/brz/remove-bazaar

# Copyright (C) 2006 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Tests for the smart wire/domain protococl."""

from bzrlib import bzrdir, errors, smart, tests

from bzrlib.smart.request import SmartServerResponse

import bzrlib.smart.bzrdir

import bzrlib.smart.branch

import bzrlib.smart.repository

class TestCaseWithSmartMedium(tests.TestCaseWithTransport):

    def setUp(self):

        super(TestCaseWithSmartMedium, self).setUp()

        # We're allowed to set  the transport class here, so that we don't use

        # the default or a parameterized class, but rather use the

        # TestCaseWithTransport infrastructure to set up a smart server and

        # transport.

        self.transport_server = smart.server.SmartTCPServer_for_testing

    def get_smart_medium(self):

        """Get a smart medium to use in tests."""

        return self.get_transport().get_smart_medium()

class TestSmartServerResponse(tests.TestCase):

    def test__eq__(self):

        self.assertEqual(SmartServerResponse(('ok', )),

            SmartServerResponse(('ok', )))

        self.assertEqual(SmartServerResponse(('ok', ), 'body'),

            SmartServerResponse(('ok', ), 'body'))

        self.assertNotEqual(SmartServerResponse(('ok', )),

            SmartServerResponse(('notok', )))

        self.assertNotEqual(SmartServerResponse(('ok', ), 'body'),

            SmartServerResponse(('ok', )))

        self.assertNotEqual(None,

            SmartServerResponse(('ok', )))

class TestSmartServerRequestFindRepository(tests.TestCaseWithTransport):

    """Tests for BzrDir.find_repository."""

    def test_no_repository(self):

        """When there is no repository to be found, ('norepository', ) is returned."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestFindRepository(backing)

        self.make_bzrdir('.')

        self.assertEqual(SmartServerResponse(('norepository', )),

            request.execute(backing.local_abspath('')))

    def test_nonshared_repository(self):

        # nonshared repositorys only allow 'find' to return a handle when the 

        # path the repository is being searched on is the same as that that 

        # the repository is at.

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestFindRepository(backing)

        result = self._make_repository_and_result()

        self.assertEqual(result, request.execute(backing.local_abspath('')))

        self.make_bzrdir('subdir')

        self.assertEqual(SmartServerResponse(('norepository', )),

            request.execute(backing.local_abspath('subdir')))

    def _make_repository_and_result(self, shared=False, format=None):

        """Convenience function to setup a repository.

        :result: The SmartServerResponse to expect when opening it.

        """

        repo = self.make_repository('.', shared=shared, format=format)

        if repo.supports_rich_root():

            rich_root = 'True'

        else:

            rich_root = 'False'

        if repo._format.supports_tree_reference:

            subtrees = 'True'

        else:

            subtrees = 'False'

        return SmartServerResponse(('ok', '', rich_root, subtrees))

    def test_shared_repository(self):

        """When there is a shared repository, we get 'ok', 'relpath-to-repo'."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestFindRepository(backing)

        result = self._make_repository_and_result(shared=True)

        self.assertEqual(result, request.execute(backing.local_abspath('')))

        self.make_bzrdir('subdir')

        result2 = SmartServerResponse(result.args[0:1] + ('..', ) + result.args[2:])

        self.assertEqual(result2,

            request.execute(backing.local_abspath('subdir')))

        self.make_bzrdir('subdir/deeper')

        result3 = SmartServerResponse(result.args[0:1] + ('../..', ) + result.args[2:])

        self.assertEqual(result3,

            request.execute(backing.local_abspath('subdir/deeper')))

    def test_rich_root_and_subtree_encoding(self):

        """Test for the format attributes for rich root and subtree support."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestFindRepository(backing)

        result = self._make_repository_and_result(format='dirstate-with-subtree')

        # check the test will be valid

        self.assertEqual('True', result.args[2])

        self.assertEqual('True', result.args[3])

        self.assertEqual(result, request.execute(backing.local_abspath('')))

class TestSmartServerRequestInitializeBzrDir(tests.TestCaseWithTransport):

    def test_empty_dir(self):

        """Initializing an empty dir should succeed and do it."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestInitializeBzrDir(backing)

        self.assertEqual(SmartServerResponse(('ok', )),

            request.execute(backing.local_abspath('.')))

        made_dir = bzrdir.BzrDir.open_from_transport(backing)

        # no branch, tree or repository is expected with the current 

        # default formart.

        self.assertRaises(errors.NoWorkingTree, made_dir.open_workingtree)

        self.assertRaises(errors.NotBranchError, made_dir.open_branch)

        self.assertRaises(errors.NoRepositoryPresent, made_dir.open_repository)

    def test_missing_dir(self):

        """Initializing a missing directory should fail like the bzrdir api."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestInitializeBzrDir(backing)

        self.assertRaises(errors.NoSuchFile,

            request.execute, backing.local_abspath('subdir'))

    def test_initialized_dir(self):

        """Initializing an extant bzrdir should fail like the bzrdir api."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestInitializeBzrDir(backing)

        self.make_bzrdir('subdir')

        self.assertRaises(errors.FileExists,

            request.execute, backing.local_abspath('subdir'))

class TestSmartServerRequestOpenBranch(tests.TestCaseWithTransport):

    def test_no_branch(self):

        """When there is no branch, ('nobranch', ) is returned."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestOpenBranch(backing)

        self.make_bzrdir('.')

        self.assertEqual(SmartServerResponse(('nobranch', )),

            request.execute(backing.local_abspath('')))

    def test_branch(self):

        """When there is a branch, 'ok' is returned."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestOpenBranch(backing)

        self.make_branch('.')

        self.assertEqual(SmartServerResponse(('ok', '')),

            request.execute(backing.local_abspath('')))

    def test_branch_reference(self):

        """When there is a branch reference, the reference URL is returned."""

        backing = self.get_transport()

        request = smart.bzrdir.SmartServerRequestOpenBranch(backing)

        branch = self.make_branch('branch')

        checkout = branch.create_checkout('reference',lightweight=True)

        # TODO: once we have an API to probe for references of any sort, we

        # can use it here.

        reference_url = backing.abspath('branch') + '/'

        self.assertFileEqual(reference_url, 'reference/.bzr/branch/location')

        self.assertEqual(SmartServerResponse(('ok', reference_url)),

            request.execute(backing.local_abspath('reference')))

class TestSmartServerRequestRevisionHistory(tests.TestCaseWithTransport):

    def test_empty(self):

        """For an empty branch, the body is empty."""

        backing = self.get_transport()

        request = smart.branch.SmartServerRequestRevisionHistory(backing)

        self.make_branch('.')

        self.assertEqual(SmartServerResponse(('ok', ), ''),

            request.execute(backing.local_abspath('')))

    def test_not_empty(self):

        """For a non-empty branch, the body is empty."""

        backing = self.get_transport()

        request = smart.branch.SmartServerRequestRevisionHistory(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        r1 = tree.commit('1st commit')

        r2 = tree.commit('2nd commit', rev_id=u'\xc8'.encode('utf-8'))

        tree.unlock()

        self.assertEqual(

            SmartServerResponse(('ok', ), ('\x00'.join([r1, r2]))),

            request.execute(backing.local_abspath('')))

class TestSmartServerBranchRequest(tests.TestCaseWithTransport):

    def test_no_branch(self):

        """When there is a bzrdir and no branch, NotBranchError is raised."""

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequest(backing)

        self.make_bzrdir('.')

        self.assertRaises(errors.NotBranchError,

            request.execute, backing.local_abspath(''))

    def test_branch_reference(self):

        """When there is a branch reference, NotBranchError is raised."""

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequest(backing)

        branch = self.make_branch('branch')

        checkout = branch.create_checkout('reference',lightweight=True)

        self.assertRaises(errors.NotBranchError,

            request.execute, backing.local_abspath('checkout'))

class TestSmartServerBranchRequestLastRevisionInfo(tests.TestCaseWithTransport):

    def test_empty(self):

        """For an empty branch, the result is ('ok', '0', '')."""

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLastRevisionInfo(backing)

        self.make_branch('.')

        self.assertEqual(SmartServerResponse(('ok', '0', '')),

            request.execute(backing.local_abspath('')))

    def test_not_empty(self):

        """For a non-empty branch, the result is ('ok', 'revno', 'revid')."""

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLastRevisionInfo(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        rev_id_utf8 = u'\xc8'.encode('utf-8')

        r1 = tree.commit('1st commit')

        r2 = tree.commit('2nd commit', rev_id=rev_id_utf8)

        tree.unlock()

        self.assertEqual(

            SmartServerResponse(('ok', '2', rev_id_utf8)),

            request.execute(backing.local_abspath('')))

class TestSmartServerBranchRequestGetConfigFile(tests.TestCaseWithTransport):

    def test_default(self):

        """With no file, we get empty content."""

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchGetConfigFile(backing)

        branch = self.make_branch('.')

        # there should be no file by default

        content = ''

        self.assertEqual(SmartServerResponse(('ok', ), content),

            request.execute(backing.local_abspath('')))

    def test_with_content(self):

        # SmartServerBranchGetConfigFile should return the content from

        # branch.control_files.get('branch.conf') for now - in the future it may

        # perform more complex processing. 

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchGetConfigFile(backing)

        branch = self.make_branch('.')

        branch.control_files.put_utf8('branch.conf', 'foo bar baz')

        self.assertEqual(SmartServerResponse(('ok', ), 'foo bar baz'),

            request.execute(backing.local_abspath('')))

class TestSmartServerBranchRequestSetLastRevision(tests.TestCaseWithTransport):

    def test_empty(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestSetLastRevision(backing)

        b = self.make_branch('.')

        branch_token = b.lock_write()

        repo_token = b.repository.lock_write()

        b.repository.unlock()

        try:

            self.assertEqual(SmartServerResponse(('ok',)),

                request.execute(

                    backing.local_abspath(''), branch_token, repo_token, ''))

        finally:

            b.unlock()

    def test_not_present_revision_id(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestSetLastRevision(backing)

        b = self.make_branch('.')

        branch_token = b.lock_write()

        repo_token = b.repository.lock_write()

        b.repository.unlock()

        try:

            revision_id = 'non-existent revision'

            self.assertEqual(

                SmartServerResponse(('NoSuchRevision', revision_id)),

                request.execute(

                    backing.local_abspath(''), branch_token, repo_token,

                    revision_id))

        finally:

            b.unlock()

    def test_revision_id_present(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestSetLastRevision(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        rev_id_utf8 = u'\xc8'.encode('utf-8')

        r1 = tree.commit('1st commit', rev_id=rev_id_utf8)

        r2 = tree.commit('2nd commit')

        tree.unlock()

        branch_token = tree.branch.lock_write()

        repo_token = tree.branch.repository.lock_write()

        tree.branch.repository.unlock()

        try:

            self.assertEqual(

                SmartServerResponse(('ok',)),

                request.execute(

                    backing.local_abspath(''), branch_token, repo_token,

                    rev_id_utf8))

            self.assertEqual([rev_id_utf8], tree.branch.revision_history())

        finally:

            tree.branch.unlock()

    def test_revision_id_present2(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestSetLastRevision(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        rev_id_utf8 = u'\xc8'.encode('utf-8')

        r1 = tree.commit('1st commit', rev_id=rev_id_utf8)

        r2 = tree.commit('2nd commit')

        tree.unlock()

        tree.branch.set_revision_history([])

        branch_token = tree.branch.lock_write()

        repo_token = tree.branch.repository.lock_write()

        tree.branch.repository.unlock()

        try:

            self.assertEqual(

                SmartServerResponse(('ok',)),

                request.execute(

                    backing.local_abspath(''), branch_token, repo_token,

                    rev_id_utf8))

            self.assertEqual([rev_id_utf8], tree.branch.revision_history())

        finally:

            tree.branch.unlock()

class TestSmartServerBranchRequestLockWrite(tests.TestCaseWithTransport):

    def setUp(self):

        tests.TestCaseWithTransport.setUp(self)

        self.reduceLockdirTimeout()

    def test_lock_write_on_unlocked_branch(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        repository = branch.repository

        response = request.execute(backing.local_abspath(''))

        branch_nonce = branch.control_files._lock.peek().get('nonce')

        repository_nonce = repository.control_files._lock.peek().get('nonce')

        self.assertEqual(

            SmartServerResponse(('ok', branch_nonce, repository_nonce)),

            response)

        # The branch (and associated repository) is now locked.  Verify that

        # with a new branch object.

        new_branch = repository.bzrdir.open_branch()

        self.assertRaises(errors.LockContention, new_branch.lock_write)

    def test_lock_write_on_locked_branch(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        branch.lock_write()

        branch.leave_lock_in_place()

        branch.unlock()

        response = request.execute(backing.local_abspath(''))

        self.assertEqual(

            SmartServerResponse(('LockContention',)), response)

    def test_lock_write_with_tokens_on_locked_branch(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        branch_token = branch.lock_write()

        repo_token = branch.repository.lock_write()

        branch.repository.unlock()

        branch.leave_lock_in_place()

        branch.repository.leave_lock_in_place()

        branch.unlock()

        response = request.execute(backing.local_abspath(''),

                                   branch_token, repo_token)

        self.assertEqual(

            SmartServerResponse(('ok', branch_token, repo_token)), response)

    def test_lock_write_with_mismatched_tokens_on_locked_branch(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        branch_token = branch.lock_write()

        repo_token = branch.repository.lock_write()

        branch.repository.unlock()

        branch.leave_lock_in_place()

        branch.repository.leave_lock_in_place()

        branch.unlock()

        response = request.execute(backing.local_abspath(''),

                                   branch_token+'xxx', repo_token)

        self.assertEqual(

            SmartServerResponse(('TokenMismatch',)), response)

    def test_lock_write_on_locked_repo(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        branch.repository.lock_write()

        branch.repository.leave_lock_in_place()

        branch.repository.unlock()

        response = request.execute(backing.local_abspath(''))

        self.assertEqual(

            SmartServerResponse(('LockContention',)), response)

    def test_lock_write_on_readonly_transport(self):

        backing = self.get_readonly_transport()

        request = smart.branch.SmartServerBranchRequestLockWrite(backing)

        branch = self.make_branch('.')

        response = request.execute('')

        self.assertEqual(

            SmartServerResponse(('UnlockableTransport',)), response)

class TestSmartServerBranchRequestUnlock(tests.TestCaseWithTransport):

    def setUp(self):

        tests.TestCaseWithTransport.setUp(self)

        self.reduceLockdirTimeout()

    def test_unlock_on_locked_branch_and_repo(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestUnlock(backing)

        branch = self.make_branch('.')

        # Lock the branch

        branch_token = branch.lock_write()

        repo_token = branch.repository.lock_write()

        branch.repository.unlock()

        # Unlock the branch (and repo) object, leaving the physical locks

        # in place.

        branch.leave_lock_in_place()

        branch.repository.leave_lock_in_place()

        branch.unlock()

        response = request.execute(backing.local_abspath(''),

                                   branch_token, repo_token)

        self.assertEqual(

            SmartServerResponse(('ok',)), response)

        # The branch is now unlocked.  Verify that with a new branch

        # object.

        new_branch = branch.bzrdir.open_branch()

        new_branch.lock_write()

        new_branch.unlock()

    def test_unlock_on_unlocked_branch_unlocked_repo(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestUnlock(backing)

        branch = self.make_branch('.')

        response = request.execute(

            backing.local_abspath(''), 'branch token', 'repo token')

        self.assertEqual(

            SmartServerResponse(('TokenMismatch',)), response)

    def test_unlock_on_unlocked_branch_locked_repo(self):

        backing = self.get_transport()

        request = smart.branch.SmartServerBranchRequestUnlock(backing)

        branch = self.make_branch('.')

        # Lock the repository.

        repo_token = branch.repository.lock_write()

        branch.repository.leave_lock_in_place()

        branch.repository.unlock()

        # Issue branch lock_write request on the unlocked branch (with locked

        # repo).

        response = request.execute(

            backing.local_abspath(''), 'branch token', repo_token)

        self.assertEqual(

            SmartServerResponse(('TokenMismatch',)), response)

class TestSmartServerRepositoryRequest(tests.TestCaseWithTransport):

    def test_no_repository(self):

        """Raise NoRepositoryPresent when there is a bzrdir and no repo."""

        # we test this using a shared repository above the named path,

        # thus checking the right search logic is used - that is, that

        # its the exact path being looked at and the server is not

        # searching.

        backing = self.get_transport()

        request = smart.repository.SmartServerRepositoryRequest(backing)

        self.make_repository('.', shared=True)

        self.make_bzrdir('subdir')

        self.assertRaises(errors.NoRepositoryPresent,

            request.execute, backing.local_abspath('subdir'))

class TestSmartServerRepositoryGetRevisionGraph(tests.TestCaseWithTransport):

    def test_none_argument(self):

        backing = self.get_transport()

        request = smart.repository.SmartServerRepositoryGetRevisionGraph(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        r1 = tree.commit('1st commit')

        r2 = tree.commit('2nd commit', rev_id=u'\xc8'.encode('utf-8'))

        tree.unlock()

        # the lines of revision_id->revision_parent_list has no guaranteed

        # order coming out of a dict, so sort both our test and response

        lines = sorted([' '.join([r2, r1]), r1])

        response = request.execute(backing.local_abspath(''), '')

        response.body = '\n'.join(sorted(response.body.split('\n')))

        self.assertEqual(

            SmartServerResponse(('ok', ), '\n'.join(lines)), response)

    def test_specific_revision_argument(self):

        backing = self.get_transport()

        request = smart.repository.SmartServerRepositoryGetRevisionGraph(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        rev_id_utf8 = u'\xc9'.encode('utf-8')

        r1 = tree.commit('1st commit', rev_id=rev_id_utf8)

        r2 = tree.commit('2nd commit', rev_id=u'\xc8'.encode('utf-8'))

        tree.unlock()

        self.assertEqual(SmartServerResponse(('ok', ), rev_id_utf8),

            request.execute(backing.local_abspath(''), rev_id_utf8))

    def test_no_such_revision(self):

        backing = self.get_transport()

        request = smart.repository.SmartServerRepositoryGetRevisionGraph(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        r1 = tree.commit('1st commit')

        tree.unlock()

        # Note that it still returns body (of zero bytes).

        self.assertEqual(

            SmartServerResponse(('nosuchrevision', 'missingrevision', ), ''),

            request.execute(backing.local_abspath(''), 'missingrevision'))

class TestSmartServerRequestHasRevision(tests.TestCaseWithTransport):

    def test_missing_revision(self):

        """For a missing revision, ('no', ) is returned."""

        backing = self.get_transport()

        request = smart.repository.SmartServerRequestHasRevision(backing)

        self.make_repository('.')

        self.assertEqual(SmartServerResponse(('no', )),

            request.execute(backing.local_abspath(''), 'revid'))

    def test_present_revision(self):

        """For a present revision, ('ok', ) is returned."""

        backing = self.get_transport()

        request = smart.repository.SmartServerRequestHasRevision(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        rev_id_utf8 = u'\xc8abc'.encode('utf-8')

        r1 = tree.commit('a commit', rev_id=rev_id_utf8)

        tree.unlock()

        self.assertTrue(tree.branch.repository.has_revision(rev_id_utf8))

        self.assertEqual(SmartServerResponse(('ok', )),

            request.execute(backing.local_abspath(''), rev_id_utf8))

class TestSmartServerRepositoryGatherStats(tests.TestCaseWithTransport):

    def test_empty_revid(self):

        """With an empty revid, we get only size an number and revisions"""

        backing = self.get_transport()

        request = smart.repository.SmartServerRepositoryGatherStats(backing)

        repository = self.make_repository('.')

        stats = repository.gather_stats()

        size = stats['size']

        expected_body = 'revisions: 0\nsize: %d\n' % size

        self.assertEqual(SmartServerResponse(('ok', ), expected_body),

                         request.execute(backing.local_abspath(''), '', 'no'))

    def test_revid_with_committers(self):

        """For a revid we get more infos."""

        backing = self.get_transport()

        rev_id_utf8 = u'\xc8abc'.encode('utf-8')

        request = smart.repository.SmartServerRepositoryGatherStats(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        # Let's build a predictable result

        tree.commit('a commit', timestamp=123456.2, timezone=3600)

        tree.commit('a commit', timestamp=654321.4, timezone=0,

                    rev_id=rev_id_utf8)

        tree.unlock()

        stats = tree.branch.repository.gather_stats()

        size = stats['size']

        expected_body = ('firstrev: 123456.200 3600\n'

                         'latestrev: 654321.400 0\n'

                         'revisions: 2\n'

                         'size: %d\n' % size)

        self.assertEqual(SmartServerResponse(('ok', ), expected_body),

                         request.execute(backing.local_abspath(''),

                                         rev_id_utf8, 'no'))

    def test_not_empty_repository_with_committers(self):

        """For a revid and requesting committers we get the whole thing."""

        backing = self.get_transport()

        rev_id_utf8 = u'\xc8abc'.encode('utf-8')

        request = smart.repository.SmartServerRepositoryGatherStats(backing)

        tree = self.make_branch_and_memory_tree('.')

        tree.lock_write()

        tree.add('')

        # Let's build a predictable result