# Copyright (C) 2005-2011 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Tests for branch implementations - tests a branch format."""

from bzrlib import (
    branch as _mod_branch,
    bzrdir,
    config,
    delta as _mod_delta,
    errors,
    gpg,
    merge,
    urlutils,
    transport,
    remote,
    repository,
    revision,
    symbol_versioning,
    tests,
    )
from bzrlib.tests import (
    per_branch,
    )
from bzrlib.tests.http_server import HttpServer
from bzrlib.transport import memory


class TestTestCaseWithBranch(per_branch.TestCaseWithBranch):

    def test_branch_format_matches_bzrdir_branch_format(self):
        bzrdir_branch_format = self.bzrdir_format.get_branch_format()
        self.assertIs(self.branch_format.__class__,
                      bzrdir_branch_format.__class__)

    def test_make_branch_gets_expected_format(self):
        branch = self.make_branch('.')
        self.assertIs(self.branch_format.__class__,
            branch._format.__class__)


class TestBranch(per_branch.TestCaseWithBranch):

    def test_create_tree_with_merge(self):
        tree = self.create_tree_with_merge()
        tree.lock_read()
        self.addCleanup(tree.unlock)
        graph = tree.branch.repository.get_graph()
        ancestry_graph = graph.get_parent_map(
            tree.branch.repository.all_revision_ids())
        self.assertEqual({'rev-1':('null:',),
                          'rev-2':('rev-1', ),
                          'rev-1.1.1':('rev-1', ),
                          'rev-3':('rev-2', 'rev-1.1.1', ),
                         }, ancestry_graph)

    def test_revision_ids_are_utf8(self):
        wt = self.make_branch_and_tree('tree')
        wt.commit('f', rev_id='rev1')
        wt.commit('f', rev_id='rev2')
        wt.commit('f', rev_id='rev3')

        br = self.get_branch()
        br.fetch(wt.branch)
        br.generate_revision_history('rev3')
        rh = br.revision_history()
        self.assertEqual(['rev1', 'rev2', 'rev3'], rh)
        for revision_id in rh:
            self.assertIsInstance(revision_id, str)
        last = br.last_revision()
        self.assertEqual('rev3', last)
        self.assertIsInstance(last, str)
        revno, last = br.last_revision_info()
        self.assertEqual(3, revno)
        self.assertEqual('rev3', last)
        self.assertIsInstance(last, str)

    def test_fetch_revisions(self):
        """Test fetch-revision operation."""
        wt = self.make_branch_and_tree('b1')
        b1 = wt.branch
        self.build_tree_contents([('b1/foo', 'hello')])
        wt.add(['foo'], ['foo-id'])
        wt.commit('lala!', rev_id='revision-1', allow_pointless=False)

        b2 = self.make_branch('b2')
        b2.fetch(b1)

        rev = b2.repository.get_revision('revision-1')
        tree = b2.repository.revision_tree('revision-1')
        tree.lock_read()
        self.addCleanup(tree.unlock)
        self.assertEqual(tree.get_file_text('foo-id'), 'hello')

    def test_get_revision_delta(self):
        tree_a = self.make_branch_and_tree('a')
        self.build_tree(['a/foo'])
        tree_a.add('foo', 'file1')
        tree_a.commit('rev1', rev_id='rev1')
        self.build_tree(['a/vla'])
        tree_a.add('vla', 'file2')
        tree_a.commit('rev2', rev_id='rev2')

        delta = tree_a.branch.get_revision_delta(1)
        self.assertIsInstance(delta, _mod_delta.TreeDelta)
        self.assertEqual([('foo', 'file1', 'file')], delta.added)
        delta = tree_a.branch.get_revision_delta(2)
        self.assertIsInstance(delta, _mod_delta.TreeDelta)
        self.assertEqual([('vla', 'file2', 'file')], delta.added)

    def get_unbalanced_tree_pair(self):
        """Return two branches, a and b, with one file in a."""
        tree_a = self.make_branch_and_tree('a')
        self.build_tree_contents([('a/b', 'b')])
        tree_a.add('b')
        tree_a.commit("silly commit", rev_id='A')

        tree_b = self.make_branch_and_tree('b')
        return tree_a, tree_b

    def get_balanced_branch_pair(self):
        """Returns br_a, br_b as with one commit in a, and b has a's stores."""
        tree_a, tree_b = self.get_unbalanced_tree_pair()
        tree_b.branch.repository.fetch(tree_a.branch.repository)
        return tree_a, tree_b

    def test_clone_partial(self):
        """Copy only part of the history of a branch."""
        # TODO: RBC 20060208 test with a revision not on revision-history.
        #       what should that behaviour be ? Emailed the list.
        # First, make a branch with two commits.
        wt_a = self.make_branch_and_tree('a')
        self.build_tree(['a/one'])
        wt_a.add(['one'])
        wt_a.commit('commit one', rev_id='1')
        self.build_tree(['a/two'])
        wt_a.add(['two'])
        wt_a.commit('commit two', rev_id='2')
        # Now make a copy of the repository.
        repo_b = self.make_repository('b')
        wt_a.branch.repository.copy_content_into(repo_b)
        # wt_a might be a lightweight checkout, so get a hold of the actual
        # branch (because you can't do a partial clone of a lightweight
        # checkout).
        branch = wt_a.branch.bzrdir.open_branch()
        # Then make a branch where the new repository is, but specify a revision
        # ID.  The new branch's history will stop at the specified revision.
        br_b = branch.clone(repo_b.bzrdir, revision_id='1')
        self.assertEqual('1', br_b.last_revision())

    def get_parented_branch(self):
        wt_a = self.make_branch_and_tree('a')
        self.build_tree(['a/one'])
        wt_a.add(['one'])
        wt_a.commit('commit one', rev_id='1')

        branch_b = wt_a.branch.bzrdir.sprout('b', revision_id='1').open_branch()
        self.assertEqual(wt_a.branch.base, branch_b.get_parent())
        return branch_b

    def test_clone_branch_nickname(self):
        # test the nick name is preserved always
        raise tests.TestSkipped('XXX branch cloning is not yet tested.')

    def test_clone_branch_parent(self):
        # test the parent is preserved always
        branch_b = self.get_parented_branch()
        repo_c = self.make_repository('c')
        branch_b.repository.copy_content_into(repo_c)
        branch_c = branch_b.clone(repo_c.bzrdir)
        self.assertNotEqual(None, branch_c.get_parent())
        self.assertEqual(branch_b.get_parent(), branch_c.get_parent())

        # We can also set a specific parent, and it should be honored
        random_parent = 'http://example.com/path/to/branch'
        branch_b.set_parent(random_parent)
        repo_d = self.make_repository('d')
        branch_b.repository.copy_content_into(repo_d)
        branch_d = branch_b.clone(repo_d.bzrdir)
        self.assertEqual(random_parent, branch_d.get_parent())

    def test_submit_branch(self):
        """Submit location can be queried and set"""
        branch = self.make_branch('branch')
        self.assertEqual(branch.get_submit_branch(), None)
        branch.set_submit_branch('sftp://example.com')
        self.assertEqual(branch.get_submit_branch(), 'sftp://example.com')
        branch.set_submit_branch('sftp://example.net')
        self.assertEqual(branch.get_submit_branch(), 'sftp://example.net')

    def test_public_branch(self):
        """public location can be queried and set"""
        branch = self.make_branch('branch')
        self.assertEqual(branch.get_public_branch(), None)
        branch.set_public_branch('sftp://example.com')
        self.assertEqual(branch.get_public_branch(), 'sftp://example.com')
        branch.set_public_branch('sftp://example.net')
        self.assertEqual(branch.get_public_branch(), 'sftp://example.net')
        branch.set_public_branch(None)
        self.assertEqual(branch.get_public_branch(), None)

    def test_record_initial_ghost(self):
        """Branches should support having ghosts."""
        wt = self.make_branch_and_tree('.')
        wt.set_parent_ids(['non:existent@rev--ision--0--2'],
            allow_leftmost_as_ghost=True)
        self.assertEqual(['non:existent@rev--ision--0--2'],
            wt.get_parent_ids())
        rev_id = wt.commit('commit against a ghost first parent.')
        rev = wt.branch.repository.get_revision(rev_id)
        self.assertEqual(rev.parent_ids, ['non:existent@rev--ision--0--2'])
        # parent_sha1s is not populated now, WTF. rbc 20051003
        self.assertEqual(len(rev.parent_sha1s), 0)

    def test_record_two_ghosts(self):
        """Recording with all ghosts works."""
        wt = self.make_branch_and_tree('.')
        wt.set_parent_ids([
                'foo@azkhazan-123123-abcabc',
                'wibble@fofof--20050401--1928390812',
            ],
            allow_leftmost_as_ghost=True)
        rev_id = wt.commit("commit from ghost base with one merge")
        # the revision should have been committed with two parents
        rev = wt.branch.repository.get_revision(rev_id)
        self.assertEqual(['foo@azkhazan-123123-abcabc',
            'wibble@fofof--20050401--1928390812'],
            rev.parent_ids)

    def test_bad_revision(self):
        self.assertRaises(errors.InvalidRevisionId,
                          self.get_branch().repository.get_revision,
                          None)

# TODO 20051003 RBC:
# compare the gpg-to-sign info for a commit with a ghost and
#     an identical tree without a ghost
# fetch missing should rewrite the TOC of weaves to list newly available parents.

    def test_sign_existing_revision(self):
        wt = self.make_branch_and_tree('.')
        branch = wt.branch
        wt.commit("base", allow_pointless=True, rev_id='A')
        from bzrlib.testament import Testament
        strategy = gpg.LoopbackGPGStrategy(None)
        branch.repository.lock_write()
        branch.repository.start_write_group()
        branch.repository.sign_revision('A', strategy)
        branch.repository.commit_write_group()
        branch.repository.unlock()
        self.assertEqual('-----BEGIN PSEUDO-SIGNED CONTENT-----\n' +
                         Testament.from_revision(branch.repository,
                         'A').as_short_text() +
                         '-----END PSEUDO-SIGNED CONTENT-----\n',
                         branch.repository.get_signature_text('A'))

    def test_store_signature(self):
        wt = self.make_branch_and_tree('.')
        branch = wt.branch
        branch.lock_write()
        try:
            branch.repository.start_write_group()
            try:
                branch.repository.store_revision_signature(
                    gpg.LoopbackGPGStrategy(None), 'FOO', 'A')
            except:
                branch.repository.abort_write_group()
                raise
            else:
                branch.repository.commit_write_group()
        finally:
            branch.unlock()
        # A signature without a revision should not be accessible.
        self.assertRaises(errors.NoSuchRevision,
                          branch.repository.has_signature_for_revision_id,
                          'A')
        wt.commit("base", allow_pointless=True, rev_id='A')
        self.assertEqual('-----BEGIN PSEUDO-SIGNED CONTENT-----\n'
                         'FOO-----END PSEUDO-SIGNED CONTENT-----\n',
                         branch.repository.get_signature_text('A'))

    def test_branch_keeps_signatures(self):
        wt = self.make_branch_and_tree('source')
        wt.commit('A', allow_pointless=True, rev_id='A')
        repo = wt.branch.repository
        repo.lock_write()
        repo.start_write_group()
        repo.sign_revision('A', gpg.LoopbackGPGStrategy(None))
        repo.commit_write_group()
        repo.unlock()
        #FIXME: clone should work to urls,
        # wt.clone should work to disks.
        self.build_tree(['target/'])
        d2 = repo.bzrdir.clone(urlutils.local_path_to_url('target'))
        self.assertEqual(repo.get_signature_text('A'),
                         d2.open_repository().get_signature_text('A'))

    def test_nicks(self):
        """Test explicit and implicit branch nicknames.

        Nicknames are implicitly the name of the branch's directory, unless an
        explicit nickname is set.  That is, an explicit nickname always
        overrides the implicit one.
        """
        t = self.get_transport()
        branch = self.make_branch('bzr.dev')
        # The nick will be 'bzr.dev', because there is no explicit nick set.
        self.assertEqual(branch.nick, 'bzr.dev')
        # Move the branch to a different directory, 'bzr.ab'.  Now that branch
        # will report its nick as 'bzr.ab'.
        t.move('bzr.dev', 'bzr.ab')
        branch = _mod_branch.Branch.open(self.get_url('bzr.ab'))
        self.assertEqual(branch.nick, 'bzr.ab')
        # Set the branch nick explicitly.  This will ensure there's a branch
        # config file in the branch.
        branch.nick = "Aaron's branch"
        if not isinstance(branch, remote.RemoteBranch):
            self.assertTrue(branch._transport.has("branch.conf"))
        # Because the nick has been set explicitly, the nick is now always
        # "Aaron's branch", regardless of directory name.
        self.assertEqual(branch.nick, "Aaron's branch")
        t.move('bzr.ab', 'integration')
        branch = _mod_branch.Branch.open(self.get_url('integration'))
        self.assertEqual(branch.nick, "Aaron's branch")
        branch.nick = u"\u1234"
        self.assertEqual(branch.nick, u"\u1234")

    def test_commit_nicks(self):
        """Nicknames are committed to the revision"""
        wt = self.make_branch_and_tree('bzr.dev')
        branch = wt.branch
        branch.nick = "My happy branch"
        wt.commit('My commit respect da nick.')
        committed = branch.repository.get_revision(branch.last_revision())
        self.assertEqual(committed.properties["branch-nick"],
                         "My happy branch")

    def test_create_colocated(self):
        try:
            repo = self.make_repository('.', shared=True)
        except errors.IncompatibleFormat:
            return
        self.assertEquals(0, len(repo.bzrdir.list_branches()))
        try:
            child_branch1 = self.branch_format.initialize(repo.bzrdir, 
                name='branch1')
        except (errors.UninitializableFormat, errors.NoColocatedBranchSupport):
            # branch references are not default init'able and
            # not all bzrdirs support colocated branches.
            return
        self.assertEquals(1, len(repo.bzrdir.list_branches()))
        self.branch_format.initialize(repo.bzrdir, name='branch2')
        self.assertEquals(2, len(repo.bzrdir.list_branches()))

    def test_create_open_branch_uses_repository(self):
        try:
            repo = self.make_repository('.', shared=True)
        except errors.IncompatibleFormat:
            return
        child_transport = repo.bzrdir.root_transport.clone('child')
        child_transport.mkdir('.')
        child_dir = self.bzrdir_format.initialize_on_transport(child_transport)
        try:
            child_branch = self.branch_format.initialize(child_dir)
        except errors.UninitializableFormat:
            # branch references are not default init'able.
            return
        self.assertEqual(repo.bzrdir.root_transport.base,
                         child_branch.repository.bzrdir.root_transport.base)
        child_branch = _mod_branch.Branch.open(self.get_url('child'))
        self.assertEqual(repo.bzrdir.root_transport.base,
                         child_branch.repository.bzrdir.root_transport.base)

    def test_format_description(self):
        tree = self.make_branch_and_tree('tree')
        text = tree.branch._format.get_format_description()
        self.assertTrue(len(text))

    def test_get_commit_builder(self):
        branch = self.make_branch(".")
        branch.lock_write()
        builder = branch.get_commit_builder([])
        self.assertIsInstance(builder, repository.CommitBuilder)
        branch.repository.commit_write_group()
        branch.unlock()

    def test_generate_revision_history(self):
        """Create a fake revision history easily."""
        tree = self.make_branch_and_tree('.')
        rev1 = tree.commit('foo')
        orig_history = tree.branch.revision_history()
        rev2 = tree.commit('bar', allow_pointless=True)
        tree.branch.generate_revision_history(rev1)
        self.assertEqual(orig_history, tree.branch.revision_history())

    def test_generate_revision_history_NULL_REVISION(self):
        tree = self.make_branch_and_tree('.')
        rev1 = tree.commit('foo')
        tree.branch.generate_revision_history(revision.NULL_REVISION)
        self.assertEqual([], tree.branch.revision_history())

    def test_create_checkout(self):
        tree_a = self.make_branch_and_tree('a')
        branch_a = tree_a.branch
        checkout_b = branch_a.create_checkout('b')
        self.assertEqual('null:', checkout_b.last_revision())
        checkout_b.commit('rev1', rev_id='rev1')
        self.assertEqual('rev1', branch_a.last_revision())
        self.assertNotEqual(checkout_b.branch.base, branch_a.base)

        checkout_c = branch_a.create_checkout('c', lightweight=True)
        self.assertEqual('rev1', checkout_c.last_revision())
        checkout_c.commit('rev2', rev_id='rev2')
        self.assertEqual('rev2', branch_a.last_revision())
        self.assertEqual(checkout_c.branch.base, branch_a.base)

        checkout_d = branch_a.create_checkout('d', lightweight=True)
        self.assertEqual('rev2', checkout_d.last_revision())
        checkout_e = branch_a.create_checkout('e')
        self.assertEqual('rev2', checkout_e.last_revision())

    def test_create_anonymous_lightweight_checkout(self):
        """A lightweight checkout from a readonly branch should succeed."""
        tree_a = self.make_branch_and_tree('a')
        rev_id = tree_a.commit('put some content in the branch')
        # open the branch via a readonly transport
        source_branch = _mod_branch.Branch.open(self.get_readonly_url('a'))
        # sanity check that the test will be valid
        self.assertRaises((errors.LockError, errors.TransportNotPossible),
            source_branch.lock_write)
        checkout = source_branch.create_checkout('c', lightweight=True)
        self.assertEqual(rev_id, checkout.last_revision())

    def test_create_anonymous_heavyweight_checkout(self):
        """A regular checkout from a readonly branch should succeed."""
        tree_a = self.make_branch_and_tree('a')
        rev_id = tree_a.commit('put some content in the branch')
        # open the branch via a readonly transport
        source_branch = _mod_branch.Branch.open(self.get_readonly_url('a'))
        # sanity check that the test will be valid
        self.assertRaises((errors.LockError, errors.TransportNotPossible),
            source_branch.lock_write)
        checkout = source_branch.create_checkout('c')
        self.assertEqual(rev_id, checkout.last_revision())

    def test_set_revision_history(self):
        tree = self.make_branch_and_tree('a')
        tree.commit('a commit', rev_id='rev1')
        br = tree.branch
        self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
            br.set_revision_history, ["rev1"])
        self.assertEquals(br.revision_history(), ["rev1"])
        self.applyDeprecated(symbol_versioning.deprecated_in((2, 4, 0)),
            br.set_revision_history, [])
        self.assertEquals(br.revision_history(), [])

    def test_heads_to_fetch(self):
        # heads_to_fetch is a method that returns a collection of revids that
        # need to be fetched to copy this branch into another repo.  At a
        # minimum this will include the tip.
        # (In native formats, this is the tip + tags, but other formats may
        # have other revs needed)
        tree = self.make_branch_and_tree('a')
        tree.commit('first commit', rev_id='rev1')
        tree.commit('second commit', rev_id='rev2')
        must_fetch, should_fetch = tree.branch.heads_to_fetch()
        self.assertTrue('rev2' in must_fetch)

    def test_heads_to_fetch_not_null_revision(self):
        # NULL_REVISION does not appear in the result of heads_to_fetch, even
        # for an empty branch.
        tree = self.make_branch_and_tree('a')
        must_fetch, should_fetch = tree.branch.heads_to_fetch()
        self.assertFalse(revision.NULL_REVISION in must_fetch)
        self.assertFalse(revision.NULL_REVISION in should_fetch)


class TestBranchFormat(per_branch.TestCaseWithBranch):

    def test_branch_format_network_name(self):
        br = self.make_branch('.')
        format = br._format
        network_name = format.network_name()
        self.assertIsInstance(network_name, str)
        # We want to test that the network_name matches the actual format on
        # disk. For local branches that means that using network_name as a key
        # in the registry gives back the same format. For remote branches we
        # check that the network_name of the RemoteBranchFormat we have locally
        # matches the actual format present on disk.
        if isinstance(format, remote.RemoteBranchFormat):
            br._ensure_real()
            real_branch = br._real_branch
            self.assertEqual(real_branch._format.network_name(), network_name)
        else:
            registry = _mod_branch.network_format_registry
            looked_up_format = registry.get(network_name)
            self.assertEqual(format.__class__, looked_up_format.__class__)


class ChrootedTests(per_branch.TestCaseWithBranch):
    """A support class that provides readonly urls outside the local namespace.

    This is done by checking if self.transport_server is a MemoryServer. if it
    is then we are chrooted already, if it is not then an HttpServer is used
    for readonly urls.
    """

    def setUp(self):
        super(ChrootedTests, self).setUp()
        if not self.vfs_transport_factory == memory.MemoryServer:
            self.transport_readonly_server = HttpServer

    def test_open_containing(self):
        self.assertRaises(errors.NotBranchError,
                          _mod_branch.Branch.open_containing,
                          self.get_readonly_url(''))
        self.assertRaises(errors.NotBranchError,
                          _mod_branch.Branch.open_containing,
                          self.get_readonly_url('g/p/q'))
        branch = self.make_branch('.')
        branch, relpath = _mod_branch.Branch.open_containing(
            self.get_readonly_url(''))
        self.assertEqual('', relpath)
        branch, relpath = _mod_branch.Branch.open_containing(
            self.get_readonly_url('g/p/q'))
        self.assertEqual('g/p/q', relpath)


class InstrumentedTransaction(object):

    def finish(self):
        self.calls.append('finish')

    def __init__(self):
        self.calls = []


class TestDecorator(object):

    def __init__(self):
        self._calls = []

    def lock_read(self):
        self._calls.append('lr')

    def lock_write(self):
        self._calls.append('lw')

    def unlock(self):
        self._calls.append('ul')

    @_mod_branch.needs_read_lock
    def do_with_read(self):
        return 1

    @_mod_branch.needs_read_lock
    def except_with_read(self):
        raise RuntimeError

    @_mod_branch.needs_write_lock
    def do_with_write(self):
        return 2

    @_mod_branch.needs_write_lock
    def except_with_write(self):
        raise RuntimeError


class TestDecorators(tests.TestCase):

    def test_needs_read_lock(self):
        branch = TestDecorator()
        self.assertEqual(1, branch.do_with_read())
        self.assertEqual(['lr', 'ul'], branch._calls)

    def test_excepts_in_read_lock(self):
        branch = TestDecorator()
        self.assertRaises(RuntimeError, branch.except_with_read)
        self.assertEqual(['lr', 'ul'], branch._calls)

    def test_needs_write_lock(self):
        branch = TestDecorator()
        self.assertEqual(2, branch.do_with_write())
        self.assertEqual(['lw', 'ul'], branch._calls)

    def test_excepts_in_write_lock(self):
        branch = TestDecorator()
        self.assertRaises(RuntimeError, branch.except_with_write)
        self.assertEqual(['lw', 'ul'], branch._calls)


class TestBranchPushLocations(per_branch.TestCaseWithBranch):

    def test_get_push_location_unset(self):
        self.assertEqual(None, self.get_branch().get_push_location())

    def test_get_push_location_exact(self):
        b = self.get_branch()
        config.LocationConfig.from_string(
            '[%s]\npush_location=foo\n' % (b.base,), b.base, save=True)
        self.assertEqual("foo", self.get_branch().get_push_location())

    def test_set_push_location(self):
        branch = self.get_branch()
        branch.set_push_location('foo')
        self.assertEqual('foo', branch.get_push_location())


class TestChildSubmitFormats(per_branch.TestCaseWithBranch):

    def test_get_child_submit_format_default(self):
        self.assertEqual(None, self.get_branch().get_child_submit_format())

    def test_get_child_submit_format(self):
        branch = self.get_branch()
        branch.get_config().set_user_option('child_submit_format', '10')
        branch = self.get_branch()
        self.assertEqual('10', branch.get_child_submit_format())


class TestFormat(per_branch.TestCaseWithBranch):
    """Tests for the format itself."""

    def test_get_reference(self):
        """get_reference on all regular branches should return None."""
        if not self.branch_format.is_supported():
            # unsupported formats are not loopback testable
            # because the default open will not open them and
            # they may not be initializable.
            return
        made_branch = self.make_branch('.')
        self.assertEqual(None,
            made_branch._format.get_reference(made_branch.bzrdir))

    def test_set_reference(self):
        """set_reference on all regular branches should be callable."""
        if not self.branch_format.is_supported():
            # unsupported formats are not loopback testable
            # because the default open will not open them and
            # they may not be initializable.
            return
        this_branch = self.make_branch('this')
        other_branch = self.make_branch('other')
        try:
            this_branch._format.set_reference(this_branch.bzrdir, None,
                other_branch)
        except NotImplementedError:
            # that's ok
            pass
        else:
            ref = this_branch._format.get_reference(this_branch.bzrdir)
            self.assertEqual(ref, other_branch.base)

    def test_format_initialize_find_open(self):
        # loopback test to check the current format initializes to itself.
        if not self.branch_format.is_supported():
            # unsupported formats are not loopback testable
            # because the default open will not open them and
            # they may not be initializable.
            return
        # supported formats must be able to init and open
        t = self.get_transport()
        readonly_t = transport.get_transport(self.get_readonly_url())
        made_branch = self.make_branch('.')
        self.assertIsInstance(made_branch, _mod_branch.Branch)

        # find it via bzrdir opening:
        opened_control = bzrdir.BzrDir.open(readonly_t.base)
        direct_opened_branch = opened_control.open_branch()
        self.assertEqual(direct_opened_branch.__class__, made_branch.__class__)
        self.assertEqual(opened_control, direct_opened_branch.bzrdir)
        self.assertIsInstance(direct_opened_branch._format,
            self.branch_format.__class__)

        # find it via Branch.open
        opened_branch = _mod_branch.Branch.open(readonly_t.base)
        self.assertIsInstance(opened_branch, made_branch.__class__)
        self.assertEqual(made_branch._format.__class__,
                         opened_branch._format.__class__)
        # if it has a unique id string, can we probe for it ?
        try:
            self.branch_format.get_format_string()
        except NotImplementedError:
            return
        self.assertEqual(self.branch_format,
                         opened_control.find_branch_format())


class TestBound(per_branch.TestCaseWithBranch):

    def test_bind_unbind(self):
        branch = self.make_branch('1')
        branch2 = self.make_branch('2')
        try:
            branch.bind(branch2)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')
        self.assertTrue(branch.unbind())
        self.assertFalse(branch.unbind())
        self.assertIs(None, branch.get_bound_location())

    def test_old_bound_location(self):
        branch = self.make_branch('branch1')
        try:
            self.assertIs(None, branch.get_old_bound_location())
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable(
                    'Format does not store old bound locations')
        branch2 = self.make_branch('branch2')
        branch.bind(branch2)
        self.assertIs(None, branch.get_old_bound_location())
        branch.unbind()
        self.assertContainsRe(branch.get_old_bound_location(), '\/branch2\/$')

    def test_bind_diverged(self):
        tree_a = self.make_branch_and_tree('tree_a')
        tree_a.commit('rev1a')
        tree_b = tree_a.bzrdir.sprout('tree_b').open_workingtree()
        tree_a.commit('rev2a')
        tree_b.commit('rev2b')
        try:
            tree_b.branch.bind(tree_a.branch)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')

    def test_unbind_clears_cached_master_branch(self):
        """b.unbind clears any cached value of b.get_master_branch."""
        master = self.make_branch('master')
        branch = self.make_branch('branch')
        try:
            branch.bind(master)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')
        self.addCleanup(branch.lock_write().unlock)
        self.assertNotEqual(None, branch.get_master_branch())
        branch.unbind()
        self.assertEqual(None, branch.get_master_branch())

    def test_unlocked_does_not_cache_master_branch(self):
        """Unlocked branches do not cache the result of get_master_branch."""
        master = self.make_branch('master')
        branch1 = self.make_branch('branch')
        try:
            branch1.bind(master)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')
        # Open branch1 again
        branch2 = branch1.bzrdir.open_branch()
        self.assertNotEqual(None, branch1.get_master_branch())
        # Unbind the branch via branch2.  branch1 isn't locked so will
        # immediately return the new value for get_master_branch.
        branch2.unbind()
        self.assertEqual(None, branch1.get_master_branch())

    def test_bind_clears_cached_master_branch(self):
        """b.bind clears any cached value of b.get_master_branch."""
        master1 = self.make_branch('master1')
        master2 = self.make_branch('master2')
        branch = self.make_branch('branch')
        try:
            branch.bind(master1)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')
        self.addCleanup(branch.lock_write().unlock)
        self.assertNotEqual(None, branch.get_master_branch())
        branch.bind(master2)
        self.assertEqual('.', urlutils.relative_url(self.get_url('master2'),
                branch.get_master_branch().base))

    def test_set_bound_location_clears_cached_master_branch(self):
        """b.set_bound_location clears any cached value of b.get_master_branch.
        """
        master1 = self.make_branch('master1')
        master2 = self.make_branch('master2')
        branch = self.make_branch('branch')
        try:
            branch.bind(master1)
        except errors.UpgradeRequired:
            raise tests.TestNotApplicable('Format does not support binding')
        self.addCleanup(branch.lock_write().unlock)
        self.assertNotEqual(None, branch.get_master_branch())
        branch.set_bound_location(self.get_url('master2'))
        self.assertEqual('.', urlutils.relative_url(self.get_url('master2'),
                branch.get_master_branch().base))


class TestStrict(per_branch.TestCaseWithBranch):

    def test_strict_history(self):
        tree1 = self.make_branch_and_tree('tree1')
        try:
            tree1.branch.set_append_revisions_only(True)
        except errors.UpgradeRequired:
            raise tests.TestSkipped('Format does not support strict history')
        tree1.commit('empty commit')
        tree2 = tree1.bzrdir.sprout('tree2').open_workingtree()
        tree2.commit('empty commit 2')
        tree1.pull(tree2.branch)
        tree1.commit('empty commit 3')
        tree2.commit('empty commit 4')
        self.assertRaises(errors.DivergedBranches, tree1.pull, tree2.branch)
        tree2.merge_from_branch(tree1.branch)
        tree2.commit('empty commit 5')
        self.assertRaises(errors.AppendRevisionsOnlyViolation, tree1.pull,
                          tree2.branch)
        tree3 = tree1.bzrdir.sprout('tree3').open_workingtree()
        tree3.merge_from_branch(tree2.branch)
        tree3.commit('empty commit 6')
        tree2.pull(tree3.branch)


class TestIgnoreFallbacksParameter(per_branch.TestCaseWithBranch):

    def make_branch_with_fallback(self):
        fallback = self.make_branch('fallback')
        if not fallback._format.supports_stacking():
            raise tests.TestNotApplicable("format does not support stacking")
        stacked = self.make_branch('stacked')
        stacked.set_stacked_on_url(fallback.base)
        return stacked

    def test_fallbacks_not_opened(self):
        stacked = self.make_branch_with_fallback()
        self.get_transport('').rename('fallback', 'moved')
        reopened = stacked.bzrdir.open_branch(ignore_fallbacks=True)
        self.assertEqual([], reopened.repository._fallback_repositories)

    def test_fallbacks_are_opened(self):
        stacked = self.make_branch_with_fallback()
        reopened = stacked.bzrdir.open_branch(ignore_fallbacks=False)
        self.assertLength(1, reopened.repository._fallback_repositories)


class TestReferenceLocation(per_branch.TestCaseWithBranch):

    def test_reference_parent(self):
        tree = self.make_branch_and_tree('tree')
        subtree = self.make_branch_and_tree('tree/subtree')
        subtree.set_root_id('subtree-id')
        try:
            tree.add_reference(subtree)
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Tree cannot hold references.')
        reference_parent = tree.branch.reference_parent('subtree-id',
                                                        'subtree')
        self.assertEqual(subtree.branch.base, reference_parent.base)

    def test_reference_parent_accepts_possible_transports(self):
        tree = self.make_branch_and_tree('tree')
        subtree = self.make_branch_and_tree('tree/subtree')
        subtree.set_root_id('subtree-id')
        try:
            tree.add_reference(subtree)
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Tree cannot hold references.')
        reference_parent = tree.branch.reference_parent('subtree-id',
            'subtree', possible_transports=[subtree.bzrdir.root_transport])

    def test_get_reference_info(self):
        branch = self.make_branch('branch')
        try:
            path, loc = branch.get_reference_info('file-id')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        self.assertIs(None, path)
        self.assertIs(None, loc)

    def test_set_reference_info(self):
        branch = self.make_branch('branch')
        try:
            branch.set_reference_info('file-id', 'path/to/location',
                                      'path/to/file')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')

    def test_set_get_reference_info(self):
        branch = self.make_branch('branch')
        try:
            branch.set_reference_info('file-id', 'path/to/file',
                                      'path/to/location')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        # Create a new instance to ensure storage is permanent
        branch = _mod_branch.Branch.open('branch')
        tree_path, branch_location = branch.get_reference_info('file-id')
        self.assertEqual('path/to/location', branch_location)

    def test_set_null_reference_info(self):
        branch = self.make_branch('branch')
        try:
            branch.set_reference_info('file-id', 'path/to/file',
                                      'path/to/location')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        branch.set_reference_info('file-id', None, None)
        tree_path, branch_location = branch.get_reference_info('file-id')
        self.assertIs(None, tree_path)
        self.assertIs(None, branch_location)

    def test_set_null_reference_info_when_null(self):
        branch = self.make_branch('branch')
        try:
            tree_path, branch_location = branch.get_reference_info('file-id')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        self.assertIs(None, tree_path)
        self.assertIs(None, branch_location)
        branch.set_reference_info('file-id', None, None)

    def test_set_null_requires_two_nones(self):
        branch = self.make_branch('branch')
        try:
            e = self.assertRaises(ValueError, branch.set_reference_info,
                                  'file-id', 'path', None)
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        self.assertEqual('tree_path must be None when branch_location is'
                         ' None.', str(e))
        e = self.assertRaises(ValueError, branch.set_reference_info,
                              'file-id', None, 'location')
        self.assertEqual('branch_location must be None when tree_path is'
                         ' None.', str(e))

    def make_branch_with_reference(self, location, reference_location,
                                   file_id='file-id'):
        branch = self.make_branch(location)
        try:
            branch.set_reference_info(file_id, 'path/to/file',
                                      reference_location)
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        return branch

    def test_reference_parent_from_reference_info_(self):
        referenced_branch = self.make_branch('reference_branch')
        branch = self.make_branch_with_reference('branch',
                                                 referenced_branch.base)
        parent = branch.reference_parent('file-id', 'path/to/file')
        self.assertEqual(parent.base, referenced_branch.base)

    def test_branch_relative_reference_location(self):
        branch = self.make_branch('branch')
        try:
            branch.set_reference_info('file-id', 'path/to/file',
            '../reference_branch')
        except errors.UnsupportedOperation:
            raise tests.TestNotApplicable('Branch cannot hold references.')
        referenced_branch = self.make_branch('reference_branch')
        parent = branch.reference_parent('file-id', 'path/to/file')
        self.assertEqual(parent.base, referenced_branch.base)

    def test_sprout_copies_reference_location(self):
        branch = self.make_branch_with_reference('branch', '../reference')
        new_branch = branch.bzrdir.sprout('new-branch').open_branch()
        self.assertEqual('../reference',
                         new_branch.get_reference_info('file-id')[1])

    def test_clone_copies_reference_location(self):
        branch = self.make_branch_with_reference('branch', '../reference')
        new_branch = branch.bzrdir.clone('new-branch').open_branch()
        self.assertEqual('../reference',
                         new_branch.get_reference_info('file-id')[1])

    def test_copied_locations_are_rebased(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = branch.bzrdir.sprout('branch/new-branch').open_branch()
        self.assertEqual('../reference',
                         new_branch.get_reference_info('file-id')[1])

    def test_update_references_retains_old_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = self.make_branch_with_reference(
            'new_branch', 'reference', 'file-id2')
        new_branch.update_references(branch)
        self.assertEqual('reference',
                         branch.get_reference_info('file-id')[1])

    def test_update_references_retains_known_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = self.make_branch_with_reference(
            'new_branch', 'reference2')
        new_branch.update_references(branch)
        self.assertEqual('reference',
                         branch.get_reference_info('file-id')[1])

    def test_update_references_skips_known_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = branch.bzrdir.sprout('branch/new-branch').open_branch()
        new_branch.set_reference_info('file-id', '../foo', '../foo')
        new_branch.update_references(branch)
        self.assertEqual('reference',
                         branch.get_reference_info('file-id')[1])

    def test_pull_updates_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = branch.bzrdir.sprout('branch/new-branch').open_branch()
        new_branch.set_reference_info('file-id2', '../foo', '../foo')
        branch.pull(new_branch)
        self.assertEqual('foo',
                         branch.get_reference_info('file-id2')[1])

    def test_push_updates_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        new_branch = branch.bzrdir.sprout('branch/new-branch').open_branch()
        new_branch.set_reference_info('file-id2', '../foo', '../foo')
        new_branch.push(branch)
        self.assertEqual('foo',
                         branch.get_reference_info('file-id2')[1])

    def test_merge_updates_references(self):
        branch = self.make_branch_with_reference('branch', 'reference')
        tree = self.make_branch_and_tree('tree')
        tree.commit('foo')
        branch.pull(tree.branch)
        checkout = branch.create_checkout('checkout', lightweight=True)
        checkout.commit('bar')
        tree.lock_write()
        self.addCleanup(tree.unlock)
        merger = merge.Merger.from_revision_ids(None, tree,
                                                branch.last_revision(),
                                                other_branch=branch)
        merger.merge_type = merge.Merge3Merger
        merger.do_merge()
        self.assertEqual('../branch/reference',
                         tree.branch.get_reference_info('file-id')[1])


class TestBranchControlComponent(per_branch.TestCaseWithBranch):
    """Branch implementations adequately implement ControlComponent."""
    
    def test_urls(self):
        br = self.make_branch('branch')
        self.assertIsInstance(br.user_url, str)
        self.assertEqual(br.user_url, br.user_transport.base)
        # for all current bzrdir implementations the user dir must be 
        # above the control dir but we might need to relax that?
        self.assertEqual(br.control_url.find(br.user_url), 0)
        self.assertEqual(br.control_url, br.control_transport.base)
