view mercurial/peer.py @ 18520:751135cca13c stable

subrepo: allows to drop courtesy phase sync (issue3781)

Publishing server may contains draft changeset when they are created locally. As
publishing is the default, it is actually fairly common. Because of this
"inconsistency" phases synchronization may be done even to publishing server.

This may cause severe issues for subrepo. It is possible to reference read-only
repository as subrepo. Push in a super repo recursively push subrepo. Those
pushes to potential read only repo are not optional, they are "suffered" not
"choosed". This does not break because as the repo is untouched the push is
supposed to be empty. If the reference repo locally contains draft changesets, a
courtesy push is triggered to turn them public. As the repo is read only, the
push fails (after possible prompt asking for credential). Failure of the
sub-push aborts the whole subrepo push. This force the user to define a custom
default-push for such subrepo.

This changeset introduce a prevention of this error client side by skipping the
courtesy phase synchronisation in problematic situation. The phases
synchronisation is skipped when four conditions are gathered:
- this is a subrepo push, (normal push to read-only repo)
- and remote support phase
- and remote is publishing
- and no changesets was pushed (if we pushed changesets, repo is not read only)

The internal config option used in this version is not definitive. It is here to
demonstrate a working fix to the issue.

In the future we probably wants to track subrepo changes and avoid pushing to
untouched one. That will prevent any attempt to push to read-only or unreachable
subrepo.

Another fix to prevent courtesy push from older clients to push to newer server
is also still needed.

# peer.py - repository base classes for mercurial
#
# Copyright 2005, 2006 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 _
import error

class peerrepository(object):

    def capable(self, name):
        '''tell whether repo supports named capability.
        return False if not supported.
        if boolean capability, return True.
        if string capability, return string.'''
        caps = self._capabilities()
        if name in caps:
            return True
        name_eq = name + '='
        for cap in caps:
            if cap.startswith(name_eq):
                return cap[len(name_eq):]
        return False

    def requirecap(self, name, purpose):
        '''raise an exception if the given capability is not present'''
        if not self.capable(name):
            raise error.CapabilityError(
                _('cannot %s; remote repository does not '
                  'support the %r capability') % (purpose, name))

    def local(self):
        '''return peer as a localrepo, or None'''
        return None

    def peer(self):
        return self

    def canpush(self):
        return True

    def close(self):
        pass