~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2009, 2010, 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 bzrlib.inventory_delta.

See doc/developer/inventory.txt for more information.

"""

from cStringIO import StringIO

from bzrlib import (

    inventory,

    inventory_delta,

    )

from bzrlib.inventory_delta import InventoryDeltaError

from bzrlib.inventory import Inventory

from bzrlib.revision import NULL_REVISION

from bzrlib.tests import TestCase

### DO NOT REFLOW THESE TEXTS. NEW LINES ARE SIGNIFICANT. ###

empty_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: null:

versioned_root: true

tree_references: true

"""

root_only_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: entry-version

versioned_root: true

tree_references: true

None\x00/\x00an-id\x00\x00a@e\xc3\xa5ample.com--2004\x00dir

"""

root_change_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: entry-version

version: changed-root

versioned_root: true

tree_references: true

/\x00an-id\x00\x00different-version\x00dir

"""

corrupt_parent_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: entry-version

version: changed-root

versioned_root: false

tree_references: false

/\x00an-id\x00\x00different-version\x00dir

"""

root_only_unversioned = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: entry-version

versioned_root: false

tree_references: false

None\x00/\x00TREE_ROOT\x00\x00entry-version\x00dir

"""

reference_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: entry-version

versioned_root: true

tree_references: true

None\x00/\x00TREE_ROOT\x00\x00a@e\xc3\xa5ample.com--2004\x00dir

None\x00/foo\x00id\x00TREE_ROOT\x00changed\x00tree\x00subtree-version

"""

change_tree_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: entry-version

version: change-tree

versioned_root: false

tree_references: false

/foo\x00id\x00TREE_ROOT\x00changed-twice\x00tree\x00subtree-version2

"""

class TestDeserialization(TestCase):

    """Test InventoryDeltaSerializer.parse_text_bytes."""

    def test_parse_no_bytes(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(

            InventoryDeltaError, deserializer.parse_text_bytes, '')

        self.assertContainsRe(str(err), 'last line not empty')

    def test_parse_bad_format(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, 'format: foo\n')

        self.assertContainsRe(str(err), 'unknown format')

    def test_parse_no_parent(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes,

            'format: bzr inventory delta v1 (bzr 1.14)\n')

        self.assertContainsRe(str(err), 'missing parent: marker')

    def test_parse_no_version(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes,

            'format: bzr inventory delta v1 (bzr 1.14)\n'

            'parent: null:\n')

        self.assertContainsRe(str(err), 'missing version: marker')

    def test_parse_duplicate_key_errors(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        double_root_lines = \

"""format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: null:

versioned_root: true

tree_references: true

None\x00/\x00an-id\x00\x00a@e\xc3\xa5ample.com--2004\x00dir\x00\x00

None\x00/\x00an-id\x00\x00a@e\xc3\xa5ample.com--2004\x00dir\x00\x00

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, double_root_lines)

        self.assertContainsRe(str(err), 'duplicate file id')

    def test_parse_versioned_root_only(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        parse_result = deserializer.parse_text_bytes(root_only_lines)

        expected_entry = inventory.make_entry(

            'directory', u'', None, 'an-id')

        expected_entry.revision = 'a@e\xc3\xa5ample.com--2004'

        self.assertEqual(

            ('null:', 'entry-version', True, True,

             [(None, '', 'an-id', expected_entry)]),

            parse_result)

    def test_parse_special_revid_not_valid_last_mod(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        root_only_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: null:

versioned_root: false

tree_references: true

None\x00/\x00TREE_ROOT\x00\x00null:\x00dir\x00\x00

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, root_only_lines)

        self.assertContainsRe(str(err), 'special revisionid found')

    def test_parse_versioned_root_versioned_disabled(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        root_only_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: null:

versioned_root: false

tree_references: true

None\x00/\x00TREE_ROOT\x00\x00a@e\xc3\xa5ample.com--2004\x00dir\x00\x00

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, root_only_lines)

        self.assertContainsRe(str(err), 'Versioned root found')

    def test_parse_unique_root_id_root_versioned_disabled(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        root_only_lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: parent-id

version: a@e\xc3\xa5ample.com--2004

versioned_root: false

tree_references: true

None\x00/\x00an-id\x00\x00parent-id\x00dir\x00\x00

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, root_only_lines)

        self.assertContainsRe(str(err), 'Versioned root found')

    def test_parse_unversioned_root_versioning_enabled(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        parse_result = deserializer.parse_text_bytes(root_only_unversioned)

        expected_entry = inventory.make_entry(

            'directory', u'', None, 'TREE_ROOT')

        expected_entry.revision = 'entry-version'

        self.assertEqual(

            ('null:', 'entry-version', False, False,

             [(None, u'', 'TREE_ROOT', expected_entry)]),

            parse_result)

    def test_parse_versioned_root_when_disabled(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer(

            allow_versioned_root=False)

        err = self.assertRaises(inventory_delta.IncompatibleInventoryDelta,

            deserializer.parse_text_bytes, root_only_lines)

        self.assertEquals("versioned_root not allowed", str(err))

    def test_parse_tree_when_disabled(self):

        deserializer = inventory_delta.InventoryDeltaDeserializer(

            allow_tree_references=False)

        err = self.assertRaises(inventory_delta.IncompatibleInventoryDelta,

            deserializer.parse_text_bytes, reference_lines)

        self.assertEquals("Tree reference not allowed", str(err))

    def test_parse_tree_when_header_disallows(self):

        # A deserializer that allows tree_references to be set or unset.

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        # A serialised inventory delta with a header saying no tree refs, but

        # that has a tree ref in its content.

        lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: entry-version

versioned_root: false

tree_references: false

None\x00/foo\x00id\x00TREE_ROOT\x00changed\x00tree\x00subtree-version

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, lines)

        self.assertContainsRe(str(err), 'Tree reference found')

    def test_parse_versioned_root_when_header_disallows(self):

        # A deserializer that allows tree_references to be set or unset.

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        # A serialised inventory delta with a header saying no tree refs, but

        # that has a tree ref in its content.

        lines = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: entry-version

versioned_root: false

tree_references: false

None\x00/\x00TREE_ROOT\x00\x00a@e\xc3\xa5ample.com--2004\x00dir

"""

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, lines)

        self.assertContainsRe(str(err), 'Versioned root found')

    def test_parse_last_line_not_empty(self):

        """newpath must start with / if it is not None."""

        # Trim the trailing newline from a valid serialization

        lines = root_only_lines[:-1]

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, lines)

        self.assertContainsRe(str(err), 'last line not empty')

    def test_parse_invalid_newpath(self):

        """newpath must start with / if it is not None."""

        lines = empty_lines

        lines += "None\x00bad\x00TREE_ROOT\x00\x00version\x00dir\n"

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, lines)

        self.assertContainsRe(str(err), 'newpath invalid')

    def test_parse_invalid_oldpath(self):

        """oldpath must start with / if it is not None."""

        lines = root_only_lines

        lines += "bad\x00/new\x00file-id\x00\x00version\x00dir\n"

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        err = self.assertRaises(InventoryDeltaError,

            deserializer.parse_text_bytes, lines)

        self.assertContainsRe(str(err), 'oldpath invalid')

    def test_parse_new_file(self):

        """a new file is parsed correctly"""

        lines = root_only_lines

        fake_sha = "deadbeef" * 5

        lines += (

            "None\x00/new\x00file-id\x00an-id\x00version\x00file\x00123\x00" +

            "\x00" + fake_sha + "\n")

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        parse_result = deserializer.parse_text_bytes(lines)

        expected_entry = inventory.make_entry(

            'file', u'new', 'an-id', 'file-id')

        expected_entry.revision = 'version'

        expected_entry.text_size = 123

        expected_entry.text_sha1 = fake_sha

        delta = parse_result[4]

        self.assertEqual(

             (None, u'new', 'file-id', expected_entry), delta[-1])

    def test_parse_delete(self):

        lines = root_only_lines

        lines += (

            "/old-file\x00None\x00deleted-id\x00\x00null:\x00deleted\x00\x00\n")

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        parse_result = deserializer.parse_text_bytes(lines)

        delta = parse_result[4]

        self.assertEqual(

             (u'old-file', None, 'deleted-id', None), delta[-1])

class TestSerialization(TestCase):

    """Tests for InventoryDeltaSerializer.delta_to_lines."""

    def test_empty_delta_to_lines(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        self.assertEqual(StringIO(empty_lines).readlines(),

            serializer.delta_to_lines(NULL_REVISION, NULL_REVISION, delta))

    def test_root_only_to_lines(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'an-id')

        root.revision = 'a@e\xc3\xa5ample.com--2004'

        new_inv.add(root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        self.assertEqual(StringIO(root_only_lines).readlines(),

            serializer.delta_to_lines(NULL_REVISION, 'entry-version', delta))

    def test_unversioned_root(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        # Implicit roots are considered modified in every revision.

        root.revision = 'entry-version'

        new_inv.add(root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=False, tree_references=False)

        serialized_lines = serializer.delta_to_lines(

            NULL_REVISION, 'entry-version', delta)

        self.assertEqual(StringIO(root_only_unversioned).readlines(),

            serialized_lines)

        deserializer = inventory_delta.InventoryDeltaDeserializer()

        self.assertEqual(

            (NULL_REVISION, 'entry-version', False, False, delta),

            deserializer.parse_text_bytes(''.join(serialized_lines)))

    def test_unversioned_non_root_errors(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        root.revision = 'a@e\xc3\xa5ample.com--2004'

        new_inv.add(root)

        non_root = new_inv.make_entry('directory', 'foo', root.file_id, 'id')

        new_inv.add(non_root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        err = self.assertRaises(InventoryDeltaError,

            serializer.delta_to_lines, NULL_REVISION, 'entry-version', delta)

        self.assertEqual(str(err), 'no version for fileid id')

    def test_richroot_unversioned_root_errors(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        new_inv.add(root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        err = self.assertRaises(InventoryDeltaError,

            serializer.delta_to_lines, NULL_REVISION, 'entry-version', delta)

        self.assertEqual(str(err), 'no version for fileid TREE_ROOT')

    def test_nonrichroot_versioned_root_errors(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        root.revision = 'a@e\xc3\xa5ample.com--2004'

        new_inv.add(root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=False, tree_references=True)

        err = self.assertRaises(InventoryDeltaError,

            serializer.delta_to_lines, NULL_REVISION, 'entry-version', delta)

        self.assertStartsWith(str(err), 'Version present for / in TREE_ROOT')

    def test_unknown_kind_errors(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'my-rich-root-id')

        root.revision = 'changed'

        new_inv.add(root)

        class StrangeInventoryEntry(inventory.InventoryEntry):

            kind = 'strange'

        non_root = StrangeInventoryEntry('id', 'foo', root.file_id)

        non_root.revision = 'changed'

        new_inv.add(non_root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        # we expect keyerror because there is little value wrapping this.

        # This test aims to prove that it errors more than how it errors.

        err = self.assertRaises(KeyError,

            serializer.delta_to_lines, NULL_REVISION, 'entry-version', delta)

        self.assertEqual(('strange',), err.args)

    def test_tree_reference_disabled(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        root.revision = 'a@e\xc3\xa5ample.com--2004'

        new_inv.add(root)

        non_root = new_inv.make_entry(

            'tree-reference', 'foo', root.file_id, 'id')

        non_root.revision = 'changed'

        non_root.reference_revision = 'subtree-version'

        new_inv.add(non_root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=False)

        # we expect keyerror because there is little value wrapping this.

        # This test aims to prove that it errors more than how it errors.

        err = self.assertRaises(KeyError,

            serializer.delta_to_lines, NULL_REVISION, 'entry-version', delta)

        self.assertEqual(('tree-reference',), err.args)

    def test_tree_reference_enabled(self):

        old_inv = Inventory(None)

        new_inv = Inventory(None)

        root = new_inv.make_entry('directory', '', None, 'TREE_ROOT')

        root.revision = 'a@e\xc3\xa5ample.com--2004'

        new_inv.add(root)

        non_root = new_inv.make_entry(

            'tree-reference', 'foo', root.file_id, 'id')

        non_root.revision = 'changed'

        non_root.reference_revision = 'subtree-version'

        new_inv.add(non_root)

        delta = new_inv._make_delta(old_inv)

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        self.assertEqual(StringIO(reference_lines).readlines(),

            serializer.delta_to_lines(NULL_REVISION, 'entry-version', delta))

    def test_to_inventory_root_id_versioned_not_permitted(self):

        root_entry = inventory.make_entry('directory', '', None, 'TREE_ROOT')

        root_entry.revision = 'some-version'

        delta = [(None, '', 'TREE_ROOT', root_entry)]

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=False, tree_references=True)

        self.assertRaises(

            InventoryDeltaError, serializer.delta_to_lines, 'old-version',

            'new-version', delta)

    def test_to_inventory_root_id_not_versioned(self):

        delta = [(None, '', 'an-id', inventory.make_entry(

            'directory', '', None, 'an-id'))]

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        self.assertRaises(

            InventoryDeltaError, serializer.delta_to_lines, 'old-version',

            'new-version', delta)

    def test_to_inventory_has_tree_not_meant_to(self):

        make_entry = inventory.make_entry

        tree_ref = make_entry('tree-reference', 'foo', 'changed-in', 'ref-id')

        tree_ref.reference_revision = 'ref-revision'

        delta = [

            (None, '', 'an-id',

             make_entry('directory', '', 'changed-in', 'an-id')),

            (None, 'foo', 'ref-id', tree_ref)

            # a file that followed the root move

            ]

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        self.assertRaises(InventoryDeltaError, serializer.delta_to_lines,

            'old-version', 'new-version', delta)

    def test_to_inventory_torture(self):

        def make_entry(kind, name, parent_id, file_id, **attrs):

            entry = inventory.make_entry(kind, name, parent_id, file_id)

            for name, value in attrs.items():

                setattr(entry, name, value)

            return entry

        # this delta is crafted to have all the following:

        # - deletes

        # - renamed roots

        # - deep dirs

        # - files moved after parent dir was renamed

        # - files with and without exec bit

        delta = [

            # new root:

            (None, '', 'new-root-id',

                make_entry('directory', '', None, 'new-root-id',

                    revision='changed-in')),

            # an old root:

            ('', 'old-root', 'TREE_ROOT',

                make_entry('directory', 'subdir-now', 'new-root-id',

                'TREE_ROOT', revision='moved-root')),

            # a file that followed the root move

            ('under-old-root', 'old-root/under-old-root', 'moved-id',

                make_entry('file', 'under-old-root', 'TREE_ROOT', 'moved-id',

                   revision='old-rev', executable=False, text_size=30,

                   text_sha1='some-sha')),

            # a deleted path

            ('old-file', None, 'deleted-id', None),

            # a tree reference moved to the new root

            ('ref', 'ref', 'ref-id',

                make_entry('tree-reference', 'ref', 'new-root-id', 'ref-id',

                    reference_revision='tree-reference-id',

                    revision='new-rev')),

            # a symlink now in a deep dir

            ('dir/link', 'old-root/dir/link', 'link-id',

                make_entry('symlink', 'link', 'deep-id', 'link-id',

                   symlink_target='target', revision='new-rev')),

            # a deep dir

            ('dir', 'old-root/dir', 'deep-id',

                make_entry('directory', 'dir', 'TREE_ROOT', 'deep-id',

                    revision='new-rev')),

            # a file with an exec bit set

            (None, 'configure', 'exec-id',

                make_entry('file', 'configure', 'new-root-id', 'exec-id',

                   executable=True, text_size=30, text_sha1='some-sha',

                   revision='old-rev')),

            ]

        serializer = inventory_delta.InventoryDeltaSerializer(

            versioned_root=True, tree_references=True)

        lines = serializer.delta_to_lines(NULL_REVISION, 'something', delta)

        expected = """format: bzr inventory delta v1 (bzr 1.14)

parent: null:

version: something

versioned_root: true

tree_references: true

/\x00/old-root\x00TREE_ROOT\x00new-root-id\x00moved-root\x00dir

/dir\x00/old-root/dir\x00deep-id\x00TREE_ROOT\x00new-rev\x00dir

/dir/link\x00/old-root/dir/link\x00link-id\x00deep-id\x00new-rev\x00link\x00target

/old-file\x00None\x00deleted-id\x00\x00null:\x00deleted\x00\x00

/ref\x00/ref\x00ref-id\x00new-root-id\x00new-rev\x00tree\x00tree-reference-id

/under-old-root\x00/old-root/under-old-root\x00moved-id\x00TREE_ROOT\x00old-rev\x00file\x0030\x00\x00some-sha

None\x00/\x00new-root-id\x00\x00changed-in\x00dir

None\x00/configure\x00exec-id\x00new-root-id\x00old-rev\x00file\x0030\x00Y\x00some-sha

"""

        serialized = ''.join(lines)

        self.assertIsInstance(serialized, str)

        self.assertEqual(expected, serialized)

class TestContent(TestCase):

    """Test serialization of the content part of a line."""

    def test_dir(self):

        entry = inventory.make_entry('directory', 'a dir', None)

        self.assertEqual('dir', inventory_delta._directory_content(entry))

    def test_file_0_short_sha(self):

        file_entry = inventory.make_entry('file', 'a file', None, 'file-id')

        file_entry.text_sha1 = ''

        file_entry.text_size = 0

        self.assertEqual('file\x000\x00\x00',

            inventory_delta._file_content(file_entry))

    def test_file_10_foo(self):

        file_entry = inventory.make_entry('file', 'a file', None, 'file-id')

        file_entry.text_sha1 = 'foo'

        file_entry.text_size = 10

        self.assertEqual('file\x0010\x00\x00foo',

            inventory_delta._file_content(file_entry))

    def test_file_executable(self):

        file_entry = inventory.make_entry('file', 'a file', None, 'file-id')

        file_entry.executable = True

        file_entry.text_sha1 = 'foo'

        file_entry.text_size = 10

        self.assertEqual('file\x0010\x00Y\x00foo',

            inventory_delta._file_content(file_entry))

    def test_file_without_size(self):

        file_entry = inventory.make_entry('file', 'a file', None, 'file-id')

        file_entry.text_sha1 = 'foo'

        self.assertRaises(InventoryDeltaError,

            inventory_delta._file_content, file_entry)

    def test_file_without_sha1(self):

        file_entry = inventory.make_entry('file', 'a file', None, 'file-id')

        file_entry.text_size = 10

        self.assertRaises(InventoryDeltaError,

            inventory_delta._file_content, file_entry)

    def test_link_empty_target(self):

        entry = inventory.make_entry('symlink', 'a link', None)

        entry.symlink_target = ''

        self.assertEqual('link\x00',

            inventory_delta._link_content(entry))

    def test_link_unicode_target(self):

        entry = inventory.make_entry('symlink', 'a link', None)

        entry.symlink_target = ' \xc3\xa5'.decode('utf8')

        self.assertEqual('link\x00 \xc3\xa5',

            inventory_delta._link_content(entry))

    def test_link_space_target(self):

        entry = inventory.make_entry('symlink', 'a link', None)

        entry.symlink_target = ' '

        self.assertEqual('link\x00 ',

            inventory_delta._link_content(entry))

    def test_link_no_target(self):

        entry = inventory.make_entry('symlink', 'a link', None)

        self.assertRaises(InventoryDeltaError,

            inventory_delta._link_content, entry)

    def test_reference_null(self):

        entry = inventory.make_entry('tree-reference', 'a tree', None)

        entry.reference_revision = NULL_REVISION

        self.assertEqual('tree\x00null:',

            inventory_delta._reference_content(entry))

    def test_reference_revision(self):

        entry = inventory.make_entry('tree-reference', 'a tree', None)

        entry.reference_revision = 'foo@\xc3\xa5b-lah'

        self.assertEqual('tree\x00foo@\xc3\xa5b-lah',

            inventory_delta._reference_content(entry))

    def test_reference_no_reference(self):

        entry = inventory.make_entry('tree-reference', 'a tree', None)

        self.assertRaises(InventoryDeltaError,

            inventory_delta._reference_content, entry)