comparison hgext/rebase.py @ 34022:af609bb3487f

rebase: change internal format to support destination map

A later patch will add multiple destination support. This patch changes
internal state and the rebase state file format to support that. But the
external interface still only supports single destination.

A test was added to make sure rebase still supports legacy state file.

The new state file is incompatible with old clients. We had done similar
state file format change before: 5eac7ab, 92409f8, and 72412af. The state
file is transient, so the impact of incompatibility is limited. Besides,
the old client won't support multiple destinations anyway so it does not
really make sense to make the file format compatible with them.

Differential Revision: https://phab.mercurial-scm.org/D348

34021:ba9d5d48bf95

import errno
import os

from mercurial.i18n import _
from mercurial.node import (
    hex,
    nullid,
    nullrev,
    short,
)
from mercurial import (

# 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

# legacy revstates no longer needed in current code
# -2: nullmerge, -3: revignored, -4: revprecursor, -5: revpruned
legacystates = {'-2', '-3', '-4', '-5'}

        # 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.dest = None
        self.skipped = set()

        self.collapsef = opts.get('collapse', False)
        self.collapsemsg = cmdutil.logmessage(ui, opts)
        self.date = opts.get('date', None)

                self._writestatus(f)

    def _writestatus(self, f):
        repo = self.repo.unfiltered()
        f.write(repo[self.originalwd].hex() + '\n')
        f.write(repo[self.dest].hex() + '\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 ''))
        for d, v in self.state.iteritems():
            oldrev = repo[d].hex()
            if v >= 0:
                newrev = repo[v].hex()
            elif v == revtodo:
                # To maintain format compatibility, we have to use nullid.
                # Please do remove this special case when upgrading the format.
                newrev = hex(nullid)
            else:
                newrev = v
            f.write("%s:%s\n" % (oldrev, newrev))
        repo.ui.debug('rebase status stored\n')

    def restorestatus(self):
        """Restore a previously stored status"""
        repo = self.repo
        keepbranches = None
        dest = None
        collapse = False
        external = nullrev
        activebookmark = None
        state = {}

        try:
            f = repo.vfs("rebasestate")
            for i, l in enumerate(f.read().splitlines()):
                if i == 0:
                    originalwd = repo[l].rev()
                elif i == 1:
                    dest = repo[l].rev()
                elif i == 2:
                    external = repo[l].rev()
                elif i == 3:
                    collapse = bool(int(l))
                elif i == 4:

                    # line 6 is a recent addition, so for backwards
                    # compatibility check that the line doesn't look like the
                    # oldrev:newrev lines
                    activebookmark = l
                else:
                    oldrev, newrev = l.split(':')
                    if newrev in legacystates:
                        continue
                    elif newrev == nullid:
                        state[repo[oldrev].rev()] = revtodo
                        # Legacy compat special case
                    else:
                        state[repo[oldrev].rev()] = repo[newrev].rev()

            raise error.Abort(_('.hg/rebasestate is incomplete'))

        skipped = set()
        # recompute the set of skipped revs
        if not collapse:
            seen = {dest}
            for old, new in sorted(state.items()):
                if new != revtodo and new in seen:
                    skipped.add(old)
                seen.add(new)
        repo.ui.debug('computed skipped revs: %s\n' %
                        (' '.join(str(r) for r in sorted(skipped)) or None))
        repo.ui.debug('rebase status resumed\n')
        _setrebasesetvisibility(repo, set(state.keys()) | {originalwd})

        self.originalwd = originalwd
        self.dest = dest
        self.state = state
        self.skipped = skipped
        self.collapsef = collapse
        self.keepf = keep
        self.keepbranchesf = keepbranches
        self.external = external
        self.activebookmark = activebookmark

    def _handleskippingobsolete(self, rebaserevs, obsoleterevs, dest):
        """Compute structures necessary for skipping obsolete revisions

        rebaserevs:     iterable of all revisions that are to be rebased
        obsoleterevs:   iterable of all obsolete revisions in rebaseset
        dest:           a destination revision for the rebase operation
        """
        self.obsoletenotrebased = {}
        if not self.ui.configbool('experimental', 'rebaseskipobsolete',
                                  default=True):
            return
        obsoleteset = set(obsoleterevs)
        self.obsoletenotrebased = _computeobsoletenotrebased(self.repo,
                                    obsoleteset, dest)
        skippedset = set(self.obsoletenotrebased)
        _checkobsrebase(self.repo, self.ui, obsoleteset, skippedset)

    def _prepareabortorcontinue(self, isabort):
        try:

            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.dest,
                         self.state, activebookmark=self.activebookmark)

    def _preparenewrebase(self, dest, rebaseset):
        if dest is None:
            return _nothingtorebase()

        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'))

        obsrevs = _filterobsoleterevs(self.repo, set(rebaseset))
        self._handleskippingobsolete(rebaseset, obsrevs, dest.rev())

        result = buildstate(self.repo, dest, rebaseset, self.collapsef,
                            self.obsoletenotrebased)

        if not result:
            # Empty state built, nothing to rebase
            self.ui.status(_('nothing to rebase\n'))

            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.dest, self.state) = result
        if self.collapsef:
            destancestors = self.repo.changelog.ancestors([self.dest],
                                                          inclusive=True)
            self.external = externalparent(self.repo, self.state, destancestors)

        if dest.closesbranch() and not self.keepbranchesf:
            self.ui.status(_('reopening closed branch head %s\n') % dest)

    def _performrebase(self, tr):
        repo, ui, opts = self.repo, self.ui, self.opts
        if self.keepbranchesf:
            # insert _savebranch at the start of extrafns so if

        sortedrevs = repo.revs('sort(%ld, -topo)', self.state)
        cands = [k for k, v in self.state.iteritems() if v == revtodo]
        total = len(cands)
        pos = 0
        for rev in sortedrevs:
            ctx = repo[rev]
            desc = _ctxdesc(ctx)
            if self.state[rev] == rev:
                ui.status(_('already rebased %s\n') % desc)
            elif self.state[rev] == revtodo:
                pos += 1
                ui.status(_('rebasing %s\n') % desc)
                ui.progress(_("rebasing"), pos, ("%d:%s" % (rev, ctx)),
                            _('changesets'), total)
                p1, p2, base = defineparents(repo, rev, self.dest, self.state)
                self.storestatus(tr=tr)
                storecollapsemsg(repo, self.collapsemsg)
                if len(repo[None].parents()) == 2:
                    repo.ui.debug('resuming interrupted rebase\n')
                else:
                    try:
                        ui.setconfig('ui', 'forcemerge', opts.get('tool', ''),
                                     'rebase')
                        stats = rebasenode(repo, rev, p1, base, self.state,
                                           self.collapsef, self.dest)
                        if stats and stats[3] > 0:
                            raise error.InterventionRequired(
                                _('unresolved conflicts (see hg '
                                  'resolve, then hg rebase --continue)'))
                    finally:

        ui.note(_('rebase merging completed\n'))

    def _finishrebase(self):
        repo, ui, opts = self.repo, self.ui, self.opts
        if self.collapsef and not self.keepopen:
            p1, p2, _base = defineparents(repo, min(self.state),
                                          self.dest, self.state)
            editopt = opts.get('edit')
            editform = 'rebase.collapse'
            if self.collapsemsg:
                commitmsg = self.collapsemsg
            else:

        if not self.keepf:
            collapsedas = None
            if self.collapsef:
                collapsedas = newnode
            clearrebased(ui, repo, self.dest, self.state, self.skipped,
                         collapsedas)

        clearstatus(repo)
        clearcollapsemsg(repo)

            retcode = rbsrt._prepareabortorcontinue(abortf)
            if retcode is not None:
                return retcode
        else:
            dest, rebaseset = _definesets(ui, repo, destf, srcf, basef, revf,
                                          destspace=destspace)
            retcode = rbsrt._preparenewrebase(dest, rebaseset)
            if retcode is not None:
                return retcode

        tr = None
        dsguard = None

            with util.acceptintervention(dsguard):
                rbsrt._performrebase(tr)

        rbsrt._finishrebase()

def _definesets(ui, repo, destf=None, srcf=None, basef=None, revf=None,
                destspace=None):
    """use revisions argument to define destination and rebase set
    """
    if revf is None:
        revf = []

    # destspace is here to work around issues with `hg pull --rebase` see
    # issue5214 for details

    if revf:
        rebaseset = scmutil.revrange(repo, revf)
        if not rebaseset:
            ui.status(_('empty "rev" revision set - nothing to rebase\n'))
            return None, None
    elif srcf:
        src = scmutil.revrange(repo, [srcf])
        if not src:
            ui.status(_('empty "source" revision set - nothing to rebase\n'))
            return None, 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, None
        if not destf:
            dest = repo[_destrebase(repo, base, destspace=destspace)]
            destf = str(dest)

        roots = [] # selected children of branching points

                                '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(str(repo[r]) for r in base), dest))
            return None, None

    if not destf:
        dest = repo[_destrebase(repo, rebaseset, destspace=destspace)]
        destf = str(dest)

    return dest, rebaseset

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.

        # performed in the destination.
        p1rev = repo[rev].p1().rev()
        copies.duplicatecopies(repo, rev, p1rev, skiprev=dest)
    return stats

def adjustdest(repo, rev, dest, state):
    """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.

        | |/        |
        | B         | ...
        |/          |/
        A           A
    """
    # pick already rebased revs from state
    source = [s for s, d in state.items() if d > 0]

    result = []
    for prev in repo.changelog.parentrevs(rev):
        adjusted = dest
        if prev != nullrev:

    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, dest, state):
    """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,

            return True
        elif a > b:
            return False
        return cl.isancestor(cl.node(a), cl.node(b))

    oldps = repo.changelog.parentrevs(rev) # old parents
    newps = [nullrev, nullrev] # new parents
    dests = adjustdest(repo, rev, dest, state) # adjusted destinations
    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]

    if firstunrebased in parents:
        return True

    return False

def abort(repo, originalwd, dest, state, activebookmark=None):
    '''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
        # dstates list must must not contain the dest rev (issue4896)
        dstates = [s for s in state.values() if s >= 0 and s != dest]
        immutable = [d for d in dstates if not repo[d].mutable()]
        cleanup = True
        if immutable:
            repo.ui.warn(_("warning: can't clean up public changesets %s\n")
                        % ', '.join(str(repo[r]) for r in immutable),

                           "branch, can't strip\n"))
            cleanup = False

        if cleanup:
            shouldupdate = False
            rebased = filter(lambda x: x >= 0 and x != dest, state.values())
            if rebased:
                strippoints = [
                        c.node() for c in repo.set('roots(%ld)', rebased)]

            updateifonnodes = set(rebased)
            updateifonnodes.add(dest)
            updateifonnodes.add(originalwd)
            shouldupdate = repo['.'].rev() in updateifonnodes

            # Update away from the rebase if necessary
            if shouldupdate or needupdate(repo, state):

        clearstatus(repo)
        clearcollapsemsg(repo)
        repo.ui.warn(_('rebase aborted\n'))
    return 0

def buildstate(repo, dest, rebaseset, collapse, obsoletenotrebased):
    '''Define which revisions are going to be rebased and where

    repo: repo
    dest: context
    rebaseset: set of rev
    '''
    originalwd = repo['.'].rev()
    _setrebasesetvisibility(repo, set(rebaseset) | {originalwd})

    # 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() and (dest.node() in
                            [s.node for s in repo.mq.applied]):
        raise error.Abort(_('cannot rebase onto an applied mq patch'))

    roots = list(repo.set('roots(%ld)', rebaseset))
    if not roots:
        raise error.Abort(_('no matching revisions'))
    roots.sort()
    state = dict.fromkeys(rebaseset, revtodo)
    emptyrebase = True
    for root in roots:
        commonbase = root.ancestor(dest)
        if commonbase == root:
            raise error.Abort(_('source is ancestor of destination'))
        if commonbase == dest:
            wctx = repo[None]

        desc = _ctxdesc(unfi[r])
        succ = obsoletenotrebased[r]
        if succ is None:
            msg = _('note: not rebasing %s, it has no successor\n') % desc
            del state[r]
        else:
            destctx = unfi[succ]
            destdesc = '%d:%s "%s"' % (destctx.rev(), destctx,
                                       destctx.description().split('\n', 1)[0])
            msg = (_('note: not rebasing %s, already in destination as %s\n')
                   % (desc, destdesc))
            del state[r]
        repo.ui.status(msg)
    return originalwd, dest.rev(), state

def clearrebased(ui, repo, dest, state, skipped, collapsedas=None):
    """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."""
    tonode = repo.changelog.node
    # Move bookmark of skipped nodes to destination. This cannot be handled
    # by scmutil.cleanupnodes since it will treat rev as removed (no successor)
    # and move bookmark backwards.
    bmchanges = [(name, tonode(max(adjustdest(repo, rev, dest, state))))
                 for rev in skipped
                 for name in repo.nodebookmarks(tonode(rev))]
    if bmchanges:
        with repo.transaction('rebase') as tr:
            repo._bookmarks.applychanges(repo, tr, bmchanges)

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, dest):
    """return a mapping obsolete => successor for all obsolete nodes to be
    rebased that have a successors in the destination

    obsolete => None entries in the mapping indicate nodes with no successor"""
    obsoletenotrebased = {}

    cl = repo.unfiltered().changelog
    nodemap = cl.nodemap
    destnode = cl.node(dest)
    for srcrev in rebaseobsrevs:
        srcnode = cl.node(srcrev)
        # XXX: more advanced APIs are required to handle split correctly
        successors = list(obsutil.allsuccessors(repo.obsstore, [srcnode]))
        if len(successors) == 1:
            # obsutil.allsuccessors includes node itself. When the list only
            # contains one element, it means there are no successors.

34022:af609bb3487f

import errno
import os

from mercurial.i18n import _
from mercurial.node import (
    nullid,
    nullrev,
    short,
)
from mercurial import (

# 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'}

        # 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)

                self._writestatus(f)

    def _writestatus(self, f):
        repo = self.repo.unfiltered()
        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 = 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"""
        repo = self.repo
        keepbranches = None
        legacydest = None
        collapse = False
        external = nullrev
        activebookmark = None
        state = {}
        destmap = {}

        try:
            f = repo.vfs("rebasestate")
            for i, l in enumerate(f.read().splitlines()):
                if i == 0:
                    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:
                    external = repo[l].rev()
                elif i == 3:
                    collapse = bool(int(l))
                elif i == 4:

                    # line 6 is a recent addition, so for backwards
                    # compatibility check that the line doesn't look like the
                    # oldrev:newrev lines
                    activebookmark = l
                else:
                    args = l.split(':')
                    oldrev = args[0]
                    newrev = args[1]
                    if newrev in legacystates:
                        continue
                    if len(args) > 2:
                        destnode = args[2]
                    else:
                        destnode = legacydest
                    destmap[repo[oldrev].rev()] = repo[destnode].rev()
                    if newrev in (nullid, revtodostr):
                        state[repo[oldrev].rev()] = revtodo
                        # Legacy compat special case
                    else:
                        state[repo[oldrev].rev()] = repo[newrev].rev()

            raise error.Abort(_('.hg/rebasestate is incomplete'))

        skipped = set()
        # recompute the set of skipped revs
        if not 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)
        repo.ui.debug('computed skipped revs: %s\n' %
                        (' '.join(str(r) for r in sorted(skipped)) or None))
        repo.ui.debug('rebase status resumed\n')
        _setrebasesetvisibility(repo, set(state.keys()) | {originalwd})

        self.originalwd = originalwd
        self.destmap = destmap
        self.state = state
        self.skipped = skipped
        self.collapsef = collapse
        self.keepf = keep
        self.keepbranchesf = keepbranches
        self.external = external
        self.activebookmark = activebookmark

    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',
                                  default=True):
            return
        obsoleteset = set(obsoleterevs)
        self.obsoletenotrebased = _computeobsoletenotrebased(self.repo,
                                    obsoleteset, destmap)
        skippedset = set(self.obsoletenotrebased)
        _checkobsrebase(self.repo, self.ui, obsoleteset, skippedset)

    def _prepareabortorcontinue(self, isabort):
        try:

            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)

    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'))

        obsrevs = _filterobsoleterevs(self.repo, rebaseset)
        self._handleskippingobsolete(obsrevs, destmap)

        result = buildstate(self.repo, destmap, self.collapsef,
                            self.obsoletenotrebased)

        if not result:
            # Empty state built, nothing to rebase
            self.ui.status(_('nothing to rebase\n'))

            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)

    def _performrebase(self, tr):
        repo, ui, opts = self.repo, self.ui, self.opts
        if self.keepbranchesf:
            # insert _savebranch at the start of extrafns so if

        sortedrevs = repo.revs('sort(%ld, -topo)', self.state)
        cands = [k for k, v in self.state.iteritems() if v == revtodo]
        total = len(cands)
        pos = 0
        for rev in sortedrevs:
            dest = self.destmap[rev]
            ctx = repo[rev]
            desc = _ctxdesc(ctx)
            if self.state[rev] == rev:
                ui.status(_('already rebased %s\n') % desc)
            elif self.state[rev] == revtodo:
                pos += 1
                ui.status(_('rebasing %s\n') % desc)
                ui.progress(_("rebasing"), pos, ("%d:%s" % (rev, ctx)),
                            _('changesets'), total)
                p1, p2, base = defineparents(repo, rev, self.destmap,
                                             self.state)
                self.storestatus(tr=tr)
                storecollapsemsg(repo, self.collapsemsg)
                if len(repo[None].parents()) == 2:
                    repo.ui.debug('resuming interrupted rebase\n')
                else:
                    try:
                        ui.setconfig('ui', 'forcemerge', opts.get('tool', ''),
                                     'rebase')
                        stats = rebasenode(repo, rev, p1, base, self.state,
                                           self.collapsef, dest)
                        if stats and stats[3] > 0:
                            raise error.InterventionRequired(
                                _('unresolved conflicts (see hg '
                                  'resolve, then hg rebase --continue)'))
                    finally:

        ui.note(_('rebase merging completed\n'))

    def _finishrebase(self):
        repo, ui, opts = self.repo, self.ui, self.opts
        if self.collapsef and not self.keepopen:
            p1, p2, _base = defineparents(repo, min(self.state), self.destmap,
                                          self.state)
            editopt = opts.get('edit')
            editform = 'rebase.collapse'
            if self.collapsemsg:
                commitmsg = self.collapsemsg
            else:

        if not self.keepf:
            collapsedas = None
            if self.collapsef:
                collapsedas = newnode
            clearrebased(ui, repo, self.destmap, self.state, self.skipped,
                         collapsedas)

        clearstatus(repo)
        clearcollapsemsg(repo)

            retcode = rbsrt._prepareabortorcontinue(abortf)
            if retcode is not None:
                return retcode
        else:
            destmap = _definedestmap(ui, repo, destf, srcf, basef, revf,
                                     destspace=destspace)
            retcode = rbsrt._preparenewrebase(destmap)
            if retcode is not None:
                return retcode

        tr = None
        dsguard = None

            with util.acceptintervention(dsguard):
                rbsrt._performrebase(tr)

        rbsrt._finishrebase()

def _definedestmap(ui, repo, 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 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 not destf:
            dest = repo[_destrebase(repo, base, destspace=destspace)]
            destf = str(dest)

        roots = [] # selected children of branching points

                                '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(str(repo[r]) for r in base), dest))
            return None

    if not destf:
        dest = repo[_destrebase(repo, rebaseset, destspace=destspace)]
        destf = str(dest)

    # assign dest to each rev in rebaseset
    destrev = dest.rev()
    destmap = {r: destrev for r in rebaseset} # {srcrev: destrev}

    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.

        # performed in the destination.
        p1rev = repo[rev].p1().rev()
        copies.duplicatecopies(repo, rev, p1rev, skiprev=dest)
    return stats

def adjustdest(repo, rev, destmap, state):
    """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.

        | |/        |
        | B         | ...
        |/          |/
        A           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]

    result = []
    for prev in repo.changelog.parentrevs(rev):
        adjusted = dest
        if prev != nullrev:

    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):
    """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,

            return True
        elif a > b:
            return False
        return cl.isancestor(cl.node(a), cl.node(b))

    dest = destmap[rev]
    oldps = repo.changelog.parentrevs(rev) # old parents
    newps = [nullrev, nullrev] # new parents
    dests = adjustdest(repo, rev, destmap, state) # adjusted destinations
    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]

    if firstunrebased in parents:
        return True

    return False

def abort(repo, originalwd, destmap, state, activebookmark=None):
    '''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
        # dstates list must must not contain the dest rev (issue4896)
        dstates = [s for r, s in state.items() if s >= 0 and s != destmap[r]]
        immutable = [d for d in dstates if not repo[d].mutable()]
        cleanup = True
        if immutable:
            repo.ui.warn(_("warning: can't clean up public changesets %s\n")
                        % ', '.join(str(repo[r]) for r in immutable),

                           "branch, can't strip\n"))
            cleanup = False

        if cleanup:
            shouldupdate = False
            rebased = [s for r, s in state.items()
                       if s >= 0 and s != destmap[r]]
            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):

        clearstatus(repo)
        clearcollapsemsg(repo)
        repo.ui.warn(_('rebase aborted\n'))
    return 0

def buildstate(repo, destmap, collapse, obsoletenotrebased):
    '''Define which revisions are going to be rebased and where

    repo: repo
    destmap: {srcrev: destrev}
    '''
    rebaseset = destmap.keys()
    originalwd = repo['.'].rev()
    _setrebasesetvisibility(repo, set(rebaseset) | {originalwd})

    # 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'))

    roots = list(repo.set('roots(%ld)', rebaseset))
    if not roots:
        raise error.Abort(_('no matching revisions'))
    roots.sort()
    state = dict.fromkeys(rebaseset, revtodo)
    emptyrebase = True
    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]

        desc = _ctxdesc(unfi[r])
        succ = obsoletenotrebased[r]
        if succ is None:
            msg = _('note: not rebasing %s, it has no successor\n') % desc
            del state[r]
            del destmap[r]
        else:
            destctx = unfi[succ]
            destdesc = '%d:%s "%s"' % (destctx.rev(), destctx,
                                       destctx.description().split('\n', 1)[0])
            msg = (_('note: not rebasing %s, already in destination as %s\n')
                   % (desc, destdesc))
            del state[r]
            del destmap[r]
        repo.ui.status(msg)
    return originalwd, destmap, state

def clearrebased(ui, repo, destmap, state, skipped, collapsedas=None):
    """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."""
    tonode = repo.changelog.node
    # Move bookmark of skipped nodes to destination. This cannot be handled
    # by scmutil.cleanupnodes since it will treat rev as removed (no successor)
    # and move bookmark backwards.
    bmchanges = [(name, tonode(max(adjustdest(repo, rev, destmap, state))))
                 for rev in skipped
                 for name in repo.nodebookmarks(tonode(rev))]
    if bmchanges:
        with repo.transaction('rebase') as tr:
            repo._bookmarks.applychanges(repo, tr, bmchanges)

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 a mapping obsolete => successor for all obsolete nodes to be
    rebased that have a successors in the destination

    obsolete => None entries in the mapping indicate nodes with no successor"""
    obsoletenotrebased = {}

    cl = repo.unfiltered().changelog
    nodemap = cl.nodemap
    for srcrev in rebaseobsrevs:
        srcnode = cl.node(srcrev)
        destnode = cl.node(destmap[srcrev])
        # XXX: more advanced APIs are required to handle split correctly
        successors = list(obsutil.allsuccessors(repo.obsstore, [srcnode]))
        if len(successors) == 1:
            # obsutil.allsuccessors includes node itself. When the list only
            # contains one element, it means there are no successors.