--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hgext/rebase.py	Mon Aug 18 21:16:31 2008 +0200
@@ -0,0 +1,401 @@
+# rebase.py - rebasing feature for mercurial
+#
+# Copyright 2008 Stefano Tortarolo <stefano.tortarolo at gmail dot com>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+
+''' Rebasing feature
+
+This extension lets you rebase changesets in an existing Mercurial repository.
+
+For more information:
+http://www.selenic.com/mercurial/wiki/index.cgi/RebaseProject
+'''
+
+from mercurial import util, repair, merge, cmdutil, dispatch, commands
+from mercurial.commands import templateopts
+from mercurial.node import nullrev
+from mercurial.i18n import _
+import os, errno
+
+def rebase(ui, repo, **opts):
+    """move changeset (and descendants) to a different branch
+
+    Rebase uses repeated merging to graft changesets from one part of history
+    onto another. This can be useful for linearizing local changes relative to
+    a master development tree.
+
+    If a rebase is interrupted to manually resolve a merge, it can be continued
+    with --continue or aborted with --abort.
+    """
+    originalwd = target = source = None
+    external = nullrev
+    state = skipped = {}
+
+    lock = wlock = None
+    try:
+        lock = repo.lock()
+        wlock = repo.wlock()
+
+        # Validate input and define rebasing points
+        destf = opts.get('dest', None)
+        srcf = opts.get('source', None)
+        basef = opts.get('base', None)
+        contf = opts.get('continue')
+        abortf = opts.get('abort')
+        collapsef = opts.get('collapse', False)
+        if contf or abortf:
+            if contf and abortf:
+                raise dispatch.ParseError('rebase',
+                                    _('cannot use both abort and continue'))
+            if collapsef:
+                raise dispatch.ParseError('rebase',
+                        _('cannot use collapse with continue or abort'))
+
+            if (srcf or basef or destf):
+                raise dispatch.ParseError('rebase',
+                    _('abort and continue do not allow specifying revisions'))
+
+            originalwd, target, state, collapsef, external = restorestatus(repo)
+            if abortf:
+                abort(repo, originalwd, target, state)
+                return
+        else:
+            if srcf and basef:
+                raise dispatch.ParseError('rebase', _('cannot specify both a '
+                                                        'revision and a base'))
+            cmdutil.bail_if_changed(repo)
+            result = buildstate(repo, destf, srcf, basef, collapsef)
+            if result:
+                originalwd, target, state, external = result
+            else: # Empty state built, nothing to rebase
+                repo.ui.status(_('nothing to rebase\n'))
+                return
+
+        # Rebase
+        targetancestors = list(repo.changelog.ancestors(target))
+        targetancestors.append(target)
+
+        for rev in util.sort(state):
+            if state[rev] == -1:
+                storestatus(repo, originalwd, target, state, collapsef,
+                                                                external)
+                rebasenode(repo, rev, target, state, skipped, targetancestors,
+                                                                collapsef)
+        ui.note(_('rebase merging completed\n'))
+
+        if collapsef:
+            p1, p2 = defineparents(repo, min(state), target, 
+                                                        state, targetancestors)
+            concludenode(repo, rev, p1, external, state, collapsef,
+                                                last=True, skipped=skipped)
+
+        if 'qtip' in repo.tags():
+            updatemq(repo, state, skipped, **opts)
+
+        if not opts.get('keep'):
+            # Remove no more useful revisions
+            if (util.set(repo.changelog.descendants(min(state))) 
+                                                    - util.set(state.keys())):
+                ui.warn(_("warning: new changesets detected on source branch, "
+                                                        "not stripping\n"))
+            else:
+                repair.strip(repo.ui, repo, repo[min(state)].node(), "strip")
+
+        clearstatus(repo)
+        ui.status(_("rebase completed\n"))
+        if skipped:
+            ui.note(_("%d revisions have been skipped\n") % len(skipped))
+    finally:
+        del lock, wlock
+
+def concludenode(repo, rev, p1, p2, state, collapse, last=False, skipped={}):
+    """Skip commit if collapsing has been required and rev is not the last
+    revision, commit otherwise
+    """
+    repo.dirstate.setparents(repo[p1].node(), repo[p2].node())
+
+    if collapse and not last:
+        return None
+
+    # Commit, record the old nodeid
+    m, a, r = repo.status()[:3]
+    newrev = nullrev
+    try:
+        if last:
+            commitmsg = 'Collapsed revision'
+            for rebased in state:
+                if rebased not in skipped:
+                    commitmsg += '\n* %s' % repo[rebased].description()
+            commitmsg = repo.ui.edit(commitmsg, repo.ui.username())
+        else:
+            commitmsg = repo[rev].description()
+        # Commit might fail if unresolved files exist
+        newrev = repo.commit(m+a+r,
+                            text=commitmsg,
+                            user=repo[rev].user(),
+                            date=repo[rev].date(),
+                            extra={'rebase_source': repo[rev].hex()})
+        return newrev
+    except util.Abort:
+        # Invalidate the previous setparents
+        repo.dirstate.invalidate()
+        raise
+
+def rebasenode(repo, rev, target, state, skipped, targetancestors, collapse):
+    'Rebase a single revision'
+    repo.ui.debug(_("rebasing %d:%s\n") % (rev, repo[rev].node()))
+
+    p1, p2 = defineparents(repo, rev, target, state, targetancestors)
+
+    # Merge phase
+    if len(repo.parents()) != 2:
+        # Update to target and merge it with local
+        merge.update(repo, p1, False, True, False)
+        repo.dirstate.write()
+        stats = merge.update(repo, rev, True, False, False)
+
+        if stats[3] > 0:
+            raise util.Abort(_('fix unresolved conflicts with hg resolve then '
+                                                'run hg rebase --continue'))
+    else: # we have an interrupted rebase
+        repo.ui.debug(_('resuming interrupted rebase\n'))
+
+
+    newrev = concludenode(repo, rev, p1, p2, state, collapse)
+
+    # Update the state
+    if newrev is not None:
+        state[rev] = repo[newrev].rev()
+    else:
+        if not collapse:
+            repo.ui.note('no changes, revision %d skipped\n' % rev)
+            repo.ui.debug('next revision set to %s\n' % p1)
+            skipped[rev] = True
+        state[rev] = p1
+       
+def defineparents(repo, rev, target, state, targetancestors):
+    'Return the new parent relationship of the revision that will be rebased'
+    parents = repo[rev].parents()
+    p1 = p2 = nullrev
+
+    P1n = parents[0].rev()
+    if P1n in targetancestors:
+        p1 = target
+    elif P1n in state:
+        p1 = state[P1n]
+    else: # P1n external
+        p1 = target
+        p2 = P1n
+
+    if len(parents) == 2 and parents[1].rev() not in targetancestors:
+        P2n = parents[1].rev()
+        # interesting second parent
+        if P2n in state:
+            if p1 == target: # P1n in targetancestors or external
+                p1 = state[P2n]
+            else:
+                p2 = state[P2n]
+        else: # P2n external
+            if p2 != nullrev: # P1n external too => rev is a merged revision
+                raise util.Abort(_('cannot use revision %d as base, result '
+                        'would have 3 parents') % rev)
+            p2 = P2n
+    return p1, p2
+
+def updatemq(repo, state, skipped, **opts):
+    'Update rebased mq patches - finalize and then import them'
+    mqrebase = {}
+    for p in repo.mq.applied:
+        if repo[p.rev].rev() in state:
+            repo.ui.debug('revision %d is an mq patch (%s), finalize it.\n' %
+                                        (repo[p.rev].rev(), p.name))
+            mqrebase[repo[p.rev].rev()] = p.name
+
+    if mqrebase:
+        repo.mq.finish(repo, mqrebase.keys())
+
+        # We must start import from the newest revision
+        mq = mqrebase.keys()
+        mq.sort()
+        mq.reverse()
+        for rev in mq:
+            if rev not in skipped:
+                repo.ui.debug('import mq patch %d (%s)\n' % (state[rev],
+                                                            mqrebase[rev]))
+                repo.mq.qimport(repo, (), patchname=mqrebase[rev], 
+                            git=opts.get('git', False),rev=[str(state[rev])])
+        repo.mq.save_dirty()
+
+def storestatus(repo, originalwd, target, state, collapse, external):
+    'Store the current status to allow recovery'
+    f = repo.opener("rebasestate", "w")
+    f.write(repo[originalwd].hex() + '\n')
+    f.write(repo[target].hex() + '\n')
+    f.write(repo[external].hex() + '\n')
+    f.write('%d\n' % int(collapse))
+    for d, v in state.items():
+        oldrev = repo[d].hex()
+        newrev = repo[v].hex()
+        f.write("%s:%s\n" % (oldrev, newrev))
+    f.close()
+    repo.ui.debug(_('rebase status stored\n'))
+
+def clearstatus(repo):
+    'Remove the status files'
+    if os.path.exists(repo.join("rebasestate")):
+        util.unlink(repo.join("rebasestate"))
+
+def restorestatus(repo):
+    'Restore a previously stored status'
+    try:
+        target = None
+        collapse = False
+        external = nullrev
+        state = {}
+        f = repo.opener("rebasestate")
+        for i, l in enumerate(f.read().splitlines()):
+            if i == 0:
+                originalwd = repo[l].rev()
+            elif i == 1:
+                target = repo[l].rev()
+            elif i == 2:
+                external = repo[l].rev()
+            elif i == 3:
+                collapse = bool(int(l))
+            else:
+                oldrev, newrev = l.split(':')
+                state[repo[oldrev].rev()] = repo[newrev].rev()
+        repo.ui.debug(_('rebase status resumed\n'))
+        return originalwd, target, state, collapse, external
+    except IOError, err:
+        if err.errno != errno.ENOENT:
+            raise
+        raise util.Abort(_('no rebase in progress'))
+
+def abort(repo, originalwd, target, state):
+    'Restore the repository to its original state'
+    if util.set(repo.changelog.descendants(target)) - util.set(state.values()):
+        repo.ui.warn(_("warning: new changesets detected on target branch, "
+                                                    "not stripping\n"))
+    else:
+        # Strip from the first rebased revision
+        merge.update(repo, repo[originalwd].rev(), False, True, False)
+        rebased = filter(lambda x: x > -1, state.values())
+        if rebased:
+            strippoint = min(rebased)
+            repair.strip(repo.ui, repo, repo[strippoint].node(), "strip")
+        clearstatus(repo)
+        repo.ui.status(_('rebase aborted\n'))
+
+def buildstate(repo, dest, src, base, collapse):
+    'Define which revisions are going to be rebased and where'
+    state = {}
+    targetancestors = util.set()
+
+    if not dest:
+         # Destination defaults to the latest revision in the current branch
+        branch = repo[None].branch()
+        dest = repo[branch].rev()
+    else:
+        if 'qtip' in repo.tags() and (repo[dest].hex() in
+                                [s.rev for s in repo.mq.applied]):
+            raise util.Abort(_('cannot rebase onto an applied mq patch'))
+        dest = repo[dest].rev()
+
+    if src:
+        commonbase = repo[src].ancestor(repo[dest])
+        if commonbase == repo[src]:
+            raise util.Abort(_('cannot rebase an ancestor'))
+        if commonbase == repo[dest]:
+            raise util.Abort(_('cannot rebase a descendant'))
+        source = repo[src].rev()
+    else:
+        if base:
+            cwd = repo[base].rev()
+        else:
+            cwd = repo['.'].rev()
+
+        if cwd == dest:
+            repo.ui.debug(_('already working on current\n'))
+            return None
+
+        targetancestors = util.set(repo.changelog.ancestors(dest))
+        if cwd in targetancestors:
+            repo.ui.debug(_('already working on the current branch\n'))
+            return None
+
+        cwdancestors = util.set(repo.changelog.ancestors(cwd))
+        cwdancestors.add(cwd)
+        rebasingbranch = cwdancestors - targetancestors
+        source = min(rebasingbranch)
+        
+    repo.ui.debug(_('rebase onto %d starting from %d\n') % (dest, source))
+    state = dict.fromkeys(repo.changelog.descendants(source), nullrev)
+    external = nullrev
+    if collapse:
+        if not targetancestors:
+            targetancestors = util.set(repo.changelog.ancestors(dest))
+        for rev in state:
+            # Check externals and fail if there are more than one
+            for p in repo[rev].parents():
+                if (p.rev() not in state and p.rev() != source
+                            and p.rev() not in targetancestors):
+                    if external != nullrev:
+                        raise util.Abort(_('unable to collapse, there is more '
+                                'than one external parent'))
+                    external = p.rev()
+
+    state[source] = nullrev
+    return repo['.'].rev(), repo[dest].rev(), state, external
+
+def pulldelegate(pullfunction, repo, *args, **opts):
+    'Call rebase after pull if the latter has been invoked with --rebase'
+    if opts.get('rebase'):
+        if opts.get('update'):
+            raise util.Abort(_('--update and --rebase are not compatible'))
+
+        cmdutil.bail_if_changed(repo)
+        revsprepull = len(repo)
+        pullfunction(repo.ui, repo, *args, **opts)
+        revspostpull = len(repo)
+        if revspostpull > revsprepull:
+            rebase(repo.ui, repo, **opts)
+    else:
+        pullfunction(repo.ui, repo, *args, **opts)
+
+def uisetup(ui):
+    'Replace pull with a decorator to provide --rebase option'
+    # cribbed from color.py
+    aliases, entry = cmdutil.findcmd(ui, 'pull', commands.table)
+    for candidatekey, candidateentry in commands.table.iteritems():
+        if candidateentry is entry:
+            cmdkey, cmdentry = candidatekey, entry
+            break
+
+    decorator = lambda ui, repo, *args, **opts: \
+                    pulldelegate(cmdentry[0], repo, *args, **opts)
+    # make sure 'hg help cmd' still works
+    decorator.__doc__ = cmdentry[0].__doc__
+    decoratorentry = (decorator,) + cmdentry[1:]
+    rebaseopt = ('', 'rebase', None, 
+                            _("rebase working directory to branch head"))
+    decoratorentry[1].append(rebaseopt)
+    commands.table[cmdkey] = decoratorentry
+
+cmdtable = {
+"rebase":
+        (rebase,
+        [
+        ('', 'keep', False, _('keep original revisions')),
+        ('s', 'source', '', _('rebase from a given revision')),
+        ('b', 'base', '', _('rebase from the base of a given revision')),
+        ('d', 'dest', '', _('rebase onto a given revision')),
+        ('', 'collapse', False, _('collapse the rebased revisions')),
+        ('c', 'continue', False, _('continue an interrupted rebase')),
+        ('a', 'abort', False, _('abort an interrupted rebase')),] +
+         templateopts,
+        _('hg rebase [-s rev | -b rev] [-d rev] [--collapse] | [-c] | [-a] | '
+                                                                '[--keep]')),
+}