bookmarks: primarily use repo lock, not wlock

Bookmarks are repository data, not working directory data. Only the current
bookmark is working directory data.

Some lock shuffling is required to avoid lockout between the initial mock lock
and locking of the localrepo instance that is created after copying.

mercurial/bookmarks.py

@@ -1,229 +1,229 b''
 # Mercurial bookmark support code
 #
 # Copyright 2008 David Soria Parra <[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 mercurial.i18n import _
 from mercurial.node import hex
 from mercurial import encoding, error, util
 import errno, os
 
 def valid(mark):
     for c in (':', '\0', '\n', '\r'):
         if c in mark:
             return False
     return True
 
 def read(repo):
     '''Parse .hg/bookmarks file and return a dictionary
 
     Bookmarks are stored as {HASH}\\s{NAME}\\n (localtags format) values
     in the .hg/bookmarks file.
     Read the file and return a (name=>nodeid) dictionary
     '''
     bookmarks = {}
     try:
         for line in repo.opener('bookmarks'):
             line = line.strip()
             if not line:
                 continue
             if ' ' not in line:
                 repo.ui.warn(_('malformed line in .hg/bookmarks: %r\n') % line)
                 continue
             sha, refspec = line.split(' ', 1)
             refspec = encoding.tolocal(refspec)
             try:
                 bookmarks[refspec] = repo.changelog.lookup(sha)
             except error.RepoLookupError:
                 pass
     except IOError, inst:
         if inst.errno != errno.ENOENT:
             raise
     return bookmarks
 
 def readcurrent(repo):
     '''Get the current bookmark
 
     If we use gittishsh branches we have a current bookmark that
     we are on. This function returns the name of the bookmark. It
     is stored in .hg/bookmarks.current
     '''
     mark = None
     try:
         file = repo.opener('bookmarks.current')
     except IOError, inst:
         if inst.errno != errno.ENOENT:
             raise
         return None
     try:
         # No readline() in posixfile_nt, reading everything is cheap
         mark = encoding.tolocal((file.readlines() or [''])[0])
         if mark == '' or mark not in repo._bookmarks:
             mark = None
     finally:
         file.close()
     return mark
 
 def write(repo):
     '''Write bookmarks
 
     Write the given bookmark => hash dictionary to the .hg/bookmarks file
     in a format equal to those of localtags.
 
     We also store a backup of the previous state in undo.bookmarks that
     can be copied back on rollback.
     '''
     refs = repo._bookmarks
 
     if repo._bookmarkcurrent not in refs:
         setcurrent(repo, None)
     for mark in refs.keys():
         if not valid(mark):
             raise util.Abort(_("bookmark '%s' contains illegal "
                 "character" % mark))
 
-    wlock = repo.wlock()
+    lock = repo.lock()
     try:
 
         file = repo.opener('bookmarks', 'w', atomictemp=True)
         for refspec, node in refs.iteritems():
             file.write("%s %s\n" % (hex(node), encoding.fromlocal(refspec)))
         file.close()
 
         # touch 00changelog.i so hgweb reloads bookmarks (no lock needed)
         try:
             os.utime(repo.sjoin('00changelog.i'), None)
         except OSError:
             pass
 
     finally:
-        wlock.release()
+        lock.release()
 
 def setcurrent(repo, mark):
     '''Set the name of the bookmark that we are currently on
 
     Set the name of the bookmark that we are on (hg update <bookmark>).
     The name is recorded in .hg/bookmarks.current
     '''
     current = repo._bookmarkcurrent
     if current == mark:
         return
 
     if mark not in repo._bookmarks:
         mark = ''
     if not valid(mark):
         raise util.Abort(_("bookmark '%s' contains illegal "
             "character" % mark))
 
-    wlock = repo.wlock()
+    lock = repo.lock()
     try:
         file = repo.opener('bookmarks.current', 'w', atomictemp=True)
         file.write(encoding.fromlocal(mark))
         file.close()
     finally:
-        wlock.release()
+        lock.release()
     repo._bookmarkcurrent = mark
 
 def updatecurrentbookmark(repo, oldnode, curbranch):
     try:
         return update(repo, oldnode, repo.branchtags()[curbranch])
     except KeyError:
         if curbranch == "default": # no default branch!
             return update(repo, oldnode, repo.lookup("tip"))
         else:
             raise util.Abort(_("branch %s not found") % curbranch)
 
 def update(repo, parents, node):
     marks = repo._bookmarks
     update = False
     mark = repo._bookmarkcurrent
     if mark and marks[mark] in parents:
         old = repo[marks[mark]]
         new = repo[node]
         if new in old.descendants():
             marks[mark] = new.node()
             update = True
     if update:
         repo._writebookmarks(marks)
     return update
 
 def listbookmarks(repo):
     # We may try to list bookmarks on a repo type that does not
     # support it (e.g., statichttprepository).
     marks = getattr(repo, '_bookmarks', {})
 
     d = {}
     for k, v in marks.iteritems():
         # don't expose local divergent bookmarks
         if '@' not in k and not k.endswith('@'):
             d[k] = hex(v)
     return d
 
 def pushbookmark(repo, key, old, new):
-    w = repo.wlock()
+    lock = repo.lock()
     try:
         marks = repo._bookmarks
         if hex(marks.get(key, '')) != old:
             return False
         if new == '':
             del marks[key]
         else:
             if new not in repo:
                 return False
             marks[key] = repo[new].node()
         write(repo)
         return True
     finally:
-        w.release()
+        lock.release()
 
 def updatefromremote(ui, repo, remote, path):
     ui.debug("checking for updated bookmarks\n")
     rb = remote.listkeys('bookmarks')
     changed = False
     for k in rb.keys():
         if k in repo._bookmarks:
             nr, nl = rb[k], repo._bookmarks[k]
             if nr in repo:
                 cr = repo[nr]
                 cl = repo[nl]
                 if cl.rev() >= cr.rev():
                     continue
                 if cr in cl.descendants():
                     repo._bookmarks[k] = cr.node()
                     changed = True
                     ui.status(_("updating bookmark %s\n") % k)
                 else:
                     # find a unique @ suffix
                     for x in range(1, 100):
                         n = '%s@%d' % (k, x)
                         if n not in repo._bookmarks:
                             break
                     # try to use an @pathalias suffix
                     # if an @pathalias already exists, we overwrite (update) it
                     for p, u in ui.configitems("paths"):
                         if path == u:
                             n = '%s@%s' % (k, p)
 
                     repo._bookmarks[n] = cr.node()
                     changed = True
                     ui.warn(_("divergent bookmark %s stored as %s\n") % (k, n))
 
     if changed:
         write(repo)
 
 def diff(ui, repo, remote):
     ui.status(_("searching for changed bookmarks\n"))
 
     lmarks = repo.listkeys('bookmarks')
     rmarks = remote.listkeys('bookmarks')
 
     diff = sorted(set(rmarks) - set(lmarks))
     for k in diff:
         ui.write("   %-25s %s\n" % (k, rmarks[k][:12]))
 
     if len(diff) <= 0:
         ui.status(_("no changed bookmarks found\n"))
         return 1
     return 0

mercurial/hg.py

@@ -1,584 +1,589 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
 import localrepo, bundlerepo, httprepo, sshrepo, statichttprepo, bookmarks
 import lock, util, extensions, error, node
 import cmdutil, discovery
 import merge as mergemod
 import verify as verifymod
 import errno, os, shutil
 
 def _local(path):
     path = util.expandpath(util.urllocalpath(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(path, branches=None):
     '''parse url#branch, returning (url, (branch, branches))'''
 
     u = util.url(path)
     branch = None
     if u.fragment:
         branch = u.fragment
         u.fragment = None
     return str(u), (branch, branches or [])
 
 schemes = {
     'bundle': bundlerepo,
     'file': _local,
     'http': httprepo,
     'https': httprepo,
     'ssh': sshrepo,
     'static-http': statichttprepo,
 }
 
 def _peerlookup(path):
     u = util.url(path)
     scheme = u.scheme or 'file'
     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 _peerlookup(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 = _peerlookup(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 peer(uiorrepo, opts, path, create=False):
     '''return a repository peer for the specified path'''
     rui = remoteui(uiorrepo, opts)
     return repository(rui, path, create)
 
 def defaultdest(source):
     '''return default destination of clone if none is given'''
     return os.path.basename(os.path.normpath(source))
 
 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)
     util.makedir(roothg, notindexed=True)
 
     requirements = ''
     try:
         requirements = srcrepo.opener.read('requires')
     except IOError, inst:
         if inst.errno != errno.ENOENT:
             raise
 
     requirements += 'shared\n'
     util.writefile(os.path.join(roothg, 'requires'), requirements)
     util.writefile(os.path.join(roothg, 'sharedpath'), sharedpath)
 
     r = repository(ui, root)
 
     default = srcrepo.ui.config('paths', 'default')
     if default:
         fp = r.opener("hgrc", "w", text=True)
         fp.write("[paths]\n")
         fp.write("default = %s\n" % default)
         fp.close()
 
     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 copystore(ui, srcrepo, destpath):
     '''copy files from store of srcrepo in destpath
 
     returns destlock
     '''
     destlock = None
     try:
         hardlink = None
         num = 0
         srcpublishing = srcrepo.ui.configbool('phases', 'publish', True)
         for f in srcrepo.store.copylist():
             if srcpublishing and f.endswith('phaseroots'):
                 continue
             src = os.path.join(srcrepo.sharedpath, f)
             dst = os.path.join(destpath, 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
                     destlock = 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)
         return destlock
     except:
         release(destlock)
         raise
 
 def clone(ui, peeropts, 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)
         srcrepo = repository(remoteui(ui, peeropts), source)
     else:
         srcrepo = source
         branch = (None, branch or [])
         origsource = source = srcrepo.url()
     rev, checkout = addbranchrevs(srcrepo, srcrepo, branch, rev)
 
     if dest is None:
         dest = defaultdest(source)
         ui.status(_("destination directory: %s\n") % dest)
     else:
         dest = ui.expandpath(dest)
 
     dest = util.urllocalpath(dest)
     source = util.urllocalpath(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)
 
-    srclock = destlock = dircleanup = None
+    srclock = destwlock = destlock = dircleanup = None
     try:
         abspath = origsource
         if islocal(origsource):
             abspath = os.path.abspath(util.urllocalpath(origsource))
 
         if islocal(dest):
             dircleanup = DirCleanup(dest)
 
         copy = False
         if srcrepo.cancopy() and islocal(dest):
             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
                 srclock = srcrepo.lock(wait=False)
             except error.LockError:
                 copy = False
 
         if copy:
             srcrepo.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
                 dircleanup.dir_ = hgdir
             try:
                 destpath = hgdir
                 util.makedir(destpath, notindexed=True)
             except OSError, inst:
                 if inst.errno == errno.EEXIST:
                     dircleanup.close()
                     raise util.Abort(_("destination '%s' already exists")
                                      % dest)
                 raise
 
             destlock = copystore(ui, srcrepo, destpath)
 
             # we need to re-init the repo after manually copying the data
             # into it
             destrepo = repository(remoteui(ui, peeropts), dest)
+            # we need full recursive locking of the new repo instance
+            destwlock = destrepo.wlock()
+            if destlock:
+                destlock.release() # a little race condition - but no deadlock
+            destlock = destrepo.lock()
             srcrepo.hook('outgoing', source='clone',
                           node=node.hex(node.nullid))
         else:
             try:
                 destrepo = repository(remoteui(ui, peeropts), dest,
                                       create=True)
             except OSError, inst:
                 if inst.errno == errno.EEXIST:
                     dircleanup.close()
                     raise util.Abort(_("destination '%s' already exists")
                                      % dest)
                 raise
 
             revs = None
             if rev:
                 if not srcrepo.capable('lookup'):
                     raise util.Abort(_("src repository does not support "
                                        "revision lookup and so doesn't "
                                        "support clone by revision"))
                 revs = [srcrepo.lookup(r) for r in rev]
                 checkout = revs[0]
             if destrepo.local():
                 destrepo.clone(srcrepo, heads=revs, stream=stream)
             elif srcrepo.local():
                 srcrepo.push(destrepo, revs=revs)
             else:
                 raise util.Abort(_("clone from remote to remote not supported"))
 
         if dircleanup:
             dircleanup.close()
 
         # clone all bookmarks
         if destrepo.local() and srcrepo.capable("pushkey"):
             rb = srcrepo.listkeys('bookmarks')
             for k, n in rb.iteritems():
                 try:
                     m = destrepo.lookup(n)
                     destrepo._bookmarks[k] = m
                 except error.RepoLookupError:
                     pass
             if rb:
                 bookmarks.write(destrepo)
         elif srcrepo.local() and destrepo.capable("pushkey"):
             for k, n in srcrepo._bookmarks.iteritems():
                 destrepo.pushkey('bookmarks', k, '', hex(n))
 
         if destrepo.local():
             fp = destrepo.opener("hgrc", "w", text=True)
             fp.write("[paths]\n")
             u = util.url(abspath)
             u.passwd = None
             defaulturl = str(u)
             fp.write("default = %s\n" % defaulturl)
             fp.close()
 
             destrepo.ui.setconfig('paths', 'default', defaulturl)
 
             if update:
                 if update is not True:
                     checkout = update
                     if srcrepo.local():
                         checkout = srcrepo.lookup(update)
                 for test in (checkout, 'default', 'tip'):
                     if test is None:
                         continue
                     try:
                         uprev = destrepo.lookup(test)
                         break
                     except error.RepoLookupError:
                         continue
                 bn = destrepo[uprev].branch()
                 destrepo.ui.status(_("updating to branch %s\n") % bn)
                 _update(destrepo, uprev)
 
         return srcrepo, destrepo
     finally:
-        release(srclock, destlock)
+        release(srclock, destlock, destwlock)
         if dircleanup is not None:
             dircleanup.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. 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 = peer(repo, opts, source)
     ui.status(_('comparing with %s\n') % util.hidepassword(source))
     revs, checkout = addbranchrevs(repo, other, branches, opts.get('rev'))
 
     if revs:
         revs = [other.lookup(rev) for rev in revs]
     other, chlist, cleanupfn = bundlerepo.getremotechanges(ui, repo, other,
                                 revs, opts["bundle"], opts["force"])
     try:
         if not chlist:
             ui.status(_("no changes found\n"))
             return subreporecurse()
 
         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:
         cleanupfn()
     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'))
     ui.status(_('comparing with %s\n') % util.hidepassword(dest))
     revs, checkout = addbranchrevs(repo, repo, branches, opts.get('rev'))
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
 
     other = peer(repo, opts, dest)
     outgoing = discovery.findcommonoutgoing(repo, other, revs,
                                             force=opts.get('force'))
     o = outgoing.missing
     if not o:
         ui.status(_("no changes found\n"))
         return None
     return o
 
 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 util.safehasattr(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 selected local settings to the remote ui
     for sect in ('auth', 'hostfingerprints', 'http_proxy'):
         for key, val in src.configitems(sect):
             dst.setconfig(sect, key, val)
     v = src.config('web', 'cacerts')
     if v:
         dst.setconfig('web', 'cacerts', util.expandpath(v))
 
     return dst