comparison hgext/evolve.py @ 589:8945a62f9096

merge with stable

583:95089805c3fc

    - alters core commands and extensions that rewrite history to use
      this feature,
    - improves some aspect of the early implementation in 2.3
'''

import random

from mercurial import util

try:
    from mercurial import obsolete
    if not obsolete._enabled:
        obsolete._enabled = True
except ImportError:
    raise util.Abort('Obsolete extension requires Mercurial 2.3 (or later)')

from mercurial import bookmarks
from mercurial import cmdutil
from mercurial import commands
from mercurial import context

### Complete troubles computation logic                           ###
#####################################################################

# there is two kind of trouble not handled by core right now:
# - latecomer: (successors for public changeset)
# - conflicting: (two changeset try to succeed to the same precursors)
#
# This section add support for those two addition trouble
#
# - Cache computation
# - revset and ctx method

    candidates = _allsuccessors(repo, repo.revs('public()'),
                                                haltonflags=latediff)
    query = '%ld - obsolete() - public()'
    return set(repo.revs(query, candidates))

@cachefor('conflicting')
def _computeconflictingset(repo):
    """the set of rev trying to obsolete public revision"""
    conflicting = set()
    obsstore = repo.obsstore
    newermap = {}
    for ctx in repo.set('(not public()) - obsolete()'):
        prec = obsstore.successors.get(ctx.node(), ())
        toprocess = set(prec)
        while toprocess:
            prec = toprocess.pop()[0]
            if prec not in newermap:
                newermap[prec] = newerversion(repo, prec)
            newer = [n for n in newermap[prec] if n] # filter kill
            if len(newer) > 1:
                conflicting.add(ctx.rev())
                break
        toprocess.update(obsstore.successors.get(prec, ()))
    return conflicting

### changectx method

@eh.addattr(context.changectx, 'latecomer')
def latecomer(ctx):

    if ctx.node() is None:
        return False
    return ctx.rev() in getobscache(ctx._repo, 'latecomer')

@eh.addattr(context.changectx, 'conflicting')
def conflicting(ctx):
    """is the changeset conflicting (Try to succeed to public change)"""
    if ctx.node() is None:
        return False
    return ctx.rev() in getobscache(ctx._repo, 'conflicting')

### revset symbol

@eh.revset('latecomer')
def revsetlatecomer(repo, subset, x):

    args = revset.getargs(x, 0, 0, 'latecomer takes no arguments')
    lates = getobscache(repo, 'latecomer')
    return [r for r in subset if r in lates]

@eh.revset('conflicting')
def revsetconflicting(repo, subset, x):
    """``conflicting()``
    Changesets marked as successors of a same changeset.
    """
    args = revset.getargs(x, 0, 0, 'conflicting takes no arguments')
    conf = getobscache(repo, 'conflicting')
    return [r for r in subset if r in conf]

@eh.revset('divergent')
def revsetdivergent(repo, subset, x):
    """``divergent()``
    Changesets marked as successors of a same changeset.
    """
    args = revset.getargs(x, 0, 0, 'divergent takes no arguments')
    conf = getobscache(repo, 'conflicting')
    return [r for r in subset if r in conf]


### Discovery wrapping

@eh.wrapfunction(discovery, 'checkheads')

        # obsolete or unstable.
        ctx = repo[h]
        if ctx.latecomer():
            raise util.Abort(_("push includes a latecomer changeset: %s!")
                             % ctx)
        if ctx.conflicting():
            raise util.Abort(_("push includes a conflicting changeset: %s!")
                             % ctx)
    return orig(repo, remote, outgoing, *args, **kwargs)

#####################################################################
### Filter extinct changesets from common operations              ###

@eh.addattr(context.changectx, 'troubles')
def troubles(ctx):
    """Return a tuple listing all the troubles that affect a changeset

    Troubles may be "unstable", "latecomer" or "conflicting".
    """
    troubles = []
    if ctx.unstable():
        troubles.append('unstable')
    if ctx.latecomer():
        troubles.append('latecomer')
    if ctx.conflicting():
        troubles.append('conflicting')
    return tuple(troubles)

### Troubled revset symbol

@eh.revset('troubled')
def revsetlatecomer(repo, subset, x):
    """``troubled()``
    Changesets with troubles.
    """
    _ = revset.getargs(x, 0, 0, 'troubled takes no arguments')
    return repo.revs('%ld and (unstable() + latecomer() + conflicting())',
                     subset)


### Obsolescence graph

        sr = nm.get(s)
        if sr is not None:
            cs.add(sr)
    return cs



def newerversion(repo, obs):
    """Return the newer version of an obsolete changeset"""
    toproceed = set([(obs,)])
    # XXX known optimization available
    newer = set()
    objectrels = repo.obsstore.precursors
    while toproceed:
        current = toproceed.pop()
        assert len(current) <= 1, 'splitting not handled yet. %r' % current
        current = [n for n in current if n != nullid]
        if current:
            n, = current
            if n in objectrels:
                markers = objectrels[n]
                for mark in markers:
                    toproceed.add(tuple(mark[1]))
            else:
                newer.add(tuple(current))
        else:
            newer.add(())
    return sorted(newer)


#####################################################################
### Extending revset and template                                 ###
#####################################################################

@eh.wrapcommand("unbundle")
def warnobserrors(orig, ui, repo, *args, **kwargs):
    """display warning is the command resulted in more instable changeset"""
    priorunstables = len(repo.revs('unstable()'))
    priorlatecomers = len(repo.revs('latecomer()'))
    priorconflictings = len(repo.revs('conflicting()'))
    ret = orig(ui, repo, *args, **kwargs)
    # workaround phase stupidity
    phases._filterunknown(ui, repo.changelog, repo._phasecache.phaseroots)
    newunstables = len(repo.revs('unstable()')) - priorunstables
    newlatecomers = len(repo.revs('latecomer()')) - priorlatecomers
    newconflictings = len(repo.revs('conflicting()')) - priorconflictings
    if newunstables > 0:
        ui.warn(_('%i new unstable changesets\n') % newunstables)
    if newlatecomers > 0:
        ui.warn(_('%i new latecomer changesets\n') % newlatecomers)
    if newconflictings > 0:
        ui.warn(_('%i new conflicting changesets\n') % newconflictings)
    return ret

@eh.reposetup
def _repostabilizesetup(ui, repo):
    """Add a hint for "hg evolve" when troubles make push fails

            ui.note(s)

    ret = orig(ui, repo, *args, **kwargs)
    nbunstable = len(getobscache(repo, 'unstable'))
    nblatecomer = len(getobscache(repo, 'latecomer'))
    nbconflicting = len(getobscache(repo, 'unstable'))
    write('unstable: %i changesets\n', nbunstable)
    write('latecomer: %i changesets\n', nblatecomer)
    write('conflicting: %i changesets\n', nbconflicting)
    return ret


#####################################################################
### Core Other extension compat                                   ###

def evolve(ui, repo, **opts):
    """Solve trouble in your repository

    - rebase unstable changeset to make it stable again,
    - create proper diff from latecomer changeset,
    - merge conflicting changeset.

    By default, take the first troubles changeset that looks relevant.

    (The logic is still a bit fuzzy)

    - For unstable, that mean the first which could be rebased as child of the
      working directory parent revision or one of its descendants and rebase
      it.

    - For conflicting this mean "." if applicable.

    With --any, evolve pick any troubled changeset to solve

    The working directory is updated to the newly created revision.
    """

    troubles = tr.troubles()
    if 'unstable' in troubles:
        return _solveunstable(ui, repo, tr, opts['dry_run'])
    elif 'latecomer' in troubles:
        return _solvelatecomer(ui, repo, tr, opts['dry_run'])
    elif 'conflicting' in troubles:
        return _solveconflicting(ui, repo, tr, opts['dry_run'])
    else:
        assert False  # WHAT? unknown troubles

def _picknexttroubled(ui, repo, pickany=False):
    """Pick a the next trouble changeset to solve"""
    tr = _stabilizableunstable(repo, repo['.'])
    if tr is None:
        wdp = repo['.']
        if 'conflicting' in wdp.troubles():
            tr = wdp
    if tr is None and pickany:
        troubled = list(repo.set('unstable()'))
        if not troubled:
            troubled = list(repo.set('latecomer()'))
        if not troubled:
            troubled = list(repo.set('conflicting()'))
        if troubled:
            tr = troubled[0]

    return tr

    """Stabilize a unstable changeset"""
    obs = orig.parents()[0]
    if not obs.obsolete():
        obs = orig.parents()[1]
    assert obs.obsolete()
    newer = newerversion(repo, obs.node())
    # search of a parent which is not killed
    while newer == [()]:
        ui.debug("stabilize target %s is plain dead,"
                 " trying to stabilize on its parent")
        obs = obs.parents()[0]
        newer = newerversion(repo, obs.node())
    if len(newer) > 1:
        ui.write_err(_("conflict rewriting. can't choose destination\n"))
        return 2
    targets = newer[0]
    assert targets

        # reroute the working copy parent to the new changeset
        repo.dirstate.setparents(newid, node.nullid)
    finally:
        wlock.release()

def _solveconflicting(ui, repo, conflicting, dryrun=False):
    base, others = conflictingdata(conflicting)
    if len(others) > 1:
        raise util.Abort("We do not handle split yet")
    other = others[0]
    if conflicting.phase() <= phases.public:
        raise util.Abort("We can't resolve this conflict from the public side")
    if len(other.parents()) > 1:
        raise util.Abort("conflicting changeset can't be a merge (yet)")
    if other.p1() not in conflicting.parents():
        raise util.Abort("parents are not common (not handled yet)")

    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
    ui.status(_('merge:'))
    if not ui.quiet:
        displayer.show(conflicting)
    ui.status(_('with: '))
    if not ui.quiet:
        displayer.show(other)
    ui.status(_('base: '))
    if not ui.quiet:
        displayer.show(base)
    if dryrun:
        ui.write('hg update -c %s &&\n' % conflicting)
        ui.write('hg merge %s &&\n' % other)
        ui.write('hg commit -m "auto merge resolving conflict between '
                 '%s and %s"&&\n' % (conflicting, other))
        ui.write('hg up -C %s &&\n' % base)
        ui.write('hg revert --all --rev tip &&\n')
        ui.write('hg commit -m "`hg log -r %s --template={desc}`";\n'
                 % conflicting)
        return
    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()
        if conflicting not in repo[None].parents():
            repo.ui.status(_('updating to "local" conflict\n'))
            hg.update(repo, conflicting.rev())
        repo.ui.note(_('merging conflicting changeset\n'))
        stats = merge.update(repo,
                             other.node(),
                             branchmerge=True,
                             force=False,
                             partial=None,

/!\ * hg up to the parent of the amended changeset (which are named W and Z)
/!\ * hg revert --all -r X
/!\ * hg ci -m "same message as the amended changeset" => new cset Y
/!\ * hg kill -n Y W Z
""")
        tr = repo.transaction('stabilize-conflicting')
        try:
            repo.dirstate.setparents(conflicting.node(), node.nullid)
            oldlen = len(repo)
            amend(ui, repo)
            if oldlen == len(repo):
                new = conflicting
                # no changes
            else:
                new = repo['.']
            createmarkers(repo, [(other, (new,))])
            phases.retractboundary(repo, other.phase(), [new.node()])

            tr.release()
    finally:
        lockmod.release(lock, wlock)


def conflictingdata(ctx):
    """return base, other part of a conflict

    This only return the first one.

    XXX this woobly function won't survive XXX
    """
    for base in ctx._repo.set('reverse(precursors(%d))', ctx):
        newer = newerversion(ctx._repo, base.node())
        # drop filter and solution including the original ctx
        newer = [n for n in newer if n and ctx.node() not in n]
        if newer:
            return base, tuple(ctx._repo[o] for o in newer[0])
    raise KeyError('Base seem unknown. This case is not handled yet.')

        if repo.revs('. and %ld', revs):
            hg.update(repo, newid)
    finally:
        lockmod.release(lock, wlock)


@eh.wrapcommand('graft')
def graftwrapper(orig, ui, repo, *revs, **kwargs):
    kwargs = dict(kwargs)
    revs = list(revs) + kwargs.get('rev', [])

589:8945a62f9096

    - alters core commands and extensions that rewrite history to use
      this feature,
    - improves some aspect of the early implementation in 2.3
'''

testedwith = '2.3 2.3.1 2.3.2'
buglink = 'https://bitbucket.org/marmoute/mutable-history/issues'


import random

from mercurial import util

try:
    from mercurial import obsolete
    if not obsolete._enabled:
        obsolete._enabled = True
except ImportError:
    raise util.Abort('Evolve extension requires Mercurial 2.3 (or later)')

try:
    getattr(obsolete, 'getrevs') # 2.4 specific
    raise util.Abort('Your version of Mercurial is too recent for this '
                     'version of evolve',
                     hint="upgrade your evolve")
except AttributeError:
    pass


from mercurial import bookmarks
from mercurial import cmdutil
from mercurial import commands
from mercurial import context

### Complete troubles computation logic                           ###
#####################################################################

# there is two kind of trouble not handled by core right now:
# - latecomer: (successors for public changeset)
# - divergent: (two changeset try to succeed to the same precursors)
#
# This section add support for those two addition trouble
#
# - Cache computation
# - revset and ctx method

    candidates = _allsuccessors(repo, repo.revs('public()'),
                                                haltonflags=latediff)
    query = '%ld - obsolete() - public()'
    return set(repo.revs(query, candidates))

@cachefor('divergent')
def _computedivergentset(repo):
    """the set of rev trying to obsolete public revision"""
    divergent = set()
    obsstore = repo.obsstore
    newermap = {}
    for ctx in repo.set('(not public()) - obsolete()'):
        mark = obsstore.successors.get(ctx.node(), ())
        toprocess = set(mark)
        while toprocess:
            prec = toprocess.pop()[0]
            if prec not in newermap:
                successorssets(repo, prec, newermap)
            newer = [n for n in newermap[prec] if n]
            if len(newer) > 1:
                divergent.add(ctx.rev())
                break
            toprocess.update(obsstore.successors.get(prec, ()))
    return divergent

### changectx method

@eh.addattr(context.changectx, 'latecomer')
def latecomer(ctx):

    if ctx.node() is None:
        return False
    return ctx.rev() in getobscache(ctx._repo, 'latecomer')

@eh.addattr(context.changectx, 'conflicting')
@eh.addattr(context.changectx, 'divergent')
def divergent(ctx):
    """is the changeset divergent (Try to succeed to public change)"""
    if ctx.node() is None:
        return False
    return ctx.rev() in getobscache(ctx._repo, 'divergent')

### revset symbol

@eh.revset('latecomer')
def revsetlatecomer(repo, subset, x):

    args = revset.getargs(x, 0, 0, 'latecomer takes no arguments')
    lates = getobscache(repo, 'latecomer')
    return [r for r in subset if r in lates]

@eh.revset('conflicting')
@eh.revset('divergent')
def revsetdivergent(repo, subset, x):
    """``divergent()``
    Changesets marked as successors of a same changeset.
    """
    args = revset.getargs(x, 0, 0, 'divergent takes no arguments')
    conf = getobscache(repo, 'divergent')
    return [r for r in subset if r in conf]



### Discovery wrapping

@eh.wrapfunction(discovery, 'checkheads')

        # obsolete or unstable.
        ctx = repo[h]
        if ctx.latecomer():
            raise util.Abort(_("push includes a latecomer changeset: %s!")
                             % ctx)
        if ctx.divergent():
            raise util.Abort(_("push includes a divergent changeset: %s!")
                             % ctx)
    return orig(repo, remote, outgoing, *args, **kwargs)

#####################################################################
### Filter extinct changesets from common operations              ###

@eh.addattr(context.changectx, 'troubles')
def troubles(ctx):
    """Return a tuple listing all the troubles that affect a changeset

    Troubles may be "unstable", "latecomer" or "divergent".
    """
    troubles = []
    if ctx.unstable():
        troubles.append('unstable')
    if ctx.latecomer():
        troubles.append('latecomer')
    if ctx.divergent():
        troubles.append('divergent')
    return tuple(troubles)

### Troubled revset symbol

@eh.revset('troubled')
def revsetlatecomer(repo, subset, x):
    """``troubled()``
    Changesets with troubles.
    """
    _ = revset.getargs(x, 0, 0, 'troubled takes no arguments')
    return repo.revs('%ld and (unstable() + latecomer() + divergent())',
                     subset)


### Obsolescence graph

        sr = nm.get(s)
        if sr is not None:
            cs.add(sr)
    return cs

nodemod = node
def successorssets(repo, initialnode, cache=None):
    """Return the newer version of an obsolete changeset"""

    # prec -> markers mapping
    markersfor = repo.obsstore.precursors

    # Stack of node need to know the last successors set
    toproceed = [initialnode]
    # set version of toproceed for fast loop detection
    stackedset = set(toproceed)
    if cache is None:
        cache = {}
    while toproceed:
        # work on the last node of the stack
        node = toproceed[-1]
        if node in cache:
            # We already have a value for it.
            # Keep working on something else.
            stackedset.remove(toproceed.pop())
        elif node not in markersfor:
            # The node is not obsolete.
            # This mean it is its own last successors.
            if node in repo:
                # We have a valid last successors.
                cache[node] = [(node,)]
            else:
                # final obsolete version is unknown locally.
                # Do not count that as a valid successors
                cache[node] = []
        else:
            # <lss> stand for Last Successors Sets
            # it contains the list of all last successors for the current node.
            lss = []
            for mark in markersfor[node]:
                # <mlss> stand for Marker Last Successors Sets
                # it contains the list of last successors set introduced by
                # this marker.
                mlss = [[]]
                # iterate over possible multiple successors
                for suc in mark[1]:
                    if suc not in cache:
                        # We do not know the last successors of that yet.
                        if suc in stackedset:
                            # Loop detected!
                            #
                            # we won't be able to ever compute a proper last
                            # successors the naive and simple approve is to
                            # consider it killed
                            cache[suc] = []
                        else:
                            # Add the successor to the stack and break the next
                            # iteration will work on this successors and the
                            # algorithm will eventually process the current
                            # node again.
                            toproceed.append(suc)
                            stackedset.add(suc)
                            break
                    # if we did not break, we can extend the possible set of
                    # last successors.
                    #
                    # I say "extends" because if the marker have multiple
                    # successors we have to generate
                    #
                    # if successors have multiple successors set (when ther are
                    # divergent themself), we do a cartesian product of
                    # possible successors set of already processed successors
                    # and newly obtains successors set.
                    newmlss = []
                    for prefix in mlss:
                        for suffix in cache[suc]:
                            newss = list(prefix)
                            for part in suffix:
                                # do not duplicated entry in successors set.
                                # first entry win.
                                if part not in newss:
                                    newss.append(part)
                            newmlss.append(newss)
                    mlss = newmlss
                else:
                    # note: mlss is still empty if the marker was a bare killing
                    # of this changeset
                    #
                    # We extends the list of all possible successors sets with
                    # successors set continuted by this marker
                    lss.extend(mlss)
                    # we use continue here to skip the break right bellow
                    continue
                # propagate "nested for" break.
                # if the nested for exited on break, it did not ran the else
                # clause and didn't "continue
                break
            else:
                # computation was succesful for *all* marker.
                # Add computed successors set to the cache
                # (will be poped from to proceeed) on the new iteration
                #
                # We remove successors set that are subset of another one
                # this fil
                candsucset = sorted(((len(ss), set(ss), ss) for ss in lss),
                                    reverse=True)
                finalsucset = []
                for cl, cs, css in candsucset:
                    if not css:
                        # remove empty successors set
                        continue
                    for fs, fss in finalsucset:
                        if cs.issubset(fs):
                            break
                    else:
                        finalsucset.append((cs, css))
                finalsucset = [s[1] for s in finalsucset]
                finalsucset.reverse()
                cache[node] = finalsucset
    return cache[initialnode]




#####################################################################
### Extending revset and template                                 ###
#####################################################################

@eh.wrapcommand("unbundle")
def warnobserrors(orig, ui, repo, *args, **kwargs):
    """display warning is the command resulted in more instable changeset"""
    priorunstables = len(repo.revs('unstable()'))
    priorlatecomers = len(repo.revs('latecomer()'))
    priordivergents = len(repo.revs('divergent()'))
    ret = orig(ui, repo, *args, **kwargs)
    # workaround phase stupidity
    phases._filterunknown(ui, repo.changelog, repo._phasecache.phaseroots)
    newunstables = len(repo.revs('unstable()')) - priorunstables
    newlatecomers = len(repo.revs('latecomer()')) - priorlatecomers
    newdivergents = len(repo.revs('divergent()')) - priordivergents
    if newunstables > 0:
        ui.warn(_('%i new unstable changesets\n') % newunstables)
    if newlatecomers > 0:
        ui.warn(_('%i new latecomer changesets\n') % newlatecomers)
    if newdivergents > 0:
        ui.warn(_('%i new divergent changesets\n') % newdivergents)
    return ret

@eh.reposetup
def _repostabilizesetup(ui, repo):
    """Add a hint for "hg evolve" when troubles make push fails

            ui.note(s)

    ret = orig(ui, repo, *args, **kwargs)
    nbunstable = len(getobscache(repo, 'unstable'))
    nblatecomer = len(getobscache(repo, 'latecomer'))
    nbdivergent = len(getobscache(repo, 'unstable'))
    write('unstable: %i changesets\n', nbunstable)
    write('latecomer: %i changesets\n', nblatecomer)
    write('divergent: %i changesets\n', nbdivergent)
    return ret


#####################################################################
### Core Other extension compat                                   ###

def evolve(ui, repo, **opts):
    """Solve trouble in your repository

    - rebase unstable changeset to make it stable again,
    - create proper diff from latecomer changeset,
    - merge divergent changeset.

    By default, take the first troubles changeset that looks relevant.

    (The logic is still a bit fuzzy)

    - For unstable, that mean the first which could be rebased as child of the
      working directory parent revision or one of its descendants and rebase
      it.

    - For divergent this mean "." if applicable.

    With --any, evolve pick any troubled changeset to solve

    The working directory is updated to the newly created revision.
    """

    troubles = tr.troubles()
    if 'unstable' in troubles:
        return _solveunstable(ui, repo, tr, opts['dry_run'])
    elif 'latecomer' in troubles:
        return _solvelatecomer(ui, repo, tr, opts['dry_run'])
    elif 'divergent' in troubles:
        return _solvedivergent(ui, repo, tr, opts['dry_run'])
    else:
        assert False  # WHAT? unknown troubles

def _picknexttroubled(ui, repo, pickany=False):
    """Pick a the next trouble changeset to solve"""
    tr = _stabilizableunstable(repo, repo['.'])
    if tr is None:
        wdp = repo['.']
        if 'divergent' in wdp.troubles():
            tr = wdp
    if tr is None and pickany:
        troubled = list(repo.set('unstable()'))
        if not troubled:
            troubled = list(repo.set('latecomer()'))
        if not troubled:
            troubled = list(repo.set('divergent()'))
        if troubled:
            tr = troubled[0]

    return tr

    """Stabilize a unstable changeset"""
    obs = orig.parents()[0]
    if not obs.obsolete():
        obs = orig.parents()[1]
    assert obs.obsolete()
    newer = successorssets(repo, obs.node())
    # search of a parent which is not killed
    while not newer or newer == [()]:
        ui.debug("stabilize target %s is plain dead,"
                 " trying to stabilize on its parent")
        obs = obs.parents()[0]
        newer = successorssets(repo, obs.node())
    if len(newer) > 1:
        ui.write_err(_("conflict rewriting. can't choose destination\n"))
        return 2
    targets = newer[0]
    assert targets

        # reroute the working copy parent to the new changeset
        repo.dirstate.setparents(newid, node.nullid)
    finally:
        wlock.release()

def _solvedivergent(ui, repo, divergent, dryrun=False):
    base, others = divergentdata(divergent)
    if len(others) > 1:
        raise util.Abort("We do not handle split yet")
    other = others[0]
    if divergent.phase() <= phases.public:
        raise util.Abort("We can't resolve this conflict from the public side")
    if len(other.parents()) > 1:
        raise util.Abort("divergent changeset can't be a merge (yet)")
    if other.p1() not in divergent.parents():
        raise util.Abort("parents are not common (not handled yet)")

    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
    ui.status(_('merge:'))
    if not ui.quiet:
        displayer.show(divergent)
    ui.status(_('with: '))
    if not ui.quiet:
        displayer.show(other)
    ui.status(_('base: '))
    if not ui.quiet:
        displayer.show(base)
    if dryrun:
        ui.write('hg update -c %s &&\n' % divergent)
        ui.write('hg merge %s &&\n' % other)
        ui.write('hg commit -m "auto merge resolving conflict between '
                 '%s and %s"&&\n' % (divergent, other))
        ui.write('hg up -C %s &&\n' % base)
        ui.write('hg revert --all --rev tip &&\n')
        ui.write('hg commit -m "`hg log -r %s --template={desc}`";\n'
                 % divergent)
        return
    wlock = lock = None
    try:
        wlock = repo.wlock()
        lock = repo.lock()
        if divergent not in repo[None].parents():
            repo.ui.status(_('updating to "local" conflict\n'))
            hg.update(repo, divergent.rev())
        repo.ui.note(_('merging divergent changeset\n'))
        stats = merge.update(repo,
                             other.node(),
                             branchmerge=True,
                             force=False,
                             partial=None,

/!\ * hg up to the parent of the amended changeset (which are named W and Z)
/!\ * hg revert --all -r X
/!\ * hg ci -m "same message as the amended changeset" => new cset Y
/!\ * hg kill -n Y W Z
""")
        tr = repo.transaction('stabilize-divergent')
        try:
            repo.dirstate.setparents(divergent.node(), node.nullid)
            oldlen = len(repo)
            amend(ui, repo)
            if oldlen == len(repo):
                new = divergent
                # no changes
            else:
                new = repo['.']
            createmarkers(repo, [(other, (new,))])
            phases.retractboundary(repo, other.phase(), [new.node()])

            tr.release()
    finally:
        lockmod.release(lock, wlock)


def divergentdata(ctx):
    """return base, other part of a conflict

    This only return the first one.

    XXX this woobly function won't survive XXX
    """
    for base in ctx._repo.set('reverse(precursors(%d))', ctx):
        newer = successorssets(ctx._repo, base.node())
        # drop filter and solution including the original ctx
        newer = [n for n in newer if n and ctx.node() not in n]
        if newer:
            return base, tuple(ctx._repo[o] for o in newer[0])
    raise KeyError('Base seem unknown. This case is not handled yet.')

        if repo.revs('. and %ld', revs):
            hg.update(repo, newid)
    finally:
        lockmod.release(lock, wlock)

if 'debugsuccessorssets' not in commands.table:

    @command('debugsuccessorssets',
        [],
        _('[REV]'))
    def debugsuccessorssets(ui, repo, *revs):
        """show set of successors for revision

        Successors set of changeset A are a consistent group of revision that
        succeed to A. Successors set contains non-obsolete changeset only.

        In most case a changeset A have zero (changeset pruned) or a single
        successors set that contains a single successors (changeset A replacement
        by A')

        But splitted changeset will result with successors set containing more than
        a single element. Divergent rewritting will result in multiple successor
        set.

        result is displayed as follows::

            <rev1>
                <successors-1A>
            <rev2>
                <successors-2A>
                <successors-2B1> <successors-2B1> <successors-2B1>

        here rev2 have two possible successors sets. One hold three elements.

        add --debug if you want full size node id.
        """
        cache = {}
        s = str
        if ui.debug:
            def s(ctx):
                return ctx.hex()
        for rev in scmutil.revrange(repo, revs):
            ctx = repo[rev]
            if ui.debug():
                ui.write('%s\n'% ctx.hex())
                s = node.hex
            else:
                ui.write('%s\n'% ctx)
                s = node.short
            for ss in successorssets(repo, ctx.node(), cache):
                if ss:
                    ui.write('    ')
                    ui.write(s(ss[0]))
                    for n in ss[1:]:
                        ui.write(' ')
                        ui.write(s(n))
                ui.write('\n')
        pass


@eh.wrapcommand('graft')
def graftwrapper(orig, ui, repo, *revs, **kwargs):
    kwargs = dict(kwargs)
    revs = list(revs) + kwargs.get('rev', [])