hgext/histedit.py

histedit: replace various nodes lists with replacement graph (and issue3582)

This changeset rewrites the change tracking logic of histedit to record every
operation it does. Tracked operations record the full list of "old" node that
will eventually be removed to the list of new nodes that replace it. Operations
on temporary nodes are tracked too. Dropped changesets are also recorded as an
"old" node replacement by nothing. This logic is similar to the obsolescence
marker one and will be used for this purpose in later commit.

This new logic implies a big amount of change in the histedit code base.

histedit action functions now always return a tuple of

    (new-ctx, [list of rewriting operations])

The old `created`, `replaced` and `tmpnodes` are no longer returned and stored
during histedit operation. When such information is necessary it is computed
from the replacement graph. This computation is done in the `processreplacement`
function.

The `replacemap` is also dropped. It is computed at the end of the command from the
graph.  The `bootstrapcontinue` methods are altered to compute this different kind of
information.

This new mechanism requires much less information to be written on disk.

Note:

    This changes allows a more accurate bookmark movement. bookmark on dropped
    changeset are now move of their parent (or replacement of their parent)
    instead of their children.

    This fix issue3582

# histedit.py - interactive history editing for mercurial
#
# Copyright 2009 Augie Fackler <[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.
"""interactive history editing

With this extension installed, Mercurial gains one new command: histedit. Usage
is as follows, assuming the following history::

 @  3[tip]   7c2fd3b9020c   2009-04-27 18:04 -0500   durin42
 |    Add delta
 |
 o  2   030b686bedc4   2009-04-27 18:04 -0500   durin42
 |    Add gamma
 |
 o  1   c561b4e977df   2009-04-27 18:04 -0500   durin42
 |    Add beta
 |
 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
      Add alpha

If you were to run ``hg histedit c561b4e977df``, you would see the following
file open in your editor::

 pick c561b4e977df Add beta
 pick 030b686bedc4 Add gamma
 pick 7c2fd3b9020c Add delta

 # Edit history between 633536316234 and 7c2fd3b9020c
 #
 # Commands:
 #  p, pick = use commit
 #  e, edit = use commit, but stop for amending
 #  f, fold = use commit, but fold into previous commit (combines N and N-1)
 #  d, drop = remove commit from history
 #  m, mess = edit message without changing commit content
 #

In this file, lines beginning with ``#`` are ignored. You must specify a rule
for each revision in your history. For example, if you had meant to add gamma
before beta, and then wanted to add delta in the same revision as beta, you
would reorganize the file to look like this::

 pick 030b686bedc4 Add gamma
 pick c561b4e977df Add beta
 fold 7c2fd3b9020c Add delta

 # Edit history between 633536316234 and 7c2fd3b9020c
 #
 # Commands:
 #  p, pick = use commit
 #  e, edit = use commit, but stop for amending
 #  f, fold = use commit, but fold into previous commit (combines N and N-1)
 #  d, drop = remove commit from history
 #  m, mess = edit message without changing commit content
 #

At which point you close the editor and ``histedit`` starts working. When you
specify a ``fold`` operation, ``histedit`` will open an editor when it folds
those revisions together, offering you a chance to clean up the commit message::

 Add beta
 ***
 Add delta

Edit the commit message to your liking, then close the editor. For
this example, let's assume that the commit message was changed to
``Add beta and delta.`` After histedit has run and had a chance to
remove any old or temporary revisions it needed, the history looks
like this::

 @  2[tip]   989b4d060121   2009-04-27 18:04 -0500   durin42
 |    Add beta and delta.
 |
 o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
 |    Add gamma
 |
 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
      Add alpha

Note that ``histedit`` does *not* remove any revisions (even its own temporary
ones) until after it has completed all the editing operations, so it will
probably perform several strip operations when it's done. For the above example,
it had to run strip twice. Strip can be slow depending on a variety of factors,
so you might need to be a little patient. You can choose to keep the original
revisions by passing the ``--keep`` flag.

The ``edit`` operation will drop you back to a command prompt,
allowing you to edit files freely, or even use ``hg record`` to commit
some changes as a separate commit. When you're done, any remaining
uncommitted changes will be committed as well. When done, run ``hg
histedit --continue`` to finish this step. You'll be prompted for a
new commit message, but the default commit message will be the
original message for the ``edit`` ed revision.

The ``message`` operation will give you a chance to revise a commit
message without changing the contents. It's a shortcut for doing
``edit`` immediately followed by `hg histedit --continue``.

If ``histedit`` encounters a conflict when moving a revision (while
handling ``pick`` or ``fold``), it'll stop in a similar manner to
``edit`` with the difference that it won't prompt you for a commit
message when done. If you decide at this point that you don't like how
much work it will be to rearrange history, or that you made a mistake,
you can use ``hg histedit --abort`` to abandon the new changes you
have made and return to the state before you attempted to edit your
history.

If we clone the example repository above and add three more changes, such that
we have the following history::

   @  6[tip]   038383181893   2009-04-27 18:04 -0500   stefan
   |    Add theta
   |
   o  5   140988835471   2009-04-27 18:04 -0500   stefan
   |    Add eta
   |
   o  4   122930637314   2009-04-27 18:04 -0500   stefan
   |    Add zeta
   |
   o  3   836302820282   2009-04-27 18:04 -0500   stefan
   |    Add epsilon
   |
   o  2   989b4d060121   2009-04-27 18:04 -0500   durin42
   |    Add beta and delta.
   |
   o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
   |    Add gamma
   |
   o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
        Add alpha

If you run ``hg histedit --outgoing`` on the clone then it is the same
as running ``hg histedit 836302820282``. If you need plan to push to a
repository that Mercurial does not detect to be related to the source
repo, you can add a ``--force`` option.
"""

try:
    import cPickle as pickle
except ImportError:
    import pickle
import os

from mercurial import bookmarks
from mercurial import cmdutil
from mercurial import discovery
from mercurial import error
from mercurial import copies
from mercurial import context
from mercurial import hg
from mercurial import lock as lockmod
from mercurial import node
from mercurial import repair
from mercurial import scmutil
from mercurial import util
from mercurial import merge as mergemod
from mercurial.i18n import _

cmdtable = {}
command = cmdutil.command(cmdtable)

testedwith = 'internal'

# i18n: command names and abbreviations must remain untranslated
editcomment = _("""# Edit history between %s and %s
#
# Commands:
#  p, pick = use commit
#  e, edit = use commit, but stop for amending
#  f, fold = use commit, but fold into previous commit (combines N and N-1)
#  d, drop = remove commit from history
#  m, mess = edit message without changing commit content
#
""")

def applychanges(ui, repo, ctx, opts):
    """Merge changeset from ctx (only) in the current working directory"""
    wcpar = repo.dirstate.parents()[0]
    if ctx.p1().node() == wcpar:
        # edition ar "in place" we do not need to make any merge,
        # just applies changes on parent for edition
        cmdutil.revert(ui, repo, ctx, (wcpar, node.nullid), all=True)
        stats = None
    else:
        try:
            # ui.forcemerge is an internal variable, do not document
            repo.ui.setconfig('ui', 'forcemerge', opts.get('tool', ''))
            stats = mergemod.update(repo, ctx.node(), True, True, False,
                                    ctx.p1().node())
        finally:
            repo.ui.setconfig('ui', 'forcemerge', '')
        repo.setparents(wcpar, node.nullid)
        repo.dirstate.write()
        # fix up dirstate for copies and renames
    cmdutil.duplicatecopies(repo, ctx.rev(), ctx.p1().rev())
    return stats

def collapse(repo, first, last, commitopts):
    """collapse the set of revisions from first to last as new one.

    Expected commit options are:
        - message
        - date
        - username
    Commit message is edited in all cases.

    This function works in memory."""
    ctxs = list(repo.set('%d::%d', first, last))
    if not ctxs:
        return None
    base = first.parents()[0]

    # commit a new version of the old changeset, including the update
    # collect all files which might be affected
    files = set()
    for ctx in ctxs:
        files.update(ctx.files())

    # Recompute copies (avoid recording a -> b -> a)
    copied = copies.pathcopies(first, last)

    # prune files which were reverted by the updates
    def samefile(f):
        if f in last.manifest():
            a = last.filectx(f)
            if f in base.manifest():
                b = base.filectx(f)
                return (a.data() == b.data()
                        and a.flags() == b.flags())
            else:
                return False
        else:
            return f not in base.manifest()
    files = [f for f in files if not samefile(f)]
    # commit version of these files as defined by head
    headmf = last.manifest()
    def filectxfn(repo, ctx, path):
        if path in headmf:
            fctx = last[path]
            flags = fctx.flags()
            mctx = context.memfilectx(fctx.path(), fctx.data(),
                                      islink='l' in flags,
                                      isexec='x' in flags,
                                      copied=copied.get(path))
            return mctx
        raise IOError()

    if commitopts.get('message'):
        message = commitopts['message']
    else:
        message = first.description()
    user = commitopts.get('user')
    date = commitopts.get('date')
    extra = first.extra()

    parents = (first.p1().node(), first.p2().node())
    new = context.memctx(repo,
                         parents=parents,
                         text=message,
                         files=files,
                         filectxfn=filectxfn,
                         user=user,
                         date=date,
                         extra=extra)
    new._text = cmdutil.commitforceeditor(repo, new, [])
    return repo.commitctx(new)

def pick(ui, repo, ctx, ha, opts):
    oldctx = repo[ha]
    if oldctx.parents()[0] == ctx:
        ui.debug('node %s unchanged\n' % ha)
        return oldctx, []
    hg.update(repo, ctx.node())
    stats = applychanges(ui, repo, oldctx, opts)
    if stats and stats[3] > 0:
        raise util.Abort(_('Fix up the change and run '
                           'hg histedit --continue'))
    # drop the second merge parent
    n = repo.commit(text=oldctx.description(), user=oldctx.user(),
                    date=oldctx.date(), extra=oldctx.extra())
    if n is None:
        ui.warn(_('%s: empty changeset\n')
                     % node.hex(ha))
        return ctx, []
    new = repo[n]
    return new, [(oldctx.node(), (n,))]


def edit(ui, repo, ctx, ha, opts):
    oldctx = repo[ha]
    hg.update(repo, ctx.node())
    applychanges(ui, repo, oldctx, opts)
    raise util.Abort(_('Make changes as needed, you may commit or record as '
                       'needed now.\nWhen you are finished, run hg'
                       ' histedit --continue to resume.'))

def fold(ui, repo, ctx, ha, opts):
    oldctx = repo[ha]
    hg.update(repo, ctx.node())
    stats = applychanges(ui, repo, oldctx, opts)
    if stats and stats[3] > 0:
        raise util.Abort(_('Fix up the change and run '
                           'hg histedit --continue'))
    n = repo.commit(text='fold-temp-revision %s' % ha, user=oldctx.user(),
                    date=oldctx.date(), extra=oldctx.extra())
    if n is None:
        ui.warn(_('%s: empty changeset')
                     % node.hex(ha))
        return ctx, []
    return finishfold(ui, repo, ctx, oldctx, n, opts, [])

def finishfold(ui, repo, ctx, oldctx, newnode, opts, internalchanges):
    parent = ctx.parents()[0].node()
    hg.update(repo, parent)
    ### prepare new commit data
    commitopts = opts.copy()
    # username
    if ctx.user() == oldctx.user():
        username = ctx.user()
    else:
        username = ui.username()
    commitopts['user'] = username
    # commit message
    newmessage = '\n***\n'.join(
        [ctx.description()] +
        [repo[r].description() for r in internalchanges] +
        [oldctx.description()]) + '\n'
    commitopts['message'] = newmessage
    # date
    commitopts['date'] = max(ctx.date(), oldctx.date())
    n = collapse(repo, ctx, repo[newnode], commitopts)
    if n is None:
        return ctx, []
    hg.update(repo, n)
    replacements = [(oldctx.node(), (newnode,)),
                     (ctx.node(), (n,)),
                     (newnode, (n,)),
                    ]
    for ich in internalchanges:
        replacements.append((ich, (n,)))
    return repo[n], replacements

def drop(ui, repo, ctx, ha, opts):
    return ctx, [(repo[ha].node(), ())]


def message(ui, repo, ctx, ha, opts):
    oldctx = repo[ha]
    hg.update(repo, ctx.node())
    stats = applychanges(ui, repo, oldctx, opts)
    if stats and stats[3] > 0:
        raise util.Abort(_('Fix up the change and run '
                           'hg histedit --continue'))
    message = oldctx.description() + '\n'
    message = ui.edit(message, ui.username())
    new = repo.commit(text=message, user=oldctx.user(), date=oldctx.date(),
                      extra=oldctx.extra())
    newctx = repo[new]
    if oldctx.node() != newctx.node():
        return newctx, [(oldctx.node(), (new,))]
    # We didn't make an edit, so just indicate no replaced nodes
    return newctx, []

actiontable = {'p': pick,
               'pick': pick,
               'e': edit,
               'edit': edit,
               'f': fold,
               'fold': fold,
               'd': drop,
               'drop': drop,
               'm': message,
               'mess': message,
               }

@command('histedit',
    [('', 'commands', '',
      _('Read history edits from the specified file.')),
     ('c', 'continue', False, _('continue an edit already in progress')),
     ('k', 'keep', False,
      _("don't strip old nodes after edit is complete")),
     ('', 'abort', False, _('abort an edit in progress')),
     ('o', 'outgoing', False, _('changesets not found in destination')),
     ('f', 'force', False,
      _('force outgoing even for unrelated repositories')),
     ('r', 'rev', [], _('first revision to be edited'))],
     _("[PARENT]"))
def histedit(ui, repo, *parent, **opts):
    """interactively edit changeset history
    """
    # TODO only abort if we try and histedit mq patches, not just
    # blanket if mq patches are applied somewhere
    mq = getattr(repo, 'mq', None)
    if mq and mq.applied:
        raise util.Abort(_('source has mq patches applied'))

    parent = list(parent) + opts.get('rev', [])
    if opts.get('outgoing'):
        if len(parent) > 1:
            raise util.Abort(
                _('only one repo argument allowed with --outgoing'))
        elif parent:
            parent = parent[0]

        dest = ui.expandpath(parent or 'default-push', parent or 'default')
        dest, revs = hg.parseurl(dest, None)[:2]
        ui.status(_('comparing with %s\n') % util.hidepassword(dest))

        revs, checkout = hg.addbranchrevs(repo, repo, revs, None)
        other = hg.peer(repo, opts, dest)

        if revs:
            revs = [repo.lookup(rev) for rev in revs]

        parent = discovery.findcommonoutgoing(
            repo, other, [], force=opts.get('force')).missing[0:1]
    else:
        if opts.get('force'):
            raise util.Abort(_('--force only allowed with --outgoing'))

    if opts.get('continue', False):
        if len(parent) != 0:
            raise util.Abort(_('no arguments allowed with --continue'))
        (parentctxnode, rules, keep, topmost, replacements) = readstate(repo)
        currentparent, wantnull = repo.dirstate.parents()
        parentctx = repo[parentctxnode]
        parentctx, repl = bootstrapcontinue(ui, repo, parentctx, rules, opts)
        replacements.extend(repl)
    elif opts.get('abort', False):
        if len(parent) != 0:
            raise util.Abort(_('no arguments allowed with --abort'))
        (parentctxnode, rules, keep, topmost, replacements) = readstate(repo)
        mapping, tmpnodes, leafs, _ntm = processreplacement(repo, replacements)
        ui.debug('restore wc to old parent %s\n' % node.short(topmost))
        hg.clean(repo, topmost)
        cleanupnode(ui, repo, 'created', tmpnodes)
        cleanupnode(ui, repo, 'temp', leafs)
        os.unlink(os.path.join(repo.path, 'histedit-state'))
        return
    else:
        cmdutil.bailifchanged(repo)
        if os.path.exists(os.path.join(repo.path, 'histedit-state')):
            raise util.Abort(_('history edit already in progress, try '
                               '--continue or --abort'))

        topmost, empty = repo.dirstate.parents()

        if len(parent) != 1:
            raise util.Abort(_('histedit requires exactly one parent revision'))
        parent = scmutil.revsingle(repo, parent[0]).node()

        keep = opts.get('keep', False)
        revs = between(repo, parent, topmost, keep)

        ctxs = [repo[r] for r in revs]
        rules = opts.get('commands', '')
        if not rules:
            rules = '\n'.join([makedesc(c) for c in ctxs])
            rules += '\n\n'
            rules += editcomment % (node.short(parent), node.short(topmost))
            rules = ui.edit(rules, ui.username())
            # Save edit rules in .hg/histedit-last-edit.txt in case
            # the user needs to ask for help after something
            # surprising happens.
            f = open(repo.join('histedit-last-edit.txt'), 'w')
            f.write(rules)
            f.close()
        else:
            f = open(rules)
            rules = f.read()
            f.close()
        rules = [l for l in (r.strip() for r in rules.splitlines())
                 if l and not l[0] == '#']
        rules = verifyrules(rules, repo, ctxs)

        parentctx = repo[parent].parents()[0]
        keep = opts.get('keep', False)
        replacements = []


    while rules:
        writestate(repo, parentctx.node(), rules, keep, topmost, replacements)
        action, ha = rules.pop(0)
        ui.debug('histedit: processing %s %s\n' % (action, ha))
        actfunc = actiontable[action]
        parentctx, replacement_ = actfunc(ui, repo, parentctx, ha, opts)
        replacements.extend(replacement_)

    hg.update(repo, parentctx.node())

    mapping, tmpnodes, created, ntm = processreplacement(repo, replacements)
    if mapping:
        for prec, succs in mapping.iteritems():
            if not succs:
                ui.debug('histedit: %s is dropped\n' % node.short(prec))
            else:
                ui.debug('histedit: %s is replaced by %s\n' % (
                    node.short(prec), node.short(succs[0])))
                if len(succs) > 1:
                    m = 'histedit:                            %s'
                    for n in succs[1:]:
                        ui.debug(m % node.short(n))

    if not keep:
        if mapping:
            movebookmarks(ui, repo, mapping, topmost, ntm)
            # TODO update mq state
        cleanupnode(ui, repo, 'replaced', mapping)

    cleanupnode(ui, repo, 'temp', tmpnodes)
    os.unlink(os.path.join(repo.path, 'histedit-state'))
    if os.path.exists(repo.sjoin('undo')):
        os.unlink(repo.sjoin('undo'))


def bootstrapcontinue(ui, repo, parentctx, rules, opts):
    action, currentnode = rules.pop(0)
    ctx = repo[currentnode]
    # is there any new commit between the expected parent and "."
    #
    # note: does not take non linear new change in account (but previous
    #       implementation didn't used them anyway (issue3655)
    newchildren = [c.node() for c in repo.set('(%d::.)', parentctx)]
    if not newchildren:
        # `parentctxnode` should match but no result. This means that
        # currentnode is not a descendant from parentctxnode.
        msg = _('working directory parent is not a descendant of %s')
        hint = _('update to %s or descendant and run "hg histedit '
                 '--continue" again') % parentctx
        raise util.Abort(msg % parentctx, hint=hint)
    newchildren.pop(0)  # remove parentctxnode
    # Commit dirty working directory if necessary
    new = None
    m, a, r, d = repo.status()[:4]
    if m or a or r or d:
        # prepare the message for the commit to comes
        if action in ('f', 'fold'):
            message = 'fold-temp-revision %s' % currentnode
        else:
            message = ctx.description() + '\n'
        if action in ('e', 'edit', 'm', 'mess'):
            editor = cmdutil.commitforceeditor
        else:
            editor = False
        new = repo.commit(text=message, user=ctx.user(),
                          date=ctx.date(), extra=ctx.extra(),
                          editor=editor)
        if new is not None:
            newchildren.append(new)

    replacements = []
    # track replacements
    if ctx.node() not in newchildren:
        # note: new children may be empty when the changeset is dropped.
        # this happen e.g during conflicting pick where we revert content
        # to parent.
        replacements.append((ctx.node(), tuple(newchildren)))

    if action in ('f', 'fold'):
        # finalize fold operation if applicable
        if new is None:
            new = newchildren[-1]
        else:
            newchildren.pop()  # remove new from internal changes
        parentctx, repl = finishfold(ui, repo, parentctx, ctx, new, opts,
                                     newchildren)
        replacements.extend(repl)
    elif newchildren:
        # otherwize update "parentctx" before proceding to further operation
        parentctx = repo[newchildren[-1]]
    return parentctx, replacements


def between(repo, old, new, keep):
    """select and validate the set of revision to edit

    When keep is false, the specified set can't have children."""
    revs = [old]
    current = old
    while current != new:
        ctx = repo[current]
        if not keep and len(ctx.children()) > 1:
            raise util.Abort(_('cannot edit history that would orphan nodes'))
        if len(ctx.parents()) != 1 and ctx.parents()[1] != node.nullid:
            raise util.Abort(_("can't edit history with merges"))
        if not ctx.children():
            current = new
        else:
            current = ctx.children()[0].node()
            revs.append(current)
    if len(repo[current].children()) and not keep:
        raise util.Abort(_('cannot edit history that would orphan nodes'))
    return revs


def writestate(repo, parentnode, rules, keep, topmost, replacements):
    fp = open(os.path.join(repo.path, 'histedit-state'), 'w')
    pickle.dump((parentnode, rules, keep, topmost, replacements), fp)
    fp.close()

def readstate(repo):
    """Returns a tuple of (parentnode, rules, keep, topmost, replacements).
    """
    fp = open(os.path.join(repo.path, 'histedit-state'))
    return pickle.load(fp)


def makedesc(c):
    """build a initial action line for a ctx `c`

    line are in the form:

      pick <hash> <rev> <summary>
    """
    summary = ''
    if c.description():
        summary = c.description().splitlines()[0]
    line = 'pick %s %d %s' % (c, c.rev(), summary)
    return line[:80]  # trim to 80 chars so it's not stupidly wide in my editor

def verifyrules(rules, repo, ctxs):
    """Verify that there exists exactly one edit rule per given changeset.

    Will abort if there are to many or too few rules, a malformed rule,
    or a rule on a changeset outside of the user-given range.
    """
    parsed = []
    if len(rules) != len(ctxs):
        raise util.Abort(_('must specify a rule for each changeset once'))
    for r in rules:
        if ' ' not in r:
            raise util.Abort(_('malformed line "%s"') % r)
        action, rest = r.split(' ', 1)
        if ' ' in rest.strip():
            ha, rest = rest.split(' ', 1)
        else:
            ha = r.strip()
        try:
            if repo[ha] not in ctxs:
                raise util.Abort(
                    _('may not use changesets other than the ones listed'))
        except error.RepoError:
            raise util.Abort(_('unknown changeset %s listed') % ha)
        if action not in actiontable:
            raise util.Abort(_('unknown action "%s"') % action)
        parsed.append([action, ha])
    return parsed

def processreplacement(repo, replacements):
    """process the list of replacements to return

    1) the final mapping between original and created nodes
    2) the list of temporary node created by histedit
    3) the list of new commit created by histedit"""
    allsuccs = set()
    replaced = set()
    fullmapping = {}
    # initialise basic set
    # fullmapping record all operation recorded in replacement
    for rep in replacements:
        allsuccs.update(rep[1])
        replaced.add(rep[0])
        fullmapping.setdefault(rep[0], set()).update(rep[1])
    new = allsuccs - replaced
    tmpnodes = allsuccs & replaced
    # Reduce content fullmapping  into direct relation between original nodes
    # and final node created during history edition
    # Dropped changeset are replaced by an empty list
    toproceed = set(fullmapping)
    final = {}
    while toproceed:
        for x in list(toproceed):
            succs = fullmapping[x]
            for s in list(succs):
                if s in toproceed:
                    # non final node with unknown closure
                    # We can't process this now
                    break
                elif s in final:
                    # non final node, replace with closure
                    succs.remove(s)
                    succs.update(final[s])
            else:
                final[x] = succs
                toproceed.remove(x)
    # remove tmpnodes from final mapping
    for n in tmpnodes:
        del final[n]
    # we expect all changes involved in final to exist in the repo
    # turn `final` into list (topologically sorted)
    nm = repo.changelog.nodemap
    for prec, succs in final.items():
        final[prec] = sorted(succs, key=nm.get)

    # computed topmost element (necessary for bookmark)
    if new:
        newtopmost = max(new, key=repo.changelog.rev)
    elif not final:
        # Nothing rewritten at all. we won't need `newtopmost`
        # It is the same as `oldtopmost` and `processreplacement` know it
        newtopmost = None
    else:
        # every body died. The newtopmost is the parent of the root.
        newtopmost = repo[min(final, key=repo.changelog.rev)].p1().node()

    return final, tmpnodes, new, newtopmost

def movebookmarks(ui, repo, mapping, oldtopmost, newtopmost):
    """Move bookmark from old to newly created node"""
    if not mapping:
        # if nothing got rewritten there is not purpose for this function
        return
    moves = []
    for bk, old in repo._bookmarks.iteritems():
        if old == oldtopmost:
            # special case ensure bookmark stay on tip. 
            #
            # This is arguably a feature and we may only want that for the
            # active bookmark. But the behavior is kept compatible with the old
            # version for now.
            moves.append((bk, newtopmost))
            continue
        base = old
        new = mapping.get(base, None)
        if new is None:
            continue
        while not new:
            # base is killed, trying with parent
            base = repo[base].p1().node()
            new = mapping.get(base, (base,))
            # nothing to move
        moves.append((bk, new[-1]))
    if moves:
        for mark, new in moves:
            old = repo._bookmarks[mark]
            ui.note(_('histedit: moving bookmarks %s from %s to %s\n')
                    % (mark, node.short(old), node.short(new)))
            repo._bookmarks[mark] = new
        bookmarks.write(repo)

def cleanupnode(ui, repo, name, nodes):
    """strip a group of nodes from the repository

    The set of node to strip may contains unknown nodes."""
    ui.debug('should strip %s nodes %s\n' %
             (name, ', '.join([node.short(n) for n in nodes])))
    lock = None
    try:
        lock = repo.lock()
        # Find all node that need to be stripped
        # (we hg %lr instead of %ln to silently ignore unknown item
        nm = repo.changelog.nodemap
        nodes = [n for n in nodes if n in nm]
        roots = [c.node() for c in repo.set("roots(%ln)", nodes)]
        for c in roots:
            # We should process node in reverse order to strip tip most first.
            # but this trigger a bug in changegroup hook.
            # This would reduce bundle overhead
            repair.strip(ui, repo, c)
    finally:
        lockmod.release(lock)