obsutil: move 'foreground' to the new modules

We have a new 'obsutil' module now. We move the high level utility there to
bring 'obsolete.py' back to a more reasonable size.

mercurial/bookmarks.py

@@ -1,807 +1,807
 # Mercurial bookmark support code
 #
 # Copyright 2008 David Soria Parra <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     short,
 )
 from . import (
     encoding,
     error,
     lock as lockmod,
-    obsolete,
+    obsutil,
     pycompat,
     scmutil,
     txnutil,
     util,
 )
 
 # label constants
 # until 3.5, bookmarks.current was the advertised name, not
 # bookmarks.active, so we must use both to avoid breaking old
 # custom styles
 activebookmarklabel = 'bookmarks.active bookmarks.current'
 
 def _getbkfile(repo):
     """Hook so that extensions that mess with the store can hook bm storage.
 
     For core, this just handles wether we should see pending
     bookmarks or the committed ones. Other extensions (like share)
     may need to tweak this behavior further.
     """
     fp, pending = txnutil.trypending(repo.root, repo.vfs, 'bookmarks')
     return fp
 
 class bmstore(dict):
     """Storage for bookmarks.
 
     This object should do all bookmark-related reads and writes, so
     that it's fairly simple to replace the storage underlying
     bookmarks without having to clone the logic surrounding
     bookmarks. This type also should manage the active bookmark, if
     any.
 
     This particular bmstore implementation stores bookmarks as
     {hash}\s{name}\n (the same format as localtags) in
     .hg/bookmarks. The mapping is stored as {name: nodeid}.
     """
 
     def __init__(self, repo):
         dict.__init__(self)
         self._repo = repo
         self._clean = True
         self._aclean = True
         nm = repo.changelog.nodemap
         tonode = bin # force local lookup
         setitem = dict.__setitem__
         try:
             with _getbkfile(repo) as bkfile:
                 for line in bkfile:
                     line = line.strip()
                     if not line:
                         continue
                     try:
                         sha, refspec = line.split(' ', 1)
                         node = tonode(sha)
                         if node in nm:
                             refspec = encoding.tolocal(refspec)
                             setitem(self, refspec, node)
                     except (TypeError, ValueError):
                         # TypeError:
                         # - bin(...)
                         # ValueError:
                         # - node in nm, for non-20-bytes entry
                         # - split(...), for string without ' '
                         repo.ui.warn(_('malformed line in .hg/bookmarks: %r\n')
                                      % line)
         except IOError as inst:
             if inst.errno != errno.ENOENT:
                 raise
         self._active = _readactive(repo, self)
 
     @property
     def active(self):
         return self._active
 
     @active.setter
     def active(self, mark):
         if mark is not None and mark not in self:
             raise AssertionError('bookmark %s does not exist!' % mark)
 
         self._active = mark
         self._aclean = False
 
     def __setitem__(self, *args, **kwargs):
         self._clean = False
         return dict.__setitem__(self, *args, **kwargs)
 
     def __delitem__(self, key):
         self._clean = False
         return dict.__delitem__(self, key)
 
     def recordchange(self, tr):
         """record that bookmarks have been changed in a transaction
 
         The transaction is then responsible for updating the file content."""
         tr.addfilegenerator('bookmarks', ('bookmarks',), self._write,
                             location='plain')
         tr.hookargs['bookmark_moved'] = '1'
 
     def _writerepo(self, repo):
         """Factored out for extensibility"""
         rbm = repo._bookmarks
         if rbm.active not in self:
             rbm.active = None
             rbm._writeactive()
 
         with repo.wlock():
             file_ = repo.vfs('bookmarks', 'w', atomictemp=True,
                              checkambig=True)
             try:
                 self._write(file_)
             except: # re-raises
                 file_.discard()
                 raise
             finally:
                 file_.close()
 
     def _writeactive(self):
         if self._aclean:
             return
         with self._repo.wlock():
             if self._active is not None:
                 f = self._repo.vfs('bookmarks.current', 'w', atomictemp=True,
                                    checkambig=True)
                 try:
                     f.write(encoding.fromlocal(self._active))
                 finally:
                     f.close()
             else:
                 self._repo.vfs.tryunlink('bookmarks.current')
         self._aclean = True
 
     def _write(self, fp):
         for name, node in self.iteritems():
             fp.write("%s %s\n" % (hex(node), encoding.fromlocal(name)))
         self._clean = True
         self._repo.invalidatevolatilesets()
 
     def expandname(self, bname):
         if bname == '.':
             if self.active:
                 return self.active
             else:
                 raise error.Abort(_("no active bookmark"))
         return bname
 
     def checkconflict(self, mark, force=False, target=None):
         """check repo for a potential clash of mark with an existing bookmark,
         branch, or hash
 
         If target is supplied, then check that we are moving the bookmark
         forward.
 
         If force is supplied, then forcibly move the bookmark to a new commit
         regardless if it is a move forward.
         """
         cur = self._repo.changectx('.').node()
         if mark in self and not force:
             if target:
                 if self[mark] == target and target == cur:
                     # re-activating a bookmark
                     return
                 rev = self._repo[target].rev()
                 anc = self._repo.changelog.ancestors([rev])
                 bmctx = self._repo[self[mark]]
                 divs = [self._repo[b].node() for b in self
                         if b.split('@', 1)[0] == mark.split('@', 1)[0]]
 
                 # allow resolving a single divergent bookmark even if moving
                 # the bookmark across branches when a revision is specified
                 # that contains a divergent bookmark
                 if bmctx.rev() not in anc and target in divs:
                     deletedivergent(self._repo, [target], mark)
                     return
 
                 deletefrom = [b for b in divs
                               if self._repo[b].rev() in anc or b == target]
                 deletedivergent(self._repo, deletefrom, mark)
                 if validdest(self._repo, bmctx, self._repo[target]):
                     self._repo.ui.status(
                         _("moving bookmark '%s' forward from %s\n") %
                         (mark, short(bmctx.node())))
                     return
             raise error.Abort(_("bookmark '%s' already exists "
                                 "(use -f to force)") % mark)
         if ((mark in self._repo.branchmap() or
              mark == self._repo.dirstate.branch()) and not force):
             raise error.Abort(
                 _("a bookmark cannot have the name of an existing branch"))
         if len(mark) > 3 and not force:
             try:
                 shadowhash = (mark in self._repo)
             except error.LookupError:  # ambiguous identifier
                 shadowhash = False
             if shadowhash:
                 self._repo.ui.warn(
                     _("bookmark %s matches a changeset hash\n"
                       "(did you leave a -r out of an 'hg bookmark' "
                       "command?)\n")
                     % mark)
 
 def _readactive(repo, marks):
     """
     Get the active bookmark. We can have an active bookmark that updates
     itself as we commit. This function returns the name of that bookmark.
     It is stored in .hg/bookmarks.current
     """
     mark = None
     try:
         file = repo.vfs('bookmarks.current')
     except IOError as inst:
         if inst.errno != errno.ENOENT:
             raise
         return None
     try:
         # No readline() in osutil.posixfile, reading everything is
         # cheap.
         # Note that it's possible for readlines() here to raise
         # IOError, since we might be reading the active mark over
         # static-http which only tries to load the file when we try
         # to read from it.
         mark = encoding.tolocal((file.readlines() or [''])[0])
         if mark == '' or mark not in marks:
             mark = None
     except IOError as inst:
         if inst.errno != errno.ENOENT:
             raise
         return None
     finally:
         file.close()
     return mark
 
 def activate(repo, mark):
     """
     Set the given bookmark to be 'active', meaning that this bookmark will
     follow new commits that are made.
     The name is recorded in .hg/bookmarks.current
     """
     repo._bookmarks.active = mark
     repo._bookmarks._writeactive()
 
 def deactivate(repo):
     """
     Unset the active bookmark in this repository.
     """
     repo._bookmarks.active = None
     repo._bookmarks._writeactive()
 
 def isactivewdirparent(repo):
     """
     Tell whether the 'active' bookmark (the one that follows new commits)
     points to one of the parents of the current working directory (wdir).
 
     While this is normally the case, it can on occasion be false; for example,
     immediately after a pull, the active bookmark can be moved to point
     to a place different than the wdir. This is solved by running `hg update`.
     """
     mark = repo._activebookmark
     marks = repo._bookmarks
     parents = [p.node() for p in repo[None].parents()]
     return (mark in marks and marks[mark] in parents)
 
 def deletedivergent(repo, deletefrom, bm):
     '''Delete divergent versions of bm on nodes in deletefrom.
 
     Return True if at least one bookmark was deleted, False otherwise.'''
     deleted = False
     marks = repo._bookmarks
     divergent = [b for b in marks if b.split('@', 1)[0] == bm.split('@', 1)[0]]
     for mark in divergent:
         if mark == '@' or '@' not in mark:
             # can't be divergent by definition
             continue
         if mark and marks[mark] in deletefrom:
             if mark != bm:
                 del marks[mark]
                 deleted = True
     return deleted
 
 def headsforactive(repo):
     """Given a repo with an active bookmark, return divergent bookmark nodes.
 
     Args:
       repo: A repository with an active bookmark.
 
     Returns:
       A list of binary node ids that is the full list of other
       revisions with bookmarks divergent from the active bookmark. If
       there were no divergent bookmarks, then this list will contain
       only one entry.
     """
     if not repo._activebookmark:
         raise ValueError(
             'headsforactive() only makes sense with an active bookmark')
     name = repo._activebookmark.split('@', 1)[0]
     heads = []
     for mark, n in repo._bookmarks.iteritems():
         if mark.split('@', 1)[0] == name:
             heads.append(n)
     return heads
 
 def calculateupdate(ui, repo, checkout):
     '''Return a tuple (targetrev, movemarkfrom) indicating the rev to
     check out and where to move the active bookmark from, if needed.'''
     movemarkfrom = None
     if checkout is None:
         activemark = repo._activebookmark
         if isactivewdirparent(repo):
             movemarkfrom = repo['.'].node()
         elif activemark:
             ui.status(_("updating to active bookmark %s\n") % activemark)
             checkout = activemark
     return (checkout, movemarkfrom)
 
 def update(repo, parents, node):
     deletefrom = parents
     marks = repo._bookmarks
     update = False
     active = marks.active
     if not active:
         return False
 
     if marks[active] in parents:
         new = repo[node]
         divs = [repo[b] for b in marks
                 if b.split('@', 1)[0] == active.split('@', 1)[0]]
         anc = repo.changelog.ancestors([new.rev()])
         deletefrom = [b.node() for b in divs if b.rev() in anc or b == new]
         if validdest(repo, repo[marks[active]], new):
             marks[active] = new.node()
             update = True
 
     if deletedivergent(repo, deletefrom, active):
         update = True
 
     if update:
         lock = tr = None
         try:
             lock = repo.lock()
             tr = repo.transaction('bookmark')
             marks.recordchange(tr)
             tr.close()
         finally:
             lockmod.release(tr, lock)
     return update
 
 def listbinbookmarks(repo):
     # We may try to list bookmarks on a repo type that does not
     # support it (e.g., statichttprepository).
     marks = getattr(repo, '_bookmarks', {})
 
     hasnode = repo.changelog.hasnode
     for k, v in marks.iteritems():
         # don't expose local divergent bookmarks
         if hasnode(v) and ('@' not in k or k.endswith('@')):
             yield k, v
 
 def listbookmarks(repo):
     d = {}
     for book, node in listbinbookmarks(repo):
         d[book] = hex(node)
     return d
 
 def pushbookmark(repo, key, old, new):
     w = l = tr = None
     try:
         w = repo.wlock()
         l = repo.lock()
         tr = repo.transaction('bookmarks')
         marks = repo._bookmarks
         existing = hex(marks.get(key, ''))
         if existing != old and existing != new:
             return False
         if new == '':
             del marks[key]
         else:
             if new not in repo:
                 return False
             marks[key] = repo[new].node()
         marks.recordchange(tr)
         tr.close()
         return True
     finally:
         lockmod.release(tr, l, w)
 
 def comparebookmarks(repo, srcmarks, dstmarks, targets=None):
     '''Compare bookmarks between srcmarks and dstmarks
 
     This returns tuple "(addsrc, adddst, advsrc, advdst, diverge,
     differ, invalid)", each are list of bookmarks below:
 
     :addsrc:  added on src side (removed on dst side, perhaps)
     :adddst:  added on dst side (removed on src side, perhaps)
     :advsrc:  advanced on src side
     :advdst:  advanced on dst side
     :diverge: diverge
     :differ:  changed, but changeset referred on src is unknown on dst
     :invalid: unknown on both side
     :same:    same on both side
 
     Each elements of lists in result tuple is tuple "(bookmark name,
     changeset ID on source side, changeset ID on destination
     side)". Each changeset IDs are 40 hexadecimal digit string or
     None.
 
     Changeset IDs of tuples in "addsrc", "adddst", "differ" or
      "invalid" list may be unknown for repo.
 
     If "targets" is specified, only bookmarks listed in it are
     examined.
     '''
 
     if targets:
         bset = set(targets)
     else:
         srcmarkset = set(srcmarks)
         dstmarkset = set(dstmarks)
         bset = srcmarkset | dstmarkset
 
     results = ([], [], [], [], [], [], [], [])
     addsrc = results[0].append
     adddst = results[1].append
     advsrc = results[2].append
     advdst = results[3].append
     diverge = results[4].append
     differ = results[5].append
     invalid = results[6].append
     same = results[7].append
 
     for b in sorted(bset):
         if b not in srcmarks:
             if b in dstmarks:
                 adddst((b, None, dstmarks[b]))
             else:
                 invalid((b, None, None))
         elif b not in dstmarks:
             addsrc((b, srcmarks[b], None))
         else:
             scid = srcmarks[b]
             dcid = dstmarks[b]
             if scid == dcid:
                 same((b, scid, dcid))
             elif scid in repo and dcid in repo:
                 sctx = repo[scid]
                 dctx = repo[dcid]
                 if sctx.rev() < dctx.rev():
                     if validdest(repo, sctx, dctx):
                         advdst((b, scid, dcid))
                     else:
                         diverge((b, scid, dcid))
                 else:
                     if validdest(repo, dctx, sctx):
                         advsrc((b, scid, dcid))
                     else:
                         diverge((b, scid, dcid))
             else:
                 # it is too expensive to examine in detail, in this case
                 differ((b, scid, dcid))
 
     return results
 
 def _diverge(ui, b, path, localmarks, remotenode):
     '''Return appropriate diverged bookmark for specified ``path``
 
     This returns None, if it is failed to assign any divergent
     bookmark name.
 
     This reuses already existing one with "@number" suffix, if it
     refers ``remotenode``.
     '''
     if b == '@':
         b = ''
     # try to use an @pathalias suffix
     # if an @pathalias already exists, we overwrite (update) it
     if path.startswith("file:"):
         path = util.url(path).path
     for p, u in ui.configitems("paths"):
         if u.startswith("file:"):
             u = util.url(u).path
         if path == u:
             return '%s@%s' % (b, p)
 
     # assign a unique "@number" suffix newly
     for x in range(1, 100):
         n = '%s@%d' % (b, x)
         if n not in localmarks or localmarks[n] == remotenode:
             return n
 
     return None
 
 def unhexlifybookmarks(marks):
     binremotemarks = {}
     for name, node in marks.items():
         binremotemarks[name] = bin(node)
     return binremotemarks
 
 def updatefromremote(ui, repo, remotemarks, path, trfunc, explicit=()):
     ui.debug("checking for updated bookmarks\n")
     localmarks = repo._bookmarks
     (addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same
     ) = comparebookmarks(repo, remotemarks, localmarks)
 
     status = ui.status
     warn = ui.warn
     if ui.configbool('ui', 'quietbookmarkmove', False):
         status = warn = ui.debug
 
     explicit = set(explicit)
     changed = []
     for b, scid, dcid in addsrc:
         if scid in repo: # add remote bookmarks for changes we already have
             changed.append((b, scid, status,
                             _("adding remote bookmark %s\n") % (b)))
         elif b in explicit:
             explicit.remove(b)
             ui.warn(_("remote bookmark %s points to locally missing %s\n")
                     % (b, hex(scid)[:12]))
 
     for b, scid, dcid in advsrc:
         changed.append((b, scid, status,
                         _("updating bookmark %s\n") % (b)))
     # remove normal movement from explicit set
     explicit.difference_update(d[0] for d in changed)
 
     for b, scid, dcid in diverge:
         if b in explicit:
             explicit.discard(b)
             changed.append((b, scid, status,
                             _("importing bookmark %s\n") % (b)))
         else:
             db = _diverge(ui, b, path, localmarks, scid)
             if db:
                 changed.append((db, scid, warn,
                                 _("divergent bookmark %s stored as %s\n") %
                                 (b, db)))
             else:
                 warn(_("warning: failed to assign numbered name "
                        "to divergent bookmark %s\n") % (b))
     for b, scid, dcid in adddst + advdst:
         if b in explicit:
             explicit.discard(b)
             changed.append((b, scid, status,
                             _("importing bookmark %s\n") % (b)))
     for b, scid, dcid in differ:
         if b in explicit:
             explicit.remove(b)
             ui.warn(_("remote bookmark %s points to locally missing %s\n")
                     % (b, hex(scid)[:12]))
 
     if changed:
         tr = trfunc()
         for b, node, writer, msg in sorted(changed):
             localmarks[b] = node
             writer(msg)
         localmarks.recordchange(tr)
 
 def incoming(ui, repo, other):
     '''Show bookmarks incoming from other to repo
     '''
     ui.status(_("searching for changed bookmarks\n"))
 
     remotemarks = unhexlifybookmarks(other.listkeys('bookmarks'))
     r = comparebookmarks(repo, remotemarks, repo._bookmarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
 
     incomings = []
     if ui.debugflag:
         getid = lambda id: id
     else:
         getid = lambda id: id[:12]
     if ui.verbose:
         def add(b, id, st):
             incomings.append("   %-25s %s %s\n" % (b, getid(id), st))
     else:
         def add(b, id, st):
             incomings.append("   %-25s %s\n" % (b, getid(id)))
     for b, scid, dcid in addsrc:
         # i18n: "added" refers to a bookmark
         add(b, hex(scid), _('added'))
     for b, scid, dcid in advsrc:
         # i18n: "advanced" refers to a bookmark
         add(b, hex(scid), _('advanced'))
     for b, scid, dcid in diverge:
         # i18n: "diverged" refers to a bookmark
         add(b, hex(scid), _('diverged'))
     for b, scid, dcid in differ:
         # i18n: "changed" refers to a bookmark
         add(b, hex(scid), _('changed'))
 
     if not incomings:
         ui.status(_("no changed bookmarks found\n"))
         return 1
 
     for s in sorted(incomings):
         ui.write(s)
 
     return 0
 
 def outgoing(ui, repo, other):
     '''Show bookmarks outgoing from repo to other
     '''
     ui.status(_("searching for changed bookmarks\n"))
 
     remotemarks = unhexlifybookmarks(other.listkeys('bookmarks'))
     r = comparebookmarks(repo, repo._bookmarks, remotemarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
 
     outgoings = []
     if ui.debugflag:
         getid = lambda id: id
     else:
         getid = lambda id: id[:12]
     if ui.verbose:
         def add(b, id, st):
             outgoings.append("   %-25s %s %s\n" % (b, getid(id), st))
     else:
         def add(b, id, st):
             outgoings.append("   %-25s %s\n" % (b, getid(id)))
     for b, scid, dcid in addsrc:
         # i18n: "added refers to a bookmark
         add(b, hex(scid), _('added'))
     for b, scid, dcid in adddst:
         # i18n: "deleted" refers to a bookmark
         add(b, ' ' * 40, _('deleted'))
     for b, scid, dcid in advsrc:
         # i18n: "advanced" refers to a bookmark
         add(b, hex(scid), _('advanced'))
     for b, scid, dcid in diverge:
         # i18n: "diverged" refers to a bookmark
         add(b, hex(scid), _('diverged'))
     for b, scid, dcid in differ:
         # i18n: "changed" refers to a bookmark
         add(b, hex(scid), _('changed'))
 
     if not outgoings:
         ui.status(_("no changed bookmarks found\n"))
         return 1
 
     for s in sorted(outgoings):
         ui.write(s)
 
     return 0
 
 def summary(repo, other):
     '''Compare bookmarks between repo and other for "hg summary" output
 
     This returns "(# of incoming, # of outgoing)" tuple.
     '''
     remotemarks = unhexlifybookmarks(other.listkeys('bookmarks'))
     r = comparebookmarks(repo, remotemarks, repo._bookmarks)
     addsrc, adddst, advsrc, advdst, diverge, differ, invalid, same = r
     return (len(addsrc), len(adddst))
 
 def validdest(repo, old, new):
     """Is the new bookmark destination a valid update from the old one"""
     repo = repo.unfiltered()
     if old == new:
         # Old == new -> nothing to update.
         return False
     elif not old:
         # old is nullrev, anything is valid.
         # (new != nullrev has been excluded by the previous check)
         return True
     elif repo.obsstore:
-        return new.node() in obsolete.foreground(repo, [old.node()])
+        return new.node() in obsutil.foreground(repo, [old.node()])
     else:
         # still an independent clause as it is lazier (and therefore faster)
         return old.descendant(new)
 
 def checkformat(repo, mark):
     """return a valid version of a potential bookmark name
 
     Raises an abort error if the bookmark name is not valid.
     """
     mark = mark.strip()
     if not mark:
         raise error.Abort(_("bookmark names cannot consist entirely of "
                             "whitespace"))
     scmutil.checknewlabel(repo, mark, 'bookmark')
     return mark
 
 def delete(repo, tr, names):
     """remove a mark from the bookmark store
 
     Raises an abort error if mark does not exist.
     """
     marks = repo._bookmarks
     for mark in names:
         if mark not in marks:
             raise error.Abort(_("bookmark '%s' does not exist") % mark)
         if mark == repo._activebookmark:
             deactivate(repo)
         del marks[mark]
     marks.recordchange(tr)
 
 def rename(repo, tr, old, new, force=False, inactive=False):
     """rename a bookmark from old to new
 
     If force is specified, then the new name can overwrite an existing
     bookmark.
 
     If inactive is specified, then do not activate the new bookmark.
 
     Raises an abort error if old is not in the bookmark store.
     """
     marks = repo._bookmarks
     mark = checkformat(repo, new)
     if old not in marks:
         raise error.Abort(_("bookmark '%s' does not exist") % old)
     marks.checkconflict(mark, force)
     marks[mark] = marks[old]
     if repo._activebookmark == old and not inactive:
         activate(repo, mark)
     del marks[old]
     marks.recordchange(tr)
 
 def addbookmarks(repo, tr, names, rev=None, force=False, inactive=False):
     """add a list of bookmarks
 
     If force is specified, then the new name can overwrite an existing
     bookmark.
 
     If inactive is specified, then do not activate any bookmark. Otherwise, the
     first bookmark is activated.
 
     Raises an abort error if old is not in the bookmark store.
     """
     marks = repo._bookmarks
     cur = repo.changectx('.').node()
     newact = None
     for mark in names:
         mark = checkformat(repo, mark)
         if newact is None:
             newact = mark
         if inactive and mark == repo._activebookmark:
             deactivate(repo)
             return
         tgt = cur
         if rev:
             tgt = scmutil.revsingle(repo, rev).node()
         marks.checkconflict(mark, force, tgt)
         marks[mark] = tgt
     if not inactive and cur == marks[newact] and not rev:
         activate(repo, newact)
     elif cur != tgt and newact == repo._activebookmark:
         deactivate(repo)
     marks.recordchange(tr)
 
 def _printbookmarks(ui, repo, bmarks, **opts):
     """private method to print bookmarks
 
     Provides a way for extensions to control how bookmarks are printed (e.g.
     prepend or postpend names)
     """
     opts = pycompat.byteskwargs(opts)
     fm = ui.formatter('bookmarks', opts)
     hexfn = fm.hexfunc
     if len(bmarks) == 0 and fm.isplain():
         ui.status(_("no bookmarks set\n"))
     for bmark, (n, prefix, label) in sorted(bmarks.iteritems()):
         fm.startitem()
         if not ui.quiet:
             fm.plain(' %s ' % prefix, label=label)
         fm.write('bookmark', '%s', bmark, label=label)
         pad = " " * (25 - encoding.colwidth(bmark))
         fm.condwrite(not ui.quiet, 'rev node', pad + ' %d:%s',
                      repo.changelog.rev(n), hexfn(n), label=label)
         fm.data(active=(activebookmarklabel in label))
         fm.plain('\n')
     fm.end()
 
 def printbookmarks(ui, repo, **opts):
     """print bookmarks to a formatter
 
     Provides a way for extensions to control how bookmarks are printed.
     """
     marks = repo._bookmarks
     bmarks = {}
     for bmark, n in sorted(marks.iteritems()):
         active = repo._activebookmark
         if bmark == active:
             prefix, label = '*', activebookmarklabel
         else:
             prefix, label = ' ', ''
 
         bmarks[bmark] = (n, prefix, label)
     _printbookmarks(ui, repo, bmarks, **opts)

mercurial/merge.py

@@ -1,1749 +1,1749
 # merge.py - directory-level update/merge handling for Mercurial
 #
 # Copyright 2006, 2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 import hashlib
 import os
 import shutil
 import struct
 
 from .i18n import _
 from .node import (
     addednodeid,
     bin,
     hex,
     modifiednodeid,
     nullhex,
     nullid,
     nullrev,
 )
 from . import (
     copies,
     error,
     filemerge,
     match as matchmod,
-    obsolete,
+    obsutil,
     pycompat,
     scmutil,
     subrepo,
     util,
     worker,
 )
 
 _pack = struct.pack
 _unpack = struct.unpack
 
 def _droponode(data):
     # used for compatibility for v1
     bits = data.split('\0')
     bits = bits[:-2] + bits[-1:]
     return '\0'.join(bits)
 
 class mergestate(object):
     '''track 3-way merge state of individual files
 
     The merge state is stored on disk when needed. Two files are used: one with
     an old format (version 1), and one with a new format (version 2). Version 2
     stores a superset of the data in version 1, including new kinds of records
     in the future. For more about the new format, see the documentation for
     `_readrecordsv2`.
 
     Each record can contain arbitrary content, and has an associated type. This
     `type` should be a letter. If `type` is uppercase, the record is mandatory:
     versions of Mercurial that don't support it should abort. If `type` is
     lowercase, the record can be safely ignored.
 
     Currently known records:
 
     L: the node of the "local" part of the merge (hexified version)
     O: the node of the "other" part of the merge (hexified version)
     F: a file to be merged entry
     C: a change/delete or delete/change conflict
     D: a file that the external merge driver will merge internally
        (experimental)
     m: the external merge driver defined for this merge plus its run state
        (experimental)
     f: a (filename, dictionary) tuple of optional values for a given file
     X: unsupported mandatory record type (used in tests)
     x: unsupported advisory record type (used in tests)
     l: the labels for the parts of the merge.
 
     Merge driver run states (experimental):
     u: driver-resolved files unmarked -- needs to be run next time we're about
        to resolve or commit
     m: driver-resolved files marked -- only needs to be run before commit
     s: success/skipped -- does not need to be run any more
 
     '''
     statepathv1 = 'merge/state'
     statepathv2 = 'merge/state2'
 
     @staticmethod
     def clean(repo, node=None, other=None, labels=None):
         """Initialize a brand new merge state, removing any existing state on
         disk."""
         ms = mergestate(repo)
         ms.reset(node, other, labels)
         return ms
 
     @staticmethod
     def read(repo):
         """Initialize the merge state, reading it from disk."""
         ms = mergestate(repo)
         ms._read()
         return ms
 
     def __init__(self, repo):
         """Initialize the merge state.
 
         Do not use this directly! Instead call read() or clean()."""
         self._repo = repo
         self._dirty = False
         self._labels = None
 
     def reset(self, node=None, other=None, labels=None):
         self._state = {}
         self._stateextras = {}
         self._local = None
         self._other = None
         self._labels = labels
         for var in ('localctx', 'otherctx'):
             if var in vars(self):
                 delattr(self, var)
         if node:
             self._local = node
             self._other = other
         self._readmergedriver = None
         if self.mergedriver:
             self._mdstate = 's'
         else:
             self._mdstate = 'u'
         shutil.rmtree(self._repo.vfs.join('merge'), True)
         self._results = {}
         self._dirty = False
 
     def _read(self):
         """Analyse each record content to restore a serialized state from disk
 
         This function process "record" entry produced by the de-serialization
         of on disk file.
         """
         self._state = {}
         self._stateextras = {}
         self._local = None
         self._other = None
         for var in ('localctx', 'otherctx'):
             if var in vars(self):
                 delattr(self, var)
         self._readmergedriver = None
         self._mdstate = 's'
         unsupported = set()
         records = self._readrecords()
         for rtype, record in records:
             if rtype == 'L':
                 self._local = bin(record)
             elif rtype == 'O':
                 self._other = bin(record)
             elif rtype == 'm':
                 bits = record.split('\0', 1)
                 mdstate = bits[1]
                 if len(mdstate) != 1 or mdstate not in 'ums':
                     # the merge driver should be idempotent, so just rerun it
                     mdstate = 'u'
 
                 self._readmergedriver = bits[0]
                 self._mdstate = mdstate
             elif rtype in 'FDC':
                 bits = record.split('\0')
                 self._state[bits[0]] = bits[1:]
             elif rtype == 'f':
                 filename, rawextras = record.split('\0', 1)
                 extraparts = rawextras.split('\0')
                 extras = {}
                 i = 0
                 while i < len(extraparts):
                     extras[extraparts[i]] = extraparts[i + 1]
                     i += 2
 
                 self._stateextras[filename] = extras
             elif rtype == 'l':
                 labels = record.split('\0', 2)
                 self._labels = [l for l in labels if len(l) > 0]
             elif not rtype.islower():
                 unsupported.add(rtype)
         self._results = {}
         self._dirty = False
 
         if unsupported:
             raise error.UnsupportedMergeRecords(unsupported)
 
     def _readrecords(self):
         """Read merge state from disk and return a list of record (TYPE, data)
 
         We read data from both v1 and v2 files and decide which one to use.
 
         V1 has been used by version prior to 2.9.1 and contains less data than
         v2. We read both versions and check if no data in v2 contradicts
         v1. If there is not contradiction we can safely assume that both v1
         and v2 were written at the same time and use the extract data in v2. If
         there is contradiction we ignore v2 content as we assume an old version
         of Mercurial has overwritten the mergestate file and left an old v2
         file around.
 
         returns list of record [(TYPE, data), ...]"""
         v1records = self._readrecordsv1()
         v2records = self._readrecordsv2()
         if self._v1v2match(v1records, v2records):
             return v2records
         else:
             # v1 file is newer than v2 file, use it
             # we have to infer the "other" changeset of the merge
             # we cannot do better than that with v1 of the format
             mctx = self._repo[None].parents()[-1]
             v1records.append(('O', mctx.hex()))
             # add place holder "other" file node information
             # nobody is using it yet so we do no need to fetch the data
             # if mctx was wrong `mctx[bits[-2]]` may fails.
             for idx, r in enumerate(v1records):
                 if r[0] == 'F':
                     bits = r[1].split('\0')
                     bits.insert(-2, '')
                     v1records[idx] = (r[0], '\0'.join(bits))
             return v1records
 
     def _v1v2match(self, v1records, v2records):
         oldv2 = set() # old format version of v2 record
         for rec in v2records:
             if rec[0] == 'L':
                 oldv2.add(rec)
             elif rec[0] == 'F':
                 # drop the onode data (not contained in v1)
                 oldv2.add(('F', _droponode(rec[1])))
         for rec in v1records:
             if rec not in oldv2:
                 return False
         else:
             return True
 
     def _readrecordsv1(self):
         """read on disk merge state for version 1 file
 
         returns list of record [(TYPE, data), ...]
 
         Note: the "F" data from this file are one entry short
               (no "other file node" entry)
         """
         records = []
         try:
             f = self._repo.vfs(self.statepathv1)
             for i, l in enumerate(f):
                 if i == 0:
                     records.append(('L', l[:-1]))
                 else:
                     records.append(('F', l[:-1]))
             f.close()
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
         return records
 
     def _readrecordsv2(self):
         """read on disk merge state for version 2 file
 
         This format is a list of arbitrary records of the form:
 
           [type][length][content]
 
         `type` is a single character, `length` is a 4 byte integer, and
         `content` is an arbitrary byte sequence of length `length`.
 
         Mercurial versions prior to 3.7 have a bug where if there are
         unsupported mandatory merge records, attempting to clear out the merge
         state with hg update --clean or similar aborts. The 't' record type
         works around that by writing out what those versions treat as an
         advisory record, but later versions interpret as special: the first
         character is the 'real' record type and everything onwards is the data.
 
         Returns list of records [(TYPE, data), ...]."""
         records = []
         try:
             f = self._repo.vfs(self.statepathv2)
             data = f.read()
             off = 0
             end = len(data)
             while off < end:
                 rtype = data[off]
                 off += 1
                 length = _unpack('>I', data[off:(off + 4)])[0]
                 off += 4
                 record = data[off:(off + length)]
                 off += length
                 if rtype == 't':
                     rtype, record = record[0], record[1:]
                 records.append((rtype, record))
             f.close()
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
         return records
 
     @util.propertycache
     def mergedriver(self):
         # protect against the following:
         # - A configures a malicious merge driver in their hgrc, then
         #   pauses the merge
         # - A edits their hgrc to remove references to the merge driver
         # - A gives a copy of their entire repo, including .hg, to B
         # - B inspects .hgrc and finds it to be clean
         # - B then continues the merge and the malicious merge driver
         #  gets invoked
         configmergedriver = self._repo.ui.config('experimental', 'mergedriver')
         if (self._readmergedriver is not None
             and self._readmergedriver != configmergedriver):
             raise error.ConfigError(
                 _("merge driver changed since merge started"),
                 hint=_("revert merge driver change or abort merge"))
 
         return configmergedriver
 
     @util.propertycache
     def localctx(self):
         if self._local is None:
             msg = "localctx accessed but self._local isn't set"
             raise error.ProgrammingError(msg)
         return self._repo[self._local]
 
     @util.propertycache
     def otherctx(self):
         if self._other is None:
             msg = "otherctx accessed but self._other isn't set"
             raise error.ProgrammingError(msg)
         return self._repo[self._other]
 
     def active(self):
         """Whether mergestate is active.
 
         Returns True if there appears to be mergestate. This is a rough proxy
         for "is a merge in progress."
         """
         # Check local variables before looking at filesystem for performance
         # reasons.
         return bool(self._local) or bool(self._state) or \
                self._repo.vfs.exists(self.statepathv1) or \
                self._repo.vfs.exists(self.statepathv2)
 
     def commit(self):
         """Write current state on disk (if necessary)"""
         if self._dirty:
             records = self._makerecords()
             self._writerecords(records)
             self._dirty = False
 
     def _makerecords(self):
         records = []
         records.append(('L', hex(self._local)))
         records.append(('O', hex(self._other)))
         if self.mergedriver:
             records.append(('m', '\0'.join([
                 self.mergedriver, self._mdstate])))
         for d, v in self._state.iteritems():
             if v[0] == 'd':
                 records.append(('D', '\0'.join([d] + v)))
             # v[1] == local ('cd'), v[6] == other ('dc') -- not supported by
             # older versions of Mercurial
             elif v[1] == nullhex or v[6] == nullhex:
                 records.append(('C', '\0'.join([d] + v)))
             else:
                 records.append(('F', '\0'.join([d] + v)))
         for filename, extras in sorted(self._stateextras.iteritems()):
             rawextras = '\0'.join('%s\0%s' % (k, v) for k, v in
                                   extras.iteritems())
             records.append(('f', '%s\0%s' % (filename, rawextras)))
         if self._labels is not None:
             labels = '\0'.join(self._labels)
             records.append(('l', labels))
         return records
 
     def _writerecords(self, records):
         """Write current state on disk (both v1 and v2)"""
         self._writerecordsv1(records)
         self._writerecordsv2(records)
 
     def _writerecordsv1(self, records):
         """Write current state on disk in a version 1 file"""
         f = self._repo.vfs(self.statepathv1, 'w')
         irecords = iter(records)
         lrecords = next(irecords)
         assert lrecords[0] == 'L'
         f.write(hex(self._local) + '\n')
         for rtype, data in irecords:
             if rtype == 'F':
                 f.write('%s\n' % _droponode(data))
         f.close()
 
     def _writerecordsv2(self, records):
         """Write current state on disk in a version 2 file
 
         See the docstring for _readrecordsv2 for why we use 't'."""
         # these are the records that all version 2 clients can read
         whitelist = 'LOF'
         f = self._repo.vfs(self.statepathv2, 'w')
         for key, data in records:
             assert len(key) == 1
             if key not in whitelist:
                 key, data = 't', '%s%s' % (key, data)
             format = '>sI%is' % len(data)
             f.write(_pack(format, key, len(data), data))
         f.close()
 
     def add(self, fcl, fco, fca, fd):
         """add a new (potentially?) conflicting file the merge state
         fcl: file context for local,
         fco: file context for remote,
         fca: file context for ancestors,
         fd:  file path of the resulting merge.
 
         note: also write the local version to the `.hg/merge` directory.
         """
         if fcl.isabsent():
             hash = nullhex
         else:
             hash = hex(hashlib.sha1(fcl.path()).digest())
             self._repo.vfs.write('merge/' + hash, fcl.data())
         self._state[fd] = ['u', hash, fcl.path(),
                            fca.path(), hex(fca.filenode()),
                            fco.path(), hex(fco.filenode()),
                            fcl.flags()]
         self._stateextras[fd] = { 'ancestorlinknode' : hex(fca.node()) }
         self._dirty = True
 
     def __contains__(self, dfile):
         return dfile in self._state
 
     def __getitem__(self, dfile):
         return self._state[dfile][0]
 
     def __iter__(self):
         return iter(sorted(self._state))
 
     def files(self):
         return self._state.keys()
 
     def mark(self, dfile, state):
         self._state[dfile][0] = state
         self._dirty = True
 
     def mdstate(self):
         return self._mdstate
 
     def unresolved(self):
         """Obtain the paths of unresolved files."""
 
         for f, entry in self._state.items():
             if entry[0] == 'u':
                 yield f
 
     def driverresolved(self):
         """Obtain the paths of driver-resolved files."""
 
         for f, entry in self._state.items():
             if entry[0] == 'd':
                 yield f
 
     def extras(self, filename):
         return self._stateextras.setdefault(filename, {})
 
     def _resolve(self, preresolve, dfile, wctx):
         """rerun merge process for file path `dfile`"""
         if self[dfile] in 'rd':
             return True, 0
         stateentry = self._state[dfile]
         state, hash, lfile, afile, anode, ofile, onode, flags = stateentry
         octx = self._repo[self._other]
         extras = self.extras(dfile)
         anccommitnode = extras.get('ancestorlinknode')
         if anccommitnode:
             actx = self._repo[anccommitnode]
         else:
             actx = None
         fcd = self._filectxorabsent(hash, wctx, dfile)
         fco = self._filectxorabsent(onode, octx, ofile)
         # TODO: move this to filectxorabsent
         fca = self._repo.filectx(afile, fileid=anode, changeid=actx)
         # "premerge" x flags
         flo = fco.flags()
         fla = fca.flags()
         if 'x' in flags + flo + fla and 'l' not in flags + flo + fla:
             if fca.node() == nullid and flags != flo:
                 if preresolve:
                     self._repo.ui.warn(
                         _('warning: cannot merge flags for %s '
                           'without common ancestor - keeping local flags\n')
                         % afile)
             elif flags == fla:
                 flags = flo
         if preresolve:
             # restore local
             if hash != nullhex:
                 f = self._repo.vfs('merge/' + hash)
                 wctx[dfile].write(f.read(), flags)
                 f.close()
             else:
                 wctx[dfile].remove(ignoremissing=True)
             complete, r, deleted = filemerge.premerge(self._repo, self._local,
                                                       lfile, fcd, fco, fca,
                                                       labels=self._labels)
         else:
             complete, r, deleted = filemerge.filemerge(self._repo, self._local,
                                                        lfile, fcd, fco, fca,
                                                        labels=self._labels)
         if r is None:
             # no real conflict
             del self._state[dfile]
             self._stateextras.pop(dfile, None)
             self._dirty = True
         elif not r:
             self.mark(dfile, 'r')
 
         if complete:
             action = None
             if deleted:
                 if fcd.isabsent():
                     # dc: local picked. Need to drop if present, which may
                     # happen on re-resolves.
                     action = 'f'
                 else:
                     # cd: remote picked (or otherwise deleted)
                     action = 'r'
             else:
                 if fcd.isabsent(): # dc: remote picked
                     action = 'g'
                 elif fco.isabsent(): # cd: local picked
                     if dfile in self.localctx:
                         action = 'am'
                     else:
                         action = 'a'
                 # else: regular merges (no action necessary)
             self._results[dfile] = r, action
 
         return complete, r
 
     def _filectxorabsent(self, hexnode, ctx, f):
         if hexnode == nullhex:
             return filemerge.absentfilectx(ctx, f)
         else:
             return ctx[f]
 
     def preresolve(self, dfile, wctx):
         """run premerge process for dfile
 
         Returns whether the merge is complete, and the exit code."""
         return self._resolve(True, dfile, wctx)
 
     def resolve(self, dfile, wctx):
         """run merge process (assuming premerge was run) for dfile
 
         Returns the exit code of the merge."""
         return self._resolve(False, dfile, wctx)[1]
 
     def counts(self):
         """return counts for updated, merged and removed files in this
         session"""
         updated, merged, removed = 0, 0, 0
         for r, action in self._results.itervalues():
             if r is None:
                 updated += 1
             elif r == 0:
                 if action == 'r':
                     removed += 1
                 else:
                     merged += 1
         return updated, merged, removed
 
     def unresolvedcount(self):
         """get unresolved count for this merge (persistent)"""
         return len([True for f, entry in self._state.iteritems()
                     if entry[0] == 'u'])
 
     def actions(self):
         """return lists of actions to perform on the dirstate"""
         actions = {'r': [], 'f': [], 'a': [], 'am': [], 'g': []}
         for f, (r, action) in self._results.iteritems():
             if action is not None:
                 actions[action].append((f, None, "merge result"))
         return actions
 
     def recordactions(self):
         """record remove/add/get actions in the dirstate"""
         branchmerge = self._repo.dirstate.p2() != nullid
         recordupdates(self._repo, self.actions(), branchmerge)
 
     def queueremove(self, f):
         """queues a file to be removed from the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, 'r'
 
     def queueadd(self, f):
         """queues a file to be added to the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, 'a'
 
     def queueget(self, f):
         """queues a file to be marked modified in the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, 'g'
 
 def _getcheckunknownconfig(repo, section, name):
     config = repo.ui.config(section, name, default='abort')
     valid = ['abort', 'ignore', 'warn']
     if config not in valid:
         validstr = ', '.join(["'" + v + "'" for v in valid])
         raise error.ConfigError(_("%s.%s not valid "
                                   "('%s' is none of %s)")
                                 % (section, name, config, validstr))
     return config
 
 def _checkunknownfile(repo, wctx, mctx, f, f2=None):
     if f2 is None:
         f2 = f
     return (repo.wvfs.audit.check(f)
         and repo.wvfs.isfileorlink(f)
         and repo.dirstate.normalize(f) not in repo.dirstate
         and mctx[f2].cmp(wctx[f]))
 
 def _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce):
     """
     Considers any actions that care about the presence of conflicting unknown
     files. For some actions, the result is to abort; for others, it is to
     choose a different action.
     """
     conflicts = set()
     warnconflicts = set()
     abortconflicts = set()
     unknownconfig = _getcheckunknownconfig(repo, 'merge', 'checkunknown')
     ignoredconfig = _getcheckunknownconfig(repo, 'merge', 'checkignored')
     if not force:
         def collectconflicts(conflicts, config):
             if config == 'abort':
                 abortconflicts.update(conflicts)
             elif config == 'warn':
                 warnconflicts.update(conflicts)
 
         for f, (m, args, msg) in actions.iteritems():
             if m in ('c', 'dc'):
                 if _checkunknownfile(repo, wctx, mctx, f):
                     conflicts.add(f)
             elif m == 'dg':
                 if _checkunknownfile(repo, wctx, mctx, f, args[0]):
                     conflicts.add(f)
 
         ignoredconflicts = set([c for c in conflicts
                                 if repo.dirstate._ignore(c)])
         unknownconflicts = conflicts - ignoredconflicts
         collectconflicts(ignoredconflicts, ignoredconfig)
         collectconflicts(unknownconflicts, unknownconfig)
     else:
         for f, (m, args, msg) in actions.iteritems():
             if m == 'cm':
                 fl2, anc = args
                 different = _checkunknownfile(repo, wctx, mctx, f)
                 if repo.dirstate._ignore(f):
                     config = ignoredconfig
                 else:
                     config = unknownconfig
 
                 # The behavior when force is True is described by this table:
                 #  config  different  mergeforce  |    action    backup
                 #    *         n          *       |      get        n
                 #    *         y          y       |     merge       -
                 #   abort      y          n       |     merge       -   (1)
                 #   warn       y          n       |  warn + get     y
                 #  ignore      y          n       |      get        y
                 #
                 # (1) this is probably the wrong behavior here -- we should
                 #     probably abort, but some actions like rebases currently
                 #     don't like an abort happening in the middle of
                 #     merge.update.
                 if not different:
                     actions[f] = ('g', (fl2, False), "remote created")
                 elif mergeforce or config == 'abort':
                     actions[f] = ('m', (f, f, None, False, anc),
                                   "remote differs from untracked local")
                 elif config == 'abort':
                     abortconflicts.add(f)
                 else:
                     if config == 'warn':
                         warnconflicts.add(f)
                     actions[f] = ('g', (fl2, True), "remote created")
 
     for f in sorted(abortconflicts):
         repo.ui.warn(_("%s: untracked file differs\n") % f)
     if abortconflicts:
         raise error.Abort(_("untracked files in working directory "
                             "differ from files in requested revision"))
 
     for f in sorted(warnconflicts):
         repo.ui.warn(_("%s: replacing untracked file\n") % f)
 
     for f, (m, args, msg) in actions.iteritems():
         backup = f in conflicts
         if m == 'c':
             flags, = args
             actions[f] = ('g', (flags, backup), msg)
 
 def _forgetremoved(wctx, mctx, branchmerge):
     """
     Forget removed files
 
     If we're jumping between revisions (as opposed to merging), and if
     neither the working directory nor the target rev has the file,
     then we need to remove it from the dirstate, to prevent the
     dirstate from listing the file when it is no longer in the
     manifest.
 
     If we're merging, and the other revision has removed a file
     that is not present in the working directory, we need to mark it
     as removed.
     """
 
     actions = {}
     m = 'f'
     if branchmerge:
         m = 'r'
     for f in wctx.deleted():
         if f not in mctx:
             actions[f] = m, None, "forget deleted"
 
     if not branchmerge:
         for f in wctx.removed():
             if f not in mctx:
                 actions[f] = 'f', None, "forget removed"
 
     return actions
 
 def _checkcollision(repo, wmf, actions):
     # build provisional merged manifest up
     pmmf = set(wmf)
 
     if actions:
         # k, dr, e and rd are no-op
         for m in 'a', 'am', 'f', 'g', 'cd', 'dc':
             for f, args, msg in actions[m]:
                 pmmf.add(f)
         for f, args, msg in actions['r']:
             pmmf.discard(f)
         for f, args, msg in actions['dm']:
             f2, flags = args
             pmmf.discard(f2)
             pmmf.add(f)
         for f, args, msg in actions['dg']:
             pmmf.add(f)
         for f, args, msg in actions['m']:
             f1, f2, fa, move, anc = args
             if move:
                 pmmf.discard(f1)
             pmmf.add(f)
 
     # check case-folding collision in provisional merged manifest
     foldmap = {}
     for f in sorted(pmmf):
         fold = util.normcase(f)
         if fold in foldmap:
             raise error.Abort(_("case-folding collision between %s and %s")
                              % (f, foldmap[fold]))
         foldmap[fold] = f
 
     # check case-folding of directories
     foldprefix = unfoldprefix = lastfull = ''
     for fold, f in sorted(foldmap.items()):
         if fold.startswith(foldprefix) and not f.startswith(unfoldprefix):
             # the folded prefix matches but actual casing is different
             raise error.Abort(_("case-folding collision between "
                                 "%s and directory of %s") % (lastfull, f))
         foldprefix = fold + '/'
         unfoldprefix = f + '/'
         lastfull = f
 
 def driverpreprocess(repo, ms, wctx, labels=None):
     """run the preprocess step of the merge driver, if any
 
     This is currently not implemented -- it's an extension point."""
     return True
 
 def driverconclude(repo, ms, wctx, labels=None):
     """run the conclude step of the merge driver, if any
 
     This is currently not implemented -- it's an extension point."""
     return True
 
 def manifestmerge(repo, wctx, p2, pa, branchmerge, force, matcher,
                   acceptremote, followcopies, forcefulldiff=False):
     """
     Merge wctx and p2 with ancestor pa and generate merge action list
 
     branchmerge and force are as passed in to update
     matcher = matcher to filter file lists
     acceptremote = accept the incoming changes without prompting
     """
     if matcher is not None and matcher.always():
         matcher = None
 
     copy, movewithdir, diverge, renamedelete, dirmove = {}, {}, {}, {}, {}
 
     # manifests fetched in order are going to be faster, so prime the caches
     [x.manifest() for x in
      sorted(wctx.parents() + [p2, pa], key=scmutil.intrev)]
 
     if followcopies:
         ret = copies.mergecopies(repo, wctx, p2, pa)
         copy, movewithdir, diverge, renamedelete, dirmove = ret
 
     boolbm = pycompat.bytestr(bool(branchmerge))
     boolf = pycompat.bytestr(bool(force))
     boolm = pycompat.bytestr(bool(matcher))
     repo.ui.note(_("resolving manifests\n"))
     repo.ui.debug(" branchmerge: %s, force: %s, partial: %s\n"
                   % (boolbm, boolf, boolm))
     repo.ui.debug(" ancestor: %s, local: %s, remote: %s\n" % (pa, wctx, p2))
 
     m1, m2, ma = wctx.manifest(), p2.manifest(), pa.manifest()
     copied = set(copy.values())
     copied.update(movewithdir.values())
 
     if '.hgsubstate' in m1:
         # check whether sub state is modified
         if any(wctx.sub(s).dirty() for s in wctx.substate):
             m1['.hgsubstate'] = modifiednodeid
 
     # Don't use m2-vs-ma optimization if:
     # - ma is the same as m1 or m2, which we're just going to diff again later
     # - The caller specifically asks for a full diff, which is useful during bid
     #   merge.
     if (pa not in ([wctx, p2] + wctx.parents()) and not forcefulldiff):
         # Identify which files are relevant to the merge, so we can limit the
         # total m1-vs-m2 diff to just those files. This has significant
         # performance benefits in large repositories.
         relevantfiles = set(ma.diff(m2).keys())
 
         # For copied and moved files, we need to add the source file too.
         for copykey, copyvalue in copy.iteritems():
             if copyvalue in relevantfiles:
                 relevantfiles.add(copykey)
         for movedirkey in movewithdir:
             relevantfiles.add(movedirkey)
         filesmatcher = scmutil.matchfiles(repo, relevantfiles)
         matcher = matchmod.intersectmatchers(matcher, filesmatcher)
 
     diff = m1.diff(m2, match=matcher)
 
     if matcher is None:
         matcher = matchmod.always('', '')
 
     actions = {}
     for f, ((n1, fl1), (n2, fl2)) in diff.iteritems():
         if n1 and n2: # file exists on both local and remote side
             if f not in ma:
                 fa = copy.get(f, None)
                 if fa is not None:
                     actions[f] = ('m', (f, f, fa, False, pa.node()),
                                   "both renamed from " + fa)
                 else:
                     actions[f] = ('m', (f, f, None, False, pa.node()),
                                   "both created")
             else:
                 a = ma[f]
                 fla = ma.flags(f)
                 nol = 'l' not in fl1 + fl2 + fla
                 if n2 == a and fl2 == fla:
                     actions[f] = ('k' , (), "remote unchanged")
                 elif n1 == a and fl1 == fla: # local unchanged - use remote
                     if n1 == n2: # optimization: keep local content
                         actions[f] = ('e', (fl2,), "update permissions")
                     else:
                         actions[f] = ('g', (fl2, False), "remote is newer")
                 elif nol and n2 == a: # remote only changed 'x'
                     actions[f] = ('e', (fl2,), "update permissions")
                 elif nol and n1 == a: # local only changed 'x'
                     actions[f] = ('g', (fl1, False), "remote is newer")
                 else: # both changed something
                     actions[f] = ('m', (f, f, f, False, pa.node()),
                                    "versions differ")
         elif n1: # file exists only on local side
             if f in copied:
                 pass # we'll deal with it on m2 side
             elif f in movewithdir: # directory rename, move local
                 f2 = movewithdir[f]
                 if f2 in m2:
                     actions[f2] = ('m', (f, f2, None, True, pa.node()),
                                    "remote directory rename, both created")
                 else:
                     actions[f2] = ('dm', (f, fl1),
                                    "remote directory rename - move from " + f)
             elif f in copy:
                 f2 = copy[f]
                 actions[f] = ('m', (f, f2, f2, False, pa.node()),
                               "local copied/moved from " + f2)
             elif f in ma: # clean, a different, no remote
                 if n1 != ma[f]:
                     if acceptremote:
                         actions[f] = ('r', None, "remote delete")
                     else:
                         actions[f] = ('cd', (f, None, f, False, pa.node()),
                                       "prompt changed/deleted")
                 elif n1 == addednodeid:
                     # This extra 'a' is added by working copy manifest to mark
                     # the file as locally added. We should forget it instead of
                     # deleting it.
                     actions[f] = ('f', None, "remote deleted")
                 else:
                     actions[f] = ('r', None, "other deleted")
         elif n2: # file exists only on remote side
             if f in copied:
                 pass # we'll deal with it on m1 side
             elif f in movewithdir:
                 f2 = movewithdir[f]
                 if f2 in m1:
                     actions[f2] = ('m', (f2, f, None, False, pa.node()),
                                    "local directory rename, both created")
                 else:
                     actions[f2] = ('dg', (f, fl2),
                                    "local directory rename - get from " + f)
             elif f in copy:
                 f2 = copy[f]
                 if f2 in m2:
                     actions[f] = ('m', (f2, f, f2, False, pa.node()),
                                   "remote copied from " + f2)
                 else:
                     actions[f] = ('m', (f2, f, f2, True, pa.node()),
                                   "remote moved from " + f2)
             elif f not in ma:
                 # local unknown, remote created: the logic is described by the
                 # following table:
                 #
                 # force  branchmerge  different  |  action
                 #   n         *           *      |   create
                 #   y         n           *      |   create
                 #   y         y           n      |   create
                 #   y         y           y      |   merge
                 #
                 # Checking whether the files are different is expensive, so we
                 # don't do that when we can avoid it.
                 if not force:
                     actions[f] = ('c', (fl2,), "remote created")
                 elif not branchmerge:
                     actions[f] = ('c', (fl2,), "remote created")
                 else:
                     actions[f] = ('cm', (fl2, pa.node()),
                                   "remote created, get or merge")
             elif n2 != ma[f]:
                 df = None
                 for d in dirmove:
                     if f.startswith(d):
                         # new file added in a directory that was moved
                         df = dirmove[d] + f[len(d):]
                         break
                 if df is not None and df in m1:
                     actions[df] = ('m', (df, f, f, False, pa.node()),
                             "local directory rename - respect move from " + f)
                 elif acceptremote:
                     actions[f] = ('c', (fl2,), "remote recreating")
                 else:
                     actions[f] = ('dc', (None, f, f, False, pa.node()),
                                   "prompt deleted/changed")
 
     return actions, diverge, renamedelete
 
 def _resolvetrivial(repo, wctx, mctx, ancestor, actions):
     """Resolves false conflicts where the nodeid changed but the content
        remained the same."""
 
     for f, (m, args, msg) in actions.items():
         if m == 'cd' and f in ancestor and not wctx[f].cmp(ancestor[f]):
             # local did change but ended up with same content
             actions[f] = 'r', None, "prompt same"
         elif m == 'dc' and f in ancestor and not mctx[f].cmp(ancestor[f]):
             # remote did change but ended up with same content
             del actions[f] # don't get = keep local deleted
 
 def calculateupdates(repo, wctx, mctx, ancestors, branchmerge, force,
                      acceptremote, followcopies, matcher=None,
                      mergeforce=False):
     "Calculate the actions needed to merge mctx into wctx using ancestors"
     if len(ancestors) == 1: # default
         actions, diverge, renamedelete = manifestmerge(
             repo, wctx, mctx, ancestors[0], branchmerge, force, matcher,
             acceptremote, followcopies)
         _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
     else: # only when merge.preferancestor=* - the default
         repo.ui.note(
             _("note: merging %s and %s using bids from ancestors %s\n") %
             (wctx, mctx, _(' and ').join(str(anc) for anc in ancestors)))
 
         # Call for bids
         fbids = {} # mapping filename to bids (action method to list af actions)
         diverge, renamedelete = None, None
         for ancestor in ancestors:
             repo.ui.note(_('\ncalculating bids for ancestor %s\n') % ancestor)
             actions, diverge1, renamedelete1 = manifestmerge(
                 repo, wctx, mctx, ancestor, branchmerge, force, matcher,
                 acceptremote, followcopies, forcefulldiff=True)
             _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
             # Track the shortest set of warning on the theory that bid
             # merge will correctly incorporate more information
             if diverge is None or len(diverge1) < len(diverge):
                 diverge = diverge1
             if renamedelete is None or len(renamedelete) < len(renamedelete1):
                 renamedelete = renamedelete1
 
             for f, a in sorted(actions.iteritems()):
                 m, args, msg = a
                 repo.ui.debug(' %s: %s -> %s\n' % (f, msg, m))
                 if f in fbids:
                     d = fbids[f]
                     if m in d:
                         d[m].append(a)
                     else:
                         d[m] = [a]
                 else:
                     fbids[f] = {m: [a]}
 
         # Pick the best bid for each file
         repo.ui.note(_('\nauction for merging merge bids\n'))
         actions = {}
         dms = [] # filenames that have dm actions
         for f, bids in sorted(fbids.items()):
             # bids is a mapping from action method to list af actions
             # Consensus?
             if len(bids) == 1: # all bids are the same kind of method
                 m, l = bids.items()[0]
                 if all(a == l[0] for a in l[1:]): # len(bids) is > 1
                     repo.ui.note(_(" %s: consensus for %s\n") % (f, m))
                     actions[f] = l[0]
                     if m == 'dm':
                         dms.append(f)
                     continue
             # If keep is an option, just do it.
             if 'k' in bids:
                 repo.ui.note(_(" %s: picking 'keep' action\n") % f)
                 actions[f] = bids['k'][0]
                 continue
             # If there are gets and they all agree [how could they not?], do it.
             if 'g' in bids:
                 ga0 = bids['g'][0]
                 if all(a == ga0 for a in bids['g'][1:]):
                     repo.ui.note(_(" %s: picking 'get' action\n") % f)
                     actions[f] = ga0
                     continue
             # TODO: Consider other simple actions such as mode changes
             # Handle inefficient democrazy.
             repo.ui.note(_(' %s: multiple bids for merge action:\n') % f)
             for m, l in sorted(bids.items()):
                 for _f, args, msg in l:
                     repo.ui.note('  %s -> %s\n' % (msg, m))
             # Pick random action. TODO: Instead, prompt user when resolving
             m, l = bids.items()[0]
             repo.ui.warn(_(' %s: ambiguous merge - picked %s action\n') %
                          (f, m))
             actions[f] = l[0]
             if m == 'dm':
                 dms.append(f)
             continue
         # Work around 'dm' that can cause multiple actions for the same file
         for f in dms:
             dm, (f0, flags), msg = actions[f]
             assert dm == 'dm', dm
             if f0 in actions and actions[f0][0] == 'r':
                 # We have one bid for removing a file and another for moving it.
                 # These two could be merged as first move and then delete ...
                 # but instead drop moving and just delete.
                 del actions[f]
         repo.ui.note(_('end of auction\n\n'))
 
     _resolvetrivial(repo, wctx, mctx, ancestors[0], actions)
 
     if wctx.rev() is None:
         fractions = _forgetremoved(wctx, mctx, branchmerge)
         actions.update(fractions)
 
     return actions, diverge, renamedelete
 
 def batchremove(repo, wctx, actions):
     """apply removes to the working directory
 
     yields tuples for progress updates
     """
     verbose = repo.ui.verbose
     try:
         cwd = pycompat.getcwd()
     except OSError as err:
         if err.errno != errno.ENOENT:
             raise
         cwd = None
     i = 0
     for f, args, msg in actions:
         repo.ui.debug(" %s: %s -> r\n" % (f, msg))
         if verbose:
             repo.ui.note(_("removing %s\n") % f)
         wctx[f].audit()
         try:
             wctx[f].remove(ignoremissing=True)
         except OSError as inst:
             repo.ui.warn(_("update failed to remove %s: %s!\n") %
                          (f, inst.strerror))
         if i == 100:
             yield i, f
             i = 0
         i += 1
     if i > 0:
         yield i, f
     if cwd:
         # cwd was present before we started to remove files
         # let's check if it is present after we removed them
         try:
             pycompat.getcwd()
         except OSError as err:
             if err.errno != errno.ENOENT:
                 raise
             # Print a warning if cwd was deleted
             repo.ui.warn(_("current directory was removed\n"
                            "(consider changing to repo root: %s)\n") %
                          repo.root)
 
 def batchget(repo, mctx, wctx, actions):
     """apply gets to the working directory
 
     mctx is the context to get from
 
     yields tuples for progress updates
     """
     verbose = repo.ui.verbose
     fctx = mctx.filectx
     ui = repo.ui
     i = 0
     with repo.wvfs.backgroundclosing(ui, expectedcount=len(actions)):
         for f, (flags, backup), msg in actions:
             repo.ui.debug(" %s: %s -> g\n" % (f, msg))
             if verbose:
                 repo.ui.note(_("getting %s\n") % f)
 
             if backup:
                 absf = repo.wjoin(f)
                 orig = scmutil.origpath(ui, repo, absf)
                 try:
                     if repo.wvfs.isfileorlink(f):
                         util.rename(absf, orig)
                 except OSError as e:
                     if e.errno != errno.ENOENT:
                         raise
 
             if repo.wvfs.isdir(f) and not repo.wvfs.islink(f):
                 repo.wvfs.removedirs(f)
             wctx[f].write(fctx(f).data(), flags, backgroundclose=True)
             if i == 100:
                 yield i, f
                 i = 0
             i += 1
     if i > 0:
         yield i, f
 
 def applyupdates(repo, actions, wctx, mctx, overwrite, labels=None):
     """apply the merge action list to the working directory
 
     wctx is the working copy context
     mctx is the context to be merged into the working copy
 
     Return a tuple of counts (updated, merged, removed, unresolved) that
     describes how many files were affected by the update.
     """
 
     updated, merged, removed = 0, 0, 0
     ms = mergestate.clean(repo, wctx.p1().node(), mctx.node(), labels)
     moves = []
     for m, l in actions.items():
         l.sort()
 
     # 'cd' and 'dc' actions are treated like other merge conflicts
     mergeactions = sorted(actions['cd'])
     mergeactions.extend(sorted(actions['dc']))
     mergeactions.extend(actions['m'])
     for f, args, msg in mergeactions:
         f1, f2, fa, move, anc = args
         if f == '.hgsubstate': # merged internally
             continue
         if f1 is None:
             fcl = filemerge.absentfilectx(wctx, fa)
         else:
             repo.ui.debug(" preserving %s for resolve of %s\n" % (f1, f))
             fcl = wctx[f1]
         if f2 is None:
             fco = filemerge.absentfilectx(mctx, fa)
         else:
             fco = mctx[f2]
         actx = repo[anc]
         if fa in actx:
             fca = actx[fa]
         else:
             # TODO: move to absentfilectx
             fca = repo.filectx(f1, fileid=nullrev)
         ms.add(fcl, fco, fca, f)
         if f1 != f and move:
             moves.append(f1)
 
     _updating = _('updating')
     _files = _('files')
     progress = repo.ui.progress
 
     # remove renamed files after safely stored
     for f in moves:
         if os.path.lexists(repo.wjoin(f)):
             repo.ui.debug("removing %s\n" % f)
             wctx[f].audit()
             wctx[f].remove()
 
     numupdates = sum(len(l) for m, l in actions.items() if m != 'k')
 
     if [a for a in actions['r'] if a[0] == '.hgsubstate']:
         subrepo.submerge(repo, wctx, mctx, wctx, overwrite, labels)
 
     # remove in parallel (must come first)
     z = 0
     prog = worker.worker(repo.ui, 0.001, batchremove, (repo, wctx),
                          actions['r'])
     for i, item in prog:
         z += i
         progress(_updating, z, item=item, total=numupdates, unit=_files)
     removed = len(actions['r'])
 
     # get in parallel
     prog = worker.worker(repo.ui, 0.001, batchget, (repo, mctx, wctx),
                          actions['g'])
     for i, item in prog:
         z += i
         progress(_updating, z, item=item, total=numupdates, unit=_files)
     updated = len(actions['g'])
 
     if [a for a in actions['g'] if a[0] == '.hgsubstate']:
         subrepo.submerge(repo, wctx, mctx, wctx, overwrite, labels)
 
     # forget (manifest only, just log it) (must come first)
     for f, args, msg in actions['f']:
         repo.ui.debug(" %s: %s -> f\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
 
     # re-add (manifest only, just log it)
     for f, args, msg in actions['a']:
         repo.ui.debug(" %s: %s -> a\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
 
     # re-add/mark as modified (manifest only, just log it)
     for f, args, msg in actions['am']:
         repo.ui.debug(" %s: %s -> am\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
 
     # keep (noop, just log it)
     for f, args, msg in actions['k']:
         repo.ui.debug(" %s: %s -> k\n" % (f, msg))
         # no progress
 
     # directory rename, move local
     for f, args, msg in actions['dm']:
         repo.ui.debug(" %s: %s -> dm\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         f0, flags = args
         repo.ui.note(_("moving %s to %s\n") % (f0, f))
         wctx[f].audit()
         wctx[f].write(wctx.filectx(f0).data(), flags)
         wctx[f0].remove()
         updated += 1
 
     # local directory rename, get
     for f, args, msg in actions['dg']:
         repo.ui.debug(" %s: %s -> dg\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         f0, flags = args
         repo.ui.note(_("getting %s to %s\n") % (f0, f))
         wctx[f].write(mctx.filectx(f0).data(), flags)
         updated += 1
 
     # exec
     for f, args, msg in actions['e']:
         repo.ui.debug(" %s: %s -> e\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         flags, = args
         wctx[f].audit()
         wctx[f].setflags('l' in flags, 'x' in flags)
         updated += 1
 
     # the ordering is important here -- ms.mergedriver will raise if the merge
     # driver has changed, and we want to be able to bypass it when overwrite is
     # True
     usemergedriver = not overwrite and mergeactions and ms.mergedriver
 
     if usemergedriver:
         ms.commit()
         proceed = driverpreprocess(repo, ms, wctx, labels=labels)
         # the driver might leave some files unresolved
         unresolvedf = set(ms.unresolved())
         if not proceed:
             # XXX setting unresolved to at least 1 is a hack to make sure we
             # error out
             return updated, merged, removed, max(len(unresolvedf), 1)
         newactions = []
         for f, args, msg in mergeactions:
             if f in unresolvedf:
                 newactions.append((f, args, msg))
         mergeactions = newactions
 
     # premerge
     tocomplete = []
     for f, args, msg in mergeactions:
         repo.ui.debug(" %s: %s -> m (premerge)\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         if f == '.hgsubstate': # subrepo states need updating
             subrepo.submerge(repo, wctx, mctx, wctx.ancestor(mctx),
                              overwrite, labels)
             continue
         wctx[f].audit()
         complete, r = ms.preresolve(f, wctx)
         if not complete:
             numupdates += 1
             tocomplete.append((f, args, msg))
 
     # merge
     for f, args, msg in tocomplete:
         repo.ui.debug(" %s: %s -> m (merge)\n" % (f, msg))
         z += 1
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         ms.resolve(f, wctx)
 
     ms.commit()
 
     unresolved = ms.unresolvedcount()
 
     if usemergedriver and not unresolved and ms.mdstate() != 's':
         if not driverconclude(repo, ms, wctx, labels=labels):
             # XXX setting unresolved to at least 1 is a hack to make sure we
             # error out
             unresolved = max(unresolved, 1)
 
         ms.commit()
 
     msupdated, msmerged, msremoved = ms.counts()
     updated += msupdated
     merged += msmerged
     removed += msremoved
 
     extraactions = ms.actions()
     if extraactions:
         mfiles = set(a[0] for a in actions['m'])
         for k, acts in extraactions.iteritems():
             actions[k].extend(acts)
             # Remove these files from actions['m'] as well. This is important
             # because in recordupdates, files in actions['m'] are processed
             # after files in other actions, and the merge driver might add
             # files to those actions via extraactions above. This can lead to a
             # file being recorded twice, with poor results. This is especially
             # problematic for actions['r'] (currently only possible with the
             # merge driver in the initial merge process; interrupted merges
             # don't go through this flow).
             #
             # The real fix here is to have indexes by both file and action so
             # that when the action for a file is changed it is automatically
             # reflected in the other action lists. But that involves a more
             # complex data structure, so this will do for now.
             #
             # We don't need to do the same operation for 'dc' and 'cd' because
             # those lists aren't consulted again.
             mfiles.difference_update(a[0] for a in acts)
 
         actions['m'] = [a for a in actions['m'] if a[0] in mfiles]
 
     progress(_updating, None, total=numupdates, unit=_files)
 
     return updated, merged, removed, unresolved
 
 def recordupdates(repo, actions, branchmerge):
     "record merge actions to the dirstate"
     # remove (must come first)
     for f, args, msg in actions.get('r', []):
         if branchmerge:
             repo.dirstate.remove(f)
         else:
             repo.dirstate.drop(f)
 
     # forget (must come first)
     for f, args, msg in actions.get('f', []):
         repo.dirstate.drop(f)
 
     # re-add
     for f, args, msg in actions.get('a', []):
         repo.dirstate.add(f)
 
     # re-add/mark as modified
     for f, args, msg in actions.get('am', []):
         if branchmerge:
             repo.dirstate.normallookup(f)
         else:
             repo.dirstate.add(f)
 
     # exec change
     for f, args, msg in actions.get('e', []):
         repo.dirstate.normallookup(f)
 
     # keep
     for f, args, msg in actions.get('k', []):
         pass
 
     # get
     for f, args, msg in actions.get('g', []):
         if branchmerge:
             repo.dirstate.otherparent(f)
         else:
             repo.dirstate.normal(f)
 
     # merge
     for f, args, msg in actions.get('m', []):
         f1, f2, fa, move, anc = args
         if branchmerge:
             # We've done a branch merge, mark this file as merged
             # so that we properly record the merger later
             repo.dirstate.merge(f)
             if f1 != f2: # copy/rename
                 if move:
                     repo.dirstate.remove(f1)
                 if f1 != f:
                     repo.dirstate.copy(f1, f)
                 else:
                     repo.dirstate.copy(f2, f)
         else:
             # We've update-merged a locally modified file, so
             # we set the dirstate to emulate a normal checkout
             # of that file some time in the past. Thus our
             # merge will appear as a normal local file
             # modification.
             if f2 == f: # file not locally copied/moved
                 repo.dirstate.normallookup(f)
             if move:
                 repo.dirstate.drop(f1)
 
     # directory rename, move local
     for f, args, msg in actions.get('dm', []):
         f0, flag = args
         if branchmerge:
             repo.dirstate.add(f)
             repo.dirstate.remove(f0)
             repo.dirstate.copy(f0, f)
         else:
             repo.dirstate.normal(f)
             repo.dirstate.drop(f0)
 
     # directory rename, get
     for f, args, msg in actions.get('dg', []):
         f0, flag = args
         if branchmerge:
             repo.dirstate.add(f)
             repo.dirstate.copy(f0, f)
         else:
             repo.dirstate.normal(f)
 
 def update(repo, node, branchmerge, force, ancestor=None,
            mergeancestor=False, labels=None, matcher=None, mergeforce=False,
            updatecheck=None):
     """
     Perform a merge between the working directory and the given node
 
     node = the node to update to
     branchmerge = whether to merge between branches
     force = whether to force branch merging or file overwriting
     matcher = a matcher to filter file lists (dirstate not updated)
     mergeancestor = whether it is merging with an ancestor. If true,
       we should accept the incoming changes for any prompts that occur.
       If false, merging with an ancestor (fast-forward) is only allowed
       between different named branches. This flag is used by rebase extension
       as a temporary fix and should be avoided in general.
     labels = labels to use for base, local and other
     mergeforce = whether the merge was run with 'merge --force' (deprecated): if
       this is True, then 'force' should be True as well.
 
     The table below shows all the behaviors of the update command
     given the -c and -C or no options, whether the working directory
     is dirty, whether a revision is specified, and the relationship of
     the parent rev to the target rev (linear or not). Match from top first. The
     -n option doesn't exist on the command line, but represents the
     experimental.updatecheck=noconflict option.
 
     This logic is tested by test-update-branches.t.
 
     -c  -C  -n  -m  dirty  rev  linear  |  result
      y   y   *   *    *     *     *     |    (1)
      y   *   y   *    *     *     *     |    (1)
      y   *   *   y    *     *     *     |    (1)
      *   y   y   *    *     *     *     |    (1)
      *   y   *   y    *     *     *     |    (1)
      *   *   y   y    *     *     *     |    (1)
      *   *   *   *    *     n     n     |     x
      *   *   *   *    n     *     *     |    ok
      n   n   n   n    y     *     y     |   merge
      n   n   n   n    y     y     n     |    (2)
      n   n   n   y    y     *     *     |   merge
      n   n   y   n    y     *     *     |  merge if no conflict
      n   y   n   n    y     *     *     |  discard
      y   n   n   n    y     *     *     |    (3)
 
     x = can't happen
     * = don't-care
     1 = incompatible options (checked in commands.py)
     2 = abort: uncommitted changes (commit or update --clean to discard changes)
     3 = abort: uncommitted changes (checked in commands.py)
 
     Return the same tuple as applyupdates().
     """
 
     # This function used to find the default destination if node was None, but
     # that's now in destutil.py.
     assert node is not None
     if not branchmerge and not force:
         # TODO: remove the default once all callers that pass branchmerge=False
         # and force=False pass a value for updatecheck. We may want to allow
         # updatecheck='abort' to better suppport some of these callers.
         if updatecheck is None:
             updatecheck = 'linear'
         assert updatecheck in ('none', 'linear', 'noconflict')
     # If we're doing a partial update, we need to skip updating
     # the dirstate, so make a note of any partial-ness to the
     # update here.
     if matcher is None or matcher.always():
         partial = False
     else:
         partial = True
     with repo.wlock():
         wc = repo[None]
         pl = wc.parents()
         p1 = pl[0]
         pas = [None]
         if ancestor is not None:
             pas = [repo[ancestor]]
 
         overwrite = force and not branchmerge
 
         p2 = repo[node]
         if pas[0] is None:
             if repo.ui.configlist('merge', 'preferancestor', ['*']) == ['*']:
                 cahs = repo.changelog.commonancestorsheads(p1.node(), p2.node())
                 pas = [repo[anc] for anc in (sorted(cahs) or [nullid])]
             else:
                 pas = [p1.ancestor(p2, warn=branchmerge)]
 
         fp1, fp2, xp1, xp2 = p1.node(), p2.node(), str(p1), str(p2)
 
         ### check phase
         if not overwrite:
             if len(pl) > 1:
                 raise error.Abort(_("outstanding uncommitted merge"))
             ms = mergestate.read(repo)
             if list(ms.unresolved()):
                 raise error.Abort(_("outstanding merge conflicts"))
         if branchmerge:
             if pas == [p2]:
                 raise error.Abort(_("merging with a working directory ancestor"
                                    " has no effect"))
             elif pas == [p1]:
                 if not mergeancestor and wc.branch() == p2.branch():
                     raise error.Abort(_("nothing to merge"),
                                      hint=_("use 'hg update' "
                                             "or check 'hg heads'"))
             if not force and (wc.files() or wc.deleted()):
                 raise error.Abort(_("uncommitted changes"),
                                  hint=_("use 'hg status' to list changes"))
             for s in sorted(wc.substate):
                 wc.sub(s).bailifchanged()
 
         elif not overwrite:
             if p1 == p2: # no-op update
                 # call the hooks and exit early
                 repo.hook('preupdate', throw=True, parent1=xp2, parent2='')
                 repo.hook('update', parent1=xp2, parent2='', error=0)
                 return 0, 0, 0, 0
 
             if (updatecheck == 'linear' and
                     pas not in ([p1], [p2])):  # nonlinear
                 dirty = wc.dirty(missing=True)
                 if dirty:
                     # Branching is a bit strange to ensure we do the minimal
-                    # amount of call to obsolete.foreground.
-                    foreground = obsolete.foreground(repo, [p1.node()])
+                    # amount of call to obsutil.foreground.
+                    foreground = obsutil.foreground(repo, [p1.node()])
                     # note: the <node> variable contains a random identifier
                     if repo[node].node() in foreground:
                         pass # allow updating to successors
                     else:
                         msg = _("uncommitted changes")
                         hint = _("commit or update --clean to discard changes")
                         raise error.UpdateAbort(msg, hint=hint)
                 else:
                     # Allow jumping branches if clean and specific rev given
                     pass
 
         if overwrite:
             pas = [wc]
         elif not branchmerge:
             pas = [p1]
 
         # deprecated config: merge.followcopies
         followcopies = repo.ui.configbool('merge', 'followcopies', True)
         if overwrite:
             followcopies = False
         elif not pas[0]:
             followcopies = False
         if not branchmerge and not wc.dirty(missing=True):
             followcopies = False
 
         ### calculate phase
         actionbyfile, diverge, renamedelete = calculateupdates(
             repo, wc, p2, pas, branchmerge, force, mergeancestor,
             followcopies, matcher=matcher, mergeforce=mergeforce)
 
         if updatecheck == 'noconflict':
             for f, (m, args, msg) in actionbyfile.iteritems():
                 if m not in ('g', 'k', 'e', 'r'):
                     msg = _("conflicting changes")
                     hint = _("commit or update --clean to discard changes")
                     raise error.Abort(msg, hint=hint)
 
         # Prompt and create actions. Most of this is in the resolve phase
         # already, but we can't handle .hgsubstate in filemerge or
         # subrepo.submerge yet so we have to keep prompting for it.
         if '.hgsubstate' in actionbyfile:
             f = '.hgsubstate'
             m, args, msg = actionbyfile[f]
             prompts = filemerge.partextras(labels)
             prompts['f'] = f
             if m == 'cd':
                 if repo.ui.promptchoice(
                     _("local%(l)s changed %(f)s which other%(o)s deleted\n"
                       "use (c)hanged version or (d)elete?"
                       "$$ &Changed $$ &Delete") % prompts, 0):
                     actionbyfile[f] = ('r', None, "prompt delete")
                 elif f in p1:
                     actionbyfile[f] = ('am', None, "prompt keep")
                 else:
                     actionbyfile[f] = ('a', None, "prompt keep")
             elif m == 'dc':
                 f1, f2, fa, move, anc = args
                 flags = p2[f2].flags()
                 if repo.ui.promptchoice(
                     _("other%(o)s changed %(f)s which local%(l)s deleted\n"
                       "use (c)hanged version or leave (d)eleted?"
                       "$$ &Changed $$ &Deleted") % prompts, 0) == 0:
                     actionbyfile[f] = ('g', (flags, False), "prompt recreating")
                 else:
                     del actionbyfile[f]
 
         # Convert to dictionary-of-lists format
         actions = dict((m, []) for m in 'a am f g cd dc r dm dg m e k'.split())
         for f, (m, args, msg) in actionbyfile.iteritems():
             if m not in actions:
                 actions[m] = []
             actions[m].append((f, args, msg))
 
         if not util.fscasesensitive(repo.path):
             # check collision between files only in p2 for clean update
             if (not branchmerge and
                 (force or not wc.dirty(missing=True, branch=False))):
                 _checkcollision(repo, p2.manifest(), None)
             else:
                 _checkcollision(repo, wc.manifest(), actions)
 
         # divergent renames
         for f, fl in sorted(diverge.iteritems()):
             repo.ui.warn(_("note: possible conflict - %s was renamed "
                            "multiple times to:\n") % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
 
         # rename and delete
         for f, fl in sorted(renamedelete.iteritems()):
             repo.ui.warn(_("note: possible conflict - %s was deleted "
                            "and renamed to:\n") % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
 
         ### apply phase
         if not branchmerge: # just jump to the new rev
             fp1, fp2, xp1, xp2 = fp2, nullid, xp2, ''
         if not partial:
             repo.hook('preupdate', throw=True, parent1=xp1, parent2=xp2)
             # note that we're in the middle of an update
             repo.vfs.write('updatestate', p2.hex())
 
         stats = applyupdates(repo, actions, wc, p2, overwrite, labels=labels)
 
         if not partial:
             with repo.dirstate.parentchange():
                 repo.setparents(fp1, fp2)
                 recordupdates(repo, actions, branchmerge)
                 # update completed, clear state
                 util.unlink(repo.vfs.join('updatestate'))
 
                 if not branchmerge:
                     repo.dirstate.setbranch(p2.branch())
 
     if not partial:
         repo.hook('update', parent1=xp1, parent2=xp2, error=stats[3])
     return stats
 
 def graft(repo, ctx, pctx, labels, keepparent=False):
     """Do a graft-like merge.
 
     This is a merge where the merge ancestor is chosen such that one
     or more changesets are grafted onto the current changeset. In
     addition to the merge, this fixes up the dirstate to include only
     a single parent (if keepparent is False) and tries to duplicate any
     renames/copies appropriately.
 
     ctx - changeset to rebase
     pctx - merge base, usually ctx.p1()
     labels - merge labels eg ['local', 'graft']
     keepparent - keep second parent if any
 
     """
     # If we're grafting a descendant onto an ancestor, be sure to pass
     # mergeancestor=True to update. This does two things: 1) allows the merge if
     # the destination is the same as the parent of the ctx (so we can use graft
     # to copy commits), and 2) informs update that the incoming changes are
     # newer than the destination so it doesn't prompt about "remote changed foo
     # which local deleted".
     mergeancestor = repo.changelog.isancestor(repo['.'].node(), ctx.node())
 
     stats = update(repo, ctx.node(), True, True, pctx.node(),
                    mergeancestor=mergeancestor, labels=labels)
 
     pother = nullid
     parents = ctx.parents()
     if keepparent and len(parents) == 2 and pctx in parents:
         parents.remove(pctx)
         pother = parents[0].node()
 
     with repo.dirstate.parentchange():
         repo.setparents(repo['.'].node(), pother)
         repo.dirstate.write(repo.currenttransaction())
         # fix up dirstate for copies and renames
         copies.duplicatecopies(repo, ctx.rev(), pctx.rev())
     return stats

mercurial/obsolete.py

@@ -1,1115 +1,1094
 # obsolete.py - obsolete markers handling
 #
 # Copyright 2012 Pierre-Yves David <[e-mail]>
 #                Logilab SA        <[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.
 
 """Obsolete marker handling
 
 An obsolete marker maps an old changeset to a list of new
 changesets. If the list of new changesets is empty, the old changeset
 is said to be "killed". Otherwise, the old changeset is being
 "replaced" by the new changesets.
 
 Obsolete markers can be used to record and distribute changeset graph
 transformations performed by history rewrite operations, and help
 building new tools to reconcile conflicting rewrite actions. To
 facilitate conflict resolution, markers include various annotations
 besides old and news changeset identifiers, such as creation date or
 author name.
 
 The old obsoleted changeset is called a "precursor" and possible
 replacements are called "successors". Markers that used changeset X as
 a precursor are called "successor markers of X" because they hold
 information about the successors of X. Markers that use changeset Y as
 a successors are call "precursor markers of Y" because they hold
 information about the precursors of Y.
 
 Examples:
 
 - When changeset A is replaced by changeset A', one marker is stored:
 
     (A, (A',))
 
 - When changesets A and B are folded into a new changeset C, two markers are
   stored:
 
     (A, (C,)) and (B, (C,))
 
 - When changeset A is simply "pruned" from the graph, a marker is created:
 
     (A, ())
 
 - When changeset A is split into B and C, a single marker is used:
 
     (A, (B, C))
 
   We use a single marker to distinguish the "split" case from the "divergence"
   case. If two independent operations rewrite the same changeset A in to A' and
   A'', we have an error case: divergent rewriting. We can detect it because
   two markers will be created independently:
 
   (A, (B,)) and (A, (C,))
 
 Format
 ------
 
 Markers are stored in an append-only file stored in
 '.hg/store/obsstore'.
 
 The file starts with a version header:
 
 - 1 unsigned byte: version number, starting at zero.
 
 The header is followed by the markers. Marker format depend of the version. See
 comment associated with each format for details.
 
 """
 from __future__ import absolute_import
 
 import errno
 import struct
 
 from .i18n import _
 from . import (
     error,
     node,
     obsutil,
     phases,
     policy,
     util,
 )
 
 parsers = policy.importmod(r'parsers')
 
 _pack = struct.pack
 _unpack = struct.unpack
 _calcsize = struct.calcsize
 propertycache = util.propertycache
 
 # the obsolete feature is not mature enough to be enabled by default.
 # you have to rely on third party extension extension to enable this.
 _enabled = False
 
 # Options for obsolescence
 createmarkersopt = 'createmarkers'
 allowunstableopt = 'allowunstable'
 exchangeopt = 'exchange'
 
 def isenabled(repo, option):
     """Returns True if the given repository has the given obsolete option
     enabled.
     """
     result = set(repo.ui.configlist('experimental', 'evolution'))
     if 'all' in result:
         return True
 
     # For migration purposes, temporarily return true if the config hasn't been
     # set but _enabled is true.
     if len(result) == 0 and _enabled:
         return True
 
     # createmarkers must be enabled if other options are enabled
     if ((allowunstableopt in result or exchangeopt in result) and
         not createmarkersopt in result):
         raise error.Abort(_("'createmarkers' obsolete option must be enabled "
                            "if other obsolete options are enabled"))
 
     return option in result
 
 ### obsolescence marker flag
 
 ## bumpedfix flag
 #
 # When a changeset A' succeed to a changeset A which became public, we call A'
 # "bumped" because it's a successors of a public changesets
 #
 # o    A' (bumped)
 # |`:
 # | o  A
 # |/
 # o    Z
 #
 # The way to solve this situation is to create a new changeset Ad as children
 # of A. This changeset have the same content than A'. So the diff from A to A'
 # is the same than the diff from A to Ad. Ad is marked as a successors of A'
 #
 # o   Ad
 # |`:
 # | x A'
 # |'|
 # o | A
 # |/
 # o Z
 #
 # But by transitivity Ad is also a successors of A. To avoid having Ad marked
 # as bumped too, we add the `bumpedfix` flag to the marker. <A', (Ad,)>.
 # This flag mean that the successors express the changes between the public and
 # bumped version and fix the situation, breaking the transitivity of
 # "bumped" here.
 bumpedfix = 1
 usingsha256 = 2
 
 ## Parsing and writing of version "0"
 #
 # The header is followed by the markers. Each marker is made of:
 #
 # - 1 uint8 : number of new changesets "N", can be zero.
 #
 # - 1 uint32: metadata size "M" in bytes.
 #
 # - 1 byte: a bit field. It is reserved for flags used in common
 #   obsolete marker operations, to avoid repeated decoding of metadata
 #   entries.
 #
 # - 20 bytes: obsoleted changeset identifier.
 #
 # - N*20 bytes: new changesets identifiers.
 #
 # - M bytes: metadata as a sequence of nul-terminated strings. Each
 #   string contains a key and a value, separated by a colon ':', without
 #   additional encoding. Keys cannot contain '\0' or ':' and values
 #   cannot contain '\0'.
 _fm0version = 0
 _fm0fixed   = '>BIB20s'
 _fm0node = '20s'
 _fm0fsize = _calcsize(_fm0fixed)
 _fm0fnodesize = _calcsize(_fm0node)
 
 def _fm0readmarkers(data, off):
     # Loop on markers
     l = len(data)
     while off + _fm0fsize <= l:
         # read fixed part
         cur = data[off:off + _fm0fsize]
         off += _fm0fsize
         numsuc, mdsize, flags, pre = _unpack(_fm0fixed, cur)
         # read replacement
         sucs = ()
         if numsuc:
             s = (_fm0fnodesize * numsuc)
             cur = data[off:off + s]
             sucs = _unpack(_fm0node * numsuc, cur)
             off += s
         # read metadata
         # (metadata will be decoded on demand)
         metadata = data[off:off + mdsize]
         if len(metadata) != mdsize:
             raise error.Abort(_('parsing obsolete marker: metadata is too '
                                'short, %d bytes expected, got %d')
                              % (mdsize, len(metadata)))
         off += mdsize
         metadata = _fm0decodemeta(metadata)
         try:
             when, offset = metadata.pop('date', '0 0').split(' ')
             date = float(when), int(offset)
         except ValueError:
             date = (0., 0)
         parents = None
         if 'p2' in metadata:
             parents = (metadata.pop('p1', None), metadata.pop('p2', None))
         elif 'p1' in metadata:
             parents = (metadata.pop('p1', None),)
         elif 'p0' in metadata:
             parents = ()
         if parents is not None:
             try:
                 parents = tuple(node.bin(p) for p in parents)
                 # if parent content is not a nodeid, drop the data
                 for p in parents:
                     if len(p) != 20:
                         parents = None
                         break
             except TypeError:
                 # if content cannot be translated to nodeid drop the data.
                 parents = None
 
         metadata = tuple(sorted(metadata.iteritems()))
 
         yield (pre, sucs, flags, metadata, date, parents)
 
 def _fm0encodeonemarker(marker):
     pre, sucs, flags, metadata, date, parents = marker
     if flags & usingsha256:
         raise error.Abort(_('cannot handle sha256 with old obsstore format'))
     metadata = dict(metadata)
     time, tz = date
     metadata['date'] = '%r %i' % (time, tz)
     if parents is not None:
         if not parents:
             # mark that we explicitly recorded no parents
             metadata['p0'] = ''
         for i, p in enumerate(parents, 1):
             metadata['p%i' % i] = node.hex(p)
     metadata = _fm0encodemeta(metadata)
     numsuc = len(sucs)
     format = _fm0fixed + (_fm0node * numsuc)
     data = [numsuc, len(metadata), flags, pre]
     data.extend(sucs)
     return _pack(format, *data) + metadata
 
 def _fm0encodemeta(meta):
     """Return encoded metadata string to string mapping.
 
     Assume no ':' in key and no '\0' in both key and value."""
     for key, value in meta.iteritems():
         if ':' in key or '\0' in key:
             raise ValueError("':' and '\0' are forbidden in metadata key'")
         if '\0' in value:
             raise ValueError("':' is forbidden in metadata value'")
     return '\0'.join(['%s:%s' % (k, meta[k]) for k in sorted(meta)])
 
 def _fm0decodemeta(data):
     """Return string to string dictionary from encoded version."""
     d = {}
     for l in data.split('\0'):
         if l:
             key, value = l.split(':')
             d[key] = value
     return d
 
 ## Parsing and writing of version "1"
 #
 # The header is followed by the markers. Each marker is made of:
 #
 # - uint32: total size of the marker (including this field)
 #
 # - float64: date in seconds since epoch
 #
 # - int16: timezone offset in minutes
 #
 # - uint16: a bit field. It is reserved for flags used in common
 #   obsolete marker operations, to avoid repeated decoding of metadata
 #   entries.
 #
 # - uint8: number of successors "N", can be zero.
 #
 # - uint8: number of parents "P", can be zero.
 #
 #     0: parents data stored but no parent,
 #     1: one parent stored,
 #     2: two parents stored,
 #     3: no parent data stored
 #
 # - uint8: number of metadata entries M
 #
 # - 20 or 32 bytes: precursor changeset identifier.
 #
 # - N*(20 or 32) bytes: successors changesets identifiers.
 #
 # - P*(20 or 32) bytes: parents of the precursors changesets.
 #
 # - M*(uint8, uint8): size of all metadata entries (key and value)
 #
 # - remaining bytes: the metadata, each (key, value) pair after the other.
 _fm1version = 1
 _fm1fixed = '>IdhHBBB20s'
 _fm1nodesha1 = '20s'
 _fm1nodesha256 = '32s'
 _fm1nodesha1size = _calcsize(_fm1nodesha1)
 _fm1nodesha256size = _calcsize(_fm1nodesha256)
 _fm1fsize = _calcsize(_fm1fixed)
 _fm1parentnone = 3
 _fm1parentshift = 14
 _fm1parentmask = (_fm1parentnone << _fm1parentshift)
 _fm1metapair = 'BB'
 _fm1metapairsize = _calcsize('BB')
 
 def _fm1purereadmarkers(data, off):
     # make some global constants local for performance
     noneflag = _fm1parentnone
     sha2flag = usingsha256
     sha1size = _fm1nodesha1size
     sha2size = _fm1nodesha256size
     sha1fmt = _fm1nodesha1
     sha2fmt = _fm1nodesha256
     metasize = _fm1metapairsize
     metafmt = _fm1metapair
     fsize = _fm1fsize
     unpack = _unpack
 
     # Loop on markers
     stop = len(data) - _fm1fsize
     ufixed = struct.Struct(_fm1fixed).unpack
 
     while off <= stop:
         # read fixed part
         o1 = off + fsize
         t, secs, tz, flags, numsuc, numpar, nummeta, prec = ufixed(data[off:o1])
 
         if flags & sha2flag:
             # FIXME: prec was read as a SHA1, needs to be amended
 
             # read 0 or more successors
             if numsuc == 1:
                 o2 = o1 + sha2size
                 sucs = (data[o1:o2],)
             else:
                 o2 = o1 + sha2size * numsuc
                 sucs = unpack(sha2fmt * numsuc, data[o1:o2])
 
             # read parents
             if numpar == noneflag:
                 o3 = o2
                 parents = None
             elif numpar == 1:
                 o3 = o2 + sha2size
                 parents = (data[o2:o3],)
             else:
                 o3 = o2 + sha2size * numpar
                 parents = unpack(sha2fmt * numpar, data[o2:o3])
         else:
             # read 0 or more successors
             if numsuc == 1:
                 o2 = o1 + sha1size
                 sucs = (data[o1:o2],)
             else:
                 o2 = o1 + sha1size * numsuc
                 sucs = unpack(sha1fmt * numsuc, data[o1:o2])
 
             # read parents
             if numpar == noneflag:
                 o3 = o2
                 parents = None
             elif numpar == 1:
                 o3 = o2 + sha1size
                 parents = (data[o2:o3],)
             else:
                 o3 = o2 + sha1size * numpar
                 parents = unpack(sha1fmt * numpar, data[o2:o3])
 
         # read metadata
         off = o3 + metasize * nummeta
         metapairsize = unpack('>' + (metafmt * nummeta), data[o3:off])
         metadata = []
         for idx in xrange(0, len(metapairsize), 2):
             o1 = off + metapairsize[idx]
             o2 = o1 + metapairsize[idx + 1]
             metadata.append((data[off:o1], data[o1:o2]))
             off = o2
 
         yield (prec, sucs, flags, tuple(metadata), (secs, tz * 60), parents)
 
 def _fm1encodeonemarker(marker):
     pre, sucs, flags, metadata, date, parents = marker
     # determine node size
     _fm1node = _fm1nodesha1
     if flags & usingsha256:
         _fm1node = _fm1nodesha256
     numsuc = len(sucs)
     numextranodes = numsuc
     if parents is None:
         numpar = _fm1parentnone
     else:
         numpar = len(parents)
         numextranodes += numpar
     formatnodes = _fm1node * numextranodes
     formatmeta = _fm1metapair * len(metadata)
     format = _fm1fixed + formatnodes + formatmeta
     # tz is stored in minutes so we divide by 60
     tz = date[1]//60
     data = [None, date[0], tz, flags, numsuc, numpar, len(metadata), pre]
     data.extend(sucs)
     if parents is not None:
         data.extend(parents)
     totalsize = _calcsize(format)
     for key, value in metadata:
         lk = len(key)
         lv = len(value)
         data.append(lk)
         data.append(lv)
         totalsize += lk + lv
     data[0] = totalsize
     data = [_pack(format, *data)]
     for key, value in metadata:
         data.append(key)
         data.append(value)
     return ''.join(data)
 
 def _fm1readmarkers(data, off):
     native = getattr(parsers, 'fm1readmarkers', None)
     if not native:
         return _fm1purereadmarkers(data, off)
     stop = len(data) - _fm1fsize
     return native(data, off, stop)
 
 # mapping to read/write various marker formats
 # <version> -> (decoder, encoder)
 formats = {_fm0version: (_fm0readmarkers, _fm0encodeonemarker),
            _fm1version: (_fm1readmarkers, _fm1encodeonemarker)}
 
 def _readmarkerversion(data):
     return _unpack('>B', data[0:1])[0]
 
 @util.nogc
 def _readmarkers(data):
     """Read and enumerate markers from raw data"""
     diskversion = _readmarkerversion(data)
     off = 1
     if diskversion not in formats:
         msg = _('parsing obsolete marker: unknown version %r') % diskversion
         raise error.UnknownVersion(msg, version=diskversion)
     return diskversion, formats[diskversion][0](data, off)
 
 def encodeheader(version=_fm0version):
     return _pack('>B', version)
 
 def encodemarkers(markers, addheader=False, version=_fm0version):
     # Kept separate from flushmarkers(), it will be reused for
     # markers exchange.
     encodeone = formats[version][1]
     if addheader:
         yield encodeheader(version)
     for marker in markers:
         yield encodeone(marker)
 
 
 class marker(object):
     """Wrap obsolete marker raw data"""
 
     def __init__(self, repo, data):
         # the repo argument will be used to create changectx in later version
         self._repo = repo
         self._data = data
         self._decodedmeta = None
 
     def __hash__(self):
         return hash(self._data)
 
     def __eq__(self, other):
         if type(other) != type(self):
             return False
         return self._data == other._data
 
     def precnode(self):
         """Precursor changeset node identifier"""
         return self._data[0]
 
     def succnodes(self):
         """List of successor changesets node identifiers"""
         return self._data[1]
 
     def parentnodes(self):
         """Parents of the precursors (None if not recorded)"""
         return self._data[5]
 
     def metadata(self):
         """Decoded metadata dictionary"""
         return dict(self._data[3])
 
     def date(self):
         """Creation date as (unixtime, offset)"""
         return self._data[4]
 
     def flags(self):
         """The flags field of the marker"""
         return self._data[2]
 
 @util.nogc
 def _addsuccessors(successors, markers):
     for mark in markers:
         successors.setdefault(mark[0], set()).add(mark)
 
 @util.nogc
 def _addprecursors(precursors, markers):
     for mark in markers:
         for suc in mark[1]:
             precursors.setdefault(suc, set()).add(mark)
 
 @util.nogc
 def _addchildren(children, markers):
     for mark in markers:
         parents = mark[5]
         if parents is not None:
             for p in parents:
                 children.setdefault(p, set()).add(mark)
 
 def _checkinvalidmarkers(markers):
     """search for marker with invalid data and raise error if needed
 
     Exist as a separated function to allow the evolve extension for a more
     subtle handling.
     """
     for mark in markers:
         if node.nullid in mark[1]:
             raise error.Abort(_('bad obsolescence marker detected: '
                                'invalid successors nullid'))
 
 class obsstore(object):
     """Store obsolete markers
 
     Markers can be accessed with two mappings:
     - precursors[x] -> set(markers on precursors edges of x)
     - successors[x] -> set(markers on successors edges of x)
     - children[x]   -> set(markers on precursors edges of children(x)
     """
 
     fields = ('prec', 'succs', 'flag', 'meta', 'date', 'parents')
     # prec:    nodeid, precursor changesets
     # succs:   tuple of nodeid, successor changesets (0-N length)
     # flag:    integer, flag field carrying modifier for the markers (see doc)
     # meta:    binary blob, encoded metadata dictionary
     # date:    (float, int) tuple, date of marker creation
     # parents: (tuple of nodeid) or None, parents of precursors
     #          None is used when no data has been recorded
 
     def __init__(self, svfs, defaultformat=_fm1version, readonly=False):
         # caches for various obsolescence related cache
         self.caches = {}
         self.svfs = svfs
         self._defaultformat = defaultformat
         self._readonly = readonly
 
     def __iter__(self):
         return iter(self._all)
 
     def __len__(self):
         return len(self._all)
 
     def __nonzero__(self):
         if not self._cached('_all'):
             try:
                 return self.svfs.stat('obsstore').st_size > 1
             except OSError as inst:
                 if inst.errno != errno.ENOENT:
                     raise
                 # just build an empty _all list if no obsstore exists, which
                 # avoids further stat() syscalls
                 pass
         return bool(self._all)
 
     __bool__ = __nonzero__
 
     @property
     def readonly(self):
         """True if marker creation is disabled
 
         Remove me in the future when obsolete marker is always on."""
         return self._readonly
 
     def create(self, transaction, prec, succs=(), flag=0, parents=None,
                date=None, metadata=None, ui=None):
         """obsolete: add a new obsolete marker
 
         * ensuring it is hashable
         * check mandatory metadata
         * encode metadata
 
         If you are a human writing code creating marker you want to use the
         `createmarkers` function in this module instead.
 
         return True if a new marker have been added, False if the markers
         already existed (no op).
         """
         if metadata is None:
             metadata = {}
         if date is None:
             if 'date' in metadata:
                 # as a courtesy for out-of-tree extensions
                 date = util.parsedate(metadata.pop('date'))
             elif ui is not None:
                 date = ui.configdate('devel', 'default-date')
                 if date is None:
                     date = util.makedate()
             else:
                 date = util.makedate()
         if len(prec) != 20:
             raise ValueError(prec)
         for succ in succs:
             if len(succ) != 20:
                 raise ValueError(succ)
         if prec in succs:
             raise ValueError(_('in-marker cycle with %s') % node.hex(prec))
 
         metadata = tuple(sorted(metadata.iteritems()))
 
         marker = (str(prec), tuple(succs), int(flag), metadata, date, parents)
         return bool(self.add(transaction, [marker]))
 
     def add(self, transaction, markers):
         """Add new markers to the store
 
         Take care of filtering duplicate.
         Return the number of new marker."""
         if self._readonly:
             raise error.Abort(_('creating obsolete markers is not enabled on '
                               'this repo'))
         known = set()
         getsuccessors = self.successors.get
         new = []
         for m in markers:
             if m not in getsuccessors(m[0], ()) and m not in known:
                 known.add(m)
                 new.append(m)
         if new:
             f = self.svfs('obsstore', 'ab')
             try:
                 offset = f.tell()
                 transaction.add('obsstore', offset)
                 # offset == 0: new file - add the version header
                 for bytes in encodemarkers(new, offset == 0, self._version):
                     f.write(bytes)
             finally:
                 # XXX: f.close() == filecache invalidation == obsstore rebuilt.
                 # call 'filecacheentry.refresh()'  here
                 f.close()
             self._addmarkers(new)
             # new marker *may* have changed several set. invalidate the cache.
             self.caches.clear()
         # records the number of new markers for the transaction hooks
         previous = int(transaction.hookargs.get('new_obsmarkers', '0'))
         transaction.hookargs['new_obsmarkers'] = str(previous + len(new))
         return len(new)
 
     def mergemarkers(self, transaction, data):
         """merge a binary stream of markers inside the obsstore
 
         Returns the number of new markers added."""
         version, markers = _readmarkers(data)
         return self.add(transaction, markers)
 
     @propertycache
     def _data(self):
         return self.svfs.tryread('obsstore')
 
     @propertycache
     def _version(self):
         if len(self._data) >= 1:
             return _readmarkerversion(self._data)
         else:
             return self._defaultformat
 
     @propertycache
     def _all(self):
         data = self._data
         if not data:
             return []
         self._version, markers = _readmarkers(data)
         markers = list(markers)
         _checkinvalidmarkers(markers)
         return markers
 
     @propertycache
     def successors(self):
         successors = {}
         _addsuccessors(successors, self._all)
         return successors
 
     @propertycache
     def precursors(self):
         precursors = {}
         _addprecursors(precursors, self._all)
         return precursors
 
     @propertycache
     def children(self):
         children = {}
         _addchildren(children, self._all)
         return children
 
     def _cached(self, attr):
         return attr in self.__dict__
 
     def _addmarkers(self, markers):
         markers = list(markers) # to allow repeated iteration
         self._all.extend(markers)
         if self._cached('successors'):
             _addsuccessors(self.successors, markers)
         if self._cached('precursors'):
             _addprecursors(self.precursors, markers)
         if self._cached('children'):
             _addchildren(self.children, markers)
         _checkinvalidmarkers(markers)
 
     def relevantmarkers(self, nodes):
         """return a set of all obsolescence markers relevant to a set of nodes.
 
         "relevant" to a set of nodes mean:
 
         - marker that use this changeset as successor
         - prune marker of direct children on this changeset
         - recursive application of the two rules on precursors of these markers
 
         It is a set so you cannot rely on order."""
 
         pendingnodes = set(nodes)
         seenmarkers = set()
         seennodes = set(pendingnodes)
         precursorsmarkers = self.precursors
         succsmarkers = self.successors
         children = self.children
         while pendingnodes:
             direct = set()
             for current in pendingnodes:
                 direct.update(precursorsmarkers.get(current, ()))
                 pruned = [m for m in children.get(current, ()) if not m[1]]
                 direct.update(pruned)
                 pruned = [m for m in succsmarkers.get(current, ()) if not m[1]]
                 direct.update(pruned)
             direct -= seenmarkers
             pendingnodes = set([m[0] for m in direct])
             seenmarkers |= direct
             pendingnodes -= seennodes
             seennodes |= pendingnodes
         return seenmarkers
 
 def makestore(ui, repo):
     """Create an obsstore instance from a repo."""
     # read default format for new obsstore.
     # developer config: format.obsstore-version
     defaultformat = ui.configint('format', 'obsstore-version', None)
     # rely on obsstore class default when possible.
     kwargs = {}
     if defaultformat is not None:
         kwargs['defaultformat'] = defaultformat
     readonly = not isenabled(repo, createmarkersopt)
     store = obsstore(repo.svfs, readonly=readonly, **kwargs)
     if store and readonly:
         ui.warn(_('obsolete feature not enabled but %i markers found!\n')
                 % len(list(store)))
     return store
 
 def commonversion(versions):
     """Return the newest version listed in both versions and our local formats.
 
     Returns None if no common version exists.
     """
     versions.sort(reverse=True)
     # search for highest version known on both side
     for v in versions:
         if v in formats:
             return v
     return None
 
 # arbitrary picked to fit into 8K limit from HTTP server
 # you have to take in account:
 # - the version header
 # - the base85 encoding
 _maxpayload = 5300
 
 def _pushkeyescape(markers):
     """encode markers into a dict suitable for pushkey exchange
 
     - binary data is base85 encoded
     - split in chunks smaller than 5300 bytes"""
     keys = {}
     parts = []
     currentlen = _maxpayload * 2  # ensure we create a new part
     for marker in markers:
         nextdata = _fm0encodeonemarker(marker)
         if (len(nextdata) + currentlen > _maxpayload):
             currentpart = []
             currentlen = 0
             parts.append(currentpart)
         currentpart.append(nextdata)
         currentlen += len(nextdata)
     for idx, part in enumerate(reversed(parts)):
         data = ''.join([_pack('>B', _fm0version)] + part)
         keys['dump%i' % idx] = util.b85encode(data)
     return keys
 
 def listmarkers(repo):
     """List markers over pushkey"""
     if not repo.obsstore:
         return {}
     return _pushkeyescape(sorted(repo.obsstore))
 
 def pushmarker(repo, key, old, new):
     """Push markers over pushkey"""
     if not key.startswith('dump'):
         repo.ui.warn(_('unknown key: %r') % key)
         return False
     if old:
         repo.ui.warn(_('unexpected old value for %r') % key)
         return False
     data = util.b85decode(new)
     lock = repo.lock()
     try:
         tr = repo.transaction('pushkey: obsolete markers')
         try:
             repo.obsstore.mergemarkers(tr, data)
             repo.invalidatevolatilesets()
             tr.close()
             return True
         finally:
             tr.release()
     finally:
         lock.release()
 
 def getmarkers(repo, nodes=None, exclusive=False):
     """returns markers known in a repository
 
     If <nodes> is specified, only markers "relevant" to those nodes are are
     returned"""
     if nodes is None:
         rawmarkers = repo.obsstore
     elif exclusive:
         rawmarkers = obsutil.exclusivemarkers(repo, nodes)
     else:
         rawmarkers = repo.obsstore.relevantmarkers(nodes)
 
     for markerdata in rawmarkers:
         yield marker(repo, markerdata)
 
 def relevantmarkers(repo, node):
     """all obsolete markers relevant to some revision"""
     for markerdata in repo.obsstore.relevantmarkers(node):
         yield marker(repo, markerdata)
 
 
 def precursormarkers(ctx):
     """obsolete marker marking this changeset as a successors"""
     for data in ctx.repo().obsstore.precursors.get(ctx.node(), ()):
         yield marker(ctx.repo(), data)
 
 def successormarkers(ctx):
     """obsolete marker making this changeset obsolete"""
     for data in ctx.repo().obsstore.successors.get(ctx.node(), ()):
         yield marker(ctx.repo(), data)
 
-def foreground(repo, nodes):
-    """return all nodes in the "foreground" of other node
-
-    The foreground of a revision is anything reachable using parent -> children
-    or precursor -> successor relation. It is very similar to "descendant" but
-    augmented with obsolescence information.
-
-    Beware that possible obsolescence cycle may result if complex situation.
-    """
-    repo = repo.unfiltered()
-    foreground = set(repo.set('%ln::', nodes))
-    if repo.obsstore:
-        # We only need this complicated logic if there is obsolescence
-        # XXX will probably deserve an optimised revset.
-        nm = repo.changelog.nodemap
-        plen = -1
-        # compute the whole set of successors or descendants
-        while len(foreground) != plen:
-            plen = len(foreground)
-            succs = set(c.node() for c in foreground)
-            mutable = [c.node() for c in foreground if c.mutable()]
-            succs.update(obsutil.allsuccessors(repo.obsstore, mutable))
-            known = (n for n in succs if n in nm)
-            foreground = set(repo.set('%ln::', known))
-    return set(c.node() for c in foreground)
-
 # keep compatibility for the 4.3 cycle
 def allprecursors(obsstore, nodes, ignoreflags=0):
     movemsg = 'obsolete.allprecursors moved to obsutil.allprecursors'
     util.nouideprecwarn(movemsg, '4.3')
     return obsutil.allprecursors(obsstore, nodes, ignoreflags)
 
 def allsuccessors(obsstore, nodes, ignoreflags=0):
     movemsg = 'obsolete.allsuccessors moved to obsutil.allsuccessors'
     util.nouideprecwarn(movemsg, '4.3')
     return obsutil.allsuccessors(obsstore, nodes, ignoreflags)
 
 def exclusivemarkers(repo, nodes):
     movemsg = 'obsolete.exclusivemarkers moved to obsutil.exclusivemarkers'
     repo.ui.deprecwarn(movemsg, '4.3')
     return obsutil.exclusivemarkers(repo, nodes)
 
+def foreground(repo, nodes):
+    movemsg = 'obsolete.foreground moved to obsutil.foreground'
+    repo.ui.deprecwarn(movemsg, '4.3')
+    return obsutil.foreground(repo, nodes)
+
 def successorssets(repo, initialnode, cache=None):
     movemsg = 'obsolete.successorssets moved to obsutil.successorssets'
     repo.ui.deprecwarn(movemsg, '4.3')
     return obsutil.successorssets(repo, initialnode, cache=cache)
 
 # mapping of 'set-name' -> <function to compute this set>
 cachefuncs = {}
 def cachefor(name):
     """Decorator to register a function as computing the cache for a set"""
     def decorator(func):
         if name in cachefuncs:
             msg = "duplicated registration for volatileset '%s' (existing: %r)"
             raise error.ProgrammingError(msg % (name, cachefuncs[name]))
         cachefuncs[name] = func
         return func
     return decorator
 
 def getrevs(repo, name):
     """Return the set of revision that belong to the <name> set
 
     Such access may compute the set and cache it for future use"""
     repo = repo.unfiltered()
     if not repo.obsstore:
         return frozenset()
     if name not in repo.obsstore.caches:
         repo.obsstore.caches[name] = cachefuncs[name](repo)
     return repo.obsstore.caches[name]
 
 # To be simple we need to invalidate obsolescence cache when:
 #
 # - new changeset is added:
 # - public phase is changed
 # - obsolescence marker are added
 # - strip is used a repo
 def clearobscaches(repo):
     """Remove all obsolescence related cache from a repo
 
     This remove all cache in obsstore is the obsstore already exist on the
     repo.
 
     (We could be smarter here given the exact event that trigger the cache
     clearing)"""
     # only clear cache is there is obsstore data in this repo
     if 'obsstore' in repo._filecache:
         repo.obsstore.caches.clear()
 
 def _mutablerevs(repo):
     """the set of mutable revision in the repository"""
     return repo._phasecache.getrevset(repo, (phases.draft, phases.secret))
 
 @cachefor('obsolete')
 def _computeobsoleteset(repo):
     """the set of obsolete revisions"""
     getnode = repo.changelog.node
     notpublic = _mutablerevs(repo)
     isobs = repo.obsstore.successors.__contains__
     obs = set(r for r in notpublic if isobs(getnode(r)))
     return obs
 
 @cachefor('unstable')
 def _computeunstableset(repo):
     """the set of non obsolete revisions with obsolete parents"""
     pfunc = repo.changelog.parentrevs
     mutable = _mutablerevs(repo)
     obsolete = getrevs(repo, 'obsolete')
     others = mutable - obsolete
     unstable = set()
     for r in sorted(others):
         # A rev is unstable if one of its parent is obsolete or unstable
         # this works since we traverse following growing rev order
         for p in pfunc(r):
             if p in obsolete or p in unstable:
                 unstable.add(r)
                 break
     return unstable
 
 @cachefor('suspended')
 def _computesuspendedset(repo):
     """the set of obsolete parents with non obsolete descendants"""
     suspended = repo.changelog.ancestors(getrevs(repo, 'unstable'))
     return set(r for r in getrevs(repo, 'obsolete') if r in suspended)
 
 @cachefor('extinct')
 def _computeextinctset(repo):
     """the set of obsolete parents without non obsolete descendants"""
     return getrevs(repo, 'obsolete') - getrevs(repo, 'suspended')
 
 
 @cachefor('bumped')
 def _computebumpedset(repo):
     """the set of revs trying to obsolete public revisions"""
     bumped = set()
     # util function (avoid attribute lookup in the loop)
     phase = repo._phasecache.phase # would be faster to grab the full list
     public = phases.public
     cl = repo.changelog
     torev = cl.nodemap.get
     for ctx in repo.set('(not public()) and (not obsolete())'):
         rev = ctx.rev()
         # We only evaluate mutable, non-obsolete revision
         node = ctx.node()
         # (future) A cache of precursors may worth if split is very common
         for pnode in obsutil.allprecursors(repo.obsstore, [node],
                                    ignoreflags=bumpedfix):
             prev = torev(pnode) # unfiltered! but so is phasecache
             if (prev is not None) and (phase(repo, prev) <= public):
                 # we have a public precursor
                 bumped.add(rev)
                 break # Next draft!
     return bumped
 
 @cachefor('divergent')
 def _computedivergentset(repo):
     """the set of rev that compete to be the final successors of some revision.
     """
     divergent = set()
     obsstore = repo.obsstore
     newermap = {}
     for ctx in repo.set('(not public()) - obsolete()'):
         mark = obsstore.precursors.get(ctx.node(), ())
         toprocess = set(mark)
         seen = set()
         while toprocess:
             prec = toprocess.pop()[0]
             if prec in seen:
                 continue # emergency cycle hanging prevention
             seen.add(prec)
             if prec not in newermap:
                 obsutil.successorssets(repo, prec, newermap)
             newer = [n for n in newermap[prec] if n]
             if len(newer) > 1:
                 divergent.add(ctx.rev())
                 break
             toprocess.update(obsstore.precursors.get(prec, ()))
     return divergent
 
 
 def createmarkers(repo, relations, flag=0, date=None, metadata=None,
                   operation=None):
     """Add obsolete markers between changesets in a repo
 
     <relations> must be an iterable of (<old>, (<new>, ...)[,{metadata}])
     tuple. `old` and `news` are changectx. metadata is an optional dictionary
     containing metadata for this marker only. It is merged with the global
     metadata specified through the `metadata` argument of this function,
 
     Trying to obsolete a public changeset will raise an exception.
 
     Current user and date are used except if specified otherwise in the
     metadata attribute.
 
     This function operates within a transaction of its own, but does
     not take any lock on the repo.
     """
     # prepare metadata
     if metadata is None:
         metadata = {}
     if 'user' not in metadata:
         metadata['user'] = repo.ui.username()
     useoperation = repo.ui.configbool('experimental',
                                       'evolution.track-operation',
                                       False)
     if useoperation and operation:
         metadata['operation'] = operation
     tr = repo.transaction('add-obsolescence-marker')
     try:
         markerargs = []
         for rel in relations:
             prec = rel[0]
             sucs = rel[1]
             localmetadata = metadata.copy()
             if 2 < len(rel):
                 localmetadata.update(rel[2])
 
             if not prec.mutable():
                 raise error.Abort(_("cannot obsolete public changeset: %s")
                                  % prec,
                                  hint="see 'hg help phases' for details")
             nprec = prec.node()
             nsucs = tuple(s.node() for s in sucs)
             npare = None
             if not nsucs:
                 npare = tuple(p.node() for p in prec.parents())
             if nprec in nsucs:
                 raise error.Abort(_("changeset %s cannot obsolete itself")
                                   % prec)
 
             # Creating the marker causes the hidden cache to become invalid,
             # which causes recomputation when we ask for prec.parents() above.
             # Resulting in n^2 behavior.  So let's prepare all of the args
             # first, then create the markers.
             markerargs.append((nprec, nsucs, npare, localmetadata))
 
         for args in markerargs:
             nprec, nsucs, npare, localmetadata = args
             repo.obsstore.create(tr, nprec, nsucs, flag, parents=npare,
                                  date=date, metadata=localmetadata,
                                  ui=repo.ui)
             repo.filteredrevcache.clear()
         tr.close()
     finally:
         tr.release()

mercurial/obsutil.py

@@ -1,409 +1,435
 # obsutil.py - utility functions for obsolescence
 #
 # Copyright 2017 Boris Feld <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 def closestpredecessors(repo, nodeid):
     """yield the list of next predecessors pointing on visible changectx nodes
 
     This function respect the repoview filtering, filtered revision will be
     considered missing.
     """
 
     precursors = repo.obsstore.precursors
     stack = [nodeid]
     seen = set(stack)
 
     while stack:
         current = stack.pop()
         currentpreccs = precursors.get(current, ())
 
         for prec in currentpreccs:
             precnodeid = prec[0]
 
             # Basic cycle protection
             if precnodeid in seen:
                 continue
             seen.add(precnodeid)
 
             if precnodeid in repo:
                 yield precnodeid
             else:
                 stack.append(precnodeid)
 
 def allprecursors(obsstore, nodes, ignoreflags=0):
     """Yield node for every precursors of <nodes>.
 
     Some precursors may be unknown locally.
 
     This is a linear yield unsuited to detecting folded changesets. It includes
     initial nodes too."""
 
     remaining = set(nodes)
     seen = set(remaining)
     while remaining:
         current = remaining.pop()
         yield current
         for mark in obsstore.precursors.get(current, ()):
             # ignore marker flagged with specified flag
             if mark[2] & ignoreflags:
                 continue
             suc = mark[0]
             if suc not in seen:
                 seen.add(suc)
                 remaining.add(suc)
 
 def allsuccessors(obsstore, nodes, ignoreflags=0):
     """Yield node for every successor of <nodes>.
 
     Some successors may be unknown locally.
 
     This is a linear yield unsuited to detecting split changesets. It includes
     initial nodes too."""
     remaining = set(nodes)
     seen = set(remaining)
     while remaining:
         current = remaining.pop()
         yield current
         for mark in obsstore.successors.get(current, ()):
             # ignore marker flagged with specified flag
             if mark[2] & ignoreflags:
                 continue
             for suc in mark[1]:
                 if suc not in seen:
                     seen.add(suc)
                     remaining.add(suc)
 
 def _filterprunes(markers):
     """return a set with no prune markers"""
     return set(m for m in markers if m[1])
 
 def exclusivemarkers(repo, nodes):
     """set of markers relevant to "nodes" but no other locally-known nodes
 
     This function compute the set of markers "exclusive" to a locally-known
     node. This means we walk the markers starting from <nodes> until we reach a
     locally-known precursors outside of <nodes>. Element of <nodes> with
     locally-known successors outside of <nodes> are ignored (since their
     precursors markers are also relevant to these successors).
 
     For example:
 
         # (A0 rewritten as A1)
         #
         # A0 <-1- A1 # Marker "1" is exclusive to A1
 
         or
 
         # (A0 rewritten as AX; AX rewritten as A1; AX is unkown locally)
         #
         # <-1- A0 <-2- AX <-3- A1 # Marker "2,3" are exclusive to A1
 
         or
 
         # (A0 has unknown precursors, A0 rewritten as A1 and A2 (divergence))
         #
         #          <-2- A1 # Marker "2" is exclusive to A0,A1
         #        /
         # <-1- A0
         #        \
         #         <-3- A2 # Marker "3" is exclusive to A0,A2
         #
         # in addition:
         #
         #  Markers "2,3" are exclusive to A1,A2
         #  Markers "1,2,3" are exclusive to A0,A1,A2
 
         See test/test-obsolete-bundle-strip.t for more examples.
 
     An example usage is strip. When stripping a changeset, we also want to
     strip the markers exclusive to this changeset. Otherwise we would have
     "dangling"" obsolescence markers from its precursors: Obsolescence markers
     marking a node as obsolete without any successors available locally.
 
     As for relevant markers, the prune markers for children will be followed.
     Of course, they will only be followed if the pruned children is
     locally-known. Since the prune markers are relevant to the pruned node.
     However, while prune markers are considered relevant to the parent of the
     pruned changesets, prune markers for locally-known changeset (with no
     successors) are considered exclusive to the pruned nodes. This allows
     to strip the prune markers (with the rest of the exclusive chain) alongside
     the pruned changesets.
     """
     # running on a filtered repository would be dangerous as markers could be
     # reported as exclusive when they are relevant for other filtered nodes.
     unfi = repo.unfiltered()
 
     # shortcut to various useful item
     nm = unfi.changelog.nodemap
     precursorsmarkers = unfi.obsstore.precursors
     successormarkers = unfi.obsstore.successors
     childrenmarkers = unfi.obsstore.children
 
     # exclusive markers (return of the function)
     exclmarkers = set()
     # we need fast membership testing
     nodes = set(nodes)
     # looking for head in the obshistory
     #
     # XXX we are ignoring all issues in regard with cycle for now.
     stack = [n for n in nodes if not _filterprunes(successormarkers.get(n, ()))]
     stack.sort()
     # nodes already stacked
     seennodes = set(stack)
     while stack:
         current = stack.pop()
         # fetch precursors markers
         markers = list(precursorsmarkers.get(current, ()))
         # extend the list with prune markers
         for mark in successormarkers.get(current, ()):
             if not mark[1]:
                 markers.append(mark)
         # and markers from children (looking for prune)
         for mark in childrenmarkers.get(current, ()):
             if not mark[1]:
                 markers.append(mark)
         # traverse the markers
         for mark in markers:
             if mark in exclmarkers:
                 # markers already selected
                 continue
 
             # If the markers is about the current node, select it
             #
             # (this delay the addition of markers from children)
             if mark[1] or mark[0] == current:
                 exclmarkers.add(mark)
 
             # should we keep traversing through the precursors?
             prec = mark[0]
 
             # nodes in the stack or already processed
             if prec in seennodes:
                 continue
 
             # is this a locally known node ?
             known = prec in nm
             # if locally-known and not in the <nodes> set the traversal
             # stop here.
             if known and prec not in nodes:
                 continue
 
             # do not keep going if there are unselected markers pointing to this
             # nodes. If we end up traversing these unselected markers later the
             # node will be taken care of at that point.
             precmarkers = _filterprunes(successormarkers.get(prec))
             if precmarkers.issubset(exclmarkers):
                 seennodes.add(prec)
                 stack.append(prec)
 
     return exclmarkers
 
+def foreground(repo, nodes):
+    """return all nodes in the "foreground" of other node
+
+    The foreground of a revision is anything reachable using parent -> children
+    or precursor -> successor relation. It is very similar to "descendant" but
+    augmented with obsolescence information.
+
+    Beware that possible obsolescence cycle may result if complex situation.
+    """
+    repo = repo.unfiltered()
+    foreground = set(repo.set('%ln::', nodes))
+    if repo.obsstore:
+        # We only need this complicated logic if there is obsolescence
+        # XXX will probably deserve an optimised revset.
+        nm = repo.changelog.nodemap
+        plen = -1
+        # compute the whole set of successors or descendants
+        while len(foreground) != plen:
+            plen = len(foreground)
+            succs = set(c.node() for c in foreground)
+            mutable = [c.node() for c in foreground if c.mutable()]
+            succs.update(allsuccessors(repo.obsstore, mutable))
+            known = (n for n in succs if n in nm)
+            foreground = set(repo.set('%ln::', known))
+    return set(c.node() for c in foreground)
+
 def successorssets(repo, initialnode, cache=None):
     """Return set of all latest successors of initial nodes
 
     The successors set of a changeset A are the group of revisions that succeed
     A. It succeeds A as a consistent whole, each revision being only a partial
     replacement. The successors set contains non-obsolete changesets only.
 
     This function returns the full list of successor sets which is why it
     returns a list of tuples and not just a single tuple. Each tuple is a valid
     successors set. Note that (A,) may be a valid successors set for changeset A
     (see below).
 
     In most cases, a changeset A will have a single element (e.g. the changeset
     A is replaced by A') in its successors set. Though, it is also common for a
     changeset A to have no elements in its successor set (e.g. the changeset
     has been pruned). Therefore, the returned list of successors sets will be
     [(A',)] or [], respectively.
 
     When a changeset A is split into A' and B', however, it will result in a
     successors set containing more than a single element, i.e. [(A',B')].
     Divergent changesets will result in multiple successors sets, i.e. [(A',),
     (A'')].
 
     If a changeset A is not obsolete, then it will conceptually have no
     successors set. To distinguish this from a pruned changeset, the successor
     set will contain itself only, i.e. [(A,)].
 
     Finally, successors unknown locally are considered to be pruned (obsoleted
     without any successors).
 
     The optional `cache` parameter is a dictionary that may contain precomputed
     successors sets. It is meant to reuse the computation of a previous call to
     `successorssets` when multiple calls are made at the same time. The cache
     dictionary is updated in place. The caller is responsible for its life
     span. Code that makes multiple calls to `successorssets` *must* use this
     cache mechanism or suffer terrible performance.
     """
 
     succmarkers = repo.obsstore.successors
 
     # Stack of nodes we search successors sets for
     toproceed = [initialnode]
     # set version of above list for fast loop detection
     # element added to "toproceed" must be added here
     stackedset = set(toproceed)
     if cache is None:
         cache = {}
 
     # This while loop is the flattened version of a recursive search for
     # successors sets
     #
     # def successorssets(x):
     #    successors = directsuccessors(x)
     #    ss = [[]]
     #    for succ in directsuccessors(x):
     #        # product as in itertools cartesian product
     #        ss = product(ss, successorssets(succ))
     #    return ss
     #
     # But we can not use plain recursive calls here:
     # - that would blow the python call stack
     # - obsolescence markers may have cycles, we need to handle them.
     #
     # The `toproceed` list act as our call stack. Every node we search
     # successors set for are stacked there.
     #
     # The `stackedset` is set version of this stack used to check if a node is
     # already stacked. This check is used to detect cycles and prevent infinite
     # loop.
     #
     # successors set of all nodes are stored in the `cache` dictionary.
     #
     # After this while loop ends we use the cache to return the successors sets
     # for the node requested by the caller.
     while toproceed:
         # Every iteration tries to compute the successors sets of the topmost
         # node of the stack: CURRENT.
         #
         # There are four possible outcomes:
         #
         # 1) We already know the successors sets of CURRENT:
         #    -> mission accomplished, pop it from the stack.
         # 2) Node is not obsolete:
         #    -> the node is its own successors sets. Add it to the cache.
         # 3) We do not know successors set of direct successors of CURRENT:
         #    -> We add those successors to the stack.
         # 4) We know successors sets of all direct successors of CURRENT:
         #    -> We can compute CURRENT successors set and add it to the
         #       cache.
         #
         current = toproceed[-1]
         if current in cache:
             # case (1): We already know the successors sets
             stackedset.remove(toproceed.pop())
         elif current not in succmarkers:
             # case (2): The node is not obsolete.
             if current in repo:
                 # We have a valid last successors.
                 cache[current] = [(current,)]
             else:
                 # Final obsolete version is unknown locally.
                 # Do not count that as a valid successors
                 cache[current] = []
         else:
             # cases (3) and (4)
             #
             # We proceed in two phases. Phase 1 aims to distinguish case (3)
             # from case (4):
             #
             #     For each direct successors of CURRENT, we check whether its
             #     successors sets are known. If they are not, we stack the
             #     unknown node and proceed to the next iteration of the while
             #     loop. (case 3)
             #
             #     During this step, we may detect obsolescence cycles: a node
             #     with unknown successors sets but already in the call stack.
             #     In such a situation, we arbitrary set the successors sets of
             #     the node to nothing (node pruned) to break the cycle.
             #
             #     If no break was encountered we proceed to phase 2.
             #
             # Phase 2 computes successors sets of CURRENT (case 4); see details
             # in phase 2 itself.
             #
             # Note the two levels of iteration in each phase.
             # - The first one handles obsolescence markers using CURRENT as
             #   precursor (successors markers of CURRENT).
             #
             #   Having multiple entry here means divergence.
             #
             # - The second one handles successors defined in each marker.
             #
             #   Having none means pruned node, multiple successors means split,
             #   single successors are standard replacement.
             #
             for mark in sorted(succmarkers[current]):
                 for suc in mark[1]:
                     if suc not in cache:
                         if suc in stackedset:
                             # cycle breaking
                             cache[suc] = []
                         else:
                             # case (3) If we have not computed successors sets
                             # of one of those successors we add it to the
                             # `toproceed` stack and stop all work for this
                             # iteration.
                             toproceed.append(suc)
                             stackedset.add(suc)
                             break
                 else:
                     continue
                 break
             else:
                 # case (4): we know all successors sets of all direct
                 # successors
                 #
                 # Successors set contributed by each marker depends on the
                 # successors sets of all its "successors" node.
                 #
                 # Each different marker is a divergence in the obsolescence
                 # history. It contributes successors sets distinct from other
                 # markers.
                 #
                 # Within a marker, a successor may have divergent successors
                 # sets. In such a case, the marker will contribute multiple
                 # divergent successors sets. If multiple successors have
                 # divergent successors sets, a Cartesian product is used.
                 #
                 # At the end we post-process successors sets to remove
                 # duplicated entry and successors set that are strict subset of
                 # another one.
                 succssets = []
                 for mark in sorted(succmarkers[current]):
                     # successors sets contributed by this marker
                     markss = [[]]
                     for suc in mark[1]:
                         # cardinal product with previous successors
                         productresult = []
                         for prefix in markss:
                             for suffix in cache[suc]:
                                 newss = list(prefix)
                                 for part in suffix:
                                     # do not duplicated entry in successors set
                                     # first entry wins.
                                     if part not in newss:
                                         newss.append(part)
                                 productresult.append(newss)
                         markss = productresult
                     succssets.extend(markss)
                 # remove duplicated and subset
                 seen = []
                 final = []
                 candidate = sorted(((set(s), s) for s in succssets if s),
                                    key=lambda x: len(x[1]), reverse=True)
                 for setversion, listversion in candidate:
                     for seenset in seen:
                         if setversion.issubset(seenset):
                             break
                     else:
                         final.append(listversion)
                         seen.append(setversion)
                 final.reverse() # put small successors set first
                 cache[current] = final
     return cache[initialnode]