text):
         fp = self.vfs('last-message.txt', 'wb')
         try:
             fp.write(text)
         finally:
             fp.close()
         return self.pathto(fp.name[len(self.root) + 1:])
 
 # used to avoid circular references so destructors work
 def aftertrans(files):
     renamefiles = [tuple(t) for t in files]
     def a():
         for vfs, src, dest in renamefiles:
             try:
                 vfs.rename(src, dest)
             except OSError: # journal file does not yet exist
                 pass
     return a
 
 def undoname(fn):
     base, name = os.path.split(fn)
     assert name.startswith('journal')
     return os.path.join(base, name.replace('journal', 'undo', 1))
 
 def instance(ui, path, create):
     return localrepository(ui, util.urllocalpath(path), create)
 
 def islocal(path):
     return True