merge: document some internal return values.

mercurial/hg.py

@@ -1,550 +1,551 b''
 # hg.py - repository classes for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[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.
 
 from i18n import _
 from lock import release
 from node import hex, nullid, nullrev, short
 import localrepo, bundlerepo, httprepo, sshrepo, statichttprepo
 import lock, util, extensions, error, encoding, node
 import cmdutil, discovery, url
 import merge as mergemod
 import verify as verifymod
 import errno, os, shutil
 
 def _local(path):
     path = util.expandpath(util.drop_scheme('file', path))
     return (os.path.isfile(path) and bundlerepo or localrepo)
 
 def addbranchrevs(lrepo, repo, branches, revs):
     hashbranch, branches = branches
     if not hashbranch and not branches:
         return revs or None, revs and revs[0] or None
     revs = revs and list(revs) or []
     if not repo.capable('branchmap'):
         if branches:
             raise util.Abort(_("remote branch lookup not supported"))
         revs.append(hashbranch)
         return revs, revs[0]
     branchmap = repo.branchmap()
 
     def primary(branch):
         if branch == '.':
             if not lrepo or not lrepo.local():
                 raise util.Abort(_("dirstate branch not accessible"))
             branch = lrepo.dirstate.branch()
         if branch in branchmap:
             revs.extend(node.hex(r) for r in reversed(branchmap[branch]))
             return True
         else:
             return False
 
     for branch in branches:
         if not primary(branch):
             raise error.RepoLookupError(_("unknown branch '%s'") % branch)
     if hashbranch:
         if not primary(hashbranch):
             revs.append(hashbranch)
     return revs, revs[0]
 
 def parseurl(url, branches=None):
     '''parse url#branch, returning (url, (branch, branches))'''
 
     if '#' not in url:
         return url, (None, branches or [])
     url, branch = url.split('#', 1)
     return url, (branch, branches or [])
 
 schemes = {
     'bundle': bundlerepo,
     'file': _local,
     'http': httprepo,
     'https': httprepo,
     'ssh': sshrepo,
     'static-http': statichttprepo,
 }
 
 def _lookup(path):
     scheme = 'file'
     if path:
         c = path.find(':')
         if c > 0:
             scheme = path[:c]
     thing = schemes.get(scheme) or schemes['file']
     try:
         return thing(path)
     except TypeError:
         return thing
 
 def islocal(repo):
     '''return true if repo or path is local'''
     if isinstance(repo, str):
         try:
             return _lookup(repo).islocal(repo)
         except AttributeError:
             return False
     return repo.local()
 
 def repository(ui, path='', create=False):
     """return a repository object for the specified path"""
     repo = _lookup(path).instance(ui, path, create)
     ui = getattr(repo, "ui", ui)
     for name, module in extensions.extensions():
         hook = getattr(module, 'reposetup', None)
         if hook:
             hook(ui, repo)
     return repo
 
 def defaultdest(source):
     '''return default destination of clone if none is given'''
     return os.path.basename(os.path.normpath(source))
 
 def localpath(path):
     if path.startswith('file://localhost/'):
         return path[16:]
     if path.startswith('file://'):
         return path[7:]
     if path.startswith('file:'):
         return path[5:]
     return path
 
 def share(ui, source, dest=None, update=True):
     '''create a shared repository'''
 
     if not islocal(source):
         raise util.Abort(_('can only share local repositories'))
 
     if not dest:
         dest = defaultdest(source)
     else:
         dest = ui.expandpath(dest)
 
     if isinstance(source, str):
         origsource = ui.expandpath(source)
         source, branches = parseurl(origsource)
         srcrepo = repository(ui, source)
         rev, checkout = addbranchrevs(srcrepo, srcrepo, branches, None)
     else:
         srcrepo = source
         origsource = source = srcrepo.url()
         checkout = None
 
     sharedpath = srcrepo.sharedpath # if our source is already sharing
 
     root = os.path.realpath(dest)
     roothg = os.path.join(root, '.hg')
 
     if os.path.exists(roothg):
         raise util.Abort(_('destination already exists'))
 
     if not os.path.isdir(root):
         os.mkdir(root)
     os.mkdir(roothg)
 
     requirements = ''
     try:
         requirements = srcrepo.opener('requires').read()
     except IOError, inst:
         if inst.errno != errno.ENOENT:
             raise
 
     requirements += 'shared\n'
     file(os.path.join(roothg, 'requires'), 'w').write(requirements)
     file(os.path.join(roothg, 'sharedpath'), 'w').write(sharedpath)
 
     default = srcrepo.ui.config('paths', 'default')
     if default:
         f = file(os.path.join(roothg, 'hgrc'), 'w')
         f.write('[paths]\ndefault = %s\n' % default)
         f.close()
 
     r = repository(ui, root)
 
     if update:
         r.ui.status(_("updating working directory\n"))
         if update is not True:
             checkout = update
         for test in (checkout, 'default', 'tip'):
             if test is None:
                 continue
             try:
                 uprev = r.lookup(test)
                 break
             except error.RepoLookupError:
                 continue
         _update(r, uprev)
 
 def clone(ui, source, dest=None, pull=False, rev=None, update=True,
           stream=False, branch=None):
     """Make a copy of an existing repository.
 
     Create a copy of an existing repository in a new directory.  The
     source and destination are URLs, as passed to the repository
     function.  Returns a pair of repository objects, the source and
     newly created destination.
 
     The location of the source is added to the new repository's
     .hg/hgrc file, as the default to be used for future pulls and
     pushes.
 
     If an exception is raised, the partly cloned/updated destination
     repository will be deleted.
 
     Arguments:
 
     source: repository object or URL
 
     dest: URL of destination repository to create (defaults to base
     name of source repository)
 
     pull: always pull from source repository, even in local case
 
     stream: stream raw data uncompressed from repository (fast over
     LAN, slow over WAN)
 
     rev: revision to clone up to (implies pull=True)
 
     update: update working directory after clone completes, if
     destination is local repository (True means update to default rev,
     anything else is treated as a revision)
 
     branch: branches to clone
     """
 
     if isinstance(source, str):
         origsource = ui.expandpath(source)
         source, branch = parseurl(origsource, branch)
         src_repo = repository(ui, source)
     else:
         src_repo = source
         branch = (None, branch or [])
         origsource = source = src_repo.url()
     rev, checkout = addbranchrevs(src_repo, src_repo, branch, rev)
 
     if dest is None:
         dest = defaultdest(source)
         ui.status(_("destination directory: %s\n") % dest)
     else:
         dest = ui.expandpath(dest)
 
     dest = localpath(dest)
     source = localpath(source)
 
     if os.path.exists(dest):
         if not os.path.isdir(dest):
             raise util.Abort(_("destination '%s' already exists") % dest)
         elif os.listdir(dest):
             raise util.Abort(_("destination '%s' is not empty") % dest)
 
     class DirCleanup(object):
         def __init__(self, dir_):
             self.rmtree = shutil.rmtree
             self.dir_ = dir_
         def close(self):
             self.dir_ = None
         def cleanup(self):
             if self.dir_:
                 self.rmtree(self.dir_, True)
 
     src_lock = dest_lock = dir_cleanup = None
     try:
         if islocal(dest):
             dir_cleanup = DirCleanup(dest)
 
         abspath = origsource
         copy = False
         if src_repo.cancopy() and islocal(dest):
             abspath = os.path.abspath(util.drop_scheme('file', origsource))
             copy = not pull and not rev
 
         if copy:
             try:
                 # we use a lock here because if we race with commit, we
                 # can end up with extra data in the cloned revlogs that's
                 # not pointed to by changesets, thus causing verify to
                 # fail
                 src_lock = src_repo.lock(wait=False)
             except error.LockError:
                 copy = False
 
         if copy:
             src_repo.hook('preoutgoing', throw=True, source='clone')
             hgdir = os.path.realpath(os.path.join(dest, ".hg"))
             if not os.path.exists(dest):
                 os.mkdir(dest)
             else:
                 # only clean up directories we create ourselves
                 dir_cleanup.dir_ = hgdir
             try:
                 dest_path = hgdir
                 os.mkdir(dest_path)
             except OSError, inst:
                 if inst.errno == errno.EEXIST:
                     dir_cleanup.close()
                     raise util.Abort(_("destination '%s' already exists")
                                      % dest)
                 raise
 
             hardlink = None
             num = 0
             for f in src_repo.store.copylist():
                 src = os.path.join(src_repo.sharedpath, f)
                 dst = os.path.join(dest_path, f)
                 dstbase = os.path.dirname(dst)
                 if dstbase and not os.path.exists(dstbase):
                     os.mkdir(dstbase)
                 if os.path.exists(src):
                     if dst.endswith('data'):
                         # lock to avoid premature writing to the target
                         dest_lock = lock.lock(os.path.join(dstbase, "lock"))
                     hardlink, n = util.copyfiles(src, dst, hardlink)
                     num += n
             if hardlink:
                 ui.debug("linked %d files\n" % num)
             else:
                 ui.debug("copied %d files\n" % num)
 
             # we need to re-init the repo after manually copying the data
             # into it
             dest_repo = repository(ui, dest)
             src_repo.hook('outgoing', source='clone',
                           node=node.hex(node.nullid))
         else:
             try:
                 dest_repo = repository(ui, dest, create=True)
             except OSError, inst:
                 if inst.errno == errno.EEXIST:
                     dir_cleanup.close()
                     raise util.Abort(_("destination '%s' already exists")
                                      % dest)
                 raise
 
             revs = None
             if rev:
                 if 'lookup' not in src_repo.capabilities:
                     raise util.Abort(_("src repository does not support "
                                        "revision lookup and so doesn't "
                                        "support clone by revision"))
                 revs = [src_repo.lookup(r) for r in rev]
                 checkout = revs[0]
             if dest_repo.local():
                 dest_repo.clone(src_repo, heads=revs, stream=stream)
             elif src_repo.local():
                 src_repo.push(dest_repo, revs=revs)
             else:
                 raise util.Abort(_("clone from remote to remote not supported"))
 
         if dir_cleanup:
             dir_cleanup.close()
 
         if dest_repo.local():
             fp = dest_repo.opener("hgrc", "w", text=True)
             fp.write("[paths]\n")
             fp.write("default = %s\n" % abspath)
             fp.close()
 
             dest_repo.ui.setconfig('paths', 'default', abspath)
 
             if update:
                 if update is not True:
                     checkout = update
                     if src_repo.local():
                         checkout = src_repo.lookup(update)
                 for test in (checkout, 'default', 'tip'):
                     if test is None:
                         continue
                     try:
                         uprev = dest_repo.lookup(test)
                         break
                     except error.RepoLookupError:
                         continue
                 bn = dest_repo[uprev].branch()
                 dest_repo.ui.status(_("updating to branch %s\n") % bn)
                 _update(dest_repo, uprev)
 
         return src_repo, dest_repo
     finally:
         release(src_lock, dest_lock)
         if dir_cleanup is not None:
             dir_cleanup.cleanup()
 
 def _showstats(repo, stats):
     repo.ui.status(_("%d files updated, %d files merged, "
                      "%d files removed, %d files unresolved\n") % stats)
 
 def update(repo, node):
     """update the working directory to node, merging linear changes"""
     stats = mergemod.update(repo, node, False, False, None)
     _showstats(repo, stats)
     if stats[3]:
         repo.ui.status(_("use 'hg resolve' to retry unresolved file merges\n"))
     return stats[3] > 0
 
 # naming conflict in clone()
 _update = update
 
 def clean(repo, node, show_stats=True):
     """forcibly switch the working directory to node, clobbering changes"""
     stats = mergemod.update(repo, node, False, True, None)
     if show_stats:
         _showstats(repo, stats)
     return stats[3] > 0
 
 def merge(repo, node, force=None, remind=True):
-    """branch merge with node, resolving changes"""
+    """Branch merge with node, resolving changes. Return true if any
+    unresolved conflicts."""
     stats = mergemod.update(repo, node, True, force, False)
     _showstats(repo, stats)
     if stats[3]:
         repo.ui.status(_("use 'hg resolve' to retry unresolved file merges "
                          "or 'hg update -C .' to abandon\n"))
     elif remind:
         repo.ui.status(_("(branch merge, don't forget to commit)\n"))
     return stats[3] > 0
 
 def _incoming(displaychlist, subreporecurse, ui, repo, source,
         opts, buffered=False):
     """
     Helper for incoming / gincoming.
     displaychlist gets called with
         (remoterepo, incomingchangesetlist, displayer) parameters,
     and is supposed to contain only code that can't be unified.
     """
     source, branches = parseurl(ui.expandpath(source), opts.get('branch'))
     other = repository(remoteui(repo, opts), source)
     ui.status(_('comparing with %s\n') % url.hidepassword(source))
     revs, checkout = addbranchrevs(repo, other, branches, opts.get('rev'))
 
     if revs:
         revs = [other.lookup(rev) for rev in revs]
     other, incoming, bundle = bundlerepo.getremotechanges(ui, repo, other, revs,
                                 opts["bundle"], opts["force"])
     if incoming is None:
         ui.status(_("no changes found\n"))
         return subreporecurse()
 
     try:
         chlist = other.changelog.nodesbetween(incoming, revs)[0]
         displayer = cmdutil.show_changeset(ui, other, opts, buffered)
 
         # XXX once graphlog extension makes it into core,
         # should be replaced by a if graph/else
         displaychlist(other, chlist, displayer)
 
         displayer.close()
     finally:
         if hasattr(other, 'close'):
             other.close()
         if bundle:
             os.unlink(bundle)
     subreporecurse()
     return 0 # exit code is zero since we found incoming changes
 
 def incoming(ui, repo, source, opts):
     def subreporecurse():
         ret = 1
         if opts.get('subrepos'):
             ctx = repo[None]
             for subpath in sorted(ctx.substate):
                 sub = ctx.sub(subpath)
                 ret = min(ret, sub.incoming(ui, source, opts))
         return ret
 
     def display(other, chlist, displayer):
         limit = cmdutil.loglimit(opts)
         if opts.get('newest_first'):
             chlist.reverse()
         count = 0
         for n in chlist:
             if limit is not None and count >= limit:
                 break
             parents = [p for p in other.changelog.parents(n) if p != nullid]
             if opts.get('no_merges') and len(parents) == 2:
                 continue
             count += 1
             displayer.show(other[n])
     return _incoming(display, subreporecurse, ui, repo, source, opts)
 
 def _outgoing(ui, repo, dest, opts):
     dest = ui.expandpath(dest or 'default-push', dest or 'default')
     dest, branches = parseurl(dest, opts.get('branch'))
     revs, checkout = addbranchrevs(repo, repo, branches, opts.get('rev'))
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
 
     other = repository(remoteui(repo, opts), dest)
     ui.status(_('comparing with %s\n') % url.hidepassword(dest))
     o = discovery.findoutgoing(repo, other, force=opts.get('force'))
     if not o:
         ui.status(_("no changes found\n"))
         return None
 
     return repo.changelog.nodesbetween(o, revs)[0]
 
 def outgoing(ui, repo, dest, opts):
     def recurse():
         ret = 1
         if opts.get('subrepos'):
             ctx = repo[None]
             for subpath in sorted(ctx.substate):
                 sub = ctx.sub(subpath)
                 ret = min(ret, sub.outgoing(ui, dest, opts))
         return ret
 
     limit = cmdutil.loglimit(opts)
     o = _outgoing(ui, repo, dest, opts)
     if o is None:
         return recurse()
 
     if opts.get('newest_first'):
         o.reverse()
     displayer = cmdutil.show_changeset(ui, repo, opts)
     count = 0
     for n in o:
         if limit is not None and count >= limit:
             break
         parents = [p for p in repo.changelog.parents(n) if p != nullid]
         if opts.get('no_merges') and len(parents) == 2:
             continue
         count += 1
         displayer.show(repo[n])
     displayer.close()
     recurse()
     return 0 # exit code is zero since we found outgoing changes
 
 def revert(repo, node, choose):
     """revert changes to revision in node without updating dirstate"""
     return mergemod.update(repo, node, False, True, choose)[3] > 0
 
 def verify(repo):
     """verify the consistency of a repository"""
     return verifymod.verify(repo)
 
 def remoteui(src, opts):
     'build a remote ui from ui or repo and opts'
     if hasattr(src, 'baseui'): # looks like a repository
         dst = src.baseui.copy() # drop repo-specific config
         src = src.ui # copy target options from repo
     else: # assume it's a global ui object
         dst = src.copy() # keep all global options
 
     # copy ssh-specific options
     for o in 'ssh', 'remotecmd':
         v = opts.get(o) or src.config('ui', o)
         if v:
             dst.setconfig("ui", o, v)
 
     # copy bundle-specific options
     r = src.config('bundle', 'mainreporoot')
     if r:
         dst.setconfig('bundle', 'mainreporoot', r)
 
     # copy auth and http_proxy section settings
     for sect in ('auth', 'http_proxy'):
         for key, val in src.configitems(sect):
             dst.setconfig(sect, key, val)
 
     return dst

mercurial/merge.py

@@ -1,544 +1,549 b''
 # merge.py - directory-level update/merge handling for Mercurial
 #
 # Copyright 2006, 2007 Matt Mackall <[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.
 
 from node import nullid, nullrev, hex, bin
 from i18n import _
 import util, filemerge, copies, subrepo
 import errno, os, shutil
 
 class mergestate(object):
     '''track 3-way merge state of individual files'''
     def __init__(self, repo):
         self._repo = repo
         self._dirty = False
         self._read()
     def reset(self, node=None):
         self._state = {}
         if node:
             self._local = node
         shutil.rmtree(self._repo.join("merge"), True)
         self._dirty = False
     def _read(self):
         self._state = {}
         try:
             f = self._repo.opener("merge/state")
             for i, l in enumerate(f):
                 if i == 0:
                     self._local = bin(l[:-1])
                 else:
                     bits = l[:-1].split("\0")
                     self._state[bits[0]] = bits[1:]
         except IOError, err:
             if err.errno != errno.ENOENT:
                 raise
         self._dirty = False
     def commit(self):
         if self._dirty:
             f = self._repo.opener("merge/state", "w")
             f.write(hex(self._local) + "\n")
             for d, v in self._state.iteritems():
                 f.write("\0".join([d] + v) + "\n")
             self._dirty = False
     def add(self, fcl, fco, fca, fd, flags):
         hash = util.sha1(fcl.path()).hexdigest()
         self._repo.opener("merge/" + hash, "w").write(fcl.data())
         self._state[fd] = ['u', hash, fcl.path(), fca.path(),
                            hex(fca.filenode()), fco.path(), flags]
         self._dirty = True
     def __contains__(self, dfile):
         return dfile in self._state
     def __getitem__(self, dfile):
         return self._state[dfile][0]
     def __iter__(self):
         l = self._state.keys()
         l.sort()
         for f in l:
             yield f
     def mark(self, dfile, state):
         self._state[dfile][0] = state
         self._dirty = True
     def resolve(self, dfile, wctx, octx):
         if self[dfile] == 'r':
             return 0
         state, hash, lfile, afile, anode, ofile, flags = self._state[dfile]
         f = self._repo.opener("merge/" + hash)
         self._repo.wwrite(dfile, f.read(), flags)
         fcd = wctx[dfile]
         fco = octx[ofile]
         fca = self._repo.filectx(afile, fileid=anode)
         r = filemerge.filemerge(self._repo, self._local, lfile, fcd, fco, fca)
         if not r:
             self.mark(dfile, 'r')
         return r
 
 def _checkunknown(wctx, mctx):
     "check for collisions between unknown files and files in mctx"
     for f in wctx.unknown():
         if f in mctx and mctx[f].cmp(wctx[f]):
             raise util.Abort(_("untracked file in working directory differs"
                                " from file in requested revision: '%s'") % f)
 
 def _checkcollision(mctx):
     "check for case folding collisions in the destination context"
     folded = {}
     for fn in mctx:
         fold = fn.lower()
         if fold in folded:
             raise util.Abort(_("case-folding collision between %s and %s")
                              % (fn, folded[fold]))
         folded[fold] = fn
 
 def _forgetremoved(wctx, mctx, branchmerge):
     """
     Forget removed files
 
     If we're jumping between revisions (as opposed to merging), and if
     neither the working directory nor the target rev has the file,
     then we need to remove it from the dirstate, to prevent the
     dirstate from listing the file when it is no longer in the
     manifest.
 
     If we're merging, and the other revision has removed a file
     that is not present in the working directory, we need to mark it
     as removed.
     """
 
     action = []
     state = branchmerge and 'r' or 'f'
     for f in wctx.deleted():
         if f not in mctx:
             action.append((f, state))
 
     if not branchmerge:
         for f in wctx.removed():
             if f not in mctx:
                 action.append((f, "f"))
 
     return action
 
 def manifestmerge(repo, p1, p2, pa, overwrite, partial):
     """
     Merge p1 and p2 with ancestor pa and generate merge action list
 
     overwrite = whether we clobber working files
     partial = function to filter file lists
     """
 
     def fmerge(f, f2, fa):
         """merge flags"""
         a, m, n = ma.flags(fa), m1.flags(f), m2.flags(f2)
         if m == n: # flags agree
             return m # unchanged
         if m and n and not a: # flags set, don't agree, differ from parent
             r = repo.ui.promptchoice(
                 _(" conflicting flags for %s\n"
                   "(n)one, e(x)ec or sym(l)ink?") % f,
                 (_("&None"), _("E&xec"), _("Sym&link")), 0)
             if r == 1:
                 return "x" # Exec
             if r == 2:
                 return "l" # Symlink
             return ""
         if m and m != a: # changed from a to m
             return m
         if n and n != a: # changed from a to n
             return n
         return '' # flag was cleared
 
     def act(msg, m, f, *args):
         repo.ui.debug(" %s: %s -> %s\n" % (f, msg, m))
         action.append((f, m) + args)
 
     action, copy = [], {}
 
     if overwrite:
         pa = p1
     elif pa == p2: # backwards
         pa = p1.p1()
     elif pa and repo.ui.configbool("merge", "followcopies", True):
         dirs = repo.ui.configbool("merge", "followdirs", True)
         copy, diverge = copies.copies(repo, p1, p2, pa, dirs)
         for of, fl in diverge.iteritems():
             act("divergent renames", "dr", of, fl)
 
     repo.ui.note(_("resolving manifests\n"))
     repo.ui.debug(" overwrite %s partial %s\n" % (overwrite, bool(partial)))
     repo.ui.debug(" ancestor %s local %s remote %s\n" % (pa, p1, p2))
 
     m1, m2, ma = p1.manifest(), p2.manifest(), pa.manifest()
     copied = set(copy.values())
 
     if '.hgsubstate' in m1:
         # check whether sub state is modified
         for s in p1.substate:
             if p1.sub(s).dirty():
                 m1['.hgsubstate'] += "+"
                 break
 
     # Compare manifests
     for f, n in m1.iteritems():
         if partial and not partial(f):
             continue
         if f in m2:
             rflags = fmerge(f, f, f)
             a = ma.get(f, nullid)
             if n == m2[f] or m2[f] == a: # same or local newer
                 # is file locally modified or flags need changing?
                 # dirstate flags may need to be made current
                 if m1.flags(f) != rflags or n[20:]:
                     act("update permissions", "e", f, rflags)
             elif n == a: # remote newer
                 act("remote is newer", "g", f, rflags)
             else: # both changed
                 act("versions differ", "m", f, f, f, rflags, False)
         elif f in copied: # files we'll deal with on m2 side
             pass
         elif f in copy:
             f2 = copy[f]
             if f2 not in m2: # directory rename
                 act("remote renamed directory to " + f2, "d",
                     f, None, f2, m1.flags(f))
             else: # case 2 A,B/B/B or case 4,21 A/B/B
                 act("local copied/moved to " + f2, "m",
                     f, f2, f, fmerge(f, f2, f2), False)
         elif f in ma: # clean, a different, no remote
             if n != ma[f]:
                 if repo.ui.promptchoice(
                     _(" local changed %s which remote deleted\n"
                       "use (c)hanged version or (d)elete?") % f,
                     (_("&Changed"), _("&Delete")), 0):
                     act("prompt delete", "r", f)
                 else:
                     act("prompt keep", "a", f)
             elif n[20:] == "a": # added, no remote
                 act("remote deleted", "f", f)
             elif n[20:] != "u":
                 act("other deleted", "r", f)
 
     for f, n in m2.iteritems():
         if partial and not partial(f):
             continue
         if f in m1 or f in copied: # files already visited
             continue
         if f in copy:
             f2 = copy[f]
             if f2 not in m1: # directory rename
                 act("local renamed directory to " + f2, "d",
                     None, f, f2, m2.flags(f))
             elif f2 in m2: # rename case 1, A/A,B/A
                 act("remote copied to " + f, "m",
                     f2, f, f, fmerge(f2, f, f2), False)
             else: # case 3,20 A/B/A
                 act("remote moved to " + f, "m",
                     f2, f, f, fmerge(f2, f, f2), True)
         elif f not in ma:
             act("remote created", "g", f, m2.flags(f))
         elif n != ma[f]:
             if repo.ui.promptchoice(
                 _("remote changed %s which local deleted\n"
                   "use (c)hanged version or leave (d)eleted?") % f,
                 (_("&Changed"), _("&Deleted")), 0) == 0:
                 act("prompt recreating", "g", f, m2.flags(f))
 
     return action
 
 def actionkey(a):
     return a[1] == 'r' and -1 or 0, a
 
 def applyupdates(repo, action, wctx, mctx, actx):
     """apply the merge action list to the working directory
 
     wctx is the working copy context
     mctx is the context to be merged into the working copy
     actx is the context of the common ancestor
+
+    Return a tuple of counts (updated, merged, removed, unresolved) that
+    describes how many files were affected by the update.
     """
 
     updated, merged, removed, unresolved = 0, 0, 0, 0
     ms = mergestate(repo)
     ms.reset(wctx.parents()[0].node())
     moves = []
     action.sort(key=actionkey)
     substate = wctx.substate # prime
 
     # prescan for merges
     u = repo.ui
     for a in action:
         f, m = a[:2]
         if m == 'm': # merge
             f2, fd, flags, move = a[2:]
             if f == '.hgsubstate': # merged internally
                 continue
             repo.ui.debug("preserving %s for resolve of %s\n" % (f, fd))
             fcl = wctx[f]
             fco = mctx[f2]
             if mctx == actx: # backwards, use working dir parent as ancestor
                 if fcl.parents():
                     fca = fcl.parents()[0]
                 else:
                     fca = repo.filectx(f, fileid=nullrev)
             else:
                 fca = fcl.ancestor(fco, actx)
             if not fca:
                 fca = repo.filectx(f, fileid=nullrev)
             ms.add(fcl, fco, fca, fd, flags)
             if f != fd and move:
                 moves.append(f)
 
     # remove renamed files after safely stored
     for f in moves:
         if os.path.lexists(repo.wjoin(f)):
             repo.ui.debug("removing %s\n" % f)
             os.unlink(repo.wjoin(f))
 
     audit_path = util.path_auditor(repo.root)
 
     numupdates = len(action)
     for i, a in enumerate(action):
         f, m = a[:2]
         u.progress(_('updating'), i + 1, item=f, total=numupdates,
                    unit=_('files'))
         if f and f[0] == "/":
             continue
         if m == "r": # remove
             repo.ui.note(_("removing %s\n") % f)
             audit_path(f)
             if f == '.hgsubstate': # subrepo states need updating
                 subrepo.submerge(repo, wctx, mctx, wctx)
             try:
                 util.unlink(repo.wjoin(f))
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     repo.ui.warn(_("update failed to remove %s: %s!\n") %
                                  (f, inst.strerror))
             removed += 1
         elif m == "m": # merge
             if f == '.hgsubstate': # subrepo states need updating
                 subrepo.submerge(repo, wctx, mctx, wctx.ancestor(mctx))
                 continue
             f2, fd, flags, move = a[2:]
             r = ms.resolve(fd, wctx, mctx)
             if r is not None and r > 0:
                 unresolved += 1
             else:
                 if r is None:
                     updated += 1
                 else:
                     merged += 1
             util.set_flags(repo.wjoin(fd), 'l' in flags, 'x' in flags)
             if f != fd and move and os.path.lexists(repo.wjoin(f)):
                 repo.ui.debug("removing %s\n" % f)
                 os.unlink(repo.wjoin(f))
         elif m == "g": # get
             flags = a[2]
             repo.ui.note(_("getting %s\n") % f)
             t = mctx.filectx(f).data()
             repo.wwrite(f, t, flags)
             t = None
             updated += 1
             if f == '.hgsubstate': # subrepo states need updating
                 subrepo.submerge(repo, wctx, mctx, wctx)
         elif m == "d": # directory rename
             f2, fd, flags = a[2:]
             if f:
                 repo.ui.note(_("moving %s to %s\n") % (f, fd))
                 t = wctx.filectx(f).data()
                 repo.wwrite(fd, t, flags)
                 util.unlink(repo.wjoin(f))
             if f2:
                 repo.ui.note(_("getting %s to %s\n") % (f2, fd))
                 t = mctx.filectx(f2).data()
                 repo.wwrite(fd, t, flags)
             updated += 1
         elif m == "dr": # divergent renames
             fl = a[2]
             repo.ui.warn(_("note: possible conflict - %s was renamed "
                            "multiple times to:\n") % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
         elif m == "e": # exec
             flags = a[2]
             util.set_flags(repo.wjoin(f), 'l' in flags, 'x' in flags)
     ms.commit()
     u.progress(_('updating'), None, total=numupdates, unit=_('files'))
 
     return updated, merged, removed, unresolved
 
 def recordupdates(repo, action, branchmerge):
     "record merge actions to the dirstate"
 
     for a in action:
         f, m = a[:2]
         if m == "r": # remove
             if branchmerge:
                 repo.dirstate.remove(f)
             else:
                 repo.dirstate.forget(f)
         elif m == "a": # re-add
             if not branchmerge:
                 repo.dirstate.add(f)
         elif m == "f": # forget
             repo.dirstate.forget(f)
         elif m == "e": # exec change
             repo.dirstate.normallookup(f)
         elif m == "g": # get
             if branchmerge:
                 repo.dirstate.otherparent(f)
             else:
                 repo.dirstate.normal(f)
         elif m == "m": # merge
             f2, fd, flag, move = a[2:]
             if branchmerge:
                 # We've done a branch merge, mark this file as merged
                 # so that we properly record the merger later
                 repo.dirstate.merge(fd)
                 if f != f2: # copy/rename
                     if move:
                         repo.dirstate.remove(f)
                     if f != fd:
                         repo.dirstate.copy(f, fd)
                     else:
                         repo.dirstate.copy(f2, fd)
             else:
                 # We've update-merged a locally modified file, so
                 # we set the dirstate to emulate a normal checkout
                 # of that file some time in the past. Thus our
                 # merge will appear as a normal local file
                 # modification.
                 if f2 == fd: # file not locally copied/moved
                     repo.dirstate.normallookup(fd)
                 if move:
                     repo.dirstate.forget(f)
         elif m == "d": # directory rename
             f2, fd, flag = a[2:]
             if not f2 and f not in repo.dirstate:
                 # untracked file moved
                 continue
             if branchmerge:
                 repo.dirstate.add(fd)
                 if f:
                     repo.dirstate.remove(f)
                     repo.dirstate.copy(f, fd)
                 if f2:
                     repo.dirstate.copy(f2, fd)
             else:
                 repo.dirstate.normal(fd)
                 if f:
                     repo.dirstate.forget(f)
 
 def update(repo, node, branchmerge, force, partial):
     """
     Perform a merge between the working directory and the given node
 
     node = the node to update to, or None if unspecified
     branchmerge = whether to merge between branches
     force = whether to force branch merging or file overwriting
     partial = a function to filter file lists (dirstate not updated)
 
     The table below shows all the behaviors of the update command
     given the -c and -C or no options, whether the working directory
     is dirty, whether a revision is specified, and the relationship of
     the parent rev to the target rev (linear, on the same named
     branch, or on another named branch).
 
     This logic is tested by test-update-branches.t.
 
     -c  -C  dirty  rev  |  linear   same  cross
      n   n    n     n   |    ok     (1)     x
      n   n    n     y   |    ok     ok     ok
      n   n    y     *   |   merge   (2)    (2)
      n   y    *     *   |    ---  discard  ---
      y   n    y     *   |    ---    (3)    ---
      y   n    n     *   |    ---    ok     ---
      y   y    *     *   |    ---    (4)    ---
 
     x = can't happen
     * = don't-care
     1 = abort: crosses branches (use 'hg merge' or 'hg update -c')
     2 = abort: crosses branches (use 'hg merge' to merge or
                  use 'hg update -C' to discard changes)
     3 = abort: uncommitted local changes
     4 = incompatible options (checked in commands.py)
+
+    Return the same tuple as applyupdates().
     """
 
     onode = node
     wlock = repo.wlock()
     try:
         wc = repo[None]
         if node is None:
             # tip of current branch
             try:
                 node = repo.branchtags()[wc.branch()]
             except KeyError:
                 if wc.branch() == "default": # no default branch!
                     node = repo.lookup("tip") # update to tip
                 else:
                     raise util.Abort(_("branch %s not found") % wc.branch())
         overwrite = force and not branchmerge
         pl = wc.parents()
         p1, p2 = pl[0], repo[node]
         pa = p1.ancestor(p2)
         fp1, fp2, xp1, xp2 = p1.node(), p2.node(), str(p1), str(p2)
         fastforward = False
 
         ### check phase
         if not overwrite and len(pl) > 1:
             raise util.Abort(_("outstanding uncommitted merges"))
         if branchmerge:
             if pa == p2:
                 raise util.Abort(_("merging with a working directory ancestor"
                                    " has no effect"))
             elif pa == p1:
                 if p1.branch() != p2.branch():
                     fastforward = True
                 else:
                     raise util.Abort(_("nothing to merge (use 'hg update'"
                                        " or check 'hg heads')"))
             if not force and (wc.files() or wc.deleted()):
                 raise util.Abort(_("outstanding uncommitted changes "
                                    "(use 'hg status' to list changes)"))
         elif not overwrite:
             if pa == p1 or pa == p2: # linear
                 pass # all good
             elif wc.files() or wc.deleted():
                 raise util.Abort(_("crosses branches (merge branches or use"
                                    " --clean to discard changes)"))
             elif onode is None:
                 raise util.Abort(_("crosses branches (merge branches or use"
                                    " --check to force update)"))
             else:
                 # Allow jumping branches if clean and specific rev given
                 overwrite = True
 
         ### calculate phase
         action = []
         wc.status(unknown=True) # prime cache
         if not force:
             _checkunknown(wc, p2)
         if not util.checkcase(repo.path):
             _checkcollision(p2)
         action += _forgetremoved(wc, p2, branchmerge)
         action += manifestmerge(repo, wc, p2, pa, overwrite, partial)
 
         ### apply phase
         if not branchmerge or fastforward: # just jump to the new rev
             fp1, fp2, xp1, xp2 = fp2, nullid, xp2, ''
         if not partial:
             repo.hook('preupdate', throw=True, parent1=xp1, parent2=xp2)
 
         stats = applyupdates(repo, action, wc, p2, pa)
 
         if not partial:
             repo.dirstate.setparents(fp1, fp2)
             recordupdates(repo, action, branchmerge and not fastforward)
             if not branchmerge and not fastforward:
                 repo.dirstate.setbranch(p2.branch())
     finally:
         wlock.release()
 
     if not partial:
         repo.hook('update', parent1=xp1, parent2=xp2, error=stats[3])
     return stats