rebase: support "history-editing-backup" config option

If you don't want to store any backup while rebasing, you can
use `history-editing-backup` config option.
[ui]
history-editing-backup =      # True or False

Current status of list of commands which supports this config:
1. histedit
2. rebase

Differential Revision: https://phab.mercurial-scm.org/D3887

tests/test-rebase-backup.t

@@ -0,0 +1,150 b''
+  $ cat << EOF >> $HGRCPATH
+  > [extensions]
+  > rebase=
+  > EOF
+
+==========================================
+Test history-editing-backup config option |
+==========================================
+Test with Pre-obsmarker rebase:
+1) When config option is not set:
+  $ hg init repo1
+  $ cd repo1
+  $ echo a>a
+  $ hg ci -qAma
+  $ echo b>b
+  $ hg ci -qAmb
+  $ echo c>c
+  $ hg ci -qAmc
+  $ hg up 0 -q
+  $ echo d>d
+  $ hg ci -qAmd
+  $ echo e>e
+  $ hg ci -qAme
+  $ hg log -GT "{rev}: {firstline(desc)}\n"
+  @  4: e
+  |
+  o  3: d
+  |
+  | o  2: c
+  | |
+  | o  1: b
+  |/
+  o  0: a
+  
+  $ hg rebase -s 1 -d .
+  rebasing 1:d2ae7f538514 "b"
+  rebasing 2:177f92b77385 "c"
+  saved backup bundle to $TESTTMP/repo1/.hg/strip-backup/d2ae7f538514-c7ed7a78-rebase.hg
+  $ hg log -GT "{rev}: {firstline(desc)}\n"
+  o  4: c
+  |
+  o  3: b
+  |
+  @  2: e
+  |
+  o  1: d
+  |
+  o  0: a
+  
+
+2) When config option is set:
+  $ cat << EOF >> $HGRCPATH
+  > [ui]
+  > history-editing-backup = False
+  > EOF
+
+  $ echo f>f
+  $ hg ci -Aqmf
+  $ echo g>g
+  $ hg ci -Aqmg
+  $ hg log -GT "{rev}: {firstline(desc)}\n"
+  @  6: g
+  |
+  o  5: f
+  |
+  | o  4: c
+  | |
+  | o  3: b
+  |/
+  o  2: e
+  |
+  o  1: d
+  |
+  o  0: a
+  
+  $ hg rebase -s 3 -d .
+  rebasing 3:05bff2a95b12 "b"
+  rebasing 4:1762bde4404d "c"
+
+  $ hg log -GT "{rev}: {firstline(desc)}\n"
+  o  6: c
+  |
+  o  5: b
+  |
+  @  4: g
+  |
+  o  3: f
+  |
+  o  2: e
+  |
+  o  1: d
+  |
+  o  0: a
+  
+Test when rebased revisions are stripped during abort:
+======================================================
+
+  $ echo conflict > c
+  $ hg ci -Am "conflict with c"
+  adding c
+  created new head
+  $ hg log -GT "{rev}: {firstline(desc)}\n"
+  @  7: conflict with c
+  |
+  | o  6: c
+  | |
+  | o  5: b
+  |/
+  o  4: g
+  |
+  o  3: f
+  |
+  o  2: e
+  |
+  o  1: d
+  |
+  o  0: a
+  
+When history-editing-backup = True:
+  $ cat << EOF >> $HGRCPATH
+  > [ui]
+  > history-editing-backup = True
+  > EOF
+  $ hg rebase -s 5 -d .
+  rebasing 5:1f8148a544ee "b"
+  rebasing 6:f8bc7d28e573 "c"
+  merging c
+  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --abort
+  saved backup bundle to $TESTTMP/repo1/.hg/strip-backup/818c1a43c916-2b644d96-backup.hg
+  rebase aborted
+
+When history-editing-backup = False:
+  $ cat << EOF >> $HGRCPATH
+  > [ui]
+  > history-editing-backup = False
+  > EOF
+  $ hg rebase -s 5 -d .
+  rebasing 5:1f8148a544ee "b"
+  rebasing 6:f8bc7d28e573 "c"
+  merging c
+  warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ hg rebase --abort
+  rebase aborted
+  $ cd ..
+

hgext/rebase.py

@@ -1,1911 +1,1922 b''
 # rebase.py - rebasing feature for mercurial
 #
 # Copyright 2008 Stefano Tortarolo <stefano.tortarolo at gmail dot com>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''command to move sets of revisions to a different ancestor
 
 This extension lets you rebase changesets in an existing Mercurial
 repository.
 
 For more information:
 https://mercurial-scm.org/wiki/RebaseExtension
 '''
 
 from __future__ import absolute_import
 
 import errno
 import os
 
 from mercurial.i18n import _
 from mercurial.node import (
     nullrev,
     short,
 )
 from mercurial import (
     bookmarks,
     cmdutil,
     commands,
     copies,
     destutil,
     dirstateguard,
     error,
     extensions,
     hg,
     merge as mergemod,
     mergeutil,
     obsolete,
     obsutil,
     patch,
     phases,
     pycompat,
     registrar,
     repair,
     revset,
     revsetlang,
     scmutil,
     smartset,
     state as statemod,
     util,
 )
 
 # The following constants are used throughout the rebase module. The ordering of
 # their values must be maintained.
 
 # Indicates that a revision needs to be rebased
 revtodo = -1
 revtodostr = '-1'
 
 # legacy revstates no longer needed in current code
 # -2: nullmerge, -3: revignored, -4: revprecursor, -5: revpruned
 legacystates = {'-2', '-3', '-4', '-5'}
 
 cmdtable = {}
 command = registrar.command(cmdtable)
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 def _nothingtorebase():
     return 1
 
 def _savegraft(ctx, extra):
     s = ctx.extra().get('source', None)
     if s is not None:
         extra['source'] = s
     s = ctx.extra().get('intermediate-source', None)
     if s is not None:
         extra['intermediate-source'] = s
 
 def _savebranch(ctx, extra):
     extra['branch'] = ctx.branch()
 
 def _destrebase(repo, sourceset, destspace=None):
     """small wrapper around destmerge to pass the right extra args
 
     Please wrap destutil.destmerge instead."""
     return destutil.destmerge(repo, action='rebase', sourceset=sourceset,
                               onheadcheck=False, destspace=destspace)
 
 revsetpredicate = registrar.revsetpredicate()
 
 @revsetpredicate('_destrebase')
 def _revsetdestrebase(repo, subset, x):
     # ``_rebasedefaultdest()``
 
     # default destination for rebase.
     # # XXX: Currently private because I expect the signature to change.
     # # XXX: - bailing out in case of ambiguity vs returning all data.
     # i18n: "_rebasedefaultdest" is a keyword
     sourceset = None
     if x is not None:
         sourceset = revset.getset(repo, smartset.fullreposet(repo), x)
     return subset & smartset.baseset([_destrebase(repo, sourceset)])
 
 @revsetpredicate('_destautoorphanrebase')
 def _revsetdestautoorphanrebase(repo, subset, x):
     """automatic rebase destination for a single orphan revision"""
     unfi = repo.unfiltered()
     obsoleted = unfi.revs('obsolete()')
 
     src = revset.getset(repo, subset, x).first()
 
     # Empty src or already obsoleted - Do not return a destination
     if not src or src in obsoleted:
         return smartset.baseset()
     dests = destutil.orphanpossibledestination(repo, src)
     if len(dests) > 1:
         raise error.Abort(
             _("ambiguous automatic rebase: %r could end up on any of %r") % (
                 src, dests))
     # We have zero or one destination, so we can just return here.
     return smartset.baseset(dests)
 
 def _ctxdesc(ctx):
     """short description for a context"""
     desc = '%d:%s "%s"' % (ctx.rev(), ctx,
                            ctx.description().split('\n', 1)[0])
     repo = ctx.repo()
     names = []
     for nsname, ns in repo.names.iteritems():
         if nsname == 'branches':
             continue
         names.extend(ns.names(repo, ctx.node()))
     if names:
         desc += ' (%s)' % ' '.join(names)
     return desc
 
 class rebaseruntime(object):
     """This class is a container for rebase runtime state"""
     def __init__(self, repo, ui, inmemory=False, opts=None):
         if opts is None:
             opts = {}
 
         # prepared: whether we have rebasestate prepared or not. Currently it
         # decides whether "self.repo" is unfiltered or not.
         # The rebasestate has explicit hash to hash instructions not depending
         # on visibility. If rebasestate exists (in-memory or on-disk), use
         # unfiltered repo to avoid visibility issues.
         # Before knowing rebasestate (i.e. when starting a new rebase (not
         # --continue or --abort)), the original repo should be used so
         # visibility-dependent revsets are correct.
         self.prepared = False
         self._repo = repo
 
         self.ui = ui
         self.opts = opts
         self.originalwd = None
         self.external = nullrev
         # Mapping between the old revision id and either what is the new rebased
         # revision or what needs to be done with the old revision. The state
         # dict will be what contains most of the rebase progress state.
         self.state = {}
         self.activebookmark = None
         self.destmap = {}
         self.skipped = set()
 
         self.collapsef = opts.get('collapse', False)
         self.collapsemsg = cmdutil.logmessage(ui, opts)
         self.date = opts.get('date', None)
 
         e = opts.get('extrafn') # internal, used by e.g. hgsubversion
         self.extrafns = [_savegraft]
         if e:
             self.extrafns = [e]
 
         self.keepf = opts.get('keep', False)
         self.keepbranchesf = opts.get('keepbranches', False)
         self.obsoletenotrebased = {}
         self.obsoletewithoutsuccessorindestination = set()
         self.inmemory = inmemory
         self.stateobj = statemod.cmdstate(repo, 'rebasestate')
 
     @property
     def repo(self):
         if self.prepared:
             return self._repo.unfiltered()
         else:
             return self._repo
 
     def storestatus(self, tr=None):
         """Store the current status to allow recovery"""
         if tr:
             tr.addfilegenerator('rebasestate', ('rebasestate',),
                                 self._writestatus, location='plain')
         else:
             with self.repo.vfs("rebasestate", "w") as f:
                 self._writestatus(f)
 
     def _writestatus(self, f):
         repo = self.repo
         assert repo.filtername is None
         f.write(repo[self.originalwd].hex() + '\n')
         # was "dest". we now write dest per src root below.
         f.write('\n')
         f.write(repo[self.external].hex() + '\n')
         f.write('%d\n' % int(self.collapsef))
         f.write('%d\n' % int(self.keepf))
         f.write('%d\n' % int(self.keepbranchesf))
         f.write('%s\n' % (self.activebookmark or ''))
         destmap = self.destmap
         for d, v in self.state.iteritems():
             oldrev = repo[d].hex()
             if v >= 0:
                 newrev = repo[v].hex()
             else:
                 newrev = "%d" % v
             destnode = repo[destmap[d]].hex()
             f.write("%s:%s:%s\n" % (oldrev, newrev, destnode))
         repo.ui.debug('rebase status stored\n')
 
     def restorestatus(self):
         """Restore a previously stored status"""
         if not self.stateobj.exists():
             cmdutil.wrongtooltocontinue(self.repo, _('rebase'))
 
         data = self._read()
         self.repo.ui.debug('rebase status resumed\n')
 
         self.originalwd = data['originalwd']
         self.destmap = data['destmap']
         self.state = data['state']
         self.skipped = data['skipped']
         self.collapsef = data['collapse']
         self.keepf = data['keep']
         self.keepbranchesf = data['keepbranches']
         self.external = data['external']
         self.activebookmark = data['activebookmark']
 
     def _read(self):
         self.prepared = True
         repo = self.repo
         assert repo.filtername is None
         data = {'keepbranches': None, 'collapse': None, 'activebookmark': None,
                 'external': nullrev, 'keep': None, 'originalwd': None}
         legacydest = None
         state = {}
         destmap = {}
 
         if True:
             f = repo.vfs("rebasestate")
             for i, l in enumerate(f.read().splitlines()):
                 if i == 0:
                     data['originalwd'] = repo[l].rev()
                 elif i == 1:
                     # this line should be empty in newer version. but legacy
                     # clients may still use it
                     if l:
                         legacydest = repo[l].rev()
                 elif i == 2:
                     data['external'] = repo[l].rev()
                 elif i == 3:
                     data['collapse'] = bool(int(l))
                 elif i == 4:
                     data['keep'] = bool(int(l))
                 elif i == 5:
                     data['keepbranches'] = bool(int(l))
                 elif i == 6 and not (len(l) == 81 and ':' in l):
                     # line 6 is a recent addition, so for backwards
                     # compatibility check that the line doesn't look like the
                     # oldrev:newrev lines
                     data['activebookmark'] = l
                 else:
                     args = l.split(':')
                     oldrev = repo[args[0]].rev()
                     newrev = args[1]
                     if newrev in legacystates:
                         continue
                     if len(args) > 2:
                         destrev = repo[args[2]].rev()
                     else:
                         destrev = legacydest
                     destmap[oldrev] = destrev
                     if newrev == revtodostr:
                         state[oldrev] = revtodo
                         # Legacy compat special case
                     else:
                         state[oldrev] = repo[newrev].rev()
 
         if data['keepbranches'] is None:
             raise error.Abort(_('.hg/rebasestate is incomplete'))
 
         data['destmap'] = destmap
         data['state'] = state
         skipped = set()
         # recompute the set of skipped revs
         if not data['collapse']:
             seen = set(destmap.values())
             for old, new in sorted(state.items()):
                 if new != revtodo and new in seen:
                     skipped.add(old)
                 seen.add(new)
         data['skipped'] = skipped
         repo.ui.debug('computed skipped revs: %s\n' %
                         (' '.join('%d' % r for r in sorted(skipped)) or ''))
 
         return data
 
     def _handleskippingobsolete(self, obsoleterevs, destmap):
         """Compute structures necessary for skipping obsolete revisions
 
         obsoleterevs:   iterable of all obsolete revisions in rebaseset
         destmap:        {srcrev: destrev} destination revisions
         """
         self.obsoletenotrebased = {}
         if not self.ui.configbool('experimental', 'rebaseskipobsolete'):
             return
         obsoleteset = set(obsoleterevs)
         (self.obsoletenotrebased,
          self.obsoletewithoutsuccessorindestination,
          obsoleteextinctsuccessors) = _computeobsoletenotrebased(
              self.repo, obsoleteset, destmap)
         skippedset = set(self.obsoletenotrebased)
         skippedset.update(self.obsoletewithoutsuccessorindestination)
         skippedset.update(obsoleteextinctsuccessors)
         _checkobsrebase(self.repo, self.ui, obsoleteset, skippedset)
 
     def _prepareabortorcontinue(self, isabort, backup=True, suppwarns=False):
         try:
             self.restorestatus()
             self.collapsemsg = restorecollapsemsg(self.repo, isabort)
         except error.RepoLookupError:
             if isabort:
                 clearstatus(self.repo)
                 clearcollapsemsg(self.repo)
                 self.repo.ui.warn(_('rebase aborted (no revision is removed,'
                                     ' only broken state is cleared)\n'))
                 return 0
             else:
                 msg = _('cannot continue inconsistent rebase')
                 hint = _('use "hg rebase --abort" to clear broken state')
                 raise error.Abort(msg, hint=hint)
         if isabort:
             return abort(self.repo, self.originalwd, self.destmap, self.state,
                          activebookmark=self.activebookmark, backup=backup,
                          suppwarns=suppwarns)
 
     def _preparenewrebase(self, destmap):
         if not destmap:
             return _nothingtorebase()
 
         rebaseset = destmap.keys()
         allowunstable = obsolete.isenabled(self.repo, obsolete.allowunstableopt)
         if (not (self.keepf or allowunstable)
               and self.repo.revs('first(children(%ld) - %ld)',
                                  rebaseset, rebaseset)):
             raise error.Abort(
                 _("can't remove original changesets with"
                   " unrebased descendants"),
                 hint=_('use --keep to keep original changesets'))
 
         result = buildstate(self.repo, destmap, self.collapsef)
 
         if not result:
             # Empty state built, nothing to rebase
             self.ui.status(_('nothing to rebase\n'))
             return _nothingtorebase()
 
         for root in self.repo.set('roots(%ld)', rebaseset):
             if not self.keepf and not root.mutable():
                 raise error.Abort(_("can't rebase public changeset %s")
                                   % root,
                                   hint=_("see 'hg help phases' for details"))
 
         (self.originalwd, self.destmap, self.state) = result
         if self.collapsef:
             dests = set(self.destmap.values())
             if len(dests) != 1:
                 raise error.Abort(
                     _('--collapse does not work with multiple destinations'))
             destrev = next(iter(dests))
             destancestors = self.repo.changelog.ancestors([destrev],
                                                           inclusive=True)
             self.external = externalparent(self.repo, self.state, destancestors)
 
         for destrev in sorted(set(destmap.values())):
             dest = self.repo[destrev]
             if dest.closesbranch() and not self.keepbranchesf:
                 self.ui.status(_('reopening closed branch head %s\n') % dest)
 
         self.prepared = True
 
     def _assignworkingcopy(self):
         if self.inmemory:
             from mercurial.context import overlayworkingctx
             self.wctx = overlayworkingctx(self.repo)
             self.repo.ui.debug("rebasing in-memory\n")
         else:
             self.wctx = self.repo[None]
             self.repo.ui.debug("rebasing on disk\n")
         self.repo.ui.log("rebase", "", rebase_imm_used=self.inmemory)
 
     def _performrebase(self, tr):
         self._assignworkingcopy()
         repo, ui = self.repo, self.ui
         if self.keepbranchesf:
             # insert _savebranch at the start of extrafns so if
             # there's a user-provided extrafn it can clobber branch if
             # desired
             self.extrafns.insert(0, _savebranch)
             if self.collapsef:
                 branches = set()
                 for rev in self.state:
                     branches.add(repo[rev].branch())
                     if len(branches) > 1:
                         raise error.Abort(_('cannot collapse multiple named '
                             'branches'))
 
         # Calculate self.obsoletenotrebased
         obsrevs = _filterobsoleterevs(self.repo, self.state)
         self._handleskippingobsolete(obsrevs, self.destmap)
 
         # Keep track of the active bookmarks in order to reset them later
         self.activebookmark = self.activebookmark or repo._activebookmark
         if self.activebookmark:
             bookmarks.deactivate(repo)
 
         # Store the state before we begin so users can run 'hg rebase --abort'
         # if we fail before the transaction closes.
         self.storestatus()
         if tr:
             # When using single transaction, store state when transaction
             # commits.
             self.storestatus(tr)
 
         cands = [k for k, v in self.state.iteritems() if v == revtodo]
         p = repo.ui.makeprogress(_("rebasing"), unit=_('changesets'),
                                  total=len(cands))
         def progress(ctx):
             p.increment(item=("%d:%s" % (ctx.rev(), ctx)))
         allowdivergence = self.ui.configbool(
             'experimental', 'evolution.allowdivergence')
         for subset in sortsource(self.destmap):
             sortedrevs = self.repo.revs('sort(%ld, -topo)', subset)
             if not allowdivergence:
                 sortedrevs -= self.repo.revs(
                     'descendants(%ld) and not %ld',
                     self.obsoletewithoutsuccessorindestination,
                     self.obsoletewithoutsuccessorindestination,
                 )
             for rev in sortedrevs:
                 self._rebasenode(tr, rev, allowdivergence, progress)
         p.complete()
         ui.note(_('rebase merging completed\n'))
 
     def _concludenode(self, rev, p1, p2, editor, commitmsg=None):
         '''Commit the wd changes with parents p1 and p2.
 
         Reuse commit info from rev but also store useful information in extra.
         Return node of committed revision.'''
         repo = self.repo
         ctx = repo[rev]
         if commitmsg is None:
             commitmsg = ctx.description()
         date = self.date
         if date is None:
             date = ctx.date()
         extra = {'rebase_source': ctx.hex()}
         for c in self.extrafns:
             c(ctx, extra)
         keepbranch = self.keepbranchesf and repo[p1].branch() != ctx.branch()
         destphase = max(ctx.phase(), phases.draft)
         overrides = {('phases', 'new-commit'): destphase}
         if keepbranch:
             overrides[('ui', 'allowemptycommit')] = True
         with repo.ui.configoverride(overrides, 'rebase'):
             if self.inmemory:
                 newnode = commitmemorynode(repo, p1, p2,
                     wctx=self.wctx,
                     extra=extra,
                     commitmsg=commitmsg,
                     editor=editor,
                     user=ctx.user(),
                     date=date)
                 mergemod.mergestate.clean(repo)
             else:
                 newnode = commitnode(repo, p1, p2,
                     extra=extra,
                     commitmsg=commitmsg,
                     editor=editor,
                     user=ctx.user(),
                     date=date)
 
             if newnode is None:
                 # If it ended up being a no-op commit, then the normal
                 # merge state clean-up path doesn't happen, so do it
                 # here. Fix issue5494
                 mergemod.mergestate.clean(repo)
             return newnode
 
     def _rebasenode(self, tr, rev, allowdivergence, progressfn):
         repo, ui, opts = self.repo, self.ui, self.opts
         dest = self.destmap[rev]
         ctx = repo[rev]
         desc = _ctxdesc(ctx)
         if self.state[rev] == rev:
             ui.status(_('already rebased %s\n') % desc)
         elif (not allowdivergence
               and rev in self.obsoletewithoutsuccessorindestination):
             msg = _('note: not rebasing %s and its descendants as '
                     'this would cause divergence\n') % desc
             repo.ui.status(msg)
             self.skipped.add(rev)
         elif rev in self.obsoletenotrebased:
             succ = self.obsoletenotrebased[rev]
             if succ is None:
                 msg = _('note: not rebasing %s, it has no '
                         'successor\n') % desc
             else:
                 succdesc = _ctxdesc(repo[succ])
                 msg = (_('note: not rebasing %s, already in '
                          'destination as %s\n') % (desc, succdesc))
             repo.ui.status(msg)
             # Make clearrebased aware state[rev] is not a true successor
             self.skipped.add(rev)
             # Record rev as moved to its desired destination in self.state.
             # This helps bookmark and working parent movement.
             dest = max(adjustdest(repo, rev, self.destmap, self.state,
                                   self.skipped))
             self.state[rev] = dest
         elif self.state[rev] == revtodo:
             ui.status(_('rebasing %s\n') % desc)
             progressfn(ctx)
             p1, p2, base = defineparents(repo, rev, self.destmap,
                                          self.state, self.skipped,
                                          self.obsoletenotrebased)
             if len(repo[None].parents()) == 2:
                 repo.ui.debug('resuming interrupted rebase\n')
             else:
                 overrides = {('ui', 'forcemerge'): opts.get('tool', '')}
                 with ui.configoverride(overrides, 'rebase'):
                     stats = rebasenode(repo, rev, p1, base, self.collapsef,
                                        dest, wctx=self.wctx)
                     if stats.unresolvedcount > 0:
                         if self.inmemory:
                             raise error.InMemoryMergeConflictsError()
                         else:
                             raise error.InterventionRequired(
                                 _('unresolved conflicts (see hg '
                                   'resolve, then hg rebase --continue)'))
             if not self.collapsef:
                 merging = p2 != nullrev
                 editform = cmdutil.mergeeditform(merging, 'rebase')
                 editor = cmdutil.getcommiteditor(editform=editform,
                                                  **pycompat.strkwargs(opts))
                 newnode = self._concludenode(rev, p1, p2, editor)
             else:
                 # Skip commit if we are collapsing
                 if self.inmemory:
                     self.wctx.setbase(repo[p1])
                 else:
                     repo.setparents(repo[p1].node())
                 newnode = None
             # Update the state
             if newnode is not None:
                 self.state[rev] = repo[newnode].rev()
                 ui.debug('rebased as %s\n' % short(newnode))
             else:
                 if not self.collapsef:
                     ui.warn(_('note: rebase of %d:%s created no changes '
                               'to commit\n') % (rev, ctx))
                     self.skipped.add(rev)
                 self.state[rev] = p1
                 ui.debug('next revision set to %d\n' % p1)
         else:
             ui.status(_('already rebased %s as %s\n') %
                       (desc, repo[self.state[rev]]))
         if not tr:
             # When not using single transaction, store state after each
             # commit is completely done. On InterventionRequired, we thus
             # won't store the status. Instead, we'll hit the "len(parents) == 2"
             # case and realize that the commit was in progress.
             self.storestatus()
 
-    def _finishrebase(self):
+    def _finishrebase(self, backup=True):
+        """
+        backup:   if False, no backup will be stored when stripping rebased
+                  revisions
+        """
         repo, ui, opts = self.repo, self.ui, self.opts
         fm = ui.formatter('rebase', opts)
         fm.startitem()
         if self.collapsef:
             p1, p2, _base = defineparents(repo, min(self.state), self.destmap,
                                           self.state, self.skipped,
                                           self.obsoletenotrebased)
             editopt = opts.get('edit')
             editform = 'rebase.collapse'
             if self.collapsemsg:
                 commitmsg = self.collapsemsg
             else:
                 commitmsg = 'Collapsed revision'
                 for rebased in sorted(self.state):
                     if rebased not in self.skipped:
                         commitmsg += '\n* %s' % repo[rebased].description()
                 editopt = True
             editor = cmdutil.getcommiteditor(edit=editopt, editform=editform)
             revtoreuse = max(self.state)
 
             newnode = self._concludenode(revtoreuse, p1, self.external,
                                          editor, commitmsg=commitmsg)
 
             if newnode is not None:
                 newrev = repo[newnode].rev()
                 for oldrev in self.state:
                     self.state[oldrev] = newrev
 
         if 'qtip' in repo.tags():
             updatemq(repo, self.state, self.skipped,
                      **pycompat.strkwargs(opts))
 
         # restore original working directory
         # (we do this before stripping)
         newwd = self.state.get(self.originalwd, self.originalwd)
         if newwd < 0:
             # original directory is a parent of rebase set root or ignored
             newwd = self.originalwd
         if newwd not in [c.rev() for c in repo[None].parents()]:
             ui.note(_("update back to initial working directory parent\n"))
             hg.updaterepo(repo, newwd, overwrite=False)
 
         collapsedas = None
         if self.collapsef and not self.keepf:
             collapsedas = newnode
         clearrebased(ui, repo, self.destmap, self.state, self.skipped,
-                     collapsedas, self.keepf, fm=fm)
+                     collapsedas, self.keepf, fm=fm, backup=backup)
 
         clearstatus(repo)
         clearcollapsemsg(repo)
 
         ui.note(_("rebase completed\n"))
         util.unlinkpath(repo.sjoin('undo'), ignoremissing=True)
         if self.skipped:
             skippedlen = len(self.skipped)
             ui.note(_("%d revisions have been skipped\n") % skippedlen)
         fm.end()
 
         if (self.activebookmark and self.activebookmark in repo._bookmarks and
             repo['.'].node() == repo._bookmarks[self.activebookmark]):
                 bookmarks.activate(repo, self.activebookmark)
 
 @command('rebase',
     [('s', 'source', '',
      _('rebase the specified changeset and descendants'), _('REV')),
     ('b', 'base', '',
      _('rebase everything from branching point of specified changeset'),
      _('REV')),
     ('r', 'rev', [],
      _('rebase these revisions'),
      _('REV')),
     ('d', 'dest', '',
      _('rebase onto the specified changeset'), _('REV')),
     ('', 'collapse', False, _('collapse the rebased changesets')),
     ('m', 'message', '',
      _('use text as collapse commit message'), _('TEXT')),
     ('e', 'edit', False, _('invoke editor on commit messages')),
     ('l', 'logfile', '',
      _('read collapse commit message from file'), _('FILE')),
     ('k', 'keep', False, _('keep original changesets')),
     ('', 'keepbranches', False, _('keep original branch names')),
     ('D', 'detach', False, _('(DEPRECATED)')),
     ('i', 'interactive', False, _('(DEPRECATED)')),
     ('t', 'tool', '', _('specify merge tool')),
     ('c', 'continue', False, _('continue an interrupted rebase')),
     ('a', 'abort', False, _('abort an interrupted rebase')),
     ('', 'auto-orphans', '', _('automatically rebase orphan revisions '
                                'in the specified revset (EXPERIMENTAL)')),
      ] + cmdutil.dryrunopts + cmdutil.formatteropts + cmdutil.confirmopts,
     _('[-s REV | -b REV] [-d REV] [OPTION]'))
 def rebase(ui, repo, **opts):
     """move changeset (and descendants) to a different branch
 
     Rebase uses repeated merging to graft changesets from one part of
     history (the source) onto another (the destination). This can be
     useful for linearizing *local* changes relative to a master
     development tree.
 
     Published commits cannot be rebased (see :hg:`help phases`).
     To copy commits, see :hg:`help graft`.
 
     If you don't specify a destination changeset (``-d/--dest``), rebase
     will use the same logic as :hg:`merge` to pick a destination.  if
     the current branch contains exactly one other head, the other head
     is merged with by default.  Otherwise, an explicit revision with
     which to merge with must be provided.  (destination changeset is not
     modified by rebasing, but new changesets are added as its
     descendants.)
 
     Here are the ways to select changesets:
 
       1. Explicitly select them using ``--rev``.
 
       2. Use ``--source`` to select a root changeset and include all of its
          descendants.
 
       3. Use ``--base`` to select a changeset; rebase will find ancestors
          and their descendants which are not also ancestors of the destination.
 
       4. If you do not specify any of ``--rev``, ``source``, or ``--base``,
          rebase will use ``--base .`` as above.
 
     If ``--source`` or ``--rev`` is used, special names ``SRC`` and ``ALLSRC``
     can be used in ``--dest``. Destination would be calculated per source
     revision with ``SRC`` substituted by that single source revision and
     ``ALLSRC`` substituted by all source revisions.
 
     Rebase will destroy original changesets unless you use ``--keep``.
     It will also move your bookmarks (even if you do).
 
     Some changesets may be dropped if they do not contribute changes
     (e.g. merges from the destination branch).
 
     Unlike ``merge``, rebase will do nothing if you are at the branch tip of
     a named branch with two heads. You will need to explicitly specify source
     and/or destination.
 
     If you need to use a tool to automate merge/conflict decisions, you
     can specify one with ``--tool``, see :hg:`help merge-tools`.
     As a caveat: the tool will not be used to mediate when a file was
     deleted, there is no hook presently available for this.
 
     If a rebase is interrupted to manually resolve a conflict, it can be
     continued with --continue/-c or aborted with --abort/-a.
 
     .. container:: verbose
 
       Examples:
 
       - move "local changes" (current commit back to branching point)
         to the current branch tip after a pull::
 
           hg rebase
 
       - move a single changeset to the stable branch::
 
           hg rebase -r 5f493448 -d stable
 
       - splice a commit and all its descendants onto another part of history::
 
           hg rebase --source c0c3 --dest 4cf9
 
       - rebase everything on a branch marked by a bookmark onto the
         default branch::
 
           hg rebase --base myfeature --dest default
 
       - collapse a sequence of changes into a single commit::
 
           hg rebase --collapse -r 1520:1525 -d .
 
       - move a named branch while preserving its name::
 
           hg rebase -r "branch(featureX)" -d 1.3 --keepbranches
 
       - stabilize orphaned changesets so history looks linear::
 
           hg rebase -r 'orphan()-obsolete()'\
  -d 'first(max((successors(max(roots(ALLSRC) & ::SRC)^)-obsolete())::) +\
  max(::((roots(ALLSRC) & ::SRC)^)-obsolete()))'
 
     Configuration Options:
 
     You can make rebase require a destination if you set the following config
     option::
 
       [commands]
       rebase.requiredest = True
 
     By default, rebase will close the transaction after each commit. For
     performance purposes, you can configure rebase to use a single transaction
     across the entire rebase. WARNING: This setting introduces a significant
     risk of losing the work you've done in a rebase if the rebase aborts
     unexpectedly::
 
       [rebase]
       singletransaction = True
 
     By default, rebase writes to the working copy, but you can configure it to
     run in-memory for for better performance, and to allow it to run if the
     working copy is dirty::
 
       [rebase]
       experimental.inmemory = True
 
     Return Values:
 
     Returns 0 on success, 1 if nothing to rebase or there are
     unresolved conflicts.
 
     """
     opts = pycompat.byteskwargs(opts)
     inmemory = ui.configbool('rebase', 'experimental.inmemory')
     dryrun = opts.get('dry_run')
     if dryrun:
         if opts.get('abort'):
             raise error.Abort(_('cannot specify both --dry-run and --abort'))
         if opts.get('continue'):
             raise error.Abort(_('cannot specify both --dry-run and --continue'))
     if opts.get('confirm'):
         dryrun = True
         if opts.get('dry_run'):
             raise error.Abort(_('cannot specify both --confirm and --dry-run'))
         if opts.get('abort'):
             raise error.Abort(_('cannot specify both --confirm and --abort'))
         if opts.get('continue'):
             raise error.Abort(_('cannot specify both --confirm and --continue'))
 
     if (opts.get('continue') or opts.get('abort') or
         repo.currenttransaction() is not None):
         # in-memory rebase is not compatible with resuming rebases.
         # (Or if it is run within a transaction, since the restart logic can
         # fail the entire transaction.)
         inmemory = False
 
     if opts.get('auto_orphans'):
         for key in opts:
             if key != 'auto_orphans' and opts.get(key):
                 raise error.Abort(_('--auto-orphans is incompatible with %s') %
                                   ('--' + key))
         userrevs = list(repo.revs(opts.get('auto_orphans')))
         opts['rev'] = [revsetlang.formatspec('%ld and orphan()', userrevs)]
         opts['dest'] = '_destautoorphanrebase(SRC)'
+    backup = ui.configbool('ui', 'history-editing-backup')
+    opts['backup'] = backup
 
     if dryrun:
         return _dryrunrebase(ui, repo, opts)
     elif inmemory:
         try:
             # in-memory merge doesn't support conflicts, so if we hit any, abort
             # and re-run as an on-disk merge.
             overrides = {('rebase', 'singletransaction'): True}
             with ui.configoverride(overrides, 'rebase'):
                 return _dorebase(ui, repo, opts, inmemory=inmemory)
         except error.InMemoryMergeConflictsError:
             ui.warn(_('hit merge conflicts; re-running rebase without in-memory'
                       ' merge\n'))
             _dorebase(ui, repo, {'abort': True})
             return _dorebase(ui, repo, opts, inmemory=False)
     else:
         return _dorebase(ui, repo, opts)
 
 def _dryrunrebase(ui, repo, opts):
     rbsrt = rebaseruntime(repo, ui, inmemory=True, opts=opts)
     confirm = opts.get('confirm')
+    backup = opts.get('backup')
     if confirm:
         ui.status(_('starting in-memory rebase\n'))
     else:
         ui.status(_('starting dry-run rebase; repository will not be '
                     'changed\n'))
     with repo.wlock(), repo.lock():
         needsabort = True
         try:
             overrides = {('rebase', 'singletransaction'): True}
             with ui.configoverride(overrides, 'rebase'):
                 _origrebase(ui, repo, opts, rbsrt, inmemory=True,
                             leaveunfinished=True)
         except error.InMemoryMergeConflictsError:
             ui.status(_('hit a merge conflict\n'))
             return 1
         else:
             if confirm:
                 ui.status(_('rebase completed successfully\n'))
                 if not ui.promptchoice(_(b'apply changes (yn)?'
                                          b'$$ &Yes $$ &No')):
                     # finish unfinished rebase
-                    rbsrt._finishrebase()
+                    rbsrt._finishrebase(backup=backup)
                 else:
                     rbsrt._prepareabortorcontinue(isabort=True, backup=False,
                                                   suppwarns=True)
                 needsabort = False
             else:
                 ui.status(_('dry-run rebase completed successfully; run without'
                             ' -n/--dry-run to perform this rebase\n'))
             return 0
         finally:
             if needsabort:
                 # no need to store backup in case of dryrun
                 rbsrt._prepareabortorcontinue(isabort=True, backup=False,
                                               suppwarns=True)
 
 def _dorebase(ui, repo, opts, inmemory=False):
     rbsrt = rebaseruntime(repo, ui, inmemory, opts)
     return _origrebase(ui, repo, opts, rbsrt, inmemory=inmemory)
 
 def _origrebase(ui, repo, opts, rbsrt, inmemory=False, leaveunfinished=False):
     with repo.wlock(), repo.lock():
         # Validate input and define rebasing points
         destf = opts.get('dest', None)
         srcf = opts.get('source', None)
         basef = opts.get('base', None)
         revf = opts.get('rev', [])
         # search default destination in this space
         # used in the 'hg pull --rebase' case, see issue 5214.
         destspace = opts.get('_destspace')
         contf = opts.get('continue')
         abortf = opts.get('abort')
+        backup = opts.get('backup')
         if opts.get('interactive'):
             try:
                 if extensions.find('histedit'):
                     enablehistedit = ''
             except KeyError:
                 enablehistedit = " --config extensions.histedit="
             help = "hg%s help -e histedit" % enablehistedit
             msg = _("interactive history editing is supported by the "
                     "'histedit' extension (see \"%s\")") % help
             raise error.Abort(msg)
 
         if rbsrt.collapsemsg and not rbsrt.collapsef:
             raise error.Abort(
                 _('message can only be specified with collapse'))
 
         if contf or abortf:
             if contf and abortf:
                 raise error.Abort(_('cannot use both abort and continue'))
             if rbsrt.collapsef:
                 raise error.Abort(
                     _('cannot use collapse with continue or abort'))
             if srcf or basef or destf:
                 raise error.Abort(
                     _('abort and continue do not allow specifying revisions'))
             if abortf and opts.get('tool', False):
                 ui.warn(_('tool option will be ignored\n'))
             if contf:
                 ms = mergemod.mergestate.read(repo)
                 mergeutil.checkunresolved(ms)
 
-            retcode = rbsrt._prepareabortorcontinue(abortf)
+            retcode = rbsrt._prepareabortorcontinue(abortf, backup=backup)
             if retcode is not None:
                 return retcode
         else:
             destmap = _definedestmap(ui, repo, inmemory, destf, srcf, basef,
                                      revf, destspace=destspace)
             retcode = rbsrt._preparenewrebase(destmap)
             if retcode is not None:
                 return retcode
             storecollapsemsg(repo, rbsrt.collapsemsg)
 
         tr = None
 
         singletr = ui.configbool('rebase', 'singletransaction')
         if singletr:
             tr = repo.transaction('rebase')
 
         # If `rebase.singletransaction` is enabled, wrap the entire operation in
         # one transaction here. Otherwise, transactions are obtained when
         # committing each node, which is slower but allows partial success.
         with util.acceptintervention(tr):
             # Same logic for the dirstate guard, except we don't create one when
             # rebasing in-memory (it's not needed).
             dsguard = None
             if singletr and not inmemory:
                 dsguard = dirstateguard.dirstateguard(repo, 'rebase')
             with util.acceptintervention(dsguard):
                 rbsrt._performrebase(tr)
                 if not leaveunfinished:
-                    rbsrt._finishrebase()
+                    rbsrt._finishrebase(backup=backup)
 
 def _definedestmap(ui, repo, inmemory, destf=None, srcf=None, basef=None,
                    revf=None, destspace=None):
     """use revisions argument to define destmap {srcrev: destrev}"""
     if revf is None:
         revf = []
 
     # destspace is here to work around issues with `hg pull --rebase` see
     # issue5214 for details
     if srcf and basef:
         raise error.Abort(_('cannot specify both a source and a base'))
     if revf and basef:
         raise error.Abort(_('cannot specify both a revision and a base'))
     if revf and srcf:
         raise error.Abort(_('cannot specify both a revision and a source'))
 
     if not inmemory:
         cmdutil.checkunfinished(repo)
         cmdutil.bailifchanged(repo)
 
     if ui.configbool('commands', 'rebase.requiredest') and not destf:
         raise error.Abort(_('you must specify a destination'),
                           hint=_('use: hg rebase -d REV'))
 
     dest = None
 
     if revf:
         rebaseset = scmutil.revrange(repo, revf)
         if not rebaseset:
             ui.status(_('empty "rev" revision set - nothing to rebase\n'))
             return None
     elif srcf:
         src = scmutil.revrange(repo, [srcf])
         if not src:
             ui.status(_('empty "source" revision set - nothing to rebase\n'))
             return None
         rebaseset = repo.revs('(%ld)::', src)
         assert rebaseset
     else:
         base = scmutil.revrange(repo, [basef or '.'])
         if not base:
             ui.status(_('empty "base" revision set - '
                         "can't compute rebase set\n"))
             return None
         if destf:
             # --base does not support multiple destinations
             dest = scmutil.revsingle(repo, destf)
         else:
             dest = repo[_destrebase(repo, base, destspace=destspace)]
             destf = bytes(dest)
 
         roots = [] # selected children of branching points
         bpbase = {} # {branchingpoint: [origbase]}
         for b in base: # group bases by branching points
             bp = repo.revs('ancestor(%d, %d)', b, dest.rev()).first()
             bpbase[bp] = bpbase.get(bp, []) + [b]
         if None in bpbase:
             # emulate the old behavior, showing "nothing to rebase" (a better
             # behavior may be abort with "cannot find branching point" error)
             bpbase.clear()
         for bp, bs in bpbase.iteritems(): # calculate roots
             roots += list(repo.revs('children(%d) & ancestors(%ld)', bp, bs))
 
         rebaseset = repo.revs('%ld::', roots)
 
         if not rebaseset:
             # transform to list because smartsets are not comparable to
             # lists. This should be improved to honor laziness of
             # smartset.
             if list(base) == [dest.rev()]:
                 if basef:
                     ui.status(_('nothing to rebase - %s is both "base"'
                                 ' and destination\n') % dest)
                 else:
                     ui.status(_('nothing to rebase - working directory '
                                 'parent is also destination\n'))
             elif not repo.revs('%ld - ::%d', base, dest.rev()):
                 if basef:
                     ui.status(_('nothing to rebase - "base" %s is '
                                 'already an ancestor of destination '
                                 '%s\n') %
                               ('+'.join(bytes(repo[r]) for r in base),
                                dest))
                 else:
                     ui.status(_('nothing to rebase - working '
                                 'directory parent is already an '
                                 'ancestor of destination %s\n') % dest)
             else: # can it happen?
                 ui.status(_('nothing to rebase from %s to %s\n') %
                           ('+'.join(bytes(repo[r]) for r in base), dest))
             return None
 
     rebasingwcp = repo['.'].rev() in rebaseset
     ui.log("rebase", "", rebase_rebasing_wcp=rebasingwcp)
     if inmemory and rebasingwcp:
         # Check these since we did not before.
         cmdutil.checkunfinished(repo)
         cmdutil.bailifchanged(repo)
 
     if not destf:
         dest = repo[_destrebase(repo, rebaseset, destspace=destspace)]
         destf = bytes(dest)
 
     allsrc = revsetlang.formatspec('%ld', rebaseset)
     alias = {'ALLSRC': allsrc}
 
     if dest is None:
         try:
             # fast path: try to resolve dest without SRC alias
             dest = scmutil.revsingle(repo, destf, localalias=alias)
         except error.RepoLookupError:
             # multi-dest path: resolve dest for each SRC separately
             destmap = {}
             for r in rebaseset:
                 alias['SRC'] = revsetlang.formatspec('%d', r)
                 # use repo.anyrevs instead of scmutil.revsingle because we
                 # don't want to abort if destset is empty.
                 destset = repo.anyrevs([destf], user=True, localalias=alias)
                 size = len(destset)
                 if size == 1:
                     destmap[r] = destset.first()
                 elif size == 0:
                     ui.note(_('skipping %s - empty destination\n') % repo[r])
                 else:
                     raise error.Abort(_('rebase destination for %s is not '
                                         'unique') % repo[r])
 
     if dest is not None:
         # single-dest case: assign dest to each rev in rebaseset
         destrev = dest.rev()
         destmap = {r: destrev for r in rebaseset} # {srcrev: destrev}
 
     if not destmap:
         ui.status(_('nothing to rebase - empty destination\n'))
         return None
 
     return destmap
 
 def externalparent(repo, state, destancestors):
     """Return the revision that should be used as the second parent
     when the revisions in state is collapsed on top of destancestors.
     Abort if there is more than one parent.
     """
     parents = set()
     source = min(state)
     for rev in state:
         if rev == source:
             continue
         for p in repo[rev].parents():
             if (p.rev() not in state
                         and p.rev() not in destancestors):
                 parents.add(p.rev())
     if not parents:
         return nullrev
     if len(parents) == 1:
         return parents.pop()
     raise error.Abort(_('unable to collapse on top of %d, there is more '
                        'than one external parent: %s') %
                      (max(destancestors),
                       ', '.join("%d" % p for p in sorted(parents))))
 
 def commitmemorynode(repo, p1, p2, wctx, editor, extra, user, date, commitmsg):
     '''Commit the memory changes with parents p1 and p2.
     Return node of committed revision.'''
     # Replicates the empty check in ``repo.commit``.
     if wctx.isempty() and not repo.ui.configbool('ui', 'allowemptycommit'):
         return None
 
     # By convention, ``extra['branch']`` (set by extrafn) clobbers
     # ``branch`` (used when passing ``--keepbranches``).
     branch = repo[p1].branch()
     if 'branch' in extra:
         branch = extra['branch']
 
     memctx = wctx.tomemctx(commitmsg, parents=(p1, p2), date=date,
         extra=extra, user=user, branch=branch, editor=editor)
     commitres = repo.commitctx(memctx)
     wctx.clean() # Might be reused
     return commitres
 
 def commitnode(repo, p1, p2, editor, extra, user, date, commitmsg):
     '''Commit the wd changes with parents p1 and p2.
     Return node of committed revision.'''
     dsguard = util.nullcontextmanager()
     if not repo.ui.configbool('rebase', 'singletransaction'):
         dsguard = dirstateguard.dirstateguard(repo, 'rebase')
     with dsguard:
         repo.setparents(repo[p1].node(), repo[p2].node())
 
         # Commit might fail if unresolved files exist
         newnode = repo.commit(text=commitmsg, user=user, date=date,
                               extra=extra, editor=editor)
 
         repo.dirstate.setbranch(repo[newnode].branch())
         return newnode
 
 def rebasenode(repo, rev, p1, base, collapse, dest, wctx):
     'Rebase a single revision rev on top of p1 using base as merge ancestor'
     # Merge phase
     # Update to destination and merge it with local
     if wctx.isinmemory():
         wctx.setbase(repo[p1])
     else:
         if repo['.'].rev() != p1:
             repo.ui.debug(" update to %d:%s\n" % (p1, repo[p1]))
             mergemod.update(repo, p1, False, True)
         else:
             repo.ui.debug(" already in destination\n")
         # This is, alas, necessary to invalidate workingctx's manifest cache,
         # as well as other data we litter on it in other places.
         wctx = repo[None]
         repo.dirstate.write(repo.currenttransaction())
     repo.ui.debug(" merge against %d:%s\n" % (rev, repo[rev]))
     if base is not None:
         repo.ui.debug("   detach base %d:%s\n" % (base, repo[base]))
     # When collapsing in-place, the parent is the common ancestor, we
     # have to allow merging with it.
     stats = mergemod.update(repo, rev, True, True, base, collapse,
                             labels=['dest', 'source'], wc=wctx)
     if collapse:
         copies.duplicatecopies(repo, wctx, rev, dest)
     else:
         # If we're not using --collapse, we need to
         # duplicate copies between the revision we're
         # rebasing and its first parent, but *not*
         # duplicate any copies that have already been
         # performed in the destination.
         p1rev = repo[rev].p1().rev()
         copies.duplicatecopies(repo, wctx, rev, p1rev, skiprev=dest)
     return stats
 
 def adjustdest(repo, rev, destmap, state, skipped):
     """adjust rebase destination given the current rebase state
 
     rev is what is being rebased. Return a list of two revs, which are the
     adjusted destinations for rev's p1 and p2, respectively. If a parent is
     nullrev, return dest without adjustment for it.
 
     For example, when doing rebasing B+E to F, C to G, rebase will first move B
     to B1, and E's destination will be adjusted from F to B1.
 
         B1 <- written during rebasing B
         |
         F <- original destination of B, E
         |
         | E <- rev, which is being rebased
         | |
         | D <- prev, one parent of rev being checked
         | |
         | x <- skipped, ex. no successor or successor in (::dest)
         | |
         | C <- rebased as C', different destination
         | |
         | B <- rebased as B1     C'
         |/                       |
         A                        G <- destination of C, different
 
     Another example about merge changeset, rebase -r C+G+H -d K, rebase will
     first move C to C1, G to G1, and when it's checking H, the adjusted
     destinations will be [C1, G1].
 
             H       C1 G1
            /|       | /
           F G       |/
         K | |  ->   K
         | C D       |
         | |/        |
         | B         | ...
         |/          |/
         A           A
 
     Besides, adjust dest according to existing rebase information. For example,
 
       B C D    B needs to be rebased on top of C, C needs to be rebased on top
        \|/     of D. We will rebase C first.
         A
 
           C'   After rebasing C, when considering B's destination, use C'
           |    instead of the original C.
       B   D
        \ /
         A
     """
     # pick already rebased revs with same dest from state as interesting source
     dest = destmap[rev]
     source = [s for s, d in state.items()
               if d > 0 and destmap[s] == dest and s not in skipped]
 
     result = []
     for prev in repo.changelog.parentrevs(rev):
         adjusted = dest
         if prev != nullrev:
             candidate = repo.revs('max(%ld and (::%d))', source, prev).first()
             if candidate is not None:
                 adjusted = state[candidate]
         if adjusted == dest and dest in state:
             adjusted = state[dest]
             if adjusted == revtodo:
                 # sortsource should produce an order that makes this impossible
                 raise error.ProgrammingError(
                     'rev %d should be rebased already at this time' % dest)
         result.append(adjusted)
     return result
 
 def _checkobsrebase(repo, ui, rebaseobsrevs, rebaseobsskipped):
     """
     Abort if rebase will create divergence or rebase is noop because of markers
 
     `rebaseobsrevs`: set of obsolete revision in source
     `rebaseobsskipped`: set of revisions from source skipped because they have
     successors in destination or no non-obsolete successor.
     """
     # Obsolete node with successors not in dest leads to divergence
     divergenceok = ui.configbool('experimental',
                                  'evolution.allowdivergence')
     divergencebasecandidates = rebaseobsrevs - rebaseobsskipped
 
     if divergencebasecandidates and not divergenceok:
         divhashes = (bytes(repo[r])
                      for r in divergencebasecandidates)
         msg = _("this rebase will cause "
                 "divergences from: %s")
         h = _("to force the rebase please set "
               "experimental.evolution.allowdivergence=True")
         raise error.Abort(msg % (",".join(divhashes),), hint=h)
 
 def successorrevs(unfi, rev):
     """yield revision numbers for successors of rev"""
     assert unfi.filtername is None
     nodemap = unfi.changelog.nodemap
     for s in obsutil.allsuccessors(unfi.obsstore, [unfi[rev].node()]):
         if s in nodemap:
             yield nodemap[s]
 
 def defineparents(repo, rev, destmap, state, skipped, obsskipped):
     """Return new parents and optionally a merge base for rev being rebased
 
     The destination specified by "dest" cannot always be used directly because
     previously rebase result could affect destination. For example,
 
           D E    rebase -r C+D+E -d B
           |/     C will be rebased to C'
         B C      D's new destination will be C' instead of B
         |/       E's new destination will be C' instead of B
         A
 
     The new parents of a merge is slightly more complicated. See the comment
     block below.
     """
     # use unfiltered changelog since successorrevs may return filtered nodes
     assert repo.filtername is None
     cl = repo.changelog
     isancestor = cl.isancestorrev
 
     dest = destmap[rev]
     oldps = repo.changelog.parentrevs(rev) # old parents
     newps = [nullrev, nullrev] # new parents
     dests = adjustdest(repo, rev, destmap, state, skipped)
     bases = list(oldps) # merge base candidates, initially just old parents
 
     if all(r == nullrev for r in oldps[1:]):
         # For non-merge changeset, just move p to adjusted dest as requested.
         newps[0] = dests[0]
     else:
         # For merge changeset, if we move p to dests[i] unconditionally, both
         # parents may change and the end result looks like "the merge loses a
         # parent", which is a surprise. This is a limit because "--dest" only
         # accepts one dest per src.
         #
         # Therefore, only move p with reasonable conditions (in this order):
         #   1. use dest, if dest is a descendent of (p or one of p's successors)
         #   2. use p's rebased result, if p is rebased (state[p] > 0)
         #
         # Comparing with adjustdest, the logic here does some additional work:
         #   1. decide which parents will not be moved towards dest
         #   2. if the above decision is "no", should a parent still be moved
         #      because it was rebased?
         #
         # For example:
         #
         #     C    # "rebase -r C -d D" is an error since none of the parents
         #    /|    # can be moved. "rebase -r B+C -d D" will move C's parent
         #   A B D  # B (using rule "2."), since B will be rebased.
         #
         # The loop tries to be not rely on the fact that a Mercurial node has
         # at most 2 parents.
         for i, p in enumerate(oldps):
             np = p # new parent
             if any(isancestor(x, dests[i]) for x in successorrevs(repo, p)):
                 np = dests[i]
             elif p in state and state[p] > 0:
                 np = state[p]
 
             # "bases" only record "special" merge bases that cannot be
             # calculated from changelog DAG (i.e. isancestor(p, np) is False).
             # For example:
             #
             #   B'   # rebase -s B -d D, when B was rebased to B'. dest for C
             #   | C  # is B', but merge base for C is B, instead of
             #   D |  # changelog.ancestor(C, B') == A. If changelog DAG and
             #   | B  # "state" edges are merged (so there will be an edge from
             #   |/   # B to B'), the merge base is still ancestor(C, B') in
             #   A    # the merged graph.
             #
             # Also see https://bz.mercurial-scm.org/show_bug.cgi?id=1950#c8
             # which uses "virtual null merge" to explain this situation.
             if isancestor(p, np):
                 bases[i] = nullrev
 
             # If one parent becomes an ancestor of the other, drop the ancestor
             for j, x in enumerate(newps[:i]):
                 if x == nullrev:
                     continue
                 if isancestor(np, x): # CASE-1
                     np = nullrev
                 elif isancestor(x, np): # CASE-2
                     newps[j] = np
                     np = nullrev
                     # New parents forming an ancestor relationship does not
                     # mean the old parents have a similar relationship. Do not
                     # set bases[x] to nullrev.
                     bases[j], bases[i] = bases[i], bases[j]
 
             newps[i] = np
 
         # "rebasenode" updates to new p1, and the old p1 will be used as merge
         # base. If only p2 changes, merging using unchanged p1 as merge base is
         # suboptimal. Therefore swap parents to make the merge sane.
         if newps[1] != nullrev and oldps[0] == newps[0]:
             assert len(newps) == 2 and len(oldps) == 2
             newps.reverse()
             bases.reverse()
 
         # No parent change might be an error because we fail to make rev a
         # descendent of requested dest. This can happen, for example:
         #
         #     C    # rebase -r C -d D
         #    /|    # None of A and B will be changed to D and rebase fails.
         #   A B D
         if set(newps) == set(oldps) and dest not in newps:
             raise error.Abort(_('cannot rebase %d:%s without '
                                 'moving at least one of its parents')
                               % (rev, repo[rev]))
 
     # Source should not be ancestor of dest. The check here guarantees it's
     # impossible. With multi-dest, the initial check does not cover complex
     # cases since we don't have abstractions to dry-run rebase cheaply.
     if any(p != nullrev and isancestor(rev, p) for p in newps):
         raise error.Abort(_('source is ancestor of destination'))
 
     # "rebasenode" updates to new p1, use the corresponding merge base.
     if bases[0] != nullrev:
         base = bases[0]
     else:
         base = None
 
     # Check if the merge will contain unwanted changes. That may happen if
     # there are multiple special (non-changelog ancestor) merge bases, which
     # cannot be handled well by the 3-way merge algorithm. For example:
     #
     #     F
     #    /|
     #   D E  # "rebase -r D+E+F -d Z", when rebasing F, if "D" was chosen
     #   | |  # as merge base, the difference between D and F will include
     #   B C  # C, so the rebased F will contain C surprisingly. If "E" was
     #   |/   #  chosen, the rebased F will contain B.
     #   A Z
     #
     # But our merge base candidates (D and E in above case) could still be
     # better than the default (ancestor(F, Z) == null). Therefore still
     # pick one (so choose p1 above).
     if sum(1 for b in bases if b != nullrev) > 1:
         unwanted = [None, None] # unwanted[i]: unwanted revs if choose bases[i]
         for i, base in enumerate(bases):
             if base == nullrev:
                 continue
             # Revisions in the side (not chosen as merge base) branch that
             # might contain "surprising" contents
             siderevs = list(repo.revs('((%ld-%d) %% (%d+%d))',
                                       bases, base, base, dest))
 
             # If those revisions are covered by rebaseset, the result is good.
             # A merge in rebaseset would be considered to cover its ancestors.
             if siderevs:
                 rebaseset = [r for r, d in state.items()
                              if d > 0 and r not in obsskipped]
                 merges = [r for r in rebaseset
                           if cl.parentrevs(r)[1] != nullrev]
                 unwanted[i] = list(repo.revs('%ld - (::%ld) - %ld',
                                              siderevs, merges, rebaseset))
 
         # Choose a merge base that has a minimal number of unwanted revs.
         l, i = min((len(revs), i)
                    for i, revs in enumerate(unwanted) if revs is not None)
         base = bases[i]
 
         # newps[0] should match merge base if possible. Currently, if newps[i]
         # is nullrev, the only case is newps[i] and newps[j] (j < i), one is
         # the other's ancestor. In that case, it's fine to not swap newps here.
         # (see CASE-1 and CASE-2 above)
         if i != 0 and newps[i] != nullrev:
             newps[0], newps[i] = newps[i], newps[0]
 
         # The merge will include unwanted revisions. Abort now. Revisit this if
         # we have a more advanced merge algorithm that handles multiple bases.
         if l > 0:
             unwanteddesc = _(' or ').join(
                 (', '.join('%d:%s' % (r, repo[r]) for r in revs)
                  for revs in unwanted if revs is not None))
             raise error.Abort(
                 _('rebasing %d:%s will include unwanted changes from %s')
                 % (rev, repo[rev], unwanteddesc))
 
     repo.ui.debug(" future parents are %d and %d\n" % tuple(newps))
 
     return newps[0], newps[1], base
 
 def isagitpatch(repo, patchname):
     'Return true if the given patch is in git format'
     mqpatch = os.path.join(repo.mq.path, patchname)
     for line in patch.linereader(open(mqpatch, 'rb')):
         if line.startswith('diff --git'):
             return True
     return False
 
 def updatemq(repo, state, skipped, **opts):
     'Update rebased mq patches - finalize and then import them'
     mqrebase = {}
     mq = repo.mq
     original_series = mq.fullseries[:]
     skippedpatches = set()
 
     for p in mq.applied:
         rev = repo[p.node].rev()
         if rev in state:
             repo.ui.debug('revision %d is an mq patch (%s), finalize it.\n' %
                                         (rev, p.name))
             mqrebase[rev] = (p.name, isagitpatch(repo, p.name))
         else:
             # Applied but not rebased, not sure this should happen
             skippedpatches.add(p.name)
 
     if mqrebase:
         mq.finish(repo, mqrebase.keys())
 
         # We must start import from the newest revision
         for rev in sorted(mqrebase, reverse=True):
             if rev not in skipped:
                 name, isgit = mqrebase[rev]
                 repo.ui.note(_('updating mq patch %s to %d:%s\n') %
                              (name, state[rev], repo[state[rev]]))
                 mq.qimport(repo, (), patchname=name, git=isgit,
                                 rev=["%d" % state[rev]])
             else:
                 # Rebased and skipped
                 skippedpatches.add(mqrebase[rev][0])
 
         # Patches were either applied and rebased and imported in
         # order, applied and removed or unapplied. Discard the removed
         # ones while preserving the original series order and guards.
         newseries = [s for s in original_series
                      if mq.guard_re.split(s, 1)[0] not in skippedpatches]
         mq.fullseries[:] = newseries
         mq.seriesdirty = True
         mq.savedirty()
 
 def storecollapsemsg(repo, collapsemsg):
     'Store the collapse message to allow recovery'
     collapsemsg = collapsemsg or ''
     f = repo.vfs("last-message.txt", "w")
     f.write("%s\n" % collapsemsg)
     f.close()
 
 def clearcollapsemsg(repo):
     'Remove collapse message file'
     repo.vfs.unlinkpath("last-message.txt", ignoremissing=True)
 
 def restorecollapsemsg(repo, isabort):
     'Restore previously stored collapse message'
     try:
         f = repo.vfs("last-message.txt")
         collapsemsg = f.readline().strip()
         f.close()
     except IOError as err:
         if err.errno != errno.ENOENT:
             raise
         if isabort:
             # Oh well, just abort like normal
             collapsemsg = ''
         else:
             raise error.Abort(_('missing .hg/last-message.txt for rebase'))
     return collapsemsg
 
 def clearstatus(repo):
     'Remove the status files'
     # Make sure the active transaction won't write the state file
     tr = repo.currenttransaction()
     if tr:
         tr.removefilegenerator('rebasestate')
     repo.vfs.unlinkpath("rebasestate", ignoremissing=True)
 
 def needupdate(repo, state):
     '''check whether we should `update --clean` away from a merge, or if
     somehow the working dir got forcibly updated, e.g. by older hg'''
     parents = [p.rev() for p in repo[None].parents()]
 
     # Are we in a merge state at all?
     if len(parents) < 2:
         return False
 
     # We should be standing on the first as-of-yet unrebased commit.
     firstunrebased = min([old for old, new in state.iteritems()
                           if new == nullrev])
     if firstunrebased in parents:
         return True
 
     return False
 
 def abort(repo, originalwd, destmap, state, activebookmark=None, backup=True,
           suppwarns=False):
     '''Restore the repository to its original state.  Additional args:
 
     activebookmark: the name of the bookmark that should be active after the
         restore'''
 
     try:
         # If the first commits in the rebased set get skipped during the rebase,
         # their values within the state mapping will be the dest rev id. The
         # rebased list must must not contain the dest rev (issue4896)
         rebased = [s for r, s in state.items()
                    if s >= 0 and s != r and s != destmap[r]]
         immutable = [d for d in rebased if not repo[d].mutable()]
         cleanup = True
         if immutable:
             repo.ui.warn(_("warning: can't clean up public changesets %s\n")
                         % ', '.join(bytes(repo[r]) for r in immutable),
                         hint=_("see 'hg help phases' for details"))
             cleanup = False
 
         descendants = set()
         if rebased:
             descendants = set(repo.changelog.descendants(rebased))
         if descendants - set(rebased):
             repo.ui.warn(_("warning: new changesets detected on destination "
                            "branch, can't strip\n"))
             cleanup = False
 
         if cleanup:
             shouldupdate = False
             if rebased:
                 strippoints = [
                         c.node() for c in repo.set('roots(%ld)', rebased)]
 
             updateifonnodes = set(rebased)
             updateifonnodes.update(destmap.values())
             updateifonnodes.add(originalwd)
             shouldupdate = repo['.'].rev() in updateifonnodes
 
             # Update away from the rebase if necessary
             if shouldupdate or needupdate(repo, state):
                 mergemod.update(repo, originalwd, False, True)
 
             # Strip from the first rebased revision
             if rebased:
                 repair.strip(repo.ui, repo, strippoints, backup=backup)
 
         if activebookmark and activebookmark in repo._bookmarks:
             bookmarks.activate(repo, activebookmark)
 
     finally:
         clearstatus(repo)
         clearcollapsemsg(repo)
         if not suppwarns:
             repo.ui.warn(_('rebase aborted\n'))
     return 0
 
 def sortsource(destmap):
     """yield source revisions in an order that we only rebase things once
 
     If source and destination overlaps, we should filter out revisions
     depending on other revisions which hasn't been rebased yet.
 
     Yield a sorted list of revisions each time.
 
     For example, when rebasing A to B, B to C. This function yields [B], then
     [A], indicating B needs to be rebased first.
 
     Raise if there is a cycle so the rebase is impossible.
     """
     srcset = set(destmap)
     while srcset:
         srclist = sorted(srcset)
         result = []
         for r in srclist:
             if destmap[r] not in srcset:
                 result.append(r)
         if not result:
             raise error.Abort(_('source and destination form a cycle'))
         srcset -= set(result)
         yield result
 
 def buildstate(repo, destmap, collapse):
     '''Define which revisions are going to be rebased and where
 
     repo: repo
     destmap: {srcrev: destrev}
     '''
     rebaseset = destmap.keys()
     originalwd = repo['.'].rev()
 
     # This check isn't strictly necessary, since mq detects commits over an
     # applied patch. But it prevents messing up the working directory when
     # a partially completed rebase is blocked by mq.
     if 'qtip' in repo.tags():
         mqapplied = set(repo[s.node].rev() for s in repo.mq.applied)
         if set(destmap.values()) & mqapplied:
             raise error.Abort(_('cannot rebase onto an applied mq patch'))
 
     # Get "cycle" error early by exhausting the generator.
     sortedsrc = list(sortsource(destmap)) # a list of sorted revs
     if not sortedsrc:
         raise error.Abort(_('no matching revisions'))
 
     # Only check the first batch of revisions to rebase not depending on other
     # rebaseset. This means "source is ancestor of destination" for the second
     # (and following) batches of revisions are not checked here. We rely on
     # "defineparents" to do that check.
     roots = list(repo.set('roots(%ld)', sortedsrc[0]))
     if not roots:
         raise error.Abort(_('no matching revisions'))
     def revof(r):
         return r.rev()
     roots = sorted(roots, key=revof)
     state = dict.fromkeys(rebaseset, revtodo)
     emptyrebase = (len(sortedsrc) == 1)
     for root in roots:
         dest = repo[destmap[root.rev()]]
         commonbase = root.ancestor(dest)
         if commonbase == root:
             raise error.Abort(_('source is ancestor of destination'))
         if commonbase == dest:
             wctx = repo[None]
             if dest == wctx.p1():
                 # when rebasing to '.', it will use the current wd branch name
                 samebranch = root.branch() == wctx.branch()
             else:
                 samebranch = root.branch() == dest.branch()
             if not collapse and samebranch and dest in root.parents():
                 # mark the revision as done by setting its new revision
                 # equal to its old (current) revisions
                 state[root.rev()] = root.rev()
                 repo.ui.debug('source is a child of destination\n')
                 continue
 
         emptyrebase = False
         repo.ui.debug('rebase onto %s starting from %s\n' % (dest, root))
     if emptyrebase:
         return None
     for rev in sorted(state):
         parents = [p for p in repo.changelog.parentrevs(rev) if p != nullrev]
         # if all parents of this revision are done, then so is this revision
         if parents and all((state.get(p) == p for p in parents)):
             state[rev] = rev
     return originalwd, destmap, state
 
 def clearrebased(ui, repo, destmap, state, skipped, collapsedas=None,
-                 keepf=False, fm=None):
+                 keepf=False, fm=None, backup=True):
     """dispose of rebased revision at the end of the rebase
 
     If `collapsedas` is not None, the rebase was a collapse whose result if the
     `collapsedas` node.
 
     If `keepf` is not True, the rebase has --keep set and no nodes should be
     removed (but bookmarks still need to be moved).
+
+    If `backup` is False, no backup will be stored when stripping rebased
+    revisions.
     """
     tonode = repo.changelog.node
     replacements = {}
     moves = {}
     for rev, newrev in sorted(state.items()):
         if newrev >= 0 and newrev != rev:
             oldnode = tonode(rev)
             newnode = collapsedas or tonode(newrev)
             moves[oldnode] = newnode
             if not keepf:
                 if rev in skipped:
                     succs = ()
                 else:
                     succs = (newnode,)
                 replacements[oldnode] = succs
-    scmutil.cleanupnodes(repo, replacements, 'rebase', moves)
+    scmutil.cleanupnodes(repo, replacements, 'rebase', moves, backup=backup)
     if fm:
         hf = fm.hexfunc
         fl = fm.formatlist
         fd = fm.formatdict
         nodechanges = fd({hf(oldn): fl([hf(n) for n in newn], name='node')
                           for oldn, newn in replacements.iteritems()},
                          key="oldnode", value="newnodes")
         fm.data(nodechanges=nodechanges)
 
 def pullrebase(orig, ui, repo, *args, **opts):
     'Call rebase after pull if the latter has been invoked with --rebase'
     ret = None
     if opts.get(r'rebase'):
         if ui.configbool('commands', 'rebase.requiredest'):
             msg = _('rebase destination required by configuration')
             hint = _('use hg pull followed by hg rebase -d DEST')
             raise error.Abort(msg, hint=hint)
 
         with repo.wlock(), repo.lock():
             if opts.get(r'update'):
                 del opts[r'update']
                 ui.debug('--update and --rebase are not compatible, ignoring '
                          'the update flag\n')
 
             cmdutil.checkunfinished(repo)
             cmdutil.bailifchanged(repo, hint=_('cannot pull with rebase: '
                 'please commit or shelve your changes first'))
 
             revsprepull = len(repo)
             origpostincoming = commands.postincoming
             def _dummy(*args, **kwargs):
                 pass
             commands.postincoming = _dummy
             try:
                 ret = orig(ui, repo, *args, **opts)
             finally:
                 commands.postincoming = origpostincoming
             revspostpull = len(repo)
             if revspostpull > revsprepull:
                 # --rev option from pull conflict with rebase own --rev
                 # dropping it
                 if r'rev' in opts:
                     del opts[r'rev']
                 # positional argument from pull conflicts with rebase's own
                 # --source.
                 if r'source' in opts:
                     del opts[r'source']
                 # revsprepull is the len of the repo, not revnum of tip.
                 destspace = list(repo.changelog.revs(start=revsprepull))
                 opts[r'_destspace'] = destspace
                 try:
                     rebase(ui, repo, **opts)
                 except error.NoMergeDestAbort:
                     # we can maybe update instead
                     rev, _a, _b = destutil.destupdate(repo)
                     if rev == repo['.'].rev():
                         ui.status(_('nothing to rebase\n'))
                     else:
                         ui.status(_('nothing to rebase - updating instead\n'))
                         # not passing argument to get the bare update behavior
                         # with warning and trumpets
                         commands.update(ui, repo)
     else:
         if opts.get(r'tool'):
             raise error.Abort(_('--tool can only be used with --rebase'))
         ret = orig(ui, repo, *args, **opts)
 
     return ret
 
 def _filterobsoleterevs(repo, revs):
     """returns a set of the obsolete revisions in revs"""
     return set(r for r in revs if repo[r].obsolete())
 
 def _computeobsoletenotrebased(repo, rebaseobsrevs, destmap):
     """Return (obsoletenotrebased, obsoletewithoutsuccessorindestination).
 
     `obsoletenotrebased` is a mapping mapping obsolete => successor for all
     obsolete nodes to be rebased given in `rebaseobsrevs`.
 
     `obsoletewithoutsuccessorindestination` is a set with obsolete revisions
     without a successor in destination.
 
     `obsoleteextinctsuccessors` is a set of obsolete revisions with only
     obsolete successors.
     """
     obsoletenotrebased = {}
     obsoletewithoutsuccessorindestination = set([])
     obsoleteextinctsuccessors = set([])
 
     assert repo.filtername is None
     cl = repo.changelog
     nodemap = cl.nodemap
     extinctrevs = set(repo.revs('extinct()'))
     for srcrev in rebaseobsrevs:
         srcnode = cl.node(srcrev)
         # XXX: more advanced APIs are required to handle split correctly
         successors = set(obsutil.allsuccessors(repo.obsstore, [srcnode]))
         # obsutil.allsuccessors includes node itself
         successors.remove(srcnode)
         succrevs = {nodemap[s] for s in successors if s in nodemap}
         if succrevs.issubset(extinctrevs):
             # all successors are extinct
             obsoleteextinctsuccessors.add(srcrev)
         if not successors:
             # no successor
             obsoletenotrebased[srcrev] = None
         else:
             dstrev = destmap[srcrev]
             for succrev in succrevs:
                 if cl.isancestorrev(succrev, dstrev):
                     obsoletenotrebased[srcrev] = succrev
                     break
             else:
                 # If 'srcrev' has a successor in rebase set but none in
                 # destination (which would be catched above), we shall skip it
                 # and its descendants to avoid divergence.
                 if any(s in destmap for s in succrevs):
                     obsoletewithoutsuccessorindestination.add(srcrev)
 
     return (
         obsoletenotrebased,
         obsoletewithoutsuccessorindestination,
         obsoleteextinctsuccessors,
     )
 
 def summaryhook(ui, repo):
     if not repo.vfs.exists('rebasestate'):
         return
     try:
         rbsrt = rebaseruntime(repo, ui, {})
         rbsrt.restorestatus()
         state = rbsrt.state
     except error.RepoLookupError:
         # i18n: column positioning for "hg summary"
         msg = _('rebase: (use "hg rebase --abort" to clear broken state)\n')
         ui.write(msg)
         return
     numrebased = len([i for i in state.itervalues() if i >= 0])
     # i18n: column positioning for "hg summary"
     ui.write(_('rebase: %s, %s (rebase --continue)\n') %
              (ui.label(_('%d rebased'), 'rebase.rebased') % numrebased,
               ui.label(_('%d remaining'), 'rebase.remaining') %
               (len(state) - numrebased)))
 
 def uisetup(ui):
     #Replace pull with a decorator to provide --rebase option
     entry = extensions.wrapcommand(commands.table, 'pull', pullrebase)
     entry[1].append(('', 'rebase', None,
                      _("rebase working directory to branch head")))
     entry[1].append(('t', 'tool', '',
                      _("specify merge tool for rebase")))
     cmdutil.summaryhooks.add('rebase', summaryhook)
     cmdutil.unfinishedstates.append(
         ['rebasestate', False, False, _('rebase in progress'),
          _("use 'hg rebase --continue' or 'hg rebase --abort'")])
     cmdutil.afterresolvedstates.append(
         ['rebasestate', _('hg rebase --continue')])

mercurial/repair.py

@@ -1,437 +1,437 b''
 # repair.py - functions for repository repair for mercurial
 #
 # Copyright 2005, 2006 Chris Mason <[e-mail]>
 # Copyright 2007 Matt Mackall
 #
 # 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
 
 from .i18n import _
 from .node import (
     hex,
     short,
 )
 from . import (
     bundle2,
     changegroup,
     discovery,
     error,
     exchange,
     obsolete,
     obsutil,
     pycompat,
     util,
 )
 from .utils import (
     stringutil,
 )
 
 def backupbundle(repo, bases, heads, node, suffix, compress=True,
                  obsolescence=True):
     """create a bundle with the specified revisions as a backup"""
 
     backupdir = "strip-backup"
     vfs = repo.vfs
     if not vfs.isdir(backupdir):
         vfs.mkdir(backupdir)
 
     # Include a hash of all the nodes in the filename for uniqueness
     allcommits = repo.set('%ln::%ln', bases, heads)
     allhashes = sorted(c.hex() for c in allcommits)
     totalhash = hashlib.sha1(''.join(allhashes)).digest()
     name = "%s/%s-%s-%s.hg" % (backupdir, short(node),
                                hex(totalhash[:4]), suffix)
 
     cgversion = changegroup.localversion(repo)
     comp = None
     if cgversion != '01':
         bundletype = "HG20"
         if compress:
             comp = 'BZ'
     elif compress:
         bundletype = "HG10BZ"
     else:
         bundletype = "HG10UN"
 
     outgoing = discovery.outgoing(repo, missingroots=bases, missingheads=heads)
     contentopts = {
         'cg.version': cgversion,
         'obsolescence': obsolescence,
         'phases': True,
     }
     return bundle2.writenewbundle(repo.ui, repo, 'strip', name, bundletype,
                                   outgoing, contentopts, vfs, compression=comp)
 
 def _collectfiles(repo, striprev):
     """find out the filelogs affected by the strip"""
     files = set()
 
     for x in pycompat.xrange(striprev, len(repo)):
         files.update(repo[x].files())
 
     return sorted(files)
 
 def _collectrevlog(revlog, striprev):
     _, brokenset = revlog.getstrippoint(striprev)
     return [revlog.linkrev(r) for r in brokenset]
 
 def _collectmanifest(repo, striprev):
     return _collectrevlog(repo.manifestlog._revlog, striprev)
 
 def _collectbrokencsets(repo, files, striprev):
     """return the changesets which will be broken by the truncation"""
     s = set()
 
     s.update(_collectmanifest(repo, striprev))
     for fname in files:
         s.update(_collectrevlog(repo.file(fname), striprev))
 
     return s
 
 def strip(ui, repo, nodelist, backup=True, topic='backup'):
     # This function requires the caller to lock the repo, but it operates
     # within a transaction of its own, and thus requires there to be no current
     # transaction when it is called.
     if repo.currenttransaction() is not None:
         raise error.ProgrammingError('cannot strip from inside a transaction')
 
     # Simple way to maintain backwards compatibility for this
     # argument.
     if backup in ['none', 'strip']:
         backup = False
 
     repo = repo.unfiltered()
     repo.destroying()
 
     cl = repo.changelog
     # TODO handle undo of merge sets
     if isinstance(nodelist, str):
         nodelist = [nodelist]
     striplist = [cl.rev(node) for node in nodelist]
     striprev = min(striplist)
 
     files = _collectfiles(repo, striprev)
     saverevs = _collectbrokencsets(repo, files, striprev)
 
     # Some revisions with rev > striprev may not be descendants of striprev.
     # We have to find these revisions and put them in a bundle, so that
     # we can restore them after the truncations.
     # To create the bundle we use repo.changegroupsubset which requires
     # the list of heads and bases of the set of interesting revisions.
     # (head = revision in the set that has no descendant in the set;
     #  base = revision in the set that has no ancestor in the set)
     tostrip = set(striplist)
     saveheads = set(saverevs)
     for r in cl.revs(start=striprev + 1):
         if any(p in tostrip for p in cl.parentrevs(r)):
             tostrip.add(r)
 
         if r not in tostrip:
             saverevs.add(r)
             saveheads.difference_update(cl.parentrevs(r))
             saveheads.add(r)
     saveheads = [cl.node(r) for r in saveheads]
 
     # compute base nodes
     if saverevs:
         descendants = set(cl.descendants(saverevs))
         saverevs.difference_update(descendants)
     savebases = [cl.node(r) for r in saverevs]
     stripbases = [cl.node(r) for r in tostrip]
 
     stripobsidx = obsmarkers = ()
     if repo.ui.configbool('devel', 'strip-obsmarkers'):
         obsmarkers = obsutil.exclusivemarkers(repo, stripbases)
     if obsmarkers:
         stripobsidx = [i for i, m in enumerate(repo.obsstore)
                        if m in obsmarkers]
 
     # For a set s, max(parents(s) - s) is the same as max(heads(::s - s)), but
     # is much faster
     newbmtarget = repo.revs('max(parents(%ld) - (%ld))', tostrip, tostrip)
     if newbmtarget:
         newbmtarget = repo[newbmtarget.first()].node()
     else:
         newbmtarget = '.'
 
     bm = repo._bookmarks
     updatebm = []
     for m in bm:
         rev = repo[bm[m]].rev()
         if rev in tostrip:
             updatebm.append(m)
 
     # create a changegroup for all the branches we need to keep
     backupfile = None
     vfs = repo.vfs
     node = nodelist[-1]
     if backup:
         backupfile = backupbundle(repo, stripbases, cl.heads(), node, topic)
         repo.ui.status(_("saved backup bundle to %s\n") %
                        vfs.join(backupfile))
         repo.ui.log("backupbundle", "saved backup bundle to %s\n",
                     vfs.join(backupfile))
     tmpbundlefile = None
     if saveheads:
         # do not compress temporary bundle if we remove it from disk later
         #
         # We do not include obsolescence, it might re-introduce prune markers
         # we are trying to strip.  This is harmless since the stripped markers
         # are already backed up and we did not touched the markers for the
         # saved changesets.
         tmpbundlefile = backupbundle(repo, savebases, saveheads, node, 'temp',
                                      compress=False, obsolescence=False)
 
     with ui.uninterruptable():
         try:
             with repo.transaction("strip") as tr:
                 offset = len(tr.entries)
 
                 tr.startgroup()
                 cl.strip(striprev, tr)
                 stripmanifest(repo, striprev, tr, files)
 
                 for fn in files:
                     repo.file(fn).strip(striprev, tr)
                 tr.endgroup()
 
                 for i in pycompat.xrange(offset, len(tr.entries)):
                     file, troffset, ignore = tr.entries[i]
                     with repo.svfs(file, 'a', checkambig=True) as fp:
                         fp.truncate(troffset)
                     if troffset == 0:
                         repo.store.markremoved(file)
 
                 deleteobsmarkers(repo.obsstore, stripobsidx)
                 del repo.obsstore
                 repo.invalidatevolatilesets()
                 repo._phasecache.filterunknown(repo)
 
             if tmpbundlefile:
                 ui.note(_("adding branch\n"))
                 f = vfs.open(tmpbundlefile, "rb")
                 gen = exchange.readbundle(ui, f, tmpbundlefile, vfs)
                 if not repo.ui.verbose:
                     # silence internal shuffling chatter
                     repo.ui.pushbuffer()
                 tmpbundleurl = 'bundle:' + vfs.join(tmpbundlefile)
                 txnname = 'strip'
                 if not isinstance(gen, bundle2.unbundle20):
                     txnname = "strip\n%s" % util.hidepassword(tmpbundleurl)
                 with repo.transaction(txnname) as tr:
                     bundle2.applybundle(repo, gen, tr, source='strip',
                                         url=tmpbundleurl)
                 if not repo.ui.verbose:
                     repo.ui.popbuffer()
                 f.close()
 
             with repo.transaction('repair') as tr:
                 bmchanges = [(m, repo[newbmtarget].node()) for m in updatebm]
                 bm.applychanges(repo, tr, bmchanges)
 
             # remove undo files
             for undovfs, undofile in repo.undofiles():
                 try:
                     undovfs.unlink(undofile)
                 except OSError as e:
                     if e.errno != errno.ENOENT:
                         ui.warn(_('error removing %s: %s\n') %
                                 (undovfs.join(undofile),
                                  stringutil.forcebytestr(e)))
 
         except: # re-raises
             if backupfile:
                 ui.warn(_("strip failed, backup bundle stored in '%s'\n")
                         % vfs.join(backupfile))
             if tmpbundlefile:
                 ui.warn(_("strip failed, unrecovered changes stored in '%s'\n")
                         % vfs.join(tmpbundlefile))
                 ui.warn(_("(fix the problem, then recover the changesets with "
                           "\"hg unbundle '%s'\")\n") % vfs.join(tmpbundlefile))
             raise
         else:
             if tmpbundlefile:
                 # Remove temporary bundle only if there were no exceptions
                 vfs.unlink(tmpbundlefile)
 
     repo.destroyed()
     # return the backup file path (or None if 'backup' was False) so
     # extensions can use it
     return backupfile
 
 def safestriproots(ui, repo, nodes):
     """return list of roots of nodes where descendants are covered by nodes"""
     torev = repo.unfiltered().changelog.rev
     revs = set(torev(n) for n in nodes)
     # tostrip = wanted - unsafe = wanted - ancestors(orphaned)
     # orphaned = affected - wanted
     # affected = descendants(roots(wanted))
     # wanted = revs
     tostrip = set(repo.revs('%ld-(::((roots(%ld)::)-%ld))', revs, revs, revs))
     notstrip = revs - tostrip
     if notstrip:
         nodestr = ', '.join(sorted(short(repo[n].node()) for n in notstrip))
         ui.warn(_('warning: orphaned descendants detected, '
                   'not stripping %s\n') % nodestr)
     return [c.node() for c in repo.set('roots(%ld)', tostrip)]
 
 class stripcallback(object):
     """used as a transaction postclose callback"""
 
     def __init__(self, ui, repo, backup, topic):
         self.ui = ui
         self.repo = repo
         self.backup = backup
         self.topic = topic or 'backup'
         self.nodelist = []
 
     def addnodes(self, nodes):
         self.nodelist.extend(nodes)
 
     def __call__(self, tr):
         roots = safestriproots(self.ui, self.repo, self.nodelist)
         if roots:
             strip(self.ui, self.repo, roots, self.backup, self.topic)
 
-def delayedstrip(ui, repo, nodelist, topic=None):
+def delayedstrip(ui, repo, nodelist, topic=None, backup=True):
     """like strip, but works inside transaction and won't strip irreverent revs
 
     nodelist must explicitly contain all descendants. Otherwise a warning will
     be printed that some nodes are not stripped.
 
-    Always do a backup. The last non-None "topic" will be used as the backup
-    topic name. The default backup topic name is "backup".
+    Will do a backup if `backup` is True. The last non-None "topic" will be
+    used as the backup topic name. The default backup topic name is "backup".
     """
     tr = repo.currenttransaction()
     if not tr:
         nodes = safestriproots(ui, repo, nodelist)
-        return strip(ui, repo, nodes, True, topic)
+        return strip(ui, repo, nodes, backup=backup, topic=topic)
     # transaction postclose callbacks are called in alphabet order.
     # use '\xff' as prefix so we are likely to be called last.
     callback = tr.getpostclose('\xffstrip')
     if callback is None:
-        callback = stripcallback(ui, repo, True, topic)
+        callback = stripcallback(ui, repo, backup=backup, topic=topic)
         tr.addpostclose('\xffstrip', callback)
     if topic:
         callback.topic = topic
     callback.addnodes(nodelist)
 
 def stripmanifest(repo, striprev, tr, files):
     revlog = repo.manifestlog._revlog
     revlog.strip(striprev, tr)
     striptrees(repo, tr, striprev, files)
 
 def striptrees(repo, tr, striprev, files):
     if 'treemanifest' in repo.requirements: # safe but unnecessary
                                             # otherwise
         for unencoded, encoded, size in repo.store.datafiles():
             if (unencoded.startswith('meta/') and
                 unencoded.endswith('00manifest.i')):
                 dir = unencoded[5:-12]
                 repo.manifestlog._revlog.dirlog(dir).strip(striprev, tr)
 
 def rebuildfncache(ui, repo):
     """Rebuilds the fncache file from repo history.
 
     Missing entries will be added. Extra entries will be removed.
     """
     repo = repo.unfiltered()
 
     if 'fncache' not in repo.requirements:
         ui.warn(_('(not rebuilding fncache because repository does not '
                   'support fncache)\n'))
         return
 
     with repo.lock():
         fnc = repo.store.fncache
         # Trigger load of fncache.
         if 'irrelevant' in fnc:
             pass
 
         oldentries = set(fnc.entries)
         newentries = set()
         seenfiles = set()
 
         progress = ui.makeprogress(_('rebuilding'), unit=_('changesets'),
                                    total=len(repo))
         for rev in repo:
             progress.update(rev)
 
             ctx = repo[rev]
             for f in ctx.files():
                 # This is to minimize I/O.
                 if f in seenfiles:
                     continue
                 seenfiles.add(f)
 
                 i = 'data/%s.i' % f
                 d = 'data/%s.d' % f
 
                 if repo.store._exists(i):
                     newentries.add(i)
                 if repo.store._exists(d):
                     newentries.add(d)
 
         progress.complete()
 
         if 'treemanifest' in repo.requirements: # safe but unnecessary otherwise
             for dir in util.dirs(seenfiles):
                 i = 'meta/%s/00manifest.i' % dir
                 d = 'meta/%s/00manifest.d' % dir
 
                 if repo.store._exists(i):
                     newentries.add(i)
                 if repo.store._exists(d):
                     newentries.add(d)
 
         addcount = len(newentries - oldentries)
         removecount = len(oldentries - newentries)
         for p in sorted(oldentries - newentries):
             ui.write(_('removing %s\n') % p)
         for p in sorted(newentries - oldentries):
             ui.write(_('adding %s\n') % p)
 
         if addcount or removecount:
             ui.write(_('%d items added, %d removed from fncache\n') %
                      (addcount, removecount))
             fnc.entries = newentries
             fnc._dirty = True
 
             with repo.transaction('fncache') as tr:
                 fnc.write(tr)
         else:
             ui.write(_('fncache already up to date\n'))
 
 def deleteobsmarkers(obsstore, indices):
     """Delete some obsmarkers from obsstore and return how many were deleted
 
     'indices' is a list of ints which are the indices
     of the markers to be deleted.
 
     Every invocation of this function completely rewrites the obsstore file,
     skipping the markers we want to be removed. The new temporary file is
     created, remaining markers are written there and on .close() this file
     gets atomically renamed to obsstore, thus guaranteeing consistency."""
     if not indices:
         # we don't want to rewrite the obsstore with the same content
         return
 
     left = []
     current = obsstore._all
     n = 0
     for i, m in enumerate(current):
         if i in indices:
             n += 1
             continue
         left.append(m)
 
     newobsstorefile = obsstore.svfs('obsstore', 'w', atomictemp=True)
     for bytes in obsolete.encodemarkers(left, True, obsstore._version):
         newobsstorefile.write(bytes)
     newobsstorefile.close()
     return n

mercurial/scmutil.py

@@ -1,1700 +1,1701 b''
 # scmutil.py - Mercurial core utility functions
 #
 #  Copyright 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 glob
 import hashlib
 import os
 import re
 import socket
 import subprocess
 import weakref
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     nullid,
     short,
     wdirid,
     wdirrev,
 )
 
 from . import (
     encoding,
     error,
     match as matchmod,
     obsolete,
     obsutil,
     pathutil,
     phases,
     pycompat,
     revsetlang,
     similar,
     url,
     util,
     vfs,
 )
 
 from .utils import (
     procutil,
     stringutil,
 )
 
 if pycompat.iswindows:
     from . import scmwindows as scmplatform
 else:
     from . import scmposix as scmplatform
 
 termsize = scmplatform.termsize
 
 class status(tuple):
     '''Named tuple with a list of files per status. The 'deleted', 'unknown'
        and 'ignored' properties are only relevant to the working copy.
     '''
 
     __slots__ = ()
 
     def __new__(cls, modified, added, removed, deleted, unknown, ignored,
                 clean):
         return tuple.__new__(cls, (modified, added, removed, deleted, unknown,
                                    ignored, clean))
 
     @property
     def modified(self):
         '''files that have been modified'''
         return self[0]
 
     @property
     def added(self):
         '''files that have been added'''
         return self[1]
 
     @property
     def removed(self):
         '''files that have been removed'''
         return self[2]
 
     @property
     def deleted(self):
         '''files that are in the dirstate, but have been deleted from the
            working copy (aka "missing")
         '''
         return self[3]
 
     @property
     def unknown(self):
         '''files not in the dirstate that are not ignored'''
         return self[4]
 
     @property
     def ignored(self):
         '''files not in the dirstate that are ignored (by _dirignore())'''
         return self[5]
 
     @property
     def clean(self):
         '''files that have not been modified'''
         return self[6]
 
     def __repr__(self, *args, **kwargs):
         return ((r'<status modified=%s, added=%s, removed=%s, deleted=%s, '
                  r'unknown=%s, ignored=%s, clean=%s>') %
                 tuple(pycompat.sysstr(stringutil.pprint(v)) for v in self))
 
 def itersubrepos(ctx1, ctx2):
     """find subrepos in ctx1 or ctx2"""
     # Create a (subpath, ctx) mapping where we prefer subpaths from
     # ctx1. The subpaths from ctx2 are important when the .hgsub file
     # has been modified (in ctx2) but not yet committed (in ctx1).
     subpaths = dict.fromkeys(ctx2.substate, ctx2)
     subpaths.update(dict.fromkeys(ctx1.substate, ctx1))
 
     missing = set()
 
     for subpath in ctx2.substate:
         if subpath not in ctx1.substate:
             del subpaths[subpath]
             missing.add(subpath)
 
     for subpath, ctx in sorted(subpaths.iteritems()):
         yield subpath, ctx.sub(subpath)
 
     # Yield an empty subrepo based on ctx1 for anything only in ctx2.  That way,
     # status and diff will have an accurate result when it does
     # 'sub.{status|diff}(rev2)'.  Otherwise, the ctx2 subrepo is compared
     # against itself.
     for subpath in missing:
         yield subpath, ctx2.nullsub(subpath, ctx1)
 
 def nochangesfound(ui, repo, excluded=None):
     '''Report no changes for push/pull, excluded is None or a list of
     nodes excluded from the push/pull.
     '''
     secretlist = []
     if excluded:
         for n in excluded:
             ctx = repo[n]
             if ctx.phase() >= phases.secret and not ctx.extinct():
                 secretlist.append(n)
 
     if secretlist:
         ui.status(_("no changes found (ignored %d secret changesets)\n")
                   % len(secretlist))
     else:
         ui.status(_("no changes found\n"))
 
 def callcatch(ui, func):
     """call func() with global exception handling
 
     return func() if no exception happens. otherwise do some error handling
     and return an exit code accordingly. does not handle all exceptions.
     """
     try:
         try:
             return func()
         except: # re-raises
             ui.traceback()
             raise
     # Global exception handling, alphabetically
     # Mercurial-specific first, followed by built-in and library exceptions
     except error.LockHeld as inst:
         if inst.errno == errno.ETIMEDOUT:
             reason = _('timed out waiting for lock held by %r') % inst.locker
         else:
             reason = _('lock held by %r') % inst.locker
         ui.error(_("abort: %s: %s\n") % (
             inst.desc or stringutil.forcebytestr(inst.filename), reason))
         if not inst.locker:
             ui.error(_("(lock might be very busy)\n"))
     except error.LockUnavailable as inst:
         ui.error(_("abort: could not lock %s: %s\n") %
                  (inst.desc or stringutil.forcebytestr(inst.filename),
                   encoding.strtolocal(inst.strerror)))
     except error.OutOfBandError as inst:
         if inst.args:
             msg = _("abort: remote error:\n")
         else:
             msg = _("abort: remote error\n")
         ui.error(msg)
         if inst.args:
             ui.error(''.join(inst.args))
         if inst.hint:
             ui.error('(%s)\n' % inst.hint)
     except error.RepoError as inst:
         ui.error(_("abort: %s!\n") % inst)
         if inst.hint:
             ui.error(_("(%s)\n") % inst.hint)
     except error.ResponseError as inst:
         ui.error(_("abort: %s") % inst.args[0])
         msg = inst.args[1]
         if isinstance(msg, type(u'')):
             msg = pycompat.sysbytes(msg)
         if not isinstance(msg, bytes):
             ui.error(" %r\n" % (msg,))
         elif not msg:
             ui.error(_(" empty string\n"))
         else:
             ui.error("\n%r\n" % pycompat.bytestr(stringutil.ellipsis(msg)))
     except error.CensoredNodeError as inst:
         ui.error(_("abort: file censored %s!\n") % inst)
     except error.RevlogError as inst:
         ui.error(_("abort: %s!\n") % inst)
     except error.InterventionRequired as inst:
         ui.error("%s\n" % inst)
         if inst.hint:
             ui.error(_("(%s)\n") % inst.hint)
         return 1
     except error.WdirUnsupported:
         ui.error(_("abort: working directory revision cannot be specified\n"))
     except error.Abort as inst:
         ui.error(_("abort: %s\n") % inst)
         if inst.hint:
             ui.error(_("(%s)\n") % inst.hint)
     except ImportError as inst:
         ui.error(_("abort: %s!\n") % stringutil.forcebytestr(inst))
         m = stringutil.forcebytestr(inst).split()[-1]
         if m in "mpatch bdiff".split():
             ui.error(_("(did you forget to compile extensions?)\n"))
         elif m in "zlib".split():
             ui.error(_("(is your Python install correct?)\n"))
     except IOError as inst:
         if util.safehasattr(inst, "code"):
             ui.error(_("abort: %s\n") % stringutil.forcebytestr(inst))
         elif util.safehasattr(inst, "reason"):
             try: # usually it is in the form (errno, strerror)
                 reason = inst.reason.args[1]
             except (AttributeError, IndexError):
                 # it might be anything, for example a string
                 reason = inst.reason
             if isinstance(reason, pycompat.unicode):
                 # SSLError of Python 2.7.9 contains a unicode
                 reason = encoding.unitolocal(reason)
             ui.error(_("abort: error: %s\n") % reason)
         elif (util.safehasattr(inst, "args")
               and inst.args and inst.args[0] == errno.EPIPE):
             pass
         elif getattr(inst, "strerror", None):
             if getattr(inst, "filename", None):
                 ui.error(_("abort: %s: %s\n") % (
                     encoding.strtolocal(inst.strerror),
                     stringutil.forcebytestr(inst.filename)))
             else:
                 ui.error(_("abort: %s\n") % encoding.strtolocal(inst.strerror))
         else:
             raise
     except OSError as inst:
         if getattr(inst, "filename", None) is not None:
             ui.error(_("abort: %s: '%s'\n") % (
                 encoding.strtolocal(inst.strerror),
                 stringutil.forcebytestr(inst.filename)))
         else:
             ui.error(_("abort: %s\n") % encoding.strtolocal(inst.strerror))
     except MemoryError:
         ui.error(_("abort: out of memory\n"))
     except SystemExit as inst:
         # Commands shouldn't sys.exit directly, but give a return code.
         # Just in case catch this and and pass exit code to caller.
         return inst.code
     except socket.error as inst:
         ui.error(_("abort: %s\n") % stringutil.forcebytestr(inst.args[-1]))
 
     return -1
 
 def checknewlabel(repo, lbl, kind):
     # Do not use the "kind" parameter in ui output.
     # It makes strings difficult to translate.
     if lbl in ['tip', '.', 'null']:
         raise error.Abort(_("the name '%s' is reserved") % lbl)
     for c in (':', '\0', '\n', '\r'):
         if c in lbl:
             raise error.Abort(
                 _("%r cannot be used in a name") % pycompat.bytestr(c))
     try:
         int(lbl)
         raise error.Abort(_("cannot use an integer as a name"))
     except ValueError:
         pass
     if lbl.strip() != lbl:
         raise error.Abort(_("leading or trailing whitespace in name %r") % lbl)
 
 def checkfilename(f):
     '''Check that the filename f is an acceptable filename for a tracked file'''
     if '\r' in f or '\n' in f:
         raise error.Abort(_("'\\n' and '\\r' disallowed in filenames: %r")
                           % pycompat.bytestr(f))
 
 def checkportable(ui, f):
     '''Check if filename f is portable and warn or abort depending on config'''
     checkfilename(f)
     abort, warn = checkportabilityalert(ui)
     if abort or warn:
         msg = util.checkwinfilename(f)
         if msg:
             msg = "%s: %s" % (msg, procutil.shellquote(f))
             if abort:
                 raise error.Abort(msg)
             ui.warn(_("warning: %s\n") % msg)
 
 def checkportabilityalert(ui):
     '''check if the user's config requests nothing, a warning, or abort for
     non-portable filenames'''
     val = ui.config('ui', 'portablefilenames')
     lval = val.lower()
     bval = stringutil.parsebool(val)
     abort = pycompat.iswindows or lval == 'abort'
     warn = bval or lval == 'warn'
     if bval is None and not (warn or abort or lval == 'ignore'):
         raise error.ConfigError(
             _("ui.portablefilenames value is invalid ('%s')") % val)
     return abort, warn
 
 class casecollisionauditor(object):
     def __init__(self, ui, abort, dirstate):
         self._ui = ui
         self._abort = abort
         allfiles = '\0'.join(dirstate._map)
         self._loweredfiles = set(encoding.lower(allfiles).split('\0'))
         self._dirstate = dirstate
         # The purpose of _newfiles is so that we don't complain about
         # case collisions if someone were to call this object with the
         # same filename twice.
         self._newfiles = set()
 
     def __call__(self, f):
         if f in self._newfiles:
             return
         fl = encoding.lower(f)
         if fl in self._loweredfiles and f not in self._dirstate:
             msg = _('possible case-folding collision for %s') % f
             if self._abort:
                 raise error.Abort(msg)
             self._ui.warn(_("warning: %s\n") % msg)
         self._loweredfiles.add(fl)
         self._newfiles.add(f)
 
 def filteredhash(repo, maxrev):
     """build hash of filtered revisions in the current repoview.
 
     Multiple caches perform up-to-date validation by checking that the
     tiprev and tipnode stored in the cache file match the current repository.
     However, this is not sufficient for validating repoviews because the set
     of revisions in the view may change without the repository tiprev and
     tipnode changing.
 
     This function hashes all the revs filtered from the view and returns
     that SHA-1 digest.
     """
     cl = repo.changelog
     if not cl.filteredrevs:
         return None
     key = None
     revs = sorted(r for r in cl.filteredrevs if r <= maxrev)
     if revs:
         s = hashlib.sha1()
         for rev in revs:
             s.update('%d;' % rev)
         key = s.digest()
     return key
 
 def walkrepos(path, followsym=False, seen_dirs=None, recurse=False):
     '''yield every hg repository under path, always recursively.
     The recurse flag will only control recursion into repo working dirs'''
     def errhandler(err):
         if err.filename == path:
             raise err
     samestat = getattr(os.path, 'samestat', None)
     if followsym and samestat is not None:
         def adddir(dirlst, dirname):
             dirstat = os.stat(dirname)
             match = any(samestat(dirstat, lstdirstat) for lstdirstat in dirlst)
             if not match:
                 dirlst.append(dirstat)
             return not match
     else:
         followsym = False
 
     if (seen_dirs is None) and followsym:
         seen_dirs = []
         adddir(seen_dirs, path)
     for root, dirs, files in os.walk(path, topdown=True, onerror=errhandler):
         dirs.sort()
         if '.hg' in dirs:
             yield root # found a repository
             qroot = os.path.join(root, '.hg', 'patches')
             if os.path.isdir(os.path.join(qroot, '.hg')):
                 yield qroot # we have a patch queue repo here
             if recurse:
                 # avoid recursing inside the .hg directory
                 dirs.remove('.hg')
             else:
                 dirs[:] = [] # don't descend further
         elif followsym:
             newdirs = []
             for d in dirs:
                 fname = os.path.join(root, d)
                 if adddir(seen_dirs, fname):
                     if os.path.islink(fname):
                         for hgname in walkrepos(fname, True, seen_dirs):
                             yield hgname
                     else:
                         newdirs.append(d)
             dirs[:] = newdirs
 
 def binnode(ctx):
     """Return binary node id for a given basectx"""
     node = ctx.node()
     if node is None:
         return wdirid
     return node
 
 def intrev(ctx):
     """Return integer for a given basectx that can be used in comparison or
     arithmetic operation"""
     rev = ctx.rev()
     if rev is None:
         return wdirrev
     return rev
 
 def formatchangeid(ctx):
     """Format changectx as '{rev}:{node|formatnode}', which is the default
     template provided by logcmdutil.changesettemplater"""
     repo = ctx.repo()
     return formatrevnode(repo.ui, intrev(ctx), binnode(ctx))
 
 def formatrevnode(ui, rev, node):
     """Format given revision and node depending on the current verbosity"""
     if ui.debugflag:
         hexfunc = hex
     else:
         hexfunc = short
     return '%d:%s' % (rev, hexfunc(node))
 
 def resolvehexnodeidprefix(repo, prefix):
     # Uses unfiltered repo because it's faster when prefix is ambiguous/
     # This matches the shortesthexnodeidprefix() function below.
     node = repo.unfiltered().changelog._partialmatch(prefix)
     if node is None:
         return
     repo.changelog.rev(node)  # make sure node isn't filtered
     return node
 
 def shortesthexnodeidprefix(repo, node, minlength=1):
     """Find the shortest unambiguous prefix that matches hexnode."""
     # _partialmatch() of filtered changelog could take O(len(repo)) time,
     # which would be unacceptably slow. so we look for hash collision in
     # unfiltered space, which means some hashes may be slightly longer.
     cl = repo.unfiltered().changelog
 
     def isrev(prefix):
         try:
             i = int(prefix)
             # if we are a pure int, then starting with zero will not be
             # confused as a rev; or, obviously, if the int is larger
             # than the value of the tip rev
             if prefix[0:1] == b'0' or i > len(cl):
                 return False
             return True
         except ValueError:
             return False
 
     def disambiguate(prefix):
         """Disambiguate against revnums."""
         hexnode = hex(node)
         for length in range(len(prefix), len(hexnode) + 1):
             prefix = hexnode[:length]
             if not isrev(prefix):
                 return prefix
 
     try:
         return disambiguate(cl.shortest(node, minlength))
     except error.LookupError:
         raise error.RepoLookupError()
 
 def isrevsymbol(repo, symbol):
     """Checks if a symbol exists in the repo.
 
     See revsymbol() for details. Raises error.LookupError if the symbol is an
     ambiguous nodeid prefix.
     """
     try:
         revsymbol(repo, symbol)
         return True
     except error.RepoLookupError:
         return False
 
 def revsymbol(repo, symbol):
     """Returns a context given a single revision symbol (as string).
 
     This is similar to revsingle(), but accepts only a single revision symbol,
     i.e. things like ".", "tip", "1234", "deadbeef", "my-bookmark" work, but
     not "max(public())".
     """
     if not isinstance(symbol, bytes):
         msg = ("symbol (%s of type %s) was not a string, did you mean "
                "repo[symbol]?" % (symbol, type(symbol)))
         raise error.ProgrammingError(msg)
     try:
         if symbol in ('.', 'tip', 'null'):
             return repo[symbol]
 
         try:
             r = int(symbol)
             if '%d' % r != symbol:
                 raise ValueError
             l = len(repo.changelog)
             if r < 0:
                 r += l
             if r < 0 or r >= l and r != wdirrev:
                 raise ValueError
             return repo[r]
         except error.FilteredIndexError:
             raise
         except (ValueError, OverflowError, IndexError):
             pass
 
         if len(symbol) == 40:
             try:
                 node = bin(symbol)
                 rev = repo.changelog.rev(node)
                 return repo[rev]
             except error.FilteredLookupError:
                 raise
             except (TypeError, LookupError):
                 pass
 
         # look up bookmarks through the name interface
         try:
             node = repo.names.singlenode(repo, symbol)
             rev = repo.changelog.rev(node)
             return repo[rev]
         except KeyError:
             pass
 
         node = resolvehexnodeidprefix(repo, symbol)
         if node is not None:
             rev = repo.changelog.rev(node)
             return repo[rev]
 
         raise error.RepoLookupError(_("unknown revision '%s'") % symbol)
 
     except error.WdirUnsupported:
         return repo[None]
     except (error.FilteredIndexError, error.FilteredLookupError,
             error.FilteredRepoLookupError):
         raise _filterederror(repo, symbol)
 
 def _filterederror(repo, changeid):
     """build an exception to be raised about a filtered changeid
 
     This is extracted in a function to help extensions (eg: evolve) to
     experiment with various message variants."""
     if repo.filtername.startswith('visible'):
 
         # Check if the changeset is obsolete
         unfilteredrepo = repo.unfiltered()
         ctx = revsymbol(unfilteredrepo, changeid)
 
         # If the changeset is obsolete, enrich the message with the reason
         # that made this changeset not visible
         if ctx.obsolete():
             msg = obsutil._getfilteredreason(repo, changeid, ctx)
         else:
             msg = _("hidden revision '%s'") % changeid
 
         hint = _('use --hidden to access hidden revisions')
 
         return error.FilteredRepoLookupError(msg, hint=hint)
     msg = _("filtered revision '%s' (not in '%s' subset)")
     msg %= (changeid, repo.filtername)
     return error.FilteredRepoLookupError(msg)
 
 def revsingle(repo, revspec, default='.', localalias=None):
     if not revspec and revspec != 0:
         return repo[default]
 
     l = revrange(repo, [revspec], localalias=localalias)
     if not l:
         raise error.Abort(_('empty revision set'))
     return repo[l.last()]
 
 def _pairspec(revspec):
     tree = revsetlang.parse(revspec)
     return tree and tree[0] in ('range', 'rangepre', 'rangepost', 'rangeall')
 
 def revpair(repo, revs):
     if not revs:
         return repo['.'], repo[None]
 
     l = revrange(repo, revs)
 
     if not l:
         first = second = None
     elif l.isascending():
         first = l.min()
         second = l.max()
     elif l.isdescending():
         first = l.max()
         second = l.min()
     else:
         first = l.first()
         second = l.last()
 
     if first is None:
         raise error.Abort(_('empty revision range'))
     if (first == second and len(revs) >= 2
         and not all(revrange(repo, [r]) for r in revs)):
         raise error.Abort(_('empty revision on one side of range'))
 
     # if top-level is range expression, the result must always be a pair
     if first == second and len(revs) == 1 and not _pairspec(revs[0]):
         return repo[first], repo[None]
 
     return repo[first], repo[second]
 
 def revrange(repo, specs, localalias=None):
     """Execute 1 to many revsets and return the union.
 
     This is the preferred mechanism for executing revsets using user-specified
     config options, such as revset aliases.
 
     The revsets specified by ``specs`` will be executed via a chained ``OR``
     expression. If ``specs`` is empty, an empty result is returned.
 
     ``specs`` can contain integers, in which case they are assumed to be
     revision numbers.
 
     It is assumed the revsets are already formatted. If you have arguments
     that need to be expanded in the revset, call ``revsetlang.formatspec()``
     and pass the result as an element of ``specs``.
 
     Specifying a single revset is allowed.
 
     Returns a ``revset.abstractsmartset`` which is a list-like interface over
     integer revisions.
     """
     allspecs = []
     for spec in specs:
         if isinstance(spec, int):
             spec = revsetlang.formatspec('rev(%d)', spec)
         allspecs.append(spec)
     return repo.anyrevs(allspecs, user=True, localalias=localalias)
 
 def meaningfulparents(repo, ctx):
     """Return list of meaningful (or all if debug) parentrevs for rev.
 
     For merges (two non-nullrev revisions) both parents are meaningful.
     Otherwise the first parent revision is considered meaningful if it
     is not the preceding revision.
     """
     parents = ctx.parents()
     if len(parents) > 1:
         return parents
     if repo.ui.debugflag:
         return [parents[0], repo['null']]
     if parents[0].rev() >= intrev(ctx) - 1:
         return []
     return parents
 
 def expandpats(pats):
     '''Expand bare globs when running on windows.
     On posix we assume it already has already been done by sh.'''
     if not util.expandglobs:
         return list(pats)
     ret = []
     for kindpat in pats:
         kind, pat = matchmod._patsplit(kindpat, None)
         if kind is None:
             try:
                 globbed = glob.glob(pat)
             except re.error:
                 globbed = [pat]
             if globbed:
                 ret.extend(globbed)
                 continue
         ret.append(kindpat)
     return ret
 
 def matchandpats(ctx, pats=(), opts=None, globbed=False, default='relpath',
                  badfn=None):
     '''Return a matcher and the patterns that were used.
     The matcher will warn about bad matches, unless an alternate badfn callback
     is provided.'''
     if pats == ("",):
         pats = []
     if opts is None:
         opts = {}
     if not globbed and default == 'relpath':
         pats = expandpats(pats or [])
 
     def bad(f, msg):
         ctx.repo().ui.warn("%s: %s\n" % (m.rel(f), msg))
 
     if badfn is None:
         badfn = bad
 
     m = ctx.match(pats, opts.get('include'), opts.get('exclude'),
                   default, listsubrepos=opts.get('subrepos'), badfn=badfn)
 
     if m.always():
         pats = []
     return m, pats
 
 def match(ctx, pats=(), opts=None, globbed=False, default='relpath',
           badfn=None):
     '''Return a matcher that will warn about bad matches.'''
     return matchandpats(ctx, pats, opts, globbed, default, badfn=badfn)[0]
 
 def matchall(repo):
     '''Return a matcher that will efficiently match everything.'''
     return matchmod.always(repo.root, repo.getcwd())
 
 def matchfiles(repo, files, badfn=None):
     '''Return a matcher that will efficiently match exactly these files.'''
     return matchmod.exact(repo.root, repo.getcwd(), files, badfn=badfn)
 
 def parsefollowlinespattern(repo, rev, pat, msg):
     """Return a file name from `pat` pattern suitable for usage in followlines
     logic.
     """
     if not matchmod.patkind(pat):
         return pathutil.canonpath(repo.root, repo.getcwd(), pat)
     else:
         ctx = repo[rev]
         m = matchmod.match(repo.root, repo.getcwd(), [pat], ctx=ctx)
         files = [f for f in ctx if m(f)]
         if len(files) != 1:
             raise error.ParseError(msg)
         return files[0]
 
 def origpath(ui, repo, filepath):
     '''customize where .orig files are created
 
     Fetch user defined path from config file: [ui] origbackuppath = <path>
     Fall back to default (filepath with .orig suffix) if not specified
     '''
     origbackuppath = ui.config('ui', 'origbackuppath')
     if not origbackuppath:
         return filepath + ".orig"
 
     # Convert filepath from an absolute path into a path inside the repo.
     filepathfromroot = util.normpath(os.path.relpath(filepath,
                                                      start=repo.root))
 
     origvfs = vfs.vfs(repo.wjoin(origbackuppath))
     origbackupdir = origvfs.dirname(filepathfromroot)
     if not origvfs.isdir(origbackupdir) or origvfs.islink(origbackupdir):
         ui.note(_('creating directory: %s\n') % origvfs.join(origbackupdir))
 
         # Remove any files that conflict with the backup file's path
         for f in reversed(list(util.finddirs(filepathfromroot))):
             if origvfs.isfileorlink(f):
                 ui.note(_('removing conflicting file: %s\n')
                         % origvfs.join(f))
                 origvfs.unlink(f)
                 break
 
         origvfs.makedirs(origbackupdir)
 
     if origvfs.isdir(filepathfromroot) and not origvfs.islink(filepathfromroot):
         ui.note(_('removing conflicting directory: %s\n')
                 % origvfs.join(filepathfromroot))
         origvfs.rmtree(filepathfromroot, forcibly=True)
 
     return origvfs.join(filepathfromroot)
 
 class _containsnode(object):
     """proxy __contains__(node) to container.__contains__ which accepts revs"""
 
     def __init__(self, repo, revcontainer):
         self._torev = repo.changelog.rev
         self._revcontains = revcontainer.__contains__
 
     def __contains__(self, node):
         return self._revcontains(self._torev(node))
 
 def cleanupnodes(repo, replacements, operation, moves=None, metadata=None,
-                 fixphase=False, targetphase=None):
+                 fixphase=False, targetphase=None, backup=True):
     """do common cleanups when old nodes are replaced by new nodes
 
     That includes writing obsmarkers or stripping nodes, and moving bookmarks.
     (we might also want to move working directory parent in the future)
 
     By default, bookmark moves are calculated automatically from 'replacements',
     but 'moves' can be used to override that. Also, 'moves' may include
     additional bookmark moves that should not have associated obsmarkers.
 
     replacements is {oldnode: [newnode]} or a iterable of nodes if they do not
     have replacements. operation is a string, like "rebase".
 
     metadata is dictionary containing metadata to be stored in obsmarker if
     obsolescence is enabled.
     """
     assert fixphase or targetphase is None
     if not replacements and not moves:
         return
 
     # translate mapping's other forms
     if not util.safehasattr(replacements, 'items'):
         replacements = {n: () for n in replacements}
 
     # Calculate bookmark movements
     if moves is None:
         moves = {}
     # Unfiltered repo is needed since nodes in replacements might be hidden.
     unfi = repo.unfiltered()
     for oldnode, newnodes in replacements.items():
         if oldnode in moves:
             continue
         if len(newnodes) > 1:
             # usually a split, take the one with biggest rev number
             newnode = next(unfi.set('max(%ln)', newnodes)).node()
         elif len(newnodes) == 0:
             # move bookmark backwards
             roots = list(unfi.set('max((::%n) - %ln)', oldnode,
                                   list(replacements)))
             if roots:
                 newnode = roots[0].node()
             else:
                 newnode = nullid
         else:
             newnode = newnodes[0]
         moves[oldnode] = newnode
 
     allnewnodes = [n for ns in replacements.values() for n in ns]
     toretract = {}
     toadvance = {}
     if fixphase:
         precursors = {}
         for oldnode, newnodes in replacements.items():
             for newnode in newnodes:
                 precursors.setdefault(newnode, []).append(oldnode)
 
         allnewnodes.sort(key=lambda n: unfi[n].rev())
         newphases = {}
         def phase(ctx):
             return newphases.get(ctx.node(), ctx.phase())
         for newnode in allnewnodes:
             ctx = unfi[newnode]
             parentphase = max(phase(p) for p in ctx.parents())
             if targetphase is None:
                 oldphase = max(unfi[oldnode].phase()
                                for oldnode in precursors[newnode])
                 newphase = max(oldphase, parentphase)
             else:
                 newphase = max(targetphase, parentphase)
             newphases[newnode] = newphase
             if newphase > ctx.phase():
                 toretract.setdefault(newphase, []).append(newnode)
             elif newphase < ctx.phase():
                 toadvance.setdefault(newphase, []).append(newnode)
 
     with repo.transaction('cleanup') as tr:
         # Move bookmarks
         bmarks = repo._bookmarks
         bmarkchanges = []
         for oldnode, newnode in moves.items():
             oldbmarks = repo.nodebookmarks(oldnode)
             if not oldbmarks:
                 continue
             from . import bookmarks # avoid import cycle
             repo.ui.debug('moving bookmarks %r from %s to %s\n' %
                           (pycompat.rapply(pycompat.maybebytestr, oldbmarks),
                            hex(oldnode), hex(newnode)))
             # Delete divergent bookmarks being parents of related newnodes
             deleterevs = repo.revs('parents(roots(%ln & (::%n))) - parents(%n)',
                                    allnewnodes, newnode, oldnode)
             deletenodes = _containsnode(repo, deleterevs)
             for name in oldbmarks:
                 bmarkchanges.append((name, newnode))
                 for b in bookmarks.divergent2delete(repo, deletenodes, name):
                     bmarkchanges.append((b, None))
 
         if bmarkchanges:
             bmarks.applychanges(repo, tr, bmarkchanges)
 
         for phase, nodes in toretract.items():
             phases.retractboundary(repo, tr, phase, nodes)
         for phase, nodes in toadvance.items():
             phases.advanceboundary(repo, tr, phase, nodes)
 
         # Obsolete or strip nodes
         if obsolete.isenabled(repo, obsolete.createmarkersopt):
             # If a node is already obsoleted, and we want to obsolete it
             # without a successor, skip that obssolete request since it's
             # unnecessary. That's the "if s or not isobs(n)" check below.
             # Also sort the node in topology order, that might be useful for
             # some obsstore logic.
             # NOTE: the filtering and sorting might belong to createmarkers.
             isobs = unfi.obsstore.successors.__contains__
             torev = unfi.changelog.rev
             sortfunc = lambda ns: torev(ns[0])
             rels = [(unfi[n], tuple(unfi[m] for m in s))
                     for n, s in sorted(replacements.items(), key=sortfunc)
                     if s or not isobs(n)]
             if rels:
                 obsolete.createmarkers(repo, rels, operation=operation,
                                        metadata=metadata)
         else:
             from . import repair # avoid import cycle
             tostrip = list(replacements)
             if tostrip:
-                repair.delayedstrip(repo.ui, repo, tostrip, operation)
+                repair.delayedstrip(repo.ui, repo, tostrip, operation,
+                                    backup=backup)
 
 def addremove(repo, matcher, prefix, opts=None):
     if opts is None:
         opts = {}
     m = matcher
     dry_run = opts.get('dry_run')
     try:
         similarity = float(opts.get('similarity') or 0)
     except ValueError:
         raise error.Abort(_('similarity must be a number'))
     if similarity < 0 or similarity > 100:
         raise error.Abort(_('similarity must be between 0 and 100'))
     similarity /= 100.0
 
     ret = 0
     join = lambda f: os.path.join(prefix, f)
 
     wctx = repo[None]
     for subpath in sorted(wctx.substate):
         submatch = matchmod.subdirmatcher(subpath, m)
         if opts.get('subrepos') or m.exact(subpath) or any(submatch.files()):
             sub = wctx.sub(subpath)
             try:
                 if sub.addremove(submatch, prefix, opts):
                     ret = 1
             except error.LookupError:
                 repo.ui.status(_("skipping missing subrepository: %s\n")
                                  % join(subpath))
 
     rejected = []
     def badfn(f, msg):
         if f in m.files():
             m.bad(f, msg)
         rejected.append(f)
 
     badmatch = matchmod.badmatch(m, badfn)
     added, unknown, deleted, removed, forgotten = _interestingfiles(repo,
                                                                     badmatch)
 
     unknownset = set(unknown + forgotten)
     toprint = unknownset.copy()
     toprint.update(deleted)
     for abs in sorted(toprint):
         if repo.ui.verbose or not m.exact(abs):
             if abs in unknownset:
                 status = _('adding %s\n') % m.uipath(abs)
             else:
                 status = _('removing %s\n') % m.uipath(abs)
             repo.ui.status(status)
 
     renames = _findrenames(repo, m, added + unknown, removed + deleted,
                            similarity)
 
     if not dry_run:
         _markchanges(repo, unknown + forgotten, deleted, renames)
 
     for f in rejected:
         if f in m.files():
             return 1
     return ret
 
 def marktouched(repo, files, similarity=0.0):
     '''Assert that files have somehow been operated upon. files are relative to
     the repo root.'''
     m = matchfiles(repo, files, badfn=lambda x, y: rejected.append(x))
     rejected = []
 
     added, unknown, deleted, removed, forgotten = _interestingfiles(repo, m)
 
     if repo.ui.verbose:
         unknownset = set(unknown + forgotten)
         toprint = unknownset.copy()
         toprint.update(deleted)
         for abs in sorted(toprint):
             if abs in unknownset:
                 status = _('adding %s\n') % abs
             else:
                 status = _('removing %s\n') % abs
             repo.ui.status(status)
 
     renames = _findrenames(repo, m, added + unknown, removed + deleted,
                            similarity)
 
     _markchanges(repo, unknown + forgotten, deleted, renames)
 
     for f in rejected:
         if f in m.files():
             return 1
     return 0
 
 def _interestingfiles(repo, matcher):
     '''Walk dirstate with matcher, looking for files that addremove would care
     about.
 
     This is different from dirstate.status because it doesn't care about
     whether files are modified or clean.'''
     added, unknown, deleted, removed, forgotten = [], [], [], [], []
     audit_path = pathutil.pathauditor(repo.root, cached=True)
 
     ctx = repo[None]
     dirstate = repo.dirstate
     walkresults = dirstate.walk(matcher, subrepos=sorted(ctx.substate),
                                 unknown=True, ignored=False, full=False)
     for abs, st in walkresults.iteritems():
         dstate = dirstate[abs]
         if dstate == '?' and audit_path.check(abs):
             unknown.append(abs)
         elif dstate != 'r' and not st:
             deleted.append(abs)
         elif dstate == 'r' and st:
             forgotten.append(abs)
         # for finding renames
         elif dstate == 'r' and not st:
             removed.append(abs)
         elif dstate == 'a':
             added.append(abs)
 
     return added, unknown, deleted, removed, forgotten
 
 def _findrenames(repo, matcher, added, removed, similarity):
     '''Find renames from removed files to added ones.'''
     renames = {}
     if similarity > 0:
         for old, new, score in similar.findrenames(repo, added, removed,
                                                    similarity):
             if (repo.ui.verbose or not matcher.exact(old)
                 or not matcher.exact(new)):
                 repo.ui.status(_('recording removal of %s as rename to %s '
                                  '(%d%% similar)\n') %
                                (matcher.rel(old), matcher.rel(new),
                                 score * 100))
             renames[new] = old
     return renames
 
 def _markchanges(repo, unknown, deleted, renames):
     '''Marks the files in unknown as added, the files in deleted as removed,
     and the files in renames as copied.'''
     wctx = repo[None]
     with repo.wlock():
         wctx.forget(deleted)
         wctx.add(unknown)
         for new, old in renames.iteritems():
             wctx.copy(old, new)
 
 def dirstatecopy(ui, repo, wctx, src, dst, dryrun=False, cwd=None):
     """Update the dirstate to reflect the intent of copying src to dst. For
     different reasons it might not end with dst being marked as copied from src.
     """
     origsrc = repo.dirstate.copied(src) or src
     if dst == origsrc: # copying back a copy?
         if repo.dirstate[dst] not in 'mn' and not dryrun:
             repo.dirstate.normallookup(dst)
     else:
         if repo.dirstate[origsrc] == 'a' and origsrc == src:
             if not ui.quiet:
                 ui.warn(_("%s has not been committed yet, so no copy "
                           "data will be stored for %s.\n")
                         % (repo.pathto(origsrc, cwd), repo.pathto(dst, cwd)))
             if repo.dirstate[dst] in '?r' and not dryrun:
                 wctx.add([dst])
         elif not dryrun:
             wctx.copy(origsrc, dst)
 
 def readrequires(opener, supported):
     '''Reads and parses .hg/requires and checks if all entries found
     are in the list of supported features.'''
     requirements = set(opener.read("requires").splitlines())
     missings = []
     for r in requirements:
         if r not in supported:
             if not r or not r[0:1].isalnum():
                 raise error.RequirementError(_(".hg/requires file is corrupt"))
             missings.append(r)
     missings.sort()
     if missings:
         raise error.RequirementError(
             _("repository requires features unknown to this Mercurial: %s")
             % " ".join(missings),
             hint=_("see https://mercurial-scm.org/wiki/MissingRequirement"
                    " for more information"))
     return requirements
 
 def writerequires(opener, requirements):
     with opener('requires', 'w') as fp:
         for r in sorted(requirements):
             fp.write("%s\n" % r)
 
 class filecachesubentry(object):
     def __init__(self, path, stat):
         self.path = path
         self.cachestat = None
         self._cacheable = None
 
         if stat:
             self.cachestat = filecachesubentry.stat(self.path)
 
             if self.cachestat:
                 self._cacheable = self.cachestat.cacheable()
             else:
                 # None means we don't know yet
                 self._cacheable = None
 
     def refresh(self):
         if self.cacheable():
             self.cachestat = filecachesubentry.stat(self.path)
 
     def cacheable(self):
         if self._cacheable is not None:
             return self._cacheable
 
         # we don't know yet, assume it is for now
         return True
 
     def changed(self):
         # no point in going further if we can't cache it
         if not self.cacheable():
             return True
 
         newstat = filecachesubentry.stat(self.path)
 
         # we may not know if it's cacheable yet, check again now
         if newstat and self._cacheable is None:
             self._cacheable = newstat.cacheable()
 
             # check again
             if not self._cacheable:
                 return True
 
         if self.cachestat != newstat:
             self.cachestat = newstat
             return True
         else:
             return False
 
     @staticmethod
     def stat(path):
         try:
             return util.cachestat(path)
         except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
 
 class filecacheentry(object):
     def __init__(self, paths, stat=True):
         self._entries = []
         for path in paths:
             self._entries.append(filecachesubentry(path, stat))
 
     def changed(self):
         '''true if any entry has changed'''
         for entry in self._entries:
             if entry.changed():
                 return True
         return False
 
     def refresh(self):
         for entry in self._entries:
             entry.refresh()
 
 class filecache(object):
     """A property like decorator that tracks files under .hg/ for updates.
 
     On first access, the files defined as arguments are stat()ed and the
     results cached. The decorated function is called. The results are stashed
     away in a ``_filecache`` dict on the object whose method is decorated.
 
     On subsequent access, the cached result is returned.
 
     On external property set operations, stat() calls are performed and the new
     value is cached.
 
     On property delete operations, cached data is removed.
 
     When using the property API, cached data is always returned, if available:
     no stat() is performed to check if the file has changed and if the function
     needs to be called to reflect file changes.
 
     Others can muck about with the state of the ``_filecache`` dict. e.g. they
     can populate an entry before the property's getter is called. In this case,
     entries in ``_filecache`` will be used during property operations,
     if available. If the underlying file changes, it is up to external callers
     to reflect this by e.g. calling ``delattr(obj, attr)`` to remove the cached
     method result as well as possibly calling ``del obj._filecache[attr]`` to
     remove the ``filecacheentry``.
     """
 
     def __init__(self, *paths):
         self.paths = paths
 
     def join(self, obj, fname):
         """Used to compute the runtime path of a cached file.
 
         Users should subclass filecache and provide their own version of this
         function to call the appropriate join function on 'obj' (an instance
         of the class that its member function was decorated).
         """
         raise NotImplementedError
 
     def __call__(self, func):
         self.func = func
         self.sname = func.__name__
         self.name = pycompat.sysbytes(self.sname)
         return self
 
     def __get__(self, obj, type=None):
         # if accessed on the class, return the descriptor itself.
         if obj is None:
             return self
         # do we need to check if the file changed?
         if self.sname in obj.__dict__:
             assert self.name in obj._filecache, self.name
             return obj.__dict__[self.sname]
 
         entry = obj._filecache.get(self.name)
 
         if entry:
             if entry.changed():
                 entry.obj = self.func(obj)
         else:
             paths = [self.join(obj, path) for path in self.paths]
 
             # We stat -before- creating the object so our cache doesn't lie if
             # a writer modified between the time we read and stat
             entry = filecacheentry(paths, True)
             entry.obj = self.func(obj)
 
             obj._filecache[self.name] = entry
 
         obj.__dict__[self.sname] = entry.obj
         return entry.obj
 
     def __set__(self, obj, value):
         if self.name not in obj._filecache:
             # we add an entry for the missing value because X in __dict__
             # implies X in _filecache
             paths = [self.join(obj, path) for path in self.paths]
             ce = filecacheentry(paths, False)
             obj._filecache[self.name] = ce
         else:
             ce = obj._filecache[self.name]
 
         ce.obj = value # update cached copy
         obj.__dict__[self.sname] = value # update copy returned by obj.x
 
     def __delete__(self, obj):
         try:
             del obj.__dict__[self.sname]
         except KeyError:
             raise AttributeError(self.sname)
 
 def extdatasource(repo, source):
     """Gather a map of rev -> value dict from the specified source
 
     A source spec is treated as a URL, with a special case shell: type
     for parsing the output from a shell command.
 
     The data is parsed as a series of newline-separated records where
     each record is a revision specifier optionally followed by a space
     and a freeform string value. If the revision is known locally, it
     is converted to a rev, otherwise the record is skipped.
 
     Note that both key and value are treated as UTF-8 and converted to
     the local encoding. This allows uniformity between local and
     remote data sources.
     """
 
     spec = repo.ui.config("extdata", source)
     if not spec:
         raise error.Abort(_("unknown extdata source '%s'") % source)
 
     data = {}
     src = proc = None
     try:
         if spec.startswith("shell:"):
             # external commands should be run relative to the repo root
             cmd = spec[6:]
             proc = subprocess.Popen(cmd, shell=True, bufsize=-1,
                                     close_fds=procutil.closefds,
                                     stdout=subprocess.PIPE, cwd=repo.root)
             src = proc.stdout
         else:
             # treat as a URL or file
             src = url.open(repo.ui, spec)
         for l in src:
             if " " in l:
                 k, v = l.strip().split(" ", 1)
             else:
                 k, v = l.strip(), ""
 
             k = encoding.tolocal(k)
             try:
                 data[revsingle(repo, k).rev()] = encoding.tolocal(v)
             except (error.LookupError, error.RepoLookupError):
                 pass # we ignore data for nodes that don't exist locally
     finally:
         if proc:
             proc.communicate()
         if src:
             src.close()
     if proc and proc.returncode != 0:
         raise error.Abort(_("extdata command '%s' failed: %s")
                           % (cmd, procutil.explainexit(proc.returncode)))
 
     return data
 
 def _locksub(repo, lock, envvar, cmd, environ=None, *args, **kwargs):
     if lock is None:
         raise error.LockInheritanceContractViolation(
             'lock can only be inherited while held')
     if environ is None:
         environ = {}
     with lock.inherit() as locker:
         environ[envvar] = locker
         return repo.ui.system(cmd, environ=environ, *args, **kwargs)
 
 def wlocksub(repo, cmd, *args, **kwargs):
     """run cmd as a subprocess that allows inheriting repo's wlock
 
     This can only be called while the wlock is held. This takes all the
     arguments that ui.system does, and returns the exit code of the
     subprocess."""
     return _locksub(repo, repo.currentwlock(), 'HG_WLOCK_LOCKER', cmd, *args,
                     **kwargs)
 
 class progress(object):
     def __init__(self, ui, topic, unit="", total=None):
         self.ui = ui
         self.pos = 0
         self.topic = topic
         self.unit = unit
         self.total = total
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, exc_tb):
         self.complete()
 
     def update(self, pos, item="", total=None):
         assert pos is not None
         if total:
             self.total = total
         self.pos = pos
         self._print(item)
 
     def increment(self, step=1, item="", total=None):
         self.update(self.pos + step, item, total)
 
     def complete(self):
         self.ui.progress(self.topic, None)
 
     def _print(self, item):
         self.ui.progress(self.topic, self.pos, item, self.unit,
                          self.total)
 
 def gdinitconfig(ui):
     """helper function to know if a repo should be created as general delta
     """
     # experimental config: format.generaldelta
     return (ui.configbool('format', 'generaldelta')
             or ui.configbool('format', 'usegeneraldelta')
             or ui.configbool('format', 'sparse-revlog'))
 
 def gddeltaconfig(ui):
     """helper function to know if incoming delta should be optimised
     """
     # experimental config: format.generaldelta
     return ui.configbool('format', 'generaldelta')
 
 class simplekeyvaluefile(object):
     """A simple file with key=value lines
 
     Keys must be alphanumerics and start with a letter, values must not
     contain '\n' characters"""
     firstlinekey = '__firstline'
 
     def __init__(self, vfs, path, keys=None):
         self.vfs = vfs
         self.path = path
 
     def read(self, firstlinenonkeyval=False):
         """Read the contents of a simple key-value file
 
         'firstlinenonkeyval' indicates whether the first line of file should
         be treated as a key-value pair or reuturned fully under the
         __firstline key."""
         lines = self.vfs.readlines(self.path)
         d = {}
         if firstlinenonkeyval:
             if not lines:
                 e = _("empty simplekeyvalue file")
                 raise error.CorruptedState(e)
             # we don't want to include '\n' in the __firstline
             d[self.firstlinekey] = lines[0][:-1]
             del lines[0]
 
         try:
             # the 'if line.strip()' part prevents us from failing on empty
             # lines which only contain '\n' therefore are not skipped
             # by 'if line'
             updatedict = dict(line[:-1].split('=', 1) for line in lines
                                                       if line.strip())
             if self.firstlinekey in updatedict:
                 e = _("%r can't be used as a key")
                 raise error.CorruptedState(e % self.firstlinekey)
             d.update(updatedict)
         except ValueError as e:
             raise error.CorruptedState(str(e))
         return d
 
     def write(self, data, firstline=None):
         """Write key=>value mapping to a file
         data is a dict. Keys must be alphanumerical and start with a letter.
         Values must not contain newline characters.
 
         If 'firstline' is not None, it is written to file before
         everything else, as it is, not in a key=value form"""
         lines = []
         if firstline is not None:
             lines.append('%s\n' % firstline)
 
         for k, v in data.items():
             if k == self.firstlinekey:
                 e = "key name '%s' is reserved" % self.firstlinekey
                 raise error.ProgrammingError(e)
             if not k[0:1].isalpha():
                 e = "keys must start with a letter in a key-value file"
                 raise error.ProgrammingError(e)
             if not k.isalnum():
                 e = "invalid key name in a simple key-value file"
                 raise error.ProgrammingError(e)
             if '\n' in v:
                 e = "invalid value in a simple key-value file"
                 raise error.ProgrammingError(e)
             lines.append("%s=%s\n" % (k, v))
         with self.vfs(self.path, mode='wb', atomictemp=True) as fp:
             fp.write(''.join(lines))
 
 _reportobsoletedsource = [
     'debugobsolete',
     'pull',
     'push',
     'serve',
     'unbundle',
 ]
 
 _reportnewcssource = [
     'pull',
     'unbundle',
 ]
 
 def prefetchfiles(repo, revs, match):
     """Invokes the registered file prefetch functions, allowing extensions to
     ensure the corresponding files are available locally, before the command
     uses them."""
     if match:
         # The command itself will complain about files that don't exist, so
         # don't duplicate the message.
         match = matchmod.badmatch(match, lambda fn, msg: None)
     else:
         match = matchall(repo)
 
     fileprefetchhooks(repo, revs, match)
 
 # a list of (repo, revs, match) prefetch functions
 fileprefetchhooks = util.hooks()
 
 # A marker that tells the evolve extension to suppress its own reporting
 _reportstroubledchangesets = True
 
 def registersummarycallback(repo, otr, txnname=''):
     """register a callback to issue a summary after the transaction is closed
     """
     def txmatch(sources):
         return any(txnname.startswith(source) for source in sources)
 
     categories = []
 
     def reportsummary(func):
         """decorator for report callbacks."""
         # The repoview life cycle is shorter than the one of the actual
         # underlying repository. So the filtered object can die before the
         # weakref is used leading to troubles. We keep a reference to the
         # unfiltered object and restore the filtering when retrieving the
         # repository through the weakref.
         filtername = repo.filtername
         reporef = weakref.ref(repo.unfiltered())
         def wrapped(tr):
             repo = reporef()
             if filtername:
                 repo = repo.filtered(filtername)
             func(repo, tr)
         newcat = '%02i-txnreport' % len(categories)
         otr.addpostclose(newcat, wrapped)
         categories.append(newcat)
         return wrapped
 
     if txmatch(_reportobsoletedsource):
         @reportsummary
         def reportobsoleted(repo, tr):
             obsoleted = obsutil.getobsoleted(repo, tr)
             if obsoleted:
                 repo.ui.status(_('obsoleted %i changesets\n')
                                % len(obsoleted))
 
     if (obsolete.isenabled(repo, obsolete.createmarkersopt) and
         repo.ui.configbool('experimental', 'evolution.report-instabilities')):
         instabilitytypes = [
             ('orphan', 'orphan'),
             ('phase-divergent', 'phasedivergent'),
             ('content-divergent', 'contentdivergent'),
         ]
 
         def getinstabilitycounts(repo):
             filtered = repo.changelog.filteredrevs
             counts = {}
             for instability, revset in instabilitytypes:
                 counts[instability] = len(set(obsolete.getrevs(repo, revset)) -
                                           filtered)
             return counts
 
         oldinstabilitycounts = getinstabilitycounts(repo)
         @reportsummary
         def reportnewinstabilities(repo, tr):
             newinstabilitycounts = getinstabilitycounts(repo)
             for instability, revset in instabilitytypes:
                 delta = (newinstabilitycounts[instability] -
                          oldinstabilitycounts[instability])
                 msg = getinstabilitymessage(delta, instability)
                 if msg:
                     repo.ui.warn(msg)
 
     if txmatch(_reportnewcssource):
         @reportsummary
         def reportnewcs(repo, tr):
             """Report the range of new revisions pulled/unbundled."""
             newrevs = tr.changes.get('revs', pycompat.xrange(0, 0))
             if not newrevs:
                 return
 
             # Compute the bounds of new revisions' range, excluding obsoletes.
             unfi = repo.unfiltered()
             revs = unfi.revs('%ld and not obsolete()', newrevs)
             if not revs:
                 # Got only obsoletes.
                 return
             minrev, maxrev = repo[revs.min()], repo[revs.max()]
 
             if minrev == maxrev:
                 revrange = minrev
             else:
                 revrange = '%s:%s' % (minrev, maxrev)
             repo.ui.status(_('new changesets %s\n') % revrange)
 
         @reportsummary
         def reportphasechanges(repo, tr):
             """Report statistics of phase changes for changesets pre-existing
             pull/unbundle.
             """
             newrevs = tr.changes.get('revs', pycompat.xrange(0, 0))
             phasetracking = tr.changes.get('phases', {})
             if not phasetracking:
                 return
             published = [
                 rev for rev, (old, new) in phasetracking.iteritems()
                 if new == phases.public and rev not in newrevs
             ]
             if not published:
                 return
             repo.ui.status(_('%d local changesets published\n')
                            % len(published))
 
 def getinstabilitymessage(delta, instability):
     """function to return the message to show warning about new instabilities
 
     exists as a separate function so that extension can wrap to show more
     information like how to fix instabilities"""
     if delta > 0:
         return _('%i new %s changesets\n') % (delta, instability)
 
 def nodesummaries(repo, nodes, maxnumnodes=4):
     if len(nodes) <= maxnumnodes or repo.ui.verbose:
         return ' '.join(short(h) for h in nodes)
     first = ' '.join(short(h) for h in nodes[:maxnumnodes])
     return _("%s and %d others") % (first, len(nodes) - maxnumnodes)
 
 def enforcesinglehead(repo, tr, desc):
     """check that no named branch has multiple heads"""
     if desc in ('strip', 'repair'):
         # skip the logic during strip
         return
     visible = repo.filtered('visible')
     # possible improvement: we could restrict the check to affected branch
     for name, heads in visible.branchmap().iteritems():
         if len(heads) > 1:
             msg = _('rejecting multiple heads on branch "%s"')
             msg %= name
             hint = _('%d heads: %s')
             hint %= (len(heads), nodesummaries(repo, heads))
             raise error.Abort(msg, hint=hint)
 
 def wrapconvertsink(sink):
     """Allow extensions to wrap the sink returned by convcmd.convertsink()
     before it is used, whether or not the convert extension was formally loaded.
     """
     return sink
 
 def unhidehashlikerevs(repo, specs, hiddentype):
     """parse the user specs and unhide changesets whose hash or revision number
     is passed.
 
     hiddentype can be: 1) 'warn': warn while unhiding changesets
                        2) 'nowarn': don't warn while unhiding changesets
 
     returns a repo object with the required changesets unhidden
     """
     if not repo.filtername or not repo.ui.configbool('experimental',
                                                      'directaccess'):
         return repo
 
     if repo.filtername not in ('visible', 'visible-hidden'):
         return repo
 
     symbols = set()
     for spec in specs:
         try:
             tree = revsetlang.parse(spec)
         except error.ParseError: # will be reported by scmutil.revrange()
             continue
 
         symbols.update(revsetlang.gethashlikesymbols(tree))
 
     if not symbols:
         return repo
 
     revs = _getrevsfromsymbols(repo, symbols)
 
     if not revs:
         return repo
 
     if hiddentype == 'warn':
         unfi = repo.unfiltered()
         revstr = ", ".join([pycompat.bytestr(unfi[l]) for l in revs])
         repo.ui.warn(_("warning: accessing hidden changesets for write "
                        "operation: %s\n") % revstr)
 
     # we have to use new filtername to separate branch/tags cache until we can
     # disbale these cache when revisions are dynamically pinned.
     return repo.filtered('visible-hidden', revs)
 
 def _getrevsfromsymbols(repo, symbols):
     """parse the list of symbols and returns a set of revision numbers of hidden
     changesets present in symbols"""
     revs = set()
     unfi = repo.unfiltered()
     unficl = unfi.changelog
     cl = repo.changelog
     tiprev = len(unficl)
     allowrevnums = repo.ui.configbool('experimental', 'directaccess.revnums')
     for s in symbols:
         try:
             n = int(s)
             if n <= tiprev:
                 if not allowrevnums:
                     continue
                 else:
                     if n not in cl:
                         revs.add(n)
                     continue
         except ValueError:
             pass
 
         try:
             s = resolvehexnodeidprefix(unfi, s)
         except (error.LookupError, error.WdirUnsupported):
             s = None
 
         if s is not None:
             rev = unficl.rev(s)
             if rev not in cl:
                 revs.add(rev)
 
     return revs
 
 def bookmarkrevs(repo, mark):
     """
     Select revisions reachable by a given bookmark
     """
     return repo.revs("ancestors(bookmark(%s)) - "
                      "ancestors(head() and not bookmark(%s)) - "
                      "ancestors(bookmark() and not bookmark(%s))",
                      mark, mark, mark)