/brz/remove-bazaar

# Copyright (C) 2007-2012, 2016 Canonical Ltd

# Authors:  Robert Collins <robert.collins@canonical.com>

#

# 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 WorkingTreeFormat4"""

import os

import time

from .. import (

    errors,

    osutils,

    )

from ..bzr import (

    bzrdir,

    dirstate,

    inventory,

    workingtree_4,

    )

from ..lockdir import LockDir

from . import TestCaseWithTransport, TestSkipped, features

from ..tree import InterTree

class TestWorkingTreeFormat4(TestCaseWithTransport):

    """Tests specific to WorkingTreeFormat4."""

    def test_disk_layout(self):

        control = bzrdir.BzrDirMetaFormat1().initialize(self.get_url())

        control.create_repository()

        control.create_branch()

        tree = workingtree_4.WorkingTreeFormat4().initialize(control)

        # we want:

        # format 'Bazaar Working Tree format 4'

        # stat-cache = ??

        t = control.get_workingtree_transport(None)

        self.assertEqualDiff('Bazaar Working Tree Format 4 (bzr 0.15)\n',

                             t.get('format').read())

        self.assertFalse(t.has('inventory.basis'))

        # no last-revision file means 'None' or 'NULLREVISION'

        self.assertFalse(t.has('last-revision'))

        state = dirstate.DirState.on_file(t.local_abspath('dirstate'))

        state.lock_read()

        try:

            self.assertEqual([], state.get_parent_ids())

        finally:

            state.unlock()

    def test_resets_ignores_on_last_unlock(self):

        # Only the last unlock call will actually reset the

        # ignores. (bug #785671)

        tree = self.make_workingtree()

        tree.lock_read()

        try:

            tree.lock_read()

            try:

                tree.is_ignored("foo")

            finally:

                tree.unlock()

            self.assertIsNot(None, tree._ignoreglobster)

        finally:

            tree.unlock()

        self.assertIs(None, tree._ignoreglobster)

    def test_uses_lockdir(self):

        """WorkingTreeFormat4 uses its own LockDir:

            - lock is a directory

            - when the WorkingTree is locked, LockDir can see that

        """

        # this test could be factored into a subclass of tests common to both

        # format 3 and 4, but for now its not much of an issue as there is only

        # one in common.

        t = self.get_transport()

        tree = self.make_workingtree()

        self.assertIsDirectory('.bzr', t)

        self.assertIsDirectory('.bzr/checkout', t)

        self.assertIsDirectory('.bzr/checkout/lock', t)

        our_lock = LockDir(t, '.bzr/checkout/lock')

        self.assertEqual(our_lock.peek(), None)

        tree.lock_write()

        self.assertTrue(our_lock.peek())

        tree.unlock()

        self.assertEqual(our_lock.peek(), None)

    def make_workingtree(self, relpath=''):

        url = self.get_url(relpath)

        if relpath:

            self.build_tree([relpath + '/'])

        dir = bzrdir.BzrDirMetaFormat1().initialize(url)

        repo = dir.create_repository()

        branch = dir.create_branch()

        try:

            return workingtree_4.WorkingTreeFormat4().initialize(dir)

        except errors.NotLocalUrl:

            raise TestSkipped('Not a local URL')

    def test_dirstate_stores_all_parent_inventories(self):

        tree = self.make_workingtree()

        # We're going to build in tree a working tree

        # with three parent trees, with some files in common.

        # We really don't want to do commit or merge in the new dirstate-based

        # tree, because that might not work yet.  So instead we build

        # revisions elsewhere and pull them across, doing by hand part of the

        # work that merge would do.

        subtree = self.make_branch_and_tree('subdir')

        # writelock the tree so its repository doesn't get readlocked by

        # the revision tree locks. This works around the bug where we dont

        # permit lock upgrading.

        subtree.lock_write()

        self.addCleanup(subtree.unlock)

        self.build_tree(['subdir/file-a',])

        subtree.add(['file-a'], [b'id-a'])

        rev1 = subtree.commit('commit in subdir')

        subtree2 = subtree.controldir.sprout('subdir2').open_workingtree()

        self.build_tree(['subdir2/file-b'])

        subtree2.add(['file-b'], [b'id-b'])

        rev2 = subtree2.commit('commit in subdir2')

        subtree.flush()

        subtree3 = subtree.controldir.sprout('subdir3').open_workingtree()

        rev3 = subtree3.commit('merge from subdir2')

        repo = tree.branch.repository

        repo.fetch(subtree.branch.repository, rev1)

        repo.fetch(subtree2.branch.repository, rev2)

        repo.fetch(subtree3.branch.repository, rev3)

        # will also pull the others...

        # create repository based revision trees

        rev1_revtree = repo.revision_tree(rev1)

        rev2_revtree = repo.revision_tree(rev2)

        rev3_revtree = repo.revision_tree(rev3)

        # tree doesn't contain a text merge yet but we'll just

        # set the parents as if a merge had taken place.

        # this should cause the tree data to be folded into the

        # dirstate.

        tree.set_parent_trees([

            (rev1, rev1_revtree),

            (rev2, rev2_revtree),

            (rev3, rev3_revtree), ])

        # create tree-sourced revision trees

        rev1_tree = tree.revision_tree(rev1)

        rev1_tree.lock_read()

        self.addCleanup(rev1_tree.unlock)

        rev2_tree = tree.revision_tree(rev2)

        rev2_tree.lock_read()

        self.addCleanup(rev2_tree.unlock)

        rev3_tree = tree.revision_tree(rev3)

        rev3_tree.lock_read()

        self.addCleanup(rev3_tree.unlock)

        # now we should be able to get them back out

        self.assertTreesEqual(rev1_revtree, rev1_tree)

        self.assertTreesEqual(rev2_revtree, rev2_tree)

        self.assertTreesEqual(rev3_revtree, rev3_tree)

    def test_dirstate_doesnt_read_parents_from_repo_when_setting(self):

        """Setting parent trees on a dirstate working tree takes

        the trees it's given and doesn't need to read them from the

        repository.

        """

        tree = self.make_workingtree()

        subtree = self.make_branch_and_tree('subdir')

        rev1 = subtree.commit('commit in subdir')

        rev1_tree = subtree.basis_tree()

        rev1_tree.lock_read()

        self.addCleanup(rev1_tree.unlock)

        tree.branch.pull(subtree.branch)

        # break the repository's legs to make sure it only uses the trees

        # it's given; any calls to forbidden methods will raise an

        # AssertionError

        repo = tree.branch.repository

        self.overrideAttr(repo, "get_revision", self.fail)

        self.overrideAttr(repo, "get_inventory", self.fail)

        self.overrideAttr(repo, "_get_inventory_xml", self.fail)

        # try to set the parent trees.

        tree.set_parent_trees([(rev1, rev1_tree)])

    def test_dirstate_doesnt_read_from_repo_when_returning_cache_tree(self):

        """Getting parent trees from a dirstate tree does not read from the

        repos inventory store. This is an important part of the dirstate

        performance optimisation work.

        """

        tree = self.make_workingtree()

        subtree = self.make_branch_and_tree('subdir')

        # writelock the tree so its repository doesn't get readlocked by

        # the revision tree locks. This works around the bug where we dont

        # permit lock upgrading.

        subtree.lock_write()

        self.addCleanup(subtree.unlock)

        rev1 = subtree.commit('commit in subdir')

        rev1_tree = subtree.basis_tree()

        rev1_tree.lock_read()

        rev1_tree.root_inventory

        self.addCleanup(rev1_tree.unlock)

        rev2 = subtree.commit('second commit in subdir', allow_pointless=True)

        rev2_tree = subtree.basis_tree()

        rev2_tree.lock_read()

        rev2_tree.root_inventory

        self.addCleanup(rev2_tree.unlock)

        tree.branch.pull(subtree.branch)

        # break the repository's legs to make sure it only uses the trees

        # it's given; any calls to forbidden methods will raise an

        # AssertionError

        repo = tree.branch.repository

        # dont uncomment this: the revision object must be accessed to

        # answer 'get_parent_ids' for the revision tree- dirstate does not

        # cache the parents of a parent tree at this point.

        #repo.get_revision = self.fail

        self.overrideAttr(repo, "get_inventory", self.fail)

        self.overrideAttr(repo, "_get_inventory_xml", self.fail)

        # set the parent trees.

        tree.set_parent_trees([(rev1, rev1_tree), (rev2, rev2_tree)])

        # read the first tree

        result_rev1_tree = tree.revision_tree(rev1)

        # read the second

        result_rev2_tree = tree.revision_tree(rev2)

        # compare - there should be no differences between the handed and

        # returned trees

        self.assertTreesEqual(rev1_tree, result_rev1_tree)

        self.assertTreesEqual(rev2_tree, result_rev2_tree)

    def test_dirstate_doesnt_cache_non_parent_trees(self):

        """Getting parent trees from a dirstate tree does not read from the

        repos inventory store. This is an important part of the dirstate

        performance optimisation work.

        """

        tree = self.make_workingtree()

        # make a tree that we can try for, which is able to be returned but

        # must not be

        subtree = self.make_branch_and_tree('subdir')

        rev1 = subtree.commit('commit in subdir')

        tree.branch.pull(subtree.branch)

        # check it fails

        self.assertRaises(errors.NoSuchRevision, tree.revision_tree, rev1)

    def test_no_dirstate_outside_lock(self):

        # temporary test until the code is mature enough to test from outside.

        """Getting a dirstate object fails if there is no lock."""

        def lock_and_call_current_dirstate(tree, lock_method):

            getattr(tree, lock_method)()

            tree.current_dirstate()

            tree.unlock()

        tree = self.make_workingtree()

        self.assertRaises(errors.ObjectNotLocked, tree.current_dirstate)

        lock_and_call_current_dirstate(tree, 'lock_read')

        self.assertRaises(errors.ObjectNotLocked, tree.current_dirstate)

        lock_and_call_current_dirstate(tree, 'lock_write')

        self.assertRaises(errors.ObjectNotLocked, tree.current_dirstate)

        lock_and_call_current_dirstate(tree, 'lock_tree_write')

        self.assertRaises(errors.ObjectNotLocked, tree.current_dirstate)

    def test_set_parent_trees_uses_update_basis_by_delta(self):

        builder = self.make_branch_builder('source')

        builder.start_series()

        self.addCleanup(builder.finish_series)

        builder.build_snapshot([], [

            ('add', ('', b'root-id', 'directory', None)),

            ('add', ('a', b'a-id', 'file', b'content\n'))],

            revision_id=b'A')

        builder.build_snapshot([b'A'], [

            ('modify', ('a', b'new content\nfor a\n')),

            ('add', ('b', b'b-id', 'file', b'b-content\n'))],

            revision_id=b'B')

        tree = self.make_workingtree('tree')

        source_branch = builder.get_branch()

        tree.branch.repository.fetch(source_branch.repository, b'B')

        tree.pull(source_branch, stop_revision=b'A')

        tree.lock_write()

        self.addCleanup(tree.unlock)

        state = tree.current_dirstate()

        called = []

        orig_update = state.update_basis_by_delta

        def log_update_basis_by_delta(delta, new_revid):

            called.append(new_revid)

            return orig_update(delta, new_revid)

        state.update_basis_by_delta = log_update_basis_by_delta

        basis = tree.basis_tree()

        self.assertEqual(b'a-id', basis.path2id('a'))

        self.assertFalse(basis.is_versioned('b'))

        def fail_set_parent_trees(trees, ghosts):

            raise AssertionError('dirstate.set_parent_trees() was called')

        state.set_parent_trees = fail_set_parent_trees

        repo = tree.branch.repository

        tree.pull(source_branch, stop_revision=b'B')

        self.assertEqual([b'B'], called)

        basis = tree.basis_tree()

        self.assertEqual(b'a-id', basis.path2id('a'))

        self.assertEqual(b'b-id', basis.path2id('b'))

    def test_set_parent_trees_handles_missing_basis(self):

        builder = self.make_branch_builder('source')

        builder.start_series()

        self.addCleanup(builder.finish_series)

        builder.build_snapshot([], [

            ('add', ('', b'root-id', 'directory', None)),

            ('add', ('a', b'a-id', 'file', b'content\n'))],

            revision_id=b'A')

        builder.build_snapshot([b'A'], [

            ('modify', ('a', b'new content\nfor a\n')),

            ('add', ('b', b'b-id', 'file', b'b-content\n'))],

            revision_id=b'B')

        builder.build_snapshot([b'A'], [

            ('add', ('c', b'c-id', 'file', b'c-content\n'))],

            revision_id=b'C')

        b_c = self.make_branch('branch_with_c')

        b_c.pull(builder.get_branch(), stop_revision=b'C')

        b_b = self.make_branch('branch_with_b')

        b_b.pull(builder.get_branch(), stop_revision=b'B')

        # This is reproducing some of what 'switch' does, just to isolate the

        # set_parent_trees() step.

        wt = b_b.create_checkout('tree', lightweight=True)

        fmt = wt.controldir.find_branch_format()

        fmt.set_reference(wt.controldir, None, b_c)

        # Re-open with the new reference

        wt = wt.controldir.open_workingtree()

        wt.set_parent_trees([(b'C', b_c.repository.revision_tree(b'C'))])

        self.assertFalse(wt.basis_tree().is_versioned('b'))

    def test_new_dirstate_on_new_lock(self):

        # until we have detection for when a dirstate can be reused, we

        # want to reparse dirstate on every new lock.

        known_dirstates = set()

        def lock_and_compare_all_current_dirstate(tree, lock_method):

            getattr(tree, lock_method)()

            state = tree.current_dirstate()

            self.assertFalse(state in known_dirstates)

            known_dirstates.add(state)

            tree.unlock()

        tree = self.make_workingtree()

        # lock twice with each type to prevent silly per-lock-type bugs.

        # each lock and compare looks for a unique state object.

        lock_and_compare_all_current_dirstate(tree, 'lock_read')

        lock_and_compare_all_current_dirstate(tree, 'lock_read')

        lock_and_compare_all_current_dirstate(tree, 'lock_tree_write')

        lock_and_compare_all_current_dirstate(tree, 'lock_tree_write')

        lock_and_compare_all_current_dirstate(tree, 'lock_write')

        lock_and_compare_all_current_dirstate(tree, 'lock_write')

    def test_constructing_invalid_interdirstate_raises(self):

        tree = self.make_workingtree()

        rev_id = tree.commit('first post')

        rev_id2 = tree.commit('second post')

        rev_tree = tree.branch.repository.revision_tree(rev_id)

        # Exception is not a great thing to raise, but this test is

        # very short, and code is used to sanity check other tests, so

        # a full error object is YAGNI.

        self.assertRaises(

            Exception, workingtree_4.InterDirStateTree, rev_tree, tree)

        self.assertRaises(

            Exception, workingtree_4.InterDirStateTree, tree, rev_tree)

    def test_revtree_to_revtree_not_interdirstate(self):

        # we should not get a dirstate optimiser for two repository sourced

        # revtrees. we can't prove a negative, so we dont do exhaustive tests

        # of all formats; though that could be written in the future it doesn't

        # seem well worth it.

        tree = self.make_workingtree()

        rev_id = tree.commit('first post')

        rev_id2 = tree.commit('second post')

        rev_tree = tree.branch.repository.revision_tree(rev_id)

        rev_tree2 = tree.branch.repository.revision_tree(rev_id2)

        optimiser = InterTree.get(rev_tree, rev_tree2)

        self.assertIsInstance(optimiser, InterTree)

        self.assertFalse(isinstance(optimiser, workingtree_4.InterDirStateTree))

        optimiser = InterTree.get(rev_tree2, rev_tree)

        self.assertIsInstance(optimiser, InterTree)

        self.assertFalse(isinstance(optimiser, workingtree_4.InterDirStateTree))

    def test_revtree_not_in_dirstate_to_dirstate_not_interdirstate(self):

        # we should not get a dirstate optimiser when the revision id for of

        # the source is not in the dirstate of the target.

        tree = self.make_workingtree()

        rev_id = tree.commit('first post')

        rev_id2 = tree.commit('second post')

        rev_tree = tree.branch.repository.revision_tree(rev_id)

        tree.lock_read()

        optimiser = InterTree.get(rev_tree, tree)

        self.assertIsInstance(optimiser, InterTree)

        self.assertFalse(isinstance(optimiser, workingtree_4.InterDirStateTree))

        optimiser = InterTree.get(tree, rev_tree)

        self.assertIsInstance(optimiser, InterTree)

        self.assertFalse(isinstance(optimiser, workingtree_4.InterDirStateTree))

        tree.unlock()

    def test_empty_basis_to_dirstate_tree(self):

        # we should get a InterDirStateTree for doing

        # 'changes_from' from the first basis dirstate revision tree to a

        # WorkingTree4.

        tree = self.make_workingtree()

        tree.lock_read()

        basis_tree = tree.basis_tree()

        basis_tree.lock_read()

        optimiser = InterTree.get(basis_tree, tree)

        tree.unlock()

        basis_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_nonempty_basis_to_dirstate_tree(self):

        # we should get a InterDirStateTree for doing

        # 'changes_from' from a non-null basis dirstate revision tree to a

        # WorkingTree4.

        tree = self.make_workingtree()

        tree.commit('first post')

        tree.lock_read()

        basis_tree = tree.basis_tree()

        basis_tree.lock_read()

        optimiser = InterTree.get(basis_tree, tree)

        tree.unlock()

        basis_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_empty_basis_revtree_to_dirstate_tree(self):

        # we should get a InterDirStateTree for doing

        # 'changes_from' from an empty repository based rev tree to a

        # WorkingTree4.

        tree = self.make_workingtree()

        tree.lock_read()

        basis_tree = tree.branch.repository.revision_tree(tree.last_revision())

        basis_tree.lock_read()

        optimiser = InterTree.get(basis_tree, tree)

        tree.unlock()

        basis_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_nonempty_basis_revtree_to_dirstate_tree(self):

        # we should get a InterDirStateTree for doing

        # 'changes_from' from a non-null repository based rev tree to a

        # WorkingTree4.

        tree = self.make_workingtree()

        tree.commit('first post')

        tree.lock_read()

        basis_tree = tree.branch.repository.revision_tree(tree.last_revision())

        basis_tree.lock_read()

        optimiser = InterTree.get(basis_tree, tree)

        tree.unlock()

        basis_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_tree_to_basis_in_other_tree(self):

        # we should get a InterDirStateTree when

        # the source revid is in the dirstate object of the target and

        # the dirstates are different. This is largely covered by testing

        # with repository revtrees, so is just for extra confidence.

        tree = self.make_workingtree('a')

        tree.commit('first post')

        tree2 = self.make_workingtree('b')

        tree2.pull(tree.branch)

        basis_tree = tree.basis_tree()

        tree2.lock_read()

        basis_tree.lock_read()

        optimiser = InterTree.get(basis_tree, tree2)

        tree2.unlock()

        basis_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_merged_revtree_to_tree(self):

        # we should get a InterDirStateTree when

        # the source tree is a merged tree present in the dirstate of target.

        tree = self.make_workingtree('a')

        tree.commit('first post')

        tree.commit('tree 1 commit 2')

        tree2 = self.make_workingtree('b')

        tree2.pull(tree.branch)

        tree2.commit('tree 2 commit 2')

        tree.merge_from_branch(tree2.branch)

        second_parent_tree = tree.revision_tree(tree.get_parent_ids()[1])

        second_parent_tree.lock_read()

        tree.lock_read()

        optimiser = InterTree.get(second_parent_tree, tree)

        tree.unlock()

        second_parent_tree.unlock()

        self.assertIsInstance(optimiser, workingtree_4.InterDirStateTree)

    def test_id2path(self):

        tree = self.make_workingtree('tree')

        self.build_tree(['tree/a', 'tree/b'])

        tree.add(['a'], [b'a-id'])

        self.assertEqual(u'a', tree.id2path(b'a-id'))

        self.assertRaises(errors.NoSuchId, tree.id2path, 'a')

        tree.commit('a')

        tree.add(['b'], [b'b-id'])

        try:

            new_path = u'b\u03bcrry'

            tree.rename_one('a', new_path)

        except UnicodeEncodeError:

            # support running the test on non-unicode platforms

            new_path = 'c'

            tree.rename_one('a', new_path)

        self.assertEqual(new_path, tree.id2path(b'a-id'))

        tree.commit(u'b\xb5rry')

        tree.unversion([new_path])

        self.assertRaises(errors.NoSuchId, tree.id2path, b'a-id')

        self.assertEqual('b', tree.id2path(b'b-id'))

        self.assertRaises(errors.NoSuchId, tree.id2path, b'c-id')

    def test_unique_root_id_per_tree(self):

        # each time you initialize a new tree, it gets a different root id

        format_name = 'development-subtree'

        tree1 = self.make_branch_and_tree('tree1',

            format=format_name)

        tree2 = self.make_branch_and_tree('tree2',

            format=format_name)

        self.assertNotEqual(tree1.get_root_id(), tree2.get_root_id())

        # when you branch, it inherits the same root id

        rev1 = tree1.commit('first post')

        tree3 = tree1.controldir.sprout('tree3').open_workingtree()

        self.assertEqual(tree3.get_root_id(), tree1.get_root_id())

    def test_set_root_id(self):

        # similar to some code that fails in the dirstate-plus-subtree branch

        # -- setting the root id while adding a parent seems to scramble the

        # dirstate invariants. -- mbp 20070303

        def validate():

            wt.lock_read()

            try:

                wt.current_dirstate()._validate()

            finally:

                wt.unlock()

        wt = self.make_workingtree('tree')

        wt.set_root_id(b'TREE-ROOTID')

        validate()

        wt.commit('somenthing')

        validate()

        # now switch and commit again

        wt.set_root_id(b'tree-rootid')

        validate()

        wt.commit('again')

        validate()

    def test_default_root_id(self):

        tree = self.make_branch_and_tree('tag', format='dirstate-tags')

        self.assertEqual(inventory.ROOT_ID, tree.get_root_id())

        tree = self.make_branch_and_tree('subtree',

                                         format='development-subtree')

        self.assertNotEqual(inventory.ROOT_ID, tree.get_root_id())

    def test_non_subtree_with_nested_trees(self):

        # prior to dirstate, st/diff/commit ignored nested trees.

        # dirstate, as opposed to development-subtree, should

        # behave the same way.

        tree = self.make_branch_and_tree('.', format='dirstate')

        self.assertFalse(tree.supports_tree_reference())

        self.build_tree(['dir/'])

        # for testing easily.

        tree.set_root_id(b'root')

        tree.add(['dir'], [b'dir-id'])

        subtree = self.make_branch_and_tree('dir')

        # the most primitive operation: kind

        self.assertEqual('directory', tree.kind('dir'))

        # a diff against the basis should give us a directory and the root (as

        # the root is new too).

        tree.lock_read()

        expected = [(b'dir-id',

            (None, u'dir'),

            True,

            (False, True),

            (None, 'root'),

            (None, u'dir'),

            (None, 'directory'),

            (None, False)),

            ('root', (None, u''), True, (False, True), (None, None),

            (None, u''), (None, 'directory'), (None, 0))]

        self.assertEqual(expected, list(tree.iter_changes(tree.basis_tree(),

            specific_files=['dir'])))

        tree.unlock()

        # do a commit, we want to trigger the dirstate fast-path too

        tree.commit('first post')

        # change the path for the subdir, which will trigger getting all

        # its data:

        os.rename('dir', 'also-dir')

        # now the diff will use the fast path

        tree.lock_read()

        expected = [(b'dir-id',

            (u'dir', u'dir'),

            True,

            (True, True),

            ('root', 'root'),

            ('dir', 'dir'),

            ('directory', None),

            (False, False))]

        self.assertEqual(expected, list(tree.iter_changes(tree.basis_tree())))

        tree.unlock()

    def test_with_subtree_supports_tree_references(self):

        # development-subtree should support tree-references.

        tree = self.make_branch_and_tree('.', format='development-subtree')

        self.assertTrue(tree.supports_tree_reference())

        # having checked this is on, the tree interface, and intertree

        # interface tests, will proceed to test the subtree support of

        # workingtree_4.

    def test_iter_changes_ignores_unversioned_dirs(self):

        """iter_changes should not descend into unversioned directories."""

        tree = self.make_branch_and_tree('.', format='dirstate')

        # We have an unversioned directory at the root, a versioned one with

        # other versioned files and an unversioned directory, and another

        # versioned dir with nothing but an unversioned directory.

        self.build_tree(['unversioned/',

                         'unversioned/a',

                         'unversioned/b/',

                         'versioned/',

                         'versioned/unversioned/',

                         'versioned/unversioned/a',

                         'versioned/unversioned/b/',

                         'versioned2/',

                         'versioned2/a',

                         'versioned2/unversioned/',

                         'versioned2/unversioned/a',

                         'versioned2/unversioned/b/',

                        ])

        tree.add(['versioned', 'versioned2', 'versioned2/a'])

        tree.commit('one', rev_id=b'rev-1')

        # Trap osutils._walkdirs_utf8 to spy on what dirs have been accessed.

        returned = []