# rebase.py - rebasing feature for mercurial
#
# Copyright 2008 Stefano Tortarolo <stefano.tortarolo at gmail dot com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''command to move sets of revisions to a different ancestor
This extension lets you rebase changesets in an existing Mercurial
repository.
For more information:
http://mercurial.selenic.com/wiki/RebaseExtension
'''
from mercurial import util, repair, merge, cmdutil, commands, error
from mercurial import extensions, ancestor, copies, patch
from mercurial.commands import templateopts
from mercurial.node import nullrev
from mercurial.lock import release
from mercurial.i18n import _
import os, errno
nullmerge = -2
def rebase(ui, repo, **opts):
"""move changeset (and descendants) to a different branch
Rebase uses repeated merging to graft changesets from one part of
history (the source) onto another (the destination). This can be
useful for linearizing *local* changes relative to a master
development tree.
You should not rebase changesets that have already been shared
with others. Doing so will force everybody else to perform the
same rebase or they will end up with duplicated changesets after
pulling in your rebased changesets.
If you don't specify a destination changeset (``-d/--dest``),
rebase uses the tipmost head of the current named branch as the
destination. (The destination changeset is not modified by
rebasing, but new changesets are added as its descendants.)
You can specify which changesets to rebase in two ways: as a
"source" changeset or as a "base" changeset. Both are shorthand
for a topologically related set of changesets (the "source
branch"). If you specify source (``-s/--source``), rebase will
rebase that changeset and all of its descendants onto dest. If you
specify base (``-b/--base``), rebase will select ancestors of base
back to but not including the common ancestor with dest. Thus,
``-b`` is less precise but more convenient than ``-s``: you can
specify any changeset in the source branch, and rebase will select
the whole branch. If you specify neither ``-s`` nor ``-b``, rebase
uses the parent of the working directory as the base.
By default, rebase recreates the changesets in the source branch
as descendants of dest and then destroys the originals. Use
``--keep`` to preserve the original source changesets. Some
changesets in the source branch (e.g. merges from the destination
branch) may be dropped if they no longer contribute any change.
One result of the rules for selecting the destination changeset
and source branch is that, unlike ``merge``, rebase will do
nothing if you are at the latest (tipmost) head of a named branch
with two heads. You need to explicitly specify source and/or
destination (or ``update`` to the other head, if it's the head of
the intended source branch).
If a rebase is interrupted to manually resolve a merge, it can be
continued with --continue/-c or aborted with --abort/-a.
"""
originalwd = target = None
external = nullrev
state = {}
skipped = set()
targetancestors = set()
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)
extrafn = opts.get('extrafn')
keepf = opts.get('keep', False)
keepbranchesf = opts.get('keepbranches', False)
detachf = opts.get('detach', False)
if contf or abortf:
if contf and abortf:
raise error.ParseError('rebase',
_('cannot use both abort and continue'))
if collapsef:
raise error.ParseError(
'rebase', _('cannot use collapse with continue or abort'))
if detachf:
raise error.ParseError(
'rebase', _('cannot use detach with continue or abort'))
if srcf or basef or destf:
raise error.ParseError('rebase',
_('abort and continue do not allow specifying revisions'))
(originalwd, target, state, collapsef, keepf,
keepbranchesf, external) = restorestatus(repo)
if abortf:
abort(repo, originalwd, target, state)
return
else:
if srcf and basef:
raise error.ParseError('rebase', _('cannot specify both a '
'revision and a base'))
if detachf:
if not srcf:
raise error.ParseError(
'rebase', _('detach requires a revision to be specified'))
if basef:
raise error.ParseError(
'rebase', _('cannot specify a base with detach'))
cmdutil.bail_if_changed(repo)
result = buildstate(repo, destf, srcf, basef, detachf)
if not result:
# Empty state built, nothing to rebase
ui.status(_('nothing to rebase\n'))
return
else:
originalwd, target, state = result
if collapsef:
targetancestors = set(repo.changelog.ancestors(target))
external = checkexternal(repo, state, targetancestors)
if keepbranchesf:
if extrafn:
raise error.ParseError(
'rebase', _('cannot use both keepbranches and extrafn'))
def extrafn(ctx, extra):
extra['branch'] = ctx.branch()
# Rebase
if not targetancestors:
targetancestors = set(repo.changelog.ancestors(target))
targetancestors.add(target)
for rev in sorted(state):
if state[rev] == -1:
ui.debug("rebasing %d:%s\n" % (rev, repo[rev]))
storestatus(repo, originalwd, target, state, collapsef, keepf,
keepbranchesf, external)
p1, p2 = defineparents(repo, rev, target, state,
targetancestors)
if len(repo.parents()) == 2:
repo.ui.debug('resuming interrupted rebase\n')
else:
stats = rebasenode(repo, rev, p1, p2, state)
if stats and stats[3] > 0:
raise util.Abort(_('fix unresolved conflicts with hg '
'resolve then run hg rebase --continue'))
updatedirstate(repo, rev, target, p2)
if not collapsef:
newrev = concludenode(repo, rev, p1, p2, extrafn=extrafn)
else:
# Skip commit if we are collapsing
repo.dirstate.setparents(repo[p1].node())
newrev = None
# Update the state
if newrev is not None:
state[rev] = repo[newrev].rev()
else:
if not collapsef:
ui.note(_('no changes, revision %d skipped\n') % rev)
ui.debug('next revision set to %s\n' % p1)
skipped.add(rev)
state[rev] = p1
ui.note(_('rebase merging completed\n'))
if collapsef:
p1, p2 = defineparents(repo, min(state), target,
state, targetancestors)
commitmsg = 'Collapsed revision'
for rebased in state:
if rebased not in skipped and state[rebased] != nullmerge:
commitmsg += '\n* %s' % repo[rebased].description()
commitmsg = ui.edit(commitmsg, repo.ui.username())
newrev = concludenode(repo, rev, p1, external, commitmsg=commitmsg,
extrafn=extrafn)
if 'qtip' in repo.tags():
updatemq(repo, state, skipped, **opts)
if not keepf:
# Remove no more useful revisions
rebased = [rev for rev in state if state[rev] != nullmerge]
if rebased:
if set(repo.changelog.descendants(min(rebased))) - set(state):
ui.warn(_("warning: new changesets detected "
"on source branch, not stripping\n"))
else:
repair.strip(ui, repo, repo[min(rebased)].node(), "strip")
clearstatus(repo)
ui.status(_("rebase completed\n"))
if os.path.exists(repo.sjoin('undo')):
util.unlink(repo.sjoin('undo'))
if skipped:
ui.note(_("%d revisions have been skipped\n") % len(skipped))
finally:
release(lock, wlock)
def rebasemerge(repo, rev, first=False):
'return the correct ancestor'
oldancestor = ancestor.ancestor
def newancestor(a, b, pfunc):
if b == rev:
return repo[rev].parents()[0].rev()
return oldancestor(a, b, pfunc)
if not first:
ancestor.ancestor = newancestor
else:
repo.ui.debug("first revision, do not change ancestor\n")
try:
stats = merge.update(repo, rev, True, True, False)
return stats
finally:
ancestor.ancestor = oldancestor
def checkexternal(repo, state, targetancestors):
"""Check whether one or more external revisions need to be taken in
consideration. In the latter case, abort.
"""
external = nullrev
source = min(state)
for rev in state:
if rev == source:
continue
# 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() not in targetancestors):
if external != nullrev:
raise util.Abort(_('unable to collapse, there is more '
'than one external parent'))
external = p.rev()
return external
def updatedirstate(repo, rev, p1, p2):
"""Keep track of renamed files in the revision that is going to be rebased
"""
# Here we simulate the copies and renames in the source changeset
cop, diver = copies.copies(repo, repo[rev], repo[p1], repo[p2], True)
m1 = repo[rev].manifest()
m2 = repo[p1].manifest()
for k, v in cop.iteritems():
if k in m1:
if v in m1 or v in m2:
repo.dirstate.copy(v, k)
if v in m2 and v not in m1:
repo.dirstate.remove(v)
def concludenode(repo, rev, p1, p2, commitmsg=None, extrafn=None):
'Commit the changes and store useful information in extra'
try:
repo.dirstate.setparents(repo[p1].node(), repo[p2].node())
if commitmsg is None:
commitmsg = repo[rev].description()
ctx = repo[rev]
extra = {'rebase_source': ctx.hex()}
if extrafn:
extrafn(ctx, extra)
# Commit might fail if unresolved files exist
newrev = repo.commit(text=commitmsg, user=ctx.user(),
date=ctx.date(), extra=extra)
repo.dirstate.setbranch(repo[newrev].branch())
return newrev
except util.Abort:
# Invalidate the previous setparents
repo.dirstate.invalidate()
raise
def rebasenode(repo, rev, p1, p2, state):
'Rebase a single revision'
# Merge phase
# Update to target and merge it with local
if repo['.'].rev() != repo[p1].rev():
repo.ui.debug(" update to %d:%s\n" % (repo[p1].rev(), repo[p1]))
merge.update(repo, p1, False, True, False)
else:
repo.ui.debug(" already in target\n")
repo.dirstate.write()
repo.ui.debug(" merge against %d:%s\n" % (repo[rev].rev(), repo[rev]))
first = repo[rev].rev() == repo[min(state)].rev()
stats = rebasemerge(repo, rev, first)
return stats
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:
if state[P1n] == nullmerge:
p1 = target
else:
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
repo.ui.debug(" future parents are %d and %d\n" %
(repo[p1].rev(), repo[p2].rev()))
return p1, p2
def isagitpatch(repo, patchname):
'Return true if the given patch is in git format'
mqpatch = os.path.join(repo.mq.path, patchname)
for line in patch.linereader(file(mqpatch, 'rb')):
if line.startswith('diff --git'):
return True
return False
def updatemq(repo, state, skipped, **opts):
'Update rebased mq patches - finalize and then import them'
mqrebase = {}
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, isagitpatch(repo, p.name))
if mqrebase:
repo.mq.finish(repo, mqrebase.keys())
# We must start import from the newest revision
for rev in sorted(mqrebase, reverse=True):
if rev not in skipped:
repo.ui.debug('import mq patch %d (%s)\n'
% (state[rev], mqrebase[rev][0]))
repo.mq.qimport(repo, (), patchname=mqrebase[rev][0],
git=mqrebase[rev][1],rev=[str(state[rev])])
repo.mq.save_dirty()
def storestatus(repo, originalwd, target, state, collapse, keep, keepbranches,
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))
f.write('%d\n' % int(keep))
f.write('%d\n' % int(keepbranches))
for d, v in state.iteritems():
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))
elif i == 4:
keep = bool(int(l))
elif i == 5:
keepbranches = 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, keep, keepbranches, 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 set(repo.changelog.descendants(target)) - 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, detach):
'Define which revisions are going to be rebased and where'
targetancestors = set()
detachset = set()
if not dest:
# Destination defaults to the latest revision in the current branch
branch = repo[None].branch()
dest = repo[branch].rev()
else:
dest = repo[dest].rev()
# This check isn't strictly necessary, since mq detects commits over an
# applied patch. But it prevents messing up the working directory when
# a partially completed rebase is blocked by mq.
if 'qtip' in repo.tags() and (repo[dest].hex() in
[s.rev for s in repo.mq.applied]):
raise util.Abort(_('cannot rebase onto an applied mq patch'))
if src:
commonbase = repo[src].ancestor(repo[dest])
if commonbase == repo[src]:
raise util.Abort(_('source is ancestor of destination'))
if commonbase == repo[dest]:
raise util.Abort(_('source is descendant of destination'))
source = repo[src].rev()
if detach:
# We need to keep track of source's ancestors up to the common base
srcancestors = set(repo.changelog.ancestors(source))
baseancestors = set(repo.changelog.ancestors(commonbase.rev()))
detachset = srcancestors - baseancestors
detachset.remove(commonbase.rev())
else:
if base:
cwd = repo[base].rev()
else:
cwd = repo['.'].rev()
if cwd == dest:
repo.ui.debug('source and destination are the same\n')
return None
targetancestors = set(repo.changelog.ancestors(dest))
if cwd in targetancestors:
repo.ui.debug('source is ancestor of destination\n')
return None
cwdancestors = set(repo.changelog.ancestors(cwd))
if dest in cwdancestors:
repo.ui.debug('source is descendant of destination\n')
return None
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)
state.update(dict.fromkeys(detachset, nullmerge))
state[source] = nullrev
return repo['.'].rev(), repo[dest].rev(), state
def pullrebase(orig, ui, repo, *args, **opts):
'Call rebase after pull if the latter has been invoked with --rebase'
if opts.get('rebase'):
if opts.get('update'):
del opts['update']
ui.debug('--update and --rebase are not compatible, ignoring '
'the update flag\n')
cmdutil.bail_if_changed(repo)
revsprepull = len(repo)
orig(ui, repo, *args, **opts)
revspostpull = len(repo)
if revspostpull > revsprepull:
rebase(ui, repo, **opts)
branch = repo[None].branch()
dest = repo[branch].rev()
if dest != repo['.'].rev():
# there was nothing to rebase we force an update
merge.update(repo, dest, False, False, False)
else:
orig(ui, repo, *args, **opts)
def uisetup(ui):
'Replace pull with a decorator to provide --rebase option'
entry = extensions.wrapcommand(commands.table, 'pull', pullrebase)
entry[1].append(('', 'rebase', None,
_("rebase working directory to branch head"))
)
cmdtable = {
"rebase":
(rebase,
[
('s', 'source', '', _('rebase from the specified changeset')),
('b', 'base', '', _('rebase from the base of the specified changeset '
'(up to greatest common ancestor of base and dest)')),
('d', 'dest', '', _('rebase onto the specified changeset')),
('', 'collapse', False, _('collapse the rebased changesets')),
('', 'keep', False, _('keep original changesets')),
('', 'keepbranches', False, _('keep original branch names')),
('', 'detach', False, _('force detaching of source from its original '
'branch')),
('c', 'continue', False, _('continue an interrupted rebase')),
('a', 'abort', False, _('abort an interrupted rebase'))] +
templateopts,
_('hg rebase [-s REV | -b REV] [-d REV] [options]\n'
'hg rebase {-a|-c}'))
}