plumbing/object: move difftree to object package

- To avoid ciclic dependency errors, we move all the difftree files to object package.
- Added Diff method to Tree object.

7 files changed, 0 insertions, 1478 deletions

diff --git a/plumbing/difftree/change.go b/plumbing/difftree/change.go
deleted file mode 100644
index c636577..0000000
--- a/plumbing/difftree/change.go
+++ /dev/null
@@ -1,121 +0,0 @@
-package difftree
-
-import (
-	"bytes"
-	"fmt"
-	"strings"
-
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/utils/merkletrie"
-)
-
-// Change values represent a detected change between two git trees.  For
-// modifications, From is the original status of the node and To is its
-// final status.  For insertions, From is the zero value and for
-// deletions To is the zero value.
-type Change struct {
-	From ChangeEntry
-	To   ChangeEntry
-}
-
-var empty = ChangeEntry{}
-
-// Action returns the kind of action represented by the change, an
-// insertion, a deletion or a modification.
-func (c *Change) Action() (merkletrie.Action, error) {
-	if c.From == empty && c.To == empty {
-		return merkletrie.Action(0),
-			fmt.Errorf("malformed change: empty from and to")
-	}
-	if c.From == empty {
-		return merkletrie.Insert, nil
-	}
-	if c.To == empty {
-		return merkletrie.Delete, nil
-	}
-
-	return merkletrie.Modify, nil
-}
-
-// Files return the files before and after a change.
-// For insertions from will be nil. For deletions to will be nil.
-func (c *Change) Files() (from, to *object.File, err error) {
-	action, err := c.Action()
-	if err != nil {
-		return
-	}
-
-	if action == merkletrie.Insert || action == merkletrie.Modify {
-		to, err = c.To.Tree.TreeEntryFile(&c.To.TreeEntry)
-		if err != nil {
-			return
-		}
-	}
-
-	if action == merkletrie.Delete || action == merkletrie.Modify {
-		from, err = c.From.Tree.TreeEntryFile(&c.From.TreeEntry)
-		if err != nil {
-			return
-		}
-	}
-
-	return
-}
-
-func (c *Change) String() string {
-	action, err := c.Action()
-	if err != nil {
-		return fmt.Sprintf("malformed change")
-	}
-
-	return fmt.Sprintf("<Action: %s, Path: %s>", action, c.name())
-}
-
-func (c *Change) name() string {
-	if c.From != empty {
-		return c.From.Name
-	}
-
-	return c.To.Name
-}
-
-// ChangeEntry values represent a node that has suffered a change.
-type ChangeEntry struct {
-	// Full path of the node using "/" as separator.
-	Name string
-	// Parent tree of the node that has changed.
-	Tree *object.Tree
-	// The entry of the node.
-	TreeEntry object.TreeEntry
-}
-
-// Changes represents a collection of changes between two git trees.
-// Implements sort.Interface lexicographically over the path of the
-// changed files.
-type Changes []*Change
-
-func (c Changes) Len() int {
-	return len(c)
-}
-
-func (c Changes) Swap(i, j int) {
-	c[i], c[j] = c[j], c[i]
-}
-
-func (c Changes) Less(i, j int) bool {
-	return strings.Compare(c[i].name(), c[j].name()) < 0
-}
-
-func (c Changes) String() string {
-	var buffer bytes.Buffer
-	buffer.WriteString("[")
-	comma := ""
-	for _, v := range c {
-		buffer.WriteString(comma)
-		buffer.WriteString(v.String())
-		comma = ", "
-	}
-	buffer.WriteString("]")
-
-	return buffer.String()
-}
diff --git a/plumbing/difftree/change_adaptor.go b/plumbing/difftree/change_adaptor.go
deleted file mode 100644
index edc20b3..0000000
--- a/plumbing/difftree/change_adaptor.go
+++ /dev/null
@@ -1,61 +0,0 @@
-package difftree
-
-// The folowing functions transform changes types form the merkletrie
-// package to changes types from this package.
-
-import (
-	"fmt"
-
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/utils/merkletrie"
-	"srcd.works/go-git.v4/utils/merkletrie/noder"
-)
-
-func newChange(c merkletrie.Change) (*Change, error) {
-	ret := &Change{}
-
-	var err error
-	if ret.From, err = newChangeEntry(c.From); err != nil {
-		return nil, fmt.Errorf("From field: ", err)
-	}
-
-	if ret.To, err = newChangeEntry(c.To); err != nil {
-		return nil, fmt.Errorf("To field: ", err)
-	}
-
-	return ret, nil
-}
-
-func newChangeEntry(p noder.Path) (ChangeEntry, error) {
-	if p == nil {
-		return empty, nil
-	}
-
-	asTreeNoder, ok := p.Last().(*treeNoder)
-	if !ok {
-		return ChangeEntry{}, fmt.Errorf("cannot transform non-TreeNoders")
-	}
-
-	return ChangeEntry{
-		Name: p.String(),
-		Tree: asTreeNoder.parent,
-		TreeEntry: object.TreeEntry{
-			Name: asTreeNoder.name,
-			Mode: asTreeNoder.mode,
-			Hash: asTreeNoder.hash,
-		},
-	}, nil
-}
-
-func newChanges(src merkletrie.Changes) (Changes, error) {
-	ret := make(Changes, len(src))
-	var err error
-	for i, e := range src {
-		ret[i], err = newChange(e)
-		if err != nil {
-			return nil, fmt.Errorf("change #%d: %s", err)
-		}
-	}
-
-	return ret, nil
-}
diff --git a/plumbing/difftree/change_adaptor_test.go b/plumbing/difftree/change_adaptor_test.go
deleted file mode 100644
index 2ce2c54..0000000
--- a/plumbing/difftree/change_adaptor_test.go
+++ /dev/null
@@ -1,413 +0,0 @@
-package difftree
-
-import (
-	"os"
-	"sort"
-
-	"srcd.works/go-git.v4/plumbing"
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/plumbing/storer"
-	"srcd.works/go-git.v4/storage/filesystem"
-	"srcd.works/go-git.v4/utils/merkletrie"
-	"srcd.works/go-git.v4/utils/merkletrie/noder"
-
-	"github.com/src-d/go-git-fixtures"
-	. "gopkg.in/check.v1"
-)
-
-type ChangeAdaptorSuite struct {
-	fixtures.Suite
-	Storer  storer.EncodedObjectStorer
-	Fixture *fixtures.Fixture
-}
-
-func (s *ChangeAdaptorSuite) SetUpSuite(c *C) {
-	s.Suite.SetUpSuite(c)
-	s.Fixture = fixtures.Basic().One()
-	sto, err := filesystem.NewStorage(s.Fixture.DotGit())
-	c.Assert(err, IsNil)
-	s.Storer = sto
-}
-
-func (s *ChangeAdaptorSuite) tree(c *C, h plumbing.Hash) *object.Tree {
-	t, err := object.GetTree(s.Storer, h)
-	c.Assert(err, IsNil)
-	return t
-}
-
-var _ = Suite(&ChangeAdaptorSuite{})
-
-// utility function to build Noders from a tree and an tree entry.
-func newNoder(t *object.Tree, e object.TreeEntry) noder.Noder {
-	return &treeNoder{
-		parent: t,
-		name:   e.Name,
-		mode:   e.Mode,
-		hash:   e.Hash,
-	}
-}
-
-// utility function to build Paths
-func newPath(nn ...noder.Noder) noder.Path { return noder.Path(nn) }
-
-func (s *ChangeAdaptorSuite) TestTreeNoderHashHasMode(c *C) {
-	hash := plumbing.NewHash("aaaa")
-	mode := object.FileMode
-
-	treeNoder := &treeNoder{
-		hash: hash,
-		mode: mode,
-	}
-
-	expected := []byte{
-		0xaa, 0xaa, 0x00, 0x00, // original hash is aaaa and 16 zeros
-		0x00, 0x00, 0x00, 0x00,
-		0x00, 0x00, 0x00, 0x00,
-		0x00, 0x00, 0x00, 0x00,
-		0x00, 0x00, 0x00, 0x00,
-		0xa4, 0x81, 0x00, 0x00, // object.FileMode in little endian
-	}
-
-	c.Assert(treeNoder.Hash(), DeepEquals, expected)
-}
-
-func (s *ChangeAdaptorSuite) TestNewChangeInsert(c *C) {
-	tree := &object.Tree{}
-	entry := object.TreeEntry{
-		Name: "name",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("aaaaa"),
-	}
-	path := newPath(newNoder(tree, entry))
-
-	expectedTo, err := newChangeEntry(path)
-	c.Assert(err, IsNil)
-
-	src := merkletrie.Change{
-		From: nil,
-		To:   path,
-	}
-
-	obtained, err := newChange(src)
-	c.Assert(err, IsNil)
-	action, err := obtained.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Insert)
-	c.Assert(obtained.From, Equals, ChangeEntry{})
-	c.Assert(obtained.To, Equals, expectedTo)
-}
-
-func (s *ChangeAdaptorSuite) TestNewChangeDelete(c *C) {
-	tree := &object.Tree{}
-	entry := object.TreeEntry{
-		Name: "name",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("aaaaa"),
-	}
-	path := newPath(newNoder(tree, entry))
-
-	expectedFrom, err := newChangeEntry(path)
-	c.Assert(err, IsNil)
-
-	src := merkletrie.Change{
-		From: path,
-		To:   nil,
-	}
-
-	obtained, err := newChange(src)
-	c.Assert(err, IsNil)
-	action, err := obtained.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Delete)
-	c.Assert(obtained.From, Equals, expectedFrom)
-	c.Assert(obtained.To, Equals, ChangeEntry{})
-}
-
-func (s *ChangeAdaptorSuite) TestNewChangeModify(c *C) {
-	treeA := &object.Tree{}
-	entryA := object.TreeEntry{
-		Name: "name",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("aaaaa"),
-	}
-	pathA := newPath(newNoder(treeA, entryA))
-	expectedFrom, err := newChangeEntry(pathA)
-	c.Assert(err, IsNil)
-
-	treeB := &object.Tree{}
-	entryB := object.TreeEntry{
-		Name: "name",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("bbbb"),
-	}
-	pathB := newPath(newNoder(treeB, entryB))
-	expectedTo, err := newChangeEntry(pathB)
-	c.Assert(err, IsNil)
-
-	src := merkletrie.Change{
-		From: pathA,
-		To:   pathB,
-	}
-
-	obtained, err := newChange(src)
-	c.Assert(err, IsNil)
-	action, err := obtained.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Modify)
-	c.Assert(obtained.From, Equals, expectedFrom)
-	c.Assert(obtained.To, Equals, expectedTo)
-}
-
-func (s *ChangeAdaptorSuite) TestEmptyChangeFails(c *C) {
-	change := &Change{
-		From: empty,
-		To:   empty,
-	}
-	_, err := change.Action()
-	c.Assert(err, ErrorMatches, "malformed change.*")
-
-	_, _, err = change.Files()
-	c.Assert(err, ErrorMatches, "malformed change.*")
-
-	str := change.String()
-	c.Assert(str, Equals, "malformed change")
-}
-
-type noderMock struct{ noder.Noder }
-
-func (s *ChangeAdaptorSuite) TestNewChangeFailsWithChangesFromOtherNoders(c *C) {
-	src := merkletrie.Change{
-		From: newPath(noderMock{}),
-		To:   nil,
-	}
-	_, err := newChange(src)
-	c.Assert(err, Not(IsNil))
-
-	src = merkletrie.Change{
-		From: nil,
-		To:   newPath(noderMock{}),
-	}
-	_, err = newChange(src)
-	c.Assert(err, Not(IsNil))
-}
-
-func (s *ChangeAdaptorSuite) TestChangeStringFrom(c *C) {
-	expected := "<Action: Delete, Path: foo>"
-	change := Change{}
-	change.From.Name = "foo"
-
-	obtained := change.String()
-	c.Assert(obtained, Equals, expected)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeStringTo(c *C) {
-	expected := "<Action: Insert, Path: foo>"
-	change := Change{}
-	change.To.Name = "foo"
-
-	obtained := change.String()
-	c.Assert(obtained, Equals, expected)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeFilesInsert(c *C) {
-	tree := s.tree(c, plumbing.NewHash("a8d315b2b1c615d43042c3a62402b8a54288cf5c"))
-
-	change := Change{}
-	change.To.Name = "json/long.json"
-	change.To.Tree = tree
-	change.To.TreeEntry.Hash = plumbing.NewHash("49c6bb89b17060d7b4deacb7b338fcc6ea2352a9")
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-	c.Assert(from, IsNil)
-	c.Assert(to.ID(), Equals, change.To.TreeEntry.Hash)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeFilesInsertNotFound(c *C) {
-	tree := s.tree(c, plumbing.NewHash("a8d315b2b1c615d43042c3a62402b8a54288cf5c"))
-
-	change := Change{}
-	change.To.Name = "json/long.json"
-	change.To.Tree = tree
-	// there is no object for this hash
-	change.To.TreeEntry.Hash = plumbing.NewHash("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
-
-	_, _, err := change.Files()
-	c.Assert(err, Not(IsNil))
-}
-
-func (s *ChangeAdaptorSuite) TestChangeFilesDelete(c *C) {
-	tree := s.tree(c, plumbing.NewHash("a8d315b2b1c615d43042c3a62402b8a54288cf5c"))
-
-	change := Change{}
-	change.From.Name = "json/long.json"
-	change.From.Tree = tree
-	change.From.TreeEntry.Hash = plumbing.NewHash("49c6bb89b17060d7b4deacb7b338fcc6ea2352a9")
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-	c.Assert(to, IsNil)
-	c.Assert(from.ID(), Equals, change.From.TreeEntry.Hash)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeFilesDeleteNotFound(c *C) {
-	tree := s.tree(c, plumbing.NewHash("a8d315b2b1c615d43042c3a62402b8a54288cf5c"))
-
-	change := Change{}
-	change.From.Name = "json/long.json"
-	change.From.Tree = tree
-	// there is no object for this hash
-	change.From.TreeEntry.Hash = plumbing.NewHash("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
-
-	_, _, err := change.Files()
-	c.Assert(err, Not(IsNil))
-}
-
-func (s *ChangeAdaptorSuite) TestChangeFilesModify(c *C) {
-	tree := s.tree(c, plumbing.NewHash("a8d315b2b1c615d43042c3a62402b8a54288cf5c"))
-
-	change := Change{}
-	change.To.Name = "json/long.json"
-	change.To.Tree = tree
-	change.To.TreeEntry.Hash = plumbing.NewHash("49c6bb89b17060d7b4deacb7b338fcc6ea2352a9")
-	change.From.Name = "json/long.json"
-	change.From.Tree = tree
-	change.From.TreeEntry.Hash = plumbing.NewHash("9a48f23120e880dfbe41f7c9b7b708e9ee62a492")
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-	c.Assert(to.ID(), Equals, change.To.TreeEntry.Hash)
-	c.Assert(from.ID(), Equals, change.From.TreeEntry.Hash)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeEntryFailsWithOtherNoders(c *C) {
-	path := noder.Path{noderMock{}}
-	_, err := newChangeEntry(path)
-	c.Assert(err, Not(IsNil))
-}
-
-func (s *ChangeAdaptorSuite) TestChangeEntryFromNilIsZero(c *C) {
-	obtained, err := newChangeEntry(nil)
-	c.Assert(err, IsNil)
-	c.Assert(obtained, Equals, ChangeEntry{})
-}
-
-func (s *ChangeAdaptorSuite) TestChangeEntryFromSortPath(c *C) {
-	tree := &object.Tree{}
-	entry := object.TreeEntry{
-		Name: "name",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("aaaaa"),
-	}
-	path := newPath(newNoder(tree, entry))
-
-	obtained, err := newChangeEntry(path)
-	c.Assert(err, IsNil)
-
-	c.Assert(obtained.Name, Equals, entry.Name)
-	c.Assert(obtained.Tree, Equals, tree)
-	c.Assert(obtained.TreeEntry, DeepEquals, entry)
-}
-
-func (s *ChangeAdaptorSuite) TestChangeEntryFromLongPath(c *C) {
-	treeA := &object.Tree{}
-	entryA := object.TreeEntry{
-		Name: "nameA",
-		Mode: os.FileMode(42),
-		Hash: plumbing.NewHash("aaaa"),
-	}
-
-	treeB := &object.Tree{}
-	entryB := object.TreeEntry{
-		Name: "nameB",
-		Mode: os.FileMode(24),
-		Hash: plumbing.NewHash("bbbb"),
-	}
-
-	path := newPath(
-		newNoder(treeA, entryA),
-		newNoder(treeB, entryB),
-	)
-
-	obtained, err := newChangeEntry(path)
-	c.Assert(err, IsNil)
-
-	c.Assert(obtained.Name, Equals, entryA.Name+"/"+entryB.Name)
-	c.Assert(obtained.Tree, Equals, treeB)
-	c.Assert(obtained.TreeEntry, Equals, entryB)
-}
-
-func (s *ChangeAdaptorSuite) TestNewChangesEmpty(c *C) {
-	expected := "[]"
-	changes, err := newChanges(nil)
-	c.Assert(err, IsNil)
-	obtained := changes.String()
-	c.Assert(obtained, Equals, expected)
-
-	expected = "[]"
-	changes, err = newChanges(merkletrie.Changes{})
-	c.Assert(err, IsNil)
-	obtained = changes.String()
-	c.Assert(obtained, Equals, expected)
-}
-
-func (s *ChangeAdaptorSuite) TestNewChanges(c *C) {
-	treeA := &object.Tree{}
-	entryA := object.TreeEntry{Name: "nameA"}
-	pathA := newPath(newNoder(treeA, entryA))
-	changeA := merkletrie.Change{
-		From: nil,
-		To:   pathA,
-	}
-
-	treeB := &object.Tree{}
-	entryB := object.TreeEntry{Name: "nameB"}
-	pathB := newPath(newNoder(treeB, entryB))
-	changeB := merkletrie.Change{
-		From: pathB,
-		To:   nil,
-	}
-	src := merkletrie.Changes{changeA, changeB}
-
-	changes, err := newChanges(src)
-	c.Assert(err, IsNil)
-	c.Assert(len(changes), Equals, 2)
-	action, err := changes[0].Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Insert)
-	c.Assert(changes[0].To.Name, Equals, "nameA")
-	action, err = changes[1].Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Delete)
-	c.Assert(changes[1].From.Name, Equals, "nameB")
-}
-
-func (s *ChangeAdaptorSuite) TestNewChangesFailsWithOtherNoders(c *C) {
-	change := merkletrie.Change{
-		From: nil,
-		To:   newPath(noderMock{}),
-	}
-	src := merkletrie.Changes{change}
-
-	_, err := newChanges(src)
-	c.Assert(err, Not(IsNil))
-}
-
-func (s *ChangeAdaptorSuite) TestSortChanges(c *C) {
-	c1 := &Change{}
-	c1.To.Name = "1"
-
-	c2 := &Change{}
-	c2.From.Name = "2"
-	c2.To.Name = "2"
-
-	c3 := &Change{}
-	c3.From.Name = "3"
-
-	changes := Changes{c3, c1, c2}
-	sort.Sort(changes)
-
-	c.Assert(changes[0].String(), Equals, "<Action: Insert, Path: 1>")
-	c.Assert(changes[1].String(), Equals, "<Action: Modify, Path: 2>")
-	c.Assert(changes[2].String(), Equals, "<Action: Delete, Path: 3>")
-}
diff --git a/plumbing/difftree/change_test.go b/plumbing/difftree/change_test.go
deleted file mode 100644
index cda4ff9..0000000
--- a/plumbing/difftree/change_test.go
+++ /dev/null
@@ -1,300 +0,0 @@
-package difftree
-
-import (
-	"os"
-	"sort"
-
-	"srcd.works/go-git.v4/plumbing"
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/plumbing/storer"
-	"srcd.works/go-git.v4/storage/filesystem"
-	"srcd.works/go-git.v4/utils/merkletrie"
-
-	fixtures "github.com/src-d/go-git-fixtures"
-	. "gopkg.in/check.v1"
-)
-
-type ChangeSuite struct {
-	fixtures.Suite
-	Storer  storer.EncodedObjectStorer
-	Fixture *fixtures.Fixture
-}
-
-func (s *ChangeSuite) SetUpSuite(c *C) {
-	s.Suite.SetUpSuite(c)
-	s.Fixture = fixtures.ByURL("https://github.com/src-d/go-git.git").
-		ByTag(".git").One()
-	sto, err := filesystem.NewStorage(s.Fixture.DotGit())
-	c.Assert(err, IsNil)
-	s.Storer = sto
-}
-
-func (s *ChangeSuite) tree(c *C, h plumbing.Hash) *object.Tree {
-	t, err := object.GetTree(s.Storer, h)
-	c.Assert(err, IsNil)
-	return t
-}
-
-var _ = Suite(&ChangeSuite{})
-
-func (s *ChangeSuite) TestInsert(c *C) {
-	// Commit a5078b19f08f63e7948abd0a5e2fb7d319d3a565 of the go-git
-	// fixture inserted "examples/clone/main.go".
-	//
-	// On that commit, the "examples/clone" tree is
-	//     6efca3ff41cab651332f9ebc0c96bb26be809615
-	//
-	// and the "examples/colone/main.go" is
-	//     f95dc8f7923add1a8b9f72ecb1e8db1402de601a
-
-	path := "examples/clone/main.go"
-	name := "main.go"
-	mode := os.FileMode(100644)
-	blob := plumbing.NewHash("f95dc8f7923add1a8b9f72ecb1e8db1402de601a")
-	tree := plumbing.NewHash("6efca3ff41cab651332f9ebc0c96bb26be809615")
-
-	change := &Change{
-		From: empty,
-		To: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, tree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: blob,
-			},
-		},
-	}
-
-	action, err := change.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Insert)
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-	c.Assert(from, IsNil)
-	c.Assert(to.Name, Equals, name)
-	c.Assert(to.Blob.Hash, Equals, blob)
-
-	str := change.String()
-	c.Assert(str, Equals, "<Action: Insert, Path: examples/clone/main.go>")
-}
-
-func (s *ChangeSuite) TestDelete(c *C) {
-	// Commit f6011d65d57c2a866e231fc21a39cb618f86f9ea of the go-git
-	// fixture deleted "utils/difftree/difftree.go".
-	//
-	// The parent of that commit is
-	//     9b4a386db3d98a4362516a00ef3d04d4698c9bcd.
-	//
-	// On that parent commit, the "utils/difftree" tree is
-	//     f3d11566401ce4b0808aab9dd6fad3d5abf1481a.
-	//
-	// and the "utils/difftree/difftree.go" is
-	//     e2cb9a5719daf634d45a063112b4044ee81da13ea.
-
-	path := "utils/difftree/difftree.go"
-	name := "difftree.go"
-	mode := os.FileMode(100644)
-	blob := plumbing.NewHash("e2cb9a5719daf634d45a063112b4044ee81da13e")
-	tree := plumbing.NewHash("f3d11566401ce4b0808aab9dd6fad3d5abf1481a")
-
-	change := &Change{
-		From: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, tree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: blob,
-			},
-		},
-		To: empty,
-	}
-
-	action, err := change.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Delete)
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-	c.Assert(to, IsNil)
-	c.Assert(from.Name, Equals, name)
-	c.Assert(from.Blob.Hash, Equals, blob)
-
-	str := change.String()
-	c.Assert(str, Equals, "<Action: Delete, Path: utils/difftree/difftree.go>")
-}
-
-func (s *ChangeSuite) TestModify(c *C) {
-	// Commit 7beaad711378a4daafccc2c04bc46d36df2a0fd1 of the go-git
-	// fixture modified "examples/latest/latest.go".
-	// the "examples/latest" tree is
-	//     b1f01b730b855c82431918cb338ad47ed558999b.
-	// and "examples/latest/latest.go" is blob
-	//     05f583ace3a9a078d8150905a53a4d82567f125f.
-	//
-	// The parent of that commit is
-	//     337148ef6d751477796922ac127b416b8478fcc4.
-	// the "examples/latest" tree is
-	//     8b0af31d2544acb5c4f3816a602f11418cbd126e.
-	// and "examples/latest/latest.go" is blob
-	//     de927fad935d172929aacf20e71f3bf0b91dd6f9.
-
-	path := "utils/difftree/difftree.go"
-	name := "difftree.go"
-	mode := os.FileMode(100644)
-	fromBlob := plumbing.NewHash("05f583ace3a9a078d8150905a53a4d82567f125f")
-	fromTree := plumbing.NewHash("b1f01b730b855c82431918cb338ad47ed558999b")
-	toBlob := plumbing.NewHash("de927fad935d172929aacf20e71f3bf0b91dd6f9")
-	toTree := plumbing.NewHash("8b0af31d2544acb5c4f3816a602f11418cbd126e")
-
-	change := &Change{
-		From: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, fromTree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: fromBlob,
-			},
-		},
-		To: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, toTree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: toBlob,
-			},
-		},
-	}
-
-	action, err := change.Action()
-	c.Assert(err, IsNil)
-	c.Assert(action, Equals, merkletrie.Modify)
-
-	from, to, err := change.Files()
-	c.Assert(err, IsNil)
-
-	c.Assert(from.Name, Equals, name)
-	c.Assert(from.Blob.Hash, Equals, fromBlob)
-	c.Assert(to.Name, Equals, name)
-	c.Assert(to.Blob.Hash, Equals, toBlob)
-
-	str := change.String()
-	c.Assert(str, Equals, "<Action: Modify, Path: utils/difftree/difftree.go>")
-}
-
-func (s *ChangeSuite) TestEmptyChangeFails(c *C) {
-	change := &Change{}
-
-	_, err := change.Action()
-	c.Assert(err, ErrorMatches, "malformed.*")
-
-	_, _, err = change.Files()
-	c.Assert(err, ErrorMatches, "malformed.*")
-
-	str := change.String()
-	c.Assert(str, Equals, "malformed change")
-}
-
-func (s *ChangeSuite) TestErrorsFindingChildsAreDetected(c *C) {
-	// Commit 7beaad711378a4daafccc2c04bc46d36df2a0fd1 of the go-git
-	// fixture modified "examples/latest/latest.go".
-	// the "examples/latest" tree is
-	//     b1f01b730b855c82431918cb338ad47ed558999b.
-	// and "examples/latest/latest.go" is blob
-	//     05f583ace3a9a078d8150905a53a4d82567f125f.
-	//
-	// The parent of that commit is
-	//     337148ef6d751477796922ac127b416b8478fcc4.
-	// the "examples/latest" tree is
-	//     8b0af31d2544acb5c4f3816a602f11418cbd126e.
-	// and "examples/latest/latest.go" is blob
-	//     de927fad935d172929aacf20e71f3bf0b91dd6f9.
-
-	path := "utils/difftree/difftree.go"
-	name := "difftree.go"
-	mode := os.FileMode(100644)
-	fromBlob := plumbing.NewHash("aaaa") // does not exists
-	fromTree := plumbing.NewHash("b1f01b730b855c82431918cb338ad47ed558999b")
-	toBlob := plumbing.NewHash("bbbb") // does not exists
-	toTree := plumbing.NewHash("8b0af31d2544acb5c4f3816a602f11418cbd126e")
-
-	change := &Change{
-		From: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, fromTree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: fromBlob,
-			},
-		},
-		To: ChangeEntry{},
-	}
-
-	_, _, err := change.Files()
-	c.Assert(err, ErrorMatches, "object not found")
-
-	change = &Change{
-		From: empty,
-		To: ChangeEntry{
-			Name: path,
-			Tree: s.tree(c, toTree),
-			TreeEntry: object.TreeEntry{
-				Name: name,
-				Mode: mode,
-				Hash: toBlob,
-			},
-		},
-	}
-
-	_, _, err = change.Files()
-	c.Assert(err, ErrorMatches, "object not found")
-}
-
-func (s *ChangeSuite) TestChangesString(c *C) {
-	expected := "[]"
-	changes := Changes{}
-	obtained := changes.String()
-	c.Assert(obtained, Equals, expected)
-
-	expected = "[<Action: Modify, Path: bla>]"
-	changes = make([]*Change, 1)
-	changes[0] = &Change{}
-	changes[0].From.Name = "bla"
-	changes[0].To.Name = "bla"
-
-	obtained = changes.String()
-	c.Assert(obtained, Equals, expected)
-
-	expected = "[<Action: Modify, Path: bla>, <Action: Delete, Path: foo/bar>]"
-	changes = make([]*Change, 2)
-	changes[0] = &Change{}
-	changes[0].From.Name = "bla"
-	changes[0].To.Name = "bla"
-	changes[1] = &Change{}
-	changes[1].From.Name = "foo/bar"
-	obtained = changes.String()
-	c.Assert(obtained, Equals, expected)
-}
-
-func (s *ChangeSuite) TestChangesSort(c *C) {
-	changes := make(Changes, 3)
-	changes[0] = &Change{}
-	changes[0].From.Name = "z"
-	changes[0].To.Name = "z"
-	changes[1] = &Change{}
-	changes[1].From.Name = "b/b"
-	changes[2] = &Change{}
-	changes[2].To.Name = "b/a"
-
-	expected := "[<Action: Insert, Path: b/a>, " +
-		"<Action: Delete, Path: b/b>, " +
-		"<Action: Modify, Path: z>]"
-
-	sort.Sort(changes)
-	c.Assert(changes.String(), Equals, expected)
-}
diff --git a/plumbing/difftree/difftree.go b/plumbing/difftree/difftree.go
deleted file mode 100644
index ff1ceaf..0000000
--- a/plumbing/difftree/difftree.go
+++ /dev/null
@@ -1,63 +0,0 @@
-package difftree
-
-import (
-	"bytes"
-	"os"
-
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/utils/merkletrie"
-	"srcd.works/go-git.v4/utils/merkletrie/noder"
-)
-
-// DiffTree compares the content and mode of the blobs found via two
-// tree objects.
-func DiffTree(a, b *object.Tree) ([]*Change, error) {
-	from := newTreeNoder(a)
-	to := newTreeNoder(b)
-
-	merkletrieChanges, err := merkletrie.DiffTree(from, to, hashEqual)
-	if err != nil {
-		return nil, err
-	}
-
-	return newChanges(merkletrieChanges)
-}
-
-// check if the hash of the contents is different, if not, check if
-// the permissions are different (but taking into account deprecated
-// file modes).  On a treenoder, the hash of the contents is codified
-// in the first 20 bytes of the data returned by Hash() and the last
-// 4 bytes is the mode.
-func hashEqual(a, b noder.Hasher) bool {
-	hashA, hashB := a.Hash(), b.Hash()
-	contentsA, contentsB := hashA[:20], hashB[:20]
-
-	sameContents := bytes.Equal(contentsA, contentsB)
-	if !sameContents {
-		return false
-	}
-
-	modeA, modeB := hashA[20:], hashB[20:]
-
-	return equivalentMode(modeA, modeB)
-}
-
-func equivalentMode(a, b []byte) bool {
-	if isFilish(a) && isFilish(b) {
-		return true
-	}
-	return bytes.Equal(a, b)
-}
-
-var (
-	file           = modeToBytes(object.FileMode)
-	fileDeprecated = modeToBytes(object.FileModeDeprecated)
-	// remove this by fixing plumbing.Object mode ASAP
-	fileGoGit = modeToBytes(os.FileMode(0644))
-)
-
-func isFilish(b []byte) bool {
-	return bytes.Equal(b, file) ||
-		bytes.Equal(b, fileDeprecated) ||
-		bytes.Equal(b, fileGoGit)
-}
diff --git a/plumbing/difftree/difftree_test.go b/plumbing/difftree/difftree_test.go
deleted file mode 100644
index 24817f1..0000000
--- a/plumbing/difftree/difftree_test.go
+++ /dev/null
@@ -1,379 +0,0 @@
-package difftree
-
-import (
-	"os"
-	"sort"
-	"testing"
-
-	"srcd.works/go-git.v4/plumbing"
-	"srcd.works/go-git.v4/plumbing/format/packfile"
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/plumbing/storer"
-	"srcd.works/go-git.v4/storage/filesystem"
-	"srcd.works/go-git.v4/storage/memory"
-	"srcd.works/go-git.v4/utils/merkletrie"
-
-	"github.com/src-d/go-git-fixtures"
-	. "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { TestingT(t) }
-
-type DiffTreeSuite struct {
-	fixtures.Suite
-	Storer  storer.EncodedObjectStorer
-	Fixture *fixtures.Fixture
-	cache   map[string]storer.EncodedObjectStorer
-}
-
-func (s *DiffTreeSuite) SetUpSuite(c *C) {
-	s.Suite.SetUpSuite(c)
-	s.Fixture = fixtures.Basic().One()
-	sto, err := filesystem.NewStorage(s.Fixture.DotGit())
-	c.Assert(err, IsNil)
-	s.Storer = sto
-	s.cache = make(map[string]storer.EncodedObjectStorer)
-}
-
-func (s *DiffTreeSuite) commitFromStorer(c *C, sto storer.EncodedObjectStorer,
-	h plumbing.Hash) *object.Commit {
-
-	commit, err := object.GetCommit(sto, h)
-	c.Assert(err, IsNil)
-	return commit
-}
-
-func (s *DiffTreeSuite) storageFromPackfile(f *fixtures.Fixture) storer.EncodedObjectStorer {
-	sto, ok := s.cache[f.URL]
-	if ok {
-		return sto
-	}
-
-	sto = memory.NewStorage()
-
-	pf := f.Packfile()
-
-	defer pf.Close()
-
-	n := packfile.NewScanner(pf)
-	d, err := packfile.NewDecoder(n, sto)
-	if err != nil {
-		panic(err)
-	}
-
-	_, err = d.Decode()
-	if err != nil {
-		panic(err)
-	}
-
-	s.cache[f.URL] = sto
-	return sto
-}
-
-var _ = Suite(&DiffTreeSuite{})
-
-type expectChange struct {
-	Action merkletrie.Action
-	Name   string
-}
-
-func assertChanges(a Changes, c *C) {
-	for _, changes := range a {
-		action, err := changes.Action()
-		c.Assert(err, IsNil)
-		switch action {
-		case merkletrie.Insert:
-			c.Assert(changes.From.Tree, IsNil)
-			c.Assert(changes.To.Tree, NotNil)
-		case merkletrie.Delete:
-			c.Assert(changes.From.Tree, NotNil)
-			c.Assert(changes.To.Tree, IsNil)
-		case merkletrie.Modify:
-			c.Assert(changes.From.Tree, NotNil)
-			c.Assert(changes.To.Tree, NotNil)
-		default:
-			c.Fatalf("unknown action: %d", action)
-		}
-	}
-}
-
-func equalChanges(a Changes, b []expectChange, c *C) bool {
-	if len(a) != len(b) {
-		return false
-	}
-
-	sort.Sort(a)
-
-	for i, va := range a {
-		vb := b[i]
-		action, err := va.Action()
-		c.Assert(err, IsNil)
-		if action != vb.Action || va.name() != vb.Name {
-			return false
-		}
-	}
-
-	return true
-}
-
-func (s *DiffTreeSuite) TestDiffTree(c *C) {
-	for i, t := range []struct {
-		repository string         // the repo name as in localRepos
-		commit1    string         // the commit of the first tree
-		commit2    string         // the commit of the second tree
-		expected   []expectChange // the expected list of []changeExpect
-	}{
-		{
-			"https://github.com/dezfowler/LiteMock.git",
-			"",
-			"",
-			[]expectChange{},
-		},
-		{
-			"https://github.com/dezfowler/LiteMock.git",
-			"b7965eaa2c4f245d07191fe0bcfe86da032d672a",
-			"b7965eaa2c4f245d07191fe0bcfe86da032d672a",
-			[]expectChange{},
-		},
-		{
-			"https://github.com/dezfowler/LiteMock.git",
-			"",
-			"b7965eaa2c4f245d07191fe0bcfe86da032d672a",
-			[]expectChange{
-				{Action: merkletrie.Insert, Name: "README"},
-			},
-		},
-		{
-			"https://github.com/dezfowler/LiteMock.git",
-			"b7965eaa2c4f245d07191fe0bcfe86da032d672a",
-			"",
-			[]expectChange{
-				{Action: merkletrie.Delete, Name: "README"},
-			},
-		},
-		{
-			"https://github.com/githubtraining/example-branches.git",
-			"",
-			"f0eb272cc8f77803478c6748103a1450aa1abd37",
-			[]expectChange{
-				{Action: merkletrie.Insert, Name: "README.md"},
-			},
-		},
-		{
-			"https://github.com/githubtraining/example-branches.git",
-			"f0eb272cc8f77803478c6748103a1450aa1abd37",
-			"",
-			[]expectChange{
-				{Action: merkletrie.Delete, Name: "README.md"},
-			},
-		},
-		{
-			"https://github.com/githubtraining/example-branches.git",
-			"f0eb272cc8f77803478c6748103a1450aa1abd37",
-			"f0eb272cc8f77803478c6748103a1450aa1abd37",
-			[]expectChange{},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"",
-			"9608eed92b3839b06ebf72d5043da547de10ce85",
-			[]expectChange{
-				{Action: merkletrie.Insert, Name: "README"},
-				{Action: merkletrie.Insert, Name: "gem_builder.rb"},
-				{Action: merkletrie.Insert, Name: "gem_eval.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"9608eed92b3839b06ebf72d5043da547de10ce85",
-			"",
-			[]expectChange{
-				{Action: merkletrie.Delete, Name: "README"},
-				{Action: merkletrie.Delete, Name: "gem_builder.rb"},
-				{Action: merkletrie.Delete, Name: "gem_eval.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"9608eed92b3839b06ebf72d5043da547de10ce85",
-			"9608eed92b3839b06ebf72d5043da547de10ce85",
-			[]expectChange{},
-		},
-		{
-			"https://github.com/toqueteos/ts3.git",
-			"",
-			"764e914b75d6d6df1fc5d832aa9840f590abf1bb",
-			[]expectChange{
-				{Action: merkletrie.Insert, Name: "README.markdown"},
-				{Action: merkletrie.Insert, Name: "examples/bot.go"},
-				{Action: merkletrie.Insert, Name: "examples/raw_shell.go"},
-				{Action: merkletrie.Insert, Name: "helpers.go"},
-				{Action: merkletrie.Insert, Name: "ts3.go"},
-			},
-		},
-		{
-			"https://github.com/toqueteos/ts3.git",
-			"764e914b75d6d6df1fc5d832aa9840f590abf1bb",
-			"",
-			[]expectChange{
-				{Action: merkletrie.Delete, Name: "README.markdown"},
-				{Action: merkletrie.Delete, Name: "examples/bot.go"},
-				{Action: merkletrie.Delete, Name: "examples/raw_shell.go"},
-				{Action: merkletrie.Delete, Name: "helpers.go"},
-				{Action: merkletrie.Delete, Name: "ts3.go"},
-			},
-		},
-		{
-			"https://github.com/toqueteos/ts3.git",
-			"764e914b75d6d6df1fc5d832aa9840f590abf1bb",
-			"764e914b75d6d6df1fc5d832aa9840f590abf1bb",
-			[]expectChange{},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"9608eed92b3839b06ebf72d5043da547de10ce85",
-			"6c41e05a17e19805879689414026eb4e279f7de0",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"6c41e05a17e19805879689414026eb4e279f7de0",
-			"89be3aac2f178719c12953cc9eaa23441f8d9371",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-				{Action: merkletrie.Insert, Name: "gem_eval_test.rb"},
-				{Action: merkletrie.Insert, Name: "security.rb"},
-				{Action: merkletrie.Insert, Name: "security_test.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"89be3aac2f178719c12953cc9eaa23441f8d9371",
-			"597240b7da22d03ad555328f15abc480b820acc0",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"597240b7da22d03ad555328f15abc480b820acc0",
-			"0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-				{Action: merkletrie.Modify, Name: "gem_eval_test.rb"},
-				{Action: merkletrie.Insert, Name: "lazy_dir.rb"},
-				{Action: merkletrie.Insert, Name: "lazy_dir_test.rb"},
-				{Action: merkletrie.Modify, Name: "security.rb"},
-				{Action: merkletrie.Modify, Name: "security_test.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
-			"597240b7da22d03ad555328f15abc480b820acc0",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-				{Action: merkletrie.Modify, Name: "gem_eval_test.rb"},
-				{Action: merkletrie.Delete, Name: "lazy_dir.rb"},
-				{Action: merkletrie.Delete, Name: "lazy_dir_test.rb"},
-				{Action: merkletrie.Modify, Name: "security.rb"},
-				{Action: merkletrie.Modify, Name: "security_test.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
-			"ca9fd470bacb6262eb4ca23ee48bb2f43711c1ff",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-				{Action: merkletrie.Modify, Name: "security.rb"},
-				{Action: merkletrie.Modify, Name: "security_test.rb"},
-			},
-		},
-		{
-			"https://github.com/github/gem-builder.git",
-			"fe3c86745f887c23a0d38c85cfd87ca957312f86",
-			"b7e3f636febf7a0cd3ab473b6d30081786d2c5b6",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "gem_eval.rb"},
-				{Action: merkletrie.Modify, Name: "gem_eval_test.rb"},
-				{Action: merkletrie.Insert, Name: "git_mock"},
-				{Action: merkletrie.Modify, Name: "lazy_dir.rb"},
-				{Action: merkletrie.Modify, Name: "lazy_dir_test.rb"},
-				{Action: merkletrie.Modify, Name: "security.rb"},
-			},
-		},
-		{
-			"https://github.com/rumpkernel/rumprun-xen.git",
-			"1831e47b0c6db750714cd0e4be97b5af17fb1eb0",
-			"51d8515578ea0c88cc8fc1a057903675cf1fc16c",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "Makefile"},
-				{Action: merkletrie.Modify, Name: "netbsd_init.c"},
-				{Action: merkletrie.Modify, Name: "rumphyper_stubs.c"},
-				{Action: merkletrie.Delete, Name: "sysproxy.c"},
-			},
-		},
-		{
-			"https://github.com/rumpkernel/rumprun-xen.git",
-			"1831e47b0c6db750714cd0e4be97b5af17fb1eb0",
-			"e13e678f7ee9badd01b120889e0ec5fdc8ae3802",
-			[]expectChange{
-				{Action: merkletrie.Modify, Name: "app-tools/rumprun"},
-			},
-		},
-	} {
-		f := fixtures.ByURL(t.repository).One()
-		sto := s.storageFromPackfile(f)
-
-		var tree1, tree2 *object.Tree
-		var err error
-		if t.commit1 != "" {
-			tree1, err = s.commitFromStorer(c, sto,
-				plumbing.NewHash(t.commit1)).Tree()
-			c.Assert(err, IsNil,
-				Commentf("subtest %d: unable to retrieve tree from commit %s and repo %s: %s", i, t.commit1, t.repository, err))
-		}
-
-		if t.commit2 != "" {
-			tree2, err = s.commitFromStorer(c, sto,
-				plumbing.NewHash(t.commit2)).Tree()
-			c.Assert(err, IsNil,
-				Commentf("subtest %d: unable to retrieve tree from commit %s and repo %s", i, t.commit2, t.repository, err))
-		}
-
-		obtained, err := DiffTree(tree1, tree2)
-		c.Assert(err, IsNil,
-			Commentf("subtest %d: unable to calculate difftree: %s", i, err))
-		c.Assert(equalChanges(obtained, t.expected, c), Equals, true,
-			Commentf("subtest:%d\nrepo=%s\ncommit1=%s\ncommit2=%s\nexpected=%s\nobtained=%s",
-				i, t.repository, t.commit1, t.commit2, t.expected, obtained))
-
-		assertChanges(obtained, c)
-	}
-}
-
-func (s *DiffTreeSuite) TestIssue279(c *C) {
-	// HashEqual should ignore files if the only change is from a 100664
-	// mode to a 100644 or vice versa.
-	from := &treeNoder{
-		hash: plumbing.NewHash("d08e895238bac36d8220586fdc28c27e1a7a76d3"),
-		mode: os.FileMode(0100664),
-	}
-	to := &treeNoder{
-		hash: plumbing.NewHash("d08e895238bac36d8220586fdc28c27e1a7a76d3"),
-		mode: os.FileMode(0100644),
-	}
-	c.Assert(hashEqual(from, to), Equals, true)
-	c.Assert(hashEqual(to, from), Equals, true)
-
-	// but should detect if the contents of the file also changed.
-	to = &treeNoder{
-		hash: plumbing.NewHash("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"),
-		mode: os.FileMode(0100644),
-	}
-	c.Assert(hashEqual(from, to), Equals, false)
-	c.Assert(hashEqual(to, from), Equals, false)
-}
diff --git a/plumbing/difftree/treenoder.go b/plumbing/difftree/treenoder.go
deleted file mode 100644
index c0ed948..0000000
--- a/plumbing/difftree/treenoder.go
+++ /dev/null
@@ -1,141 +0,0 @@
-package difftree
-
-// A treenoder is a helper type that wraps git trees into merkletrie
-// noders.
-//
-// As a merkletrie noder doesn't understand the concept of modes (e.g.
-// file permissions), the treenoder includes the mode of the git tree in
-// the hash, so changes in the modes will be detected as modifications
-// to the file contents by the merkletrie difftree algorithm.  This is
-// consistent with how the "git diff-tree" command works.
-import (
-	"encoding/binary"
-	"io"
-	"os"
-
-	"srcd.works/go-git.v4/plumbing"
-	"srcd.works/go-git.v4/plumbing/object"
-	"srcd.works/go-git.v4/utils/merkletrie/noder"
-)
-
-type treeNoder struct {
-	parent   *object.Tree // the root node is its own parent
-	name     string       // empty string for the root node
-	mode     os.FileMode
-	hash     plumbing.Hash
-	children []noder.Noder // memoized
-}
-
-func newTreeNoder(t *object.Tree) *treeNoder {
-	if t == nil {
-		return &treeNoder{}
-	}
-
-	return &treeNoder{
-		parent: t,
-		name:   "",
-		mode:   os.ModeDir,
-		hash:   t.Hash,
-	}
-}
-
-func (t *treeNoder) isRoot() bool {
-	return t.name == ""
-}
-
-func (t *treeNoder) String() string {
-	return "treeNoder <" + t.name + ">"
-}
-
-func (t *treeNoder) Hash() []byte {
-	return append(t.hash[:], modeToBytes(t.mode)...)
-}
-
-// mode in little endian (endianess is an arbitrary decission).
-func modeToBytes(m os.FileMode) []byte {
-	ret := make([]byte, 4)
-	binary.LittleEndian.PutUint32(ret, uint32(m))
-	return ret
-}
-
-func (t *treeNoder) Name() string {
-	return t.name
-}
-
-func (t *treeNoder) IsDir() bool {
-	return t.mode.IsDir()
-}
-
-// Children will return the children of a treenoder as treenoders,
-// building them from the children of the wrapped git tree.
-func (t *treeNoder) Children() ([]noder.Noder, error) {
-	if !t.mode.IsDir() {
-		return noder.NoChildren, nil
-	}
-
-	// children are memoized for efficiency
-	if t.children != nil {
-		return t.children, nil
-	}
-
-	// the parent of the returned children will be ourself as a tree if
-	// we are a not the root treenoder.  The root is special as it
-	// is is own parent.
-	parent := t.parent
-	if !t.isRoot() {
-		var err error
-		if parent, err = t.parent.Tree(t.name); err != nil {
-			return nil, err
-		}
-	}
-
-	return transformChildren(parent)
-}
-
-// Returns the children of a tree as treenoders.
-// Efficiency is key here.
-func transformChildren(t *object.Tree) ([]noder.Noder, error) {
-	var err error
-	var e object.TreeEntry
-
-	// there will be more tree entries than children in the tree,
-	// due to submodules and empty directories, but I think it is still
-	// worth it to pre-allocate the whole array now, even if sometimes
-	// is bigger than needed.
-	ret := make([]noder.Noder, 0, len(t.Entries))
-
-	walker := object.NewTreeWalker(t, false) // don't recurse
-	// don't defer walker.Close() for efficiency reasons.
-	for {
-		_, e, err = walker.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			walker.Close()
-			return nil, err
-		}
-
-		ret = append(ret, &treeNoder{
-			parent: t,
-			name:   e.Name,
-			mode:   e.Mode,
-			hash:   e.Hash,
-		})
-	}
-	walker.Close()
-
-	return ret, nil
-}
-
-// len(t.tree.Entries) != the number of elements walked by treewalker
-// for some reason because of empty directories, submodules, etc, so we
-// have to walk here.
-func (t *treeNoder) NumChildren() (int, error) {
-	children, err := t.Children()
-	if err != nil {
-		return 0, err
-	}
-
-	return len(children), nil
-}