Merge branch 'master' of github.com:src-d/go-git into f-add-tagging-support

44 files changed, 1028 insertions, 187 deletions

diff --git a/common_test.go b/common_test.go
index efe1ecc..dad0a37 100644
--- a/common_test.go
+++ b/common_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/format/packfile"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -59,10 +60,7 @@ func (s *BaseSuite) NewRepository(f *fixtures.Fixture) *Repository {
 	dotgit = f.DotGit()
 	worktree = memfs.New()
 
-	st, err := filesystem.NewStorage(dotgit)
-	if err != nil {
-		panic(err)
-	}
+	st := filesystem.NewStorage(dotgit, cache.NewObjectLRUDefault())
 
 	r, err := Open(st, worktree)
 	if err != nil {
@@ -89,10 +87,7 @@ func (s *BaseSuite) NewRepositoryWithEmptyWorktree(f *fixtures.Fixture) *Reposit
 
 	worktree := memfs.New()
 
-	st, err := filesystem.NewStorage(dotgit)
-	if err != nil {
-		panic(err)
-	}
+	st := filesystem.NewStorage(dotgit, cache.NewObjectLRUDefault())
 
 	r, err := Open(st, worktree)
 	if err != nil {
diff --git a/config/config.go b/config/config.go
index ce6506d..a637f6d 100644
--- a/config/config.go
+++ b/config/config.go
@@ -40,6 +40,9 @@ type Config struct {
 		IsBare bool
 		// Worktree is the path to the root of the working tree.
 		Worktree string
+		// CommentChar is the character indicating the start of a
+		// comment for commands like commit and tag
+		CommentChar string
 	}
 
 	Pack struct {
@@ -113,6 +116,7 @@ const (
 	urlKey           = "url"
 	bareKey          = "bare"
 	worktreeKey      = "worktree"
+	commentCharKey   = "commentChar"
 	windowKey        = "window"
 	mergeKey         = "merge"
 
@@ -151,6 +155,7 @@ func (c *Config) unmarshalCore() {
 	}
 
 	c.Core.Worktree = s.Options.Get(worktreeKey)
+	c.Core.CommentChar = s.Options.Get(commentCharKey)
 }
 
 func (c *Config) unmarshalPack() error {
diff --git a/config/config_test.go b/config/config_test.go
index 5cd713e..fe73de8 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -13,6 +13,7 @@ func (s *ConfigSuite) TestUnmarshall(c *C) {
 	input := []byte(`[core]
         bare = true
 		worktree = foo
+		commentchar = bar
 [pack]
 		window = 20
 [remote "origin"]
@@ -38,6 +39,7 @@ func (s *ConfigSuite) TestUnmarshall(c *C) {
 
 	c.Assert(cfg.Core.IsBare, Equals, true)
 	c.Assert(cfg.Core.Worktree, Equals, "foo")
+	c.Assert(cfg.Core.CommentChar, Equals, "bar")
 	c.Assert(cfg.Pack.Window, Equals, uint(20))
 	c.Assert(cfg.Remotes, HasLen, 2)
 	c.Assert(cfg.Remotes["origin"].Name, Equals, "origin")
diff --git a/plumbing/format/diff/unified_encoder.go b/plumbing/format/diff/unified_encoder.go
index 58edd95..8bd6d8a 100644
--- a/plumbing/format/diff/unified_encoder.go
+++ b/plumbing/format/diff/unified_encoder.go
@@ -237,9 +237,13 @@ func (c *hunksGenerator) addLineNumbers(la, lb int, linesBefore int, i int, op O
 	// we need to search for a reference for the next diff
 	switch {
 	case linesBefore != 0 && c.ctxLines != 0:
-		clb = lb - c.ctxLines + 1
+		if lb > c.ctxLines {
+			clb = lb - c.ctxLines + 1
+		} else {
+			clb = 1
+		}
 	case c.ctxLines == 0:
-		clb = lb - c.ctxLines
+		clb = lb
 	case i != len(c.chunks)-1:
 		next := c.chunks[i+1]
 		if next.Type() == op || next.Type() == Equal {
diff --git a/plumbing/format/diff/unified_encoder_test.go b/plumbing/format/diff/unified_encoder_test.go
index 0e419ca..7736af1 100644
--- a/plumbing/format/diff/unified_encoder_test.go
+++ b/plumbing/format/diff/unified_encoder_test.go
@@ -155,6 +155,43 @@ var fixtures []*fixture = []*fixture{{
 		filePatches: []testFilePatch{{
 			from: &testFile{
 				mode: filemode.Regular,
+				path: "README.md",
+				seed: "hello\nworld\n",
+			},
+			to: &testFile{
+				mode: filemode.Regular,
+				path: "README.md",
+				seed: "hello\nbug\n",
+			},
+			chunks: []testChunk{{
+				content: "hello",
+				op:      Equal,
+			}, {
+				content: "world",
+				op:      Delete,
+			}, {
+				content: "bug",
+				op:      Add,
+			}},
+		}},
+	},
+	desc:    "positive negative number",
+	context: 2,
+	diff: `diff --git a/README.md b/README.md
+index 94954abda49de8615a048f8d2e64b5de848e27a1..f3dad9514629b9ff9136283ae331ad1fc95748a8 100644
+--- a/README.md
++++ b/README.md
+@@ -1,2 +1,2 @@
+ hello
+-world
++bug
+`,
+}, {
+	patch: testPatch{
+		message: "",
+		filePatches: []testFilePatch{{
+			from: &testFile{
+				mode: filemode.Regular,
 				path: "test.txt",
 				seed: "test",
 			},
diff --git a/plumbing/format/gitignore/pattern.go b/plumbing/format/gitignore/pattern.go
index 2603352..098cb50 100644
--- a/plumbing/format/gitignore/pattern.go
+++ b/plumbing/format/gitignore/pattern.go
@@ -133,6 +133,9 @@ func (p *pattern) globMatch(path []string, isDir bool) bool {
 				} else if match {
 					matched = true
 					break
+				} else if len(path) == 0 {
+					// if nothing left then fail
+					matched = false
 				}
 			}
 		} else {
diff --git a/plumbing/format/gitignore/pattern_test.go b/plumbing/format/gitignore/pattern_test.go
index f94cef3..c410442 100644
--- a/plumbing/format/gitignore/pattern_test.go
+++ b/plumbing/format/gitignore/pattern_test.go
@@ -281,3 +281,9 @@ func (s *PatternSuite) TestGlobMatch_wrongPattern_onTraversal_mismatch(c *C) {
 	r := p.Match([]string{"value", "head", "vol["}, false)
 	c.Assert(r, Equals, NoMatch)
 }
+
+func (s *PatternSuite) TestGlobMatch_issue_923(c *C) {
+	p := ParsePattern("**/android/**/GeneratedPluginRegistrant.java", nil)
+	r := p.Match([]string{"packages", "flutter_tools", "lib", "src", "android", "gradle.dart"}, false)
+	c.Assert(r, Equals, NoMatch)
+}
diff --git a/plumbing/format/idxfile/idxfile.go b/plumbing/format/idxfile/idxfile.go
index c977bee..5fed278 100644
--- a/plumbing/format/idxfile/idxfile.go
+++ b/plumbing/format/idxfile/idxfile.go
@@ -3,6 +3,7 @@ package idxfile
 import (
 	"bytes"
 	"io"
+	"sort"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
 	"gopkg.in/src-d/go-git.v4/utils/binary"
@@ -34,6 +35,9 @@ type Index interface {
 	Count() (int64, error)
 	// Entries returns an iterator to retrieve all index entries.
 	Entries() (EntryIter, error)
+	// EntriesByOffset returns an iterator to retrieve all index entries ordered
+	// by offset.
+	EntriesByOffset() (EntryIter, error)
 }
 
 // MemoryIndex is the in memory representation of an idx file.
@@ -215,6 +219,36 @@ func (idx *MemoryIndex) Entries() (EntryIter, error) {
 	return &idxfileEntryIter{idx, 0, 0, 0}, nil
 }
 
+// EntriesByOffset implements the Index interface.
+func (idx *MemoryIndex) EntriesByOffset() (EntryIter, error) {
+	count, err := idx.Count()
+	if err != nil {
+		return nil, err
+	}
+
+	iter := &idxfileEntryOffsetIter{
+		entries: make(entriesByOffset, count),
+	}
+
+	entries, err := idx.Entries()
+	if err != nil {
+		return nil, err
+	}
+
+	for pos := 0; int64(pos) < count; pos++ {
+		entry, err := entries.Next()
+		if err != nil {
+			return nil, err
+		}
+
+		iter.entries[pos] = entry
+	}
+
+	sort.Sort(iter.entries)
+
+	return iter, nil
+}
+
 // EntryIter is an iterator that will return the entries in a packfile index.
 type EntryIter interface {
 	// Next returns the next entry in the packfile index.
@@ -276,3 +310,38 @@ type Entry struct {
 	CRC32  uint32
 	Offset uint64
 }
+
+type idxfileEntryOffsetIter struct {
+	entries entriesByOffset
+	pos     int
+}
+
+func (i *idxfileEntryOffsetIter) Next() (*Entry, error) {
+	if i.pos >= len(i.entries) {
+		return nil, io.EOF
+	}
+
+	entry := i.entries[i.pos]
+	i.pos++
+
+	return entry, nil
+}
+
+func (i *idxfileEntryOffsetIter) Close() error {
+	i.pos = len(i.entries) + 1
+	return nil
+}
+
+type entriesByOffset []*Entry
+
+func (o entriesByOffset) Len() int {
+	return len(o)
+}
+
+func (o entriesByOffset) Less(i int, j int) bool {
+	return o[i].Offset < o[j].Offset
+}
+
+func (o entriesByOffset) Swap(i int, j int) {
+	o[i], o[j] = o[j], o[i]
+}
diff --git a/plumbing/format/idxfile/idxfile_test.go b/plumbing/format/idxfile/idxfile_test.go
index d15accf..0e0ca2a 100644
--- a/plumbing/format/idxfile/idxfile_test.go
+++ b/plumbing/format/idxfile/idxfile_test.go
@@ -115,6 +115,21 @@ func (s *IndexSuite) TestFindHash(c *C) {
 	}
 }
 
+func (s *IndexSuite) TestEntriesByOffset(c *C) {
+	idx, err := fixtureIndex()
+	c.Assert(err, IsNil)
+
+	entries, err := idx.EntriesByOffset()
+	c.Assert(err, IsNil)
+
+	for _, pos := range fixtureOffsets {
+		e, err := entries.Next()
+		c.Assert(err, IsNil)
+
+		c.Assert(e.Offset, Equals, uint64(pos))
+	}
+}
+
 var fixtureHashes = []plumbing.Hash{
 	plumbing.NewHash("303953e5aa461c203a324821bc1717f9b4fff895"),
 	plumbing.NewHash("5296768e3d9f661387ccbff18c4dea6c997fd78c"),
diff --git a/plumbing/format/packfile/encoder_advanced_test.go b/plumbing/format/packfile/encoder_advanced_test.go
index fc1419e..e15126e 100644
--- a/plumbing/format/packfile/encoder_advanced_test.go
+++ b/plumbing/format/packfile/encoder_advanced_test.go
@@ -8,6 +8,7 @@ import (
 
 	"gopkg.in/src-d/go-billy.v4/memfs"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/format/idxfile"
 	. "gopkg.in/src-d/go-git.v4/plumbing/format/packfile"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
@@ -32,8 +33,7 @@ func (s *EncoderAdvancedSuite) TestEncodeDecode(c *C) {
 	fixs = append(fixs, fixtures.ByURL("https://github.com/src-d/go-git.git").
 		ByTag("packfile").ByTag(".git").One())
 	fixs.Test(c, func(f *fixtures.Fixture) {
-		storage, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		storage := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 		s.testEncodeDecode(c, storage, 10)
 	})
 }
@@ -47,8 +47,7 @@ func (s *EncoderAdvancedSuite) TestEncodeDecodeNoDeltaCompression(c *C) {
 	fixs = append(fixs, fixtures.ByURL("https://github.com/src-d/go-git.git").
 		ByTag("packfile").ByTag(".git").One())
 	fixs.Test(c, func(f *fixtures.Fixture) {
-		storage, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		storage := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 		s.testEncodeDecode(c, storage, 0)
 	})
 }
diff --git a/plumbing/format/packfile/fsobject.go b/plumbing/format/packfile/fsobject.go
index 6fd3ca5..330cb73 100644
--- a/plumbing/format/packfile/fsobject.go
+++ b/plumbing/format/packfile/fsobject.go
@@ -47,6 +47,16 @@ func NewFSObject(
 
 // Reader implements the plumbing.EncodedObject interface.
 func (o *FSObject) Reader() (io.ReadCloser, error) {
+	obj, ok := o.cache.Get(o.hash)
+	if ok {
+		reader, err := obj.Reader()
+		if err != nil {
+			return nil, err
+		}
+
+		return reader, nil
+	}
+
 	f, err := o.fs.Open(o.path)
 	if err != nil {
 		return nil, err
diff --git a/plumbing/format/packfile/packfile.go b/plumbing/format/packfile/packfile.go
index 5feb781..852a834 100644
--- a/plumbing/format/packfile/packfile.go
+++ b/plumbing/format/packfile/packfile.go
@@ -258,6 +258,19 @@ func (p *Packfile) nextObject() (plumbing.EncodedObject, error) {
 }
 
 func (p *Packfile) getObjectContent(offset int64) (io.ReadCloser, error) {
+	ref, err := p.FindHash(offset)
+	if err == nil {
+		obj, ok := p.cacheGet(ref)
+		if ok {
+			reader, err := obj.Reader()
+			if err != nil {
+				return nil, err
+			}
+
+			return reader, nil
+		}
+	}
+
 	if _, err := p.s.SeekFromStart(offset); err != nil {
 		return nil, err
 	}
@@ -306,6 +319,8 @@ func (p *Packfile) fillRegularObjectContent(obj plumbing.EncodedObject) error {
 	}
 
 	_, _, err = p.s.NextObject(w)
+	p.cachePut(obj)
+
 	return err
 }
 
@@ -394,7 +409,7 @@ func (p *Packfile) GetByType(typ plumbing.ObjectType) (storer.EncodedObjectIter,
 		plumbing.TreeObject,
 		plumbing.CommitObject,
 		plumbing.TagObject:
-		entries, err := p.Entries()
+		entries, err := p.EntriesByOffset()
 		if err != nil {
 			return nil, err
 		}
diff --git a/plumbing/object/change_adaptor_test.go b/plumbing/object/change_adaptor_test.go
index 803c3b8..c7c003b 100644
--- a/plumbing/object/change_adaptor_test.go
+++ b/plumbing/object/change_adaptor_test.go
@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -23,8 +24,7 @@ type ChangeAdaptorSuite struct {
 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)
+	sto := filesystem.NewStorage(s.Fixture.DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = sto
 }
 
diff --git a/plumbing/object/change_test.go b/plumbing/object/change_test.go
index b0e89c7..e2f0a23 100644
--- a/plumbing/object/change_test.go
+++ b/plumbing/object/change_test.go
@@ -5,6 +5,7 @@ import (
 	"sort"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/format/diff"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
@@ -25,8 +26,7 @@ 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)
+	sto := filesystem.NewStorage(s.Fixture.DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = sto
 }
 
@@ -253,8 +253,7 @@ func (s *ChangeSuite) TestNoFileFilemodes(c *C) {
 	s.Suite.SetUpSuite(c)
 	f := fixtures.ByURL("https://github.com/git-fixtures/submodule.git").One()
 
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 	iter, err := sto.IterEncodedObjects(plumbing.AnyObject)
 	c.Assert(err, IsNil)
diff --git a/plumbing/object/commit.go b/plumbing/object/commit.go
index 00ae3f1..e254342 100644
--- a/plumbing/object/commit.go
+++ b/plumbing/object/commit.go
@@ -199,17 +199,23 @@ func (c *Commit) Decode(o plumbing.EncodedObject) (err error) {
 			}
 
 			split := bytes.SplitN(line, []byte{' '}, 2)
+
+			var data []byte
+			if len(split) == 2 {
+				data = split[1]
+			}
+
 			switch string(split[0]) {
 			case "tree":
-				c.TreeHash = plumbing.NewHash(string(split[1]))
+				c.TreeHash = plumbing.NewHash(string(data))
 			case "parent":
-				c.ParentHashes = append(c.ParentHashes, plumbing.NewHash(string(split[1])))
+				c.ParentHashes = append(c.ParentHashes, plumbing.NewHash(string(data)))
 			case "author":
-				c.Author.Decode(split[1])
+				c.Author.Decode(data)
 			case "committer":
-				c.Committer.Decode(split[1])
+				c.Committer.Decode(data)
 			case headerpgp:
-				c.PGPSignature += string(split[1]) + "\n"
+				c.PGPSignature += string(data) + "\n"
 				pgpsig = true
 			}
 		} else {
diff --git a/plumbing/object/commit_test.go b/plumbing/object/commit_test.go
index b5dfbe3..c9acf42 100644
--- a/plumbing/object/commit_test.go
+++ b/plumbing/object/commit_test.go
@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 
 	. "gopkg.in/check.v1"
 	"gopkg.in/src-d/go-git-fixtures.v3"
@@ -247,8 +248,7 @@ func (s *SuiteCommit) TestStringMultiLine(c *C) {
 	hash := plumbing.NewHash("e7d896db87294e33ca3202e536d4d9bb16023db3")
 
 	f := fixtures.ByURL("https://github.com/src-d/go-git.git").One()
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 	o, err := sto.EncodedObject(plumbing.CommitObject, hash)
 	c.Assert(err, IsNil)
@@ -325,6 +325,22 @@ RUysgqjcpT8+iQM1PblGfHR4XAhuOqN5Fx06PSaFZhqvWFezJ28/CLyX5q+oIVk=
 	c.Assert(err, IsNil)
 	c.Assert(decoded.PGPSignature, Equals, pgpsignature)
 
+	// signature with extra empty line, it caused "index out of range" when
+	// parsing it
+
+	pgpsignature2 := "\n" + pgpsignature
+
+	commit.PGPSignature = pgpsignature2
+	encoded = &plumbing.MemoryObject{}
+	decoded = &Commit{}
+
+	err = commit.Encode(encoded)
+	c.Assert(err, IsNil)
+
+	err = decoded.Decode(encoded)
+	c.Assert(err, IsNil)
+	c.Assert(decoded.PGPSignature, Equals, pgpsignature2)
+
 	// signature in author name
 
 	commit.PGPSignature = ""
@@ -461,3 +477,21 @@ func (s *SuiteCommit) TestPatchCancel(c *C) {
 	c.Assert(err, ErrorMatches, "operation canceled")
 
 }
+
+func (s *SuiteCommit) TestMalformedHeader(c *C) {
+	encoded := &plumbing.MemoryObject{}
+	decoded := &Commit{}
+	commit := *s.Commit
+
+	commit.PGPSignature = "\n"
+	commit.Author.Name = "\n"
+	commit.Author.Email = "\n"
+	commit.Committer.Name = "\n"
+	commit.Committer.Email = "\n"
+
+	err := commit.Encode(encoded)
+	c.Assert(err, IsNil)
+
+	err = decoded.Decode(encoded)
+	c.Assert(err, IsNil)
+}
diff --git a/plumbing/object/difftree_test.go b/plumbing/object/difftree_test.go
index ff9ecbc..4af8684 100644
--- a/plumbing/object/difftree_test.go
+++ b/plumbing/object/difftree_test.go
@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/format/packfile"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
@@ -25,8 +26,7 @@ type DiffTreeSuite struct {
 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)
+	sto := filesystem.NewStorage(s.Fixture.DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = sto
 	s.cache = make(map[string]storer.EncodedObjectStorer)
 }
diff --git a/plumbing/object/file_test.go b/plumbing/object/file_test.go
index edb82d0..4b92749 100644
--- a/plumbing/object/file_test.go
+++ b/plumbing/object/file_test.go
@@ -4,6 +4,7 @@ import (
 	"io"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -44,8 +45,7 @@ var fileIterTests = []struct {
 func (s *FileSuite) TestIter(c *C) {
 	for i, t := range fileIterTests {
 		f := fixtures.ByURL(t.repo).One()
-		sto, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 		h := plumbing.NewHash(t.commit)
 		commit, err := GetCommit(sto, h)
@@ -106,8 +106,7 @@ hs_err_pid*
 func (s *FileSuite) TestContents(c *C) {
 	for i, t := range contentsTests {
 		f := fixtures.ByURL(t.repo).One()
-		sto, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 		h := plumbing.NewHash(t.commit)
 		commit, err := GetCommit(sto, h)
@@ -160,8 +159,7 @@ var linesTests = []struct {
 func (s *FileSuite) TestLines(c *C) {
 	for i, t := range linesTests {
 		f := fixtures.ByURL(t.repo).One()
-		sto, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 		h := plumbing.NewHash(t.commit)
 		commit, err := GetCommit(sto, h)
@@ -195,8 +193,7 @@ var ignoreEmptyDirEntriesTests = []struct {
 func (s *FileSuite) TestIgnoreEmptyDirEntries(c *C) {
 	for i, t := range ignoreEmptyDirEntriesTests {
 		f := fixtures.ByURL(t.repo).One()
-		sto, err := filesystem.NewStorage(f.DotGit())
-		c.Assert(err, IsNil)
+		sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 		h := plumbing.NewHash(t.commit)
 		commit, err := GetCommit(sto, h)
@@ -251,9 +248,7 @@ func (s *FileSuite) TestFileIter(c *C) {
 
 func (s *FileSuite) TestFileIterSubmodule(c *C) {
 	dotgit := fixtures.ByURL("https://github.com/git-fixtures/submodule.git").One().DotGit()
-	st, err := filesystem.NewStorage(dotgit)
-
-	c.Assert(err, IsNil)
+	st := filesystem.NewStorage(dotgit, cache.NewObjectLRUDefault())
 
 	hash := plumbing.NewHash("b685400c1f9316f350965a5993d350bc746b0bf4")
 	commit, err := GetCommit(st, hash)
diff --git a/plumbing/object/object.go b/plumbing/object/object.go
index 4b59aba..e960e50 100644
--- a/plumbing/object/object.go
+++ b/plumbing/object/object.go
@@ -152,7 +152,11 @@ func (s *Signature) decodeTimeAndTimeZone(b []byte) {
 }
 
 func (s *Signature) encodeTimeAndTimeZone(w io.Writer) error {
-	_, err := fmt.Fprintf(w, "%d %s", s.When.Unix(), s.When.Format("-0700"))
+	u := s.When.Unix()
+	if u < 0 {
+		u = 0
+	}
+	_, err := fmt.Fprintf(w, "%d %s", u, s.When.Format("-0700"))
 	return err
 }
 
diff --git a/plumbing/object/object_test.go b/plumbing/object/object_test.go
index 68aa1a1..8f0eede 100644
--- a/plumbing/object/object_test.go
+++ b/plumbing/object/object_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -26,8 +27,7 @@ type BaseObjectsSuite struct {
 func (s *BaseObjectsSuite) SetUpSuite(c *C) {
 	s.Suite.SetUpSuite(c)
 	s.Fixture = fixtures.Basic().One()
-	storer, err := filesystem.NewStorage(s.Fixture.DotGit())
-	c.Assert(err, IsNil)
+	storer := filesystem.NewStorage(s.Fixture.DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = storer
 }
 
diff --git a/plumbing/object/patch_test.go b/plumbing/object/patch_test.go
index 8eb65ec..47057fb 100644
--- a/plumbing/object/patch_test.go
+++ b/plumbing/object/patch_test.go
@@ -4,6 +4,7 @@ import (
 	. "gopkg.in/check.v1"
 	fixtures "gopkg.in/src-d/go-git-fixtures.v3"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
 )
 
@@ -14,8 +15,8 @@ type PatchSuite struct {
 var _ = Suite(&PatchSuite{})
 
 func (s *PatchSuite) TestStatsWithSubmodules(c *C) {
-	storer, err := filesystem.NewStorage(
-		fixtures.ByURL("https://github.com/git-fixtures/submodule.git").One().DotGit())
+	storer := filesystem.NewStorage(
+		fixtures.ByURL("https://github.com/git-fixtures/submodule.git").One().DotGit(), cache.NewObjectLRUDefault())
 
 	commit, err := GetCommit(storer, plumbing.NewHash("b685400c1f9316f350965a5993d350bc746b0bf4"))
 
diff --git a/plumbing/object/tag_test.go b/plumbing/object/tag_test.go
index 9900093..59c28b0 100644
--- a/plumbing/object/tag_test.go
+++ b/plumbing/object/tag_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
 	"gopkg.in/src-d/go-git.v4/storage/memory"
 
@@ -22,9 +23,7 @@ var _ = Suite(&TagSuite{})
 
 func (s *TagSuite) SetUpSuite(c *C) {
 	s.BaseObjectsSuite.SetUpSuite(c)
-	storer, err := filesystem.NewStorage(
-		fixtures.ByURL("https://github.com/git-fixtures/tags.git").One().DotGit())
-	c.Assert(err, IsNil)
+	storer := filesystem.NewStorage(fixtures.ByURL("https://github.com/git-fixtures/tags.git").One().DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = storer
 }
 
@@ -265,7 +264,7 @@ func (s *TagSuite) TestStringNonCommit(c *C) {
 	c.Assert(tag.String(), Equals,
 		"tag TAG TWO\n"+
 			"Tagger:  <>\n"+
-			"Date:   Mon Jan 01 00:00:00 0001 +0000\n"+
+			"Date:   Thu Jan 01 00:00:00 1970 +0000\n"+
 			"\n"+
 			"tag two\n")
 }
diff --git a/plumbing/object/tree_test.go b/plumbing/object/tree_test.go
index 59d5d21..7366421 100644
--- a/plumbing/object/tree_test.go
+++ b/plumbing/object/tree_test.go
@@ -5,6 +5,7 @@ import (
 	"io"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -341,8 +342,7 @@ func (s *TreeSuite) TestTreeWalkerNextNonRecursive(c *C) {
 
 func (s *TreeSuite) TestTreeWalkerNextSubmodule(c *C) {
 	dotgit := fixtures.ByURL("https://github.com/git-fixtures/submodule.git").One().DotGit()
-	st, err := filesystem.NewStorage(dotgit)
-	c.Assert(err, IsNil)
+	st := filesystem.NewStorage(dotgit, cache.NewObjectLRUDefault())
 
 	hash := plumbing.NewHash("b685400c1f9316f350965a5993d350bc746b0bf4")
 	commit, err := GetCommit(st, hash)
diff --git a/plumbing/revlist/revlist_test.go b/plumbing/revlist/revlist_test.go
index 55d9bca..dea1c73 100644
--- a/plumbing/revlist/revlist_test.go
+++ b/plumbing/revlist/revlist_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -51,8 +52,7 @@ const (
 
 func (s *RevListSuite) SetUpTest(c *C) {
 	s.Suite.SetUpSuite(c)
-	sto, err := filesystem.NewStorage(fixtures.Basic().One().DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fixtures.Basic().One().DotGit(), cache.NewObjectLRUDefault())
 	s.Storer = sto
 }
 
@@ -67,8 +67,7 @@ func (s *RevListSuite) TestRevListObjects_Submodules(c *C) {
 		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5": true,
 	}
 
-	sto, err := filesystem.NewStorage(fixtures.ByTag("submodule").One().DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fixtures.ByTag("submodule").One().DotGit(), cache.NewObjectLRUDefault())
 
 	ref, err := storer.ResolveReference(sto, plumbing.HEAD)
 	c.Assert(err, IsNil)
@@ -109,10 +108,9 @@ func (s *RevListSuite) TestRevListObjects(c *C) {
 }
 
 func (s *RevListSuite) TestRevListObjectsTagObject(c *C) {
-	sto, err := filesystem.NewStorage(
+	sto := filesystem.NewStorage(
 		fixtures.ByTag("tags").
-			ByURL("https://github.com/git-fixtures/tags.git").One().DotGit())
-	c.Assert(err, IsNil)
+			ByURL("https://github.com/git-fixtures/tags.git").One().DotGit(), cache.NewObjectLRUDefault())
 
 	expected := map[string]bool{
 		"70846e9a10ef7b41064b40f07713d5b8b9a8fc73": true,
diff --git a/plumbing/transport/server/loader.go b/plumbing/transport/server/loader.go
index c83752c..13b3526 100644
--- a/plumbing/transport/server/loader.go
+++ b/plumbing/transport/server/loader.go
@@ -1,6 +1,7 @@
 package server
 
 import (
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -43,7 +44,7 @@ func (l *fsLoader) Load(ep *transport.Endpoint) (storer.Storer, error) {
 		return nil, transport.ErrRepositoryNotFound
 	}
 
-	return filesystem.NewStorage(fs)
+	return filesystem.NewStorage(fs, cache.NewObjectLRUDefault()), nil
 }
 
 // MapLoader is a Loader that uses a lookup map of storer.Storer by
diff --git a/plumbing/transport/server/server_test.go b/plumbing/transport/server/server_test.go
index 33d74d1..302ff48 100644
--- a/plumbing/transport/server/server_test.go
+++ b/plumbing/transport/server/server_test.go
@@ -3,6 +3,7 @@ package server_test
 import (
 	"testing"
 
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport/client"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport/server"
@@ -53,8 +54,7 @@ func (s *BaseSuite) prepareRepositories(c *C) {
 	fs := fixtures.Basic().One().DotGit()
 	s.Endpoint, err = transport.NewEndpoint(fs.Root())
 	c.Assert(err, IsNil)
-	s.loader[s.Endpoint.String()], err = filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	s.loader[s.Endpoint.String()] = filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	s.EmptyEndpoint, err = transport.NewEndpoint("/empty.git")
 	c.Assert(err, IsNil)
diff --git a/plumbing/transport/ssh/auth_method.go b/plumbing/transport/ssh/auth_method.go
index 84cfab2..dbb47c5 100644
--- a/plumbing/transport/ssh/auth_method.go
+++ b/plumbing/transport/ssh/auth_method.go
@@ -236,7 +236,7 @@ func (a *PublicKeysCallback) ClientConfig() (*ssh.ClientConfig, error) {
 // NewKnownHostsCallback returns ssh.HostKeyCallback based on a file based on a
 // known_hosts file. http://man.openbsd.org/sshd#SSH_KNOWN_HOSTS_FILE_FORMAT
 //
-// If files is empty, the list of files will be read from the SSH_KNOWN_HOSTS
+// If list of files is empty, then it will be read from the SSH_KNOWN_HOSTS
 // environment variable, example:
 //   /home/foo/custom_known_hosts_file:/etc/custom_known/hosts_file
 //
@@ -244,13 +244,15 @@ func (a *PublicKeysCallback) ClientConfig() (*ssh.ClientConfig, error) {
 //   ~/.ssh/known_hosts
 //   /etc/ssh/ssh_known_hosts
 func NewKnownHostsCallback(files ...string) (ssh.HostKeyCallback, error) {
-	files, err := getDefaultKnownHostsFiles()
-	if err != nil {
-		return nil, err
+	var err error
+
+	if len(files) == 0 {
+		if files, err = getDefaultKnownHostsFiles(); err != nil {
+			return nil, err
+		}
 	}
 
-	files, err = filterKnownHostsFiles(files...)
-	if err != nil {
+	if files, err = filterKnownHostsFiles(files...); err != nil {
 		return nil, err
 	}
 
diff --git a/plumbing/transport/ssh/auth_method_test.go b/plumbing/transport/ssh/auth_method_test.go
index 0025669..0cde61e 100644
--- a/plumbing/transport/ssh/auth_method_test.go
+++ b/plumbing/transport/ssh/auth_method_test.go
@@ -1,16 +1,30 @@
 package ssh
 
 import (
+	"bufio"
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 
+	"golang.org/x/crypto/ssh"
 	"golang.org/x/crypto/ssh/testdata"
 
 	. "gopkg.in/check.v1"
 )
 
-type SuiteCommon struct{}
+type (
+	SuiteCommon struct{}
+
+	mockKnownHosts struct{}
+)
+
+func (mockKnownHosts) host() string { return "github.com" }
+func (mockKnownHosts) knownHosts() []byte {
+	return []byte(`github.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==`)
+}
+func (mockKnownHosts) Network() string { return "tcp" }
+func (mockKnownHosts) String() string  { return "github.com:22" }
 
 var _ = Suite(&SuiteCommon{})
 
@@ -149,3 +163,49 @@ func (*SuiteCommon) TestNewPublicKeysWithInvalidPEM(c *C) {
 	c.Assert(err, NotNil)
 	c.Assert(auth, IsNil)
 }
+
+func (*SuiteCommon) TestNewKnownHostsCallback(c *C) {
+	var mock = mockKnownHosts{}
+
+	f, err := ioutil.TempFile("", "known-hosts")
+	c.Assert(err, IsNil)
+
+	_, err = f.Write(mock.knownHosts())
+	c.Assert(err, IsNil)
+
+	err = f.Close()
+	c.Assert(err, IsNil)
+
+	defer os.RemoveAll(f.Name())
+
+	f, err = os.Open(f.Name())
+	c.Assert(err, IsNil)
+
+	defer f.Close()
+
+	var hostKey ssh.PublicKey
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		fields := strings.Split(scanner.Text(), " ")
+		if len(fields) != 3 {
+			continue
+		}
+		if strings.Contains(fields[0], mock.host()) {
+			var err error
+			hostKey, _, _, _, err = ssh.ParseAuthorizedKey(scanner.Bytes())
+			if err != nil {
+				c.Fatalf("error parsing %q: %v", fields[2], err)
+			}
+			break
+		}
+	}
+	if hostKey == nil {
+		c.Fatalf("no hostkey for %s", mock.host())
+	}
+
+	clb, err := NewKnownHostsCallback(f.Name())
+	c.Assert(err, IsNil)
+
+	err = clb(mock.String(), mock, hostKey)
+	c.Assert(err, IsNil)
+}
diff --git a/prune_test.go b/prune_test.go
index 60652ec..670cd07 100644
--- a/prune_test.go
+++ b/prune_test.go
@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem"
@@ -22,8 +23,7 @@ func (s *PruneSuite) testPrune(c *C, deleteTime time.Time) {
 	srcFs := fixtures.ByTag("unpacked").One().DotGit()
 	var sto storage.Storer
 	var err error
-	sto, err = filesystem.NewStorage(srcFs)
-	c.Assert(err, IsNil)
+	sto = filesystem.NewStorage(srcFs, cache.NewObjectLRUDefault())
 
 	los := sto.(storer.LooseObjectStorer)
 	c.Assert(los, NotNil)
diff --git a/remote_test.go b/remote_test.go
index dd386b0..175faed 100644
--- a/remote_test.go
+++ b/remote_test.go
@@ -9,6 +9,7 @@ import (
 
 	"gopkg.in/src-d/go-git.v4/config"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage"
@@ -238,7 +239,7 @@ func (s *RemoteSuite) TestFetchWithPackfileWriter(c *C) {
 
 	defer os.RemoveAll(dir) // clean up
 
-	fss, err := filesystem.NewStorage(osfs.New(dir))
+	fss := filesystem.NewStorage(osfs.New(dir), cache.NewObjectLRUDefault())
 	c.Assert(err, IsNil)
 
 	mock := &mockPackfileWriter{Storer: fss}
@@ -375,8 +376,7 @@ func (s *RemoteSuite) TestFetchFastForwardFS(c *C) {
 
 	defer os.RemoveAll(dir) // clean up
 
-	fss, err := filesystem.NewStorage(osfs.New(dir))
-	c.Assert(err, IsNil)
+	fss := filesystem.NewStorage(osfs.New(dir), cache.NewObjectLRUDefault())
 
 	// This exercises `storage.filesystem.Storage.CheckAndSetReference()`.
 	s.testFetchFastForward(c, fss)
@@ -400,8 +400,7 @@ func (s *RemoteSuite) TestPushToEmptyRepository(c *C) {
 	c.Assert(err, IsNil)
 
 	srcFs := fixtures.Basic().One().DotGit()
-	sto, err := filesystem.NewStorage(srcFs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(srcFs, cache.NewObjectLRUDefault())
 
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
@@ -438,8 +437,7 @@ func (s *RemoteSuite) TestPushContext(c *C) {
 	c.Assert(err, IsNil)
 
 	fs := fixtures.ByURL("https://github.com/git-fixtures/tags.git").One().DotGit()
-	sto, err := filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
@@ -461,8 +459,7 @@ func (s *RemoteSuite) TestPushTags(c *C) {
 	c.Assert(err, IsNil)
 
 	fs := fixtures.ByURL("https://github.com/git-fixtures/tags.git").One().DotGit()
-	sto, err := filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
@@ -485,15 +482,14 @@ func (s *RemoteSuite) TestPushTags(c *C) {
 
 func (s *RemoteSuite) TestPushNoErrAlreadyUpToDate(c *C) {
 	fs := fixtures.Basic().One().DotGit()
-	sto, err := filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
 		URLs: []string{fs.Root()},
 	})
 
-	err = r.Push(&PushOptions{
+	err := r.Push(&PushOptions{
 		RefSpecs: []config.RefSpec{"refs/heads/*:refs/heads/*"},
 	})
 	c.Assert(err, Equals, NoErrAlreadyUpToDate)
@@ -501,8 +497,7 @@ func (s *RemoteSuite) TestPushNoErrAlreadyUpToDate(c *C) {
 
 func (s *RemoteSuite) TestPushDeleteReference(c *C) {
 	fs := fixtures.Basic().One().DotGit()
-	sto, err := filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	r, err := PlainClone(c.MkDir(), true, &CloneOptions{
 		URL: fs.Root(),
@@ -526,8 +521,7 @@ func (s *RemoteSuite) TestPushDeleteReference(c *C) {
 
 func (s *RemoteSuite) TestPushRejectNonFastForward(c *C) {
 	fs := fixtures.Basic().One().DotGit()
-	server, err := filesystem.NewStorage(fs)
-	c.Assert(err, IsNil)
+	server := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 	r, err := PlainClone(c.MkDir(), true, &CloneOptions{
 		URL: fs.Root(),
@@ -554,12 +548,10 @@ func (s *RemoteSuite) TestPushRejectNonFastForward(c *C) {
 
 func (s *RemoteSuite) TestPushForce(c *C) {
 	f := fixtures.Basic().One()
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 	dstFs := f.DotGit()
-	dstSto, err := filesystem.NewStorage(dstFs)
-	c.Assert(err, IsNil)
+	dstSto := filesystem.NewStorage(dstFs, cache.NewObjectLRUDefault())
 
 	url := dstFs.Root()
 	r := newRemote(sto, &config.RemoteConfig{
@@ -703,8 +695,7 @@ func (s *RemoteSuite) TestPushWrongRemoteName(c *C) {
 
 func (s *RemoteSuite) TestGetHaves(c *C) {
 	f := fixtures.Basic().One()
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 
 	var localRefs = []*plumbing.Reference{
 		plumbing.NewReferenceFromStrings(
diff --git a/repository.go b/repository.go
index a132c39..be1f057 100644
--- a/repository.go
+++ b/repository.go
@@ -16,6 +16,7 @@ import (
 	"gopkg.in/src-d/go-git.v4/config"
 	"gopkg.in/src-d/go-git.v4/internal/revision"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/format/packfile"
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
@@ -228,10 +229,7 @@ func PlainInit(path string, isBare bool) (*Repository, error) {
 		dot, _ = wt.Chroot(GitDirName)
 	}
 
-	s, err := filesystem.NewStorage(dot)
-	if err != nil {
-		return nil, err
-	}
+	s := filesystem.NewStorage(dot, cache.NewObjectLRUDefault())
 
 	return Init(s, wt)
 }
@@ -243,9 +241,8 @@ func PlainOpen(path string) (*Repository, error) {
 	return PlainOpenWithOptions(path, &PlainOpenOptions{})
 }
 
-// PlainOpen opens a git repository from the given path. It detects if the
-// repository is bare or a normal one. If the path doesn't contain a valid
-// repository ErrRepositoryNotExists is returned
+// PlainOpenWithOptions opens a git repository from the given path with specific
+// options. See PlainOpen for more info.
 func PlainOpenWithOptions(path string, o *PlainOpenOptions) (*Repository, error) {
 	dot, wt, err := dotGitToOSFilesystems(path, o.DetectDotGit)
 	if err != nil {
@@ -260,10 +257,7 @@ func PlainOpenWithOptions(path string, o *PlainOpenOptions) (*Repository, error)
 		return nil, err
 	}
 
-	s, err := filesystem.NewStorage(dot)
-	if err != nil {
-		return nil, err
-	}
+	s := filesystem.NewStorage(dot, cache.NewObjectLRUDefault())
 
 	return Open(s, wt)
 }
diff --git a/repository_test.go b/repository_test.go
index 89911c0..e48f42d 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -18,6 +18,7 @@ import (
 	openpgperr "golang.org/x/crypto/openpgp/errors"
 	"gopkg.in/src-d/go-git.v4/config"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage"
@@ -54,8 +55,7 @@ func (s *RepositorySuite) TestInitNonStandardDotGit(c *C) {
 
 	fs := osfs.New(dir)
 	dot, _ := fs.Chroot("storage")
-	storage, err := filesystem.NewStorage(dot)
-	c.Assert(err, IsNil)
+	storage := filesystem.NewStorage(dot, cache.NewObjectLRUDefault())
 
 	wt, _ := fs.Chroot("worktree")
 	r, err := Init(storage, wt)
@@ -81,8 +81,7 @@ func (s *RepositorySuite) TestInitStandardDotGit(c *C) {
 
 	fs := osfs.New(dir)
 	dot, _ := fs.Chroot(".git")
-	storage, err := filesystem.NewStorage(dot)
-	c.Assert(err, IsNil)
+	storage := filesystem.NewStorage(dot, cache.NewObjectLRUDefault())
 
 	r, err := Init(storage, fs)
 	c.Assert(err, IsNil)
@@ -1061,8 +1060,7 @@ func (s *RepositorySuite) TestPushDepth(c *C) {
 
 func (s *RepositorySuite) TestPushNonExistentRemote(c *C) {
 	srcFs := fixtures.Basic().One().DotGit()
-	sto, err := filesystem.NewStorage(srcFs)
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(srcFs, cache.NewObjectLRUDefault())
 
 	r, err := Open(sto, srcFs)
 	c.Assert(err, IsNil)
@@ -1669,8 +1667,7 @@ func (s *RepositorySuite) TestDeleteTagAnnotatedUnpacked(c *C) {
 
 func (s *RepositorySuite) TestBranches(c *C) {
 	f := fixtures.ByURL("https://github.com/git-fixtures/root-references.git").One()
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 	r, err := Open(sto, f.DotGit())
 	c.Assert(err, IsNil)
 
@@ -1887,8 +1884,7 @@ func (s *RepositorySuite) TestWorktreeBare(c *C) {
 
 func (s *RepositorySuite) TestResolveRevision(c *C) {
 	f := fixtures.ByURL("https://github.com/git-fixtures/basic.git").One()
-	sto, err := filesystem.NewStorage(f.DotGit())
-	c.Assert(err, IsNil)
+	sto := filesystem.NewStorage(f.DotGit(), cache.NewObjectLRUDefault())
 	r, err := Open(sto, f.DotGit())
 	c.Assert(err, IsNil)
 
@@ -1959,8 +1955,7 @@ func (s *RepositorySuite) testRepackObjects(
 	srcFs := fixtures.ByTag("unpacked").One().DotGit()
 	var sto storage.Storer
 	var err error
-	sto, err = filesystem.NewStorage(srcFs)
-	c.Assert(err, IsNil)
+	sto = filesystem.NewStorage(srcFs, cache.NewObjectLRUDefault())
 
 	los := sto.(storer.LooseObjectStorer)
 	c.Assert(los, NotNil)
@@ -2125,10 +2120,7 @@ func BenchmarkObjects(b *testing.B) {
 
 		b.Run(f.URL, func(b *testing.B) {
 			fs := f.DotGit()
-			storer, err := filesystem.NewStorage(fs)
-			if err != nil {
-				b.Fatal(err)
-			}
+			storer := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
 
 			worktree, err := fs.Chroot(filepath.Dir(fs.Root()))
 			if err != nil {
diff --git a/status.go b/status.go
index ef8a500..ecbf793 100644
--- a/status.go
+++ b/status.go
@@ -1,7 +1,10 @@
 package git
 
-import "fmt"
-import "bytes"
+import (
+	"bytes"
+	"fmt"
+	"path/filepath"
+)
 
 // Status represents the current status of a Worktree.
 // The key of the map is the path of the file.
@@ -17,6 +20,12 @@ func (s Status) File(path string) *FileStatus {
 	return s[path]
 }
 
+// IsUntracked checks if file for given path is 'Untracked'
+func (s Status) IsUntracked(path string) bool {
+	stat, ok := (s)[filepath.ToSlash(path)]
+	return ok && stat.Worktree == Untracked
+}
+
 // IsClean returns true if all the files aren't in Unmodified status.
 func (s Status) IsClean() bool {
 	for _, status := range s {
diff --git a/storage/filesystem/dotgit/dotgit.go b/storage/filesystem/dotgit/dotgit.go
index af07eb5..a58c248 100644
--- a/storage/filesystem/dotgit/dotgit.go
+++ b/storage/filesystem/dotgit/dotgit.go
@@ -57,17 +57,48 @@ var (
 	ErrSymRefTargetNotFound = errors.New("symbolic reference target not found")
 )
 
+// Options holds configuration for the storage.
+type Options struct {
+	// ExclusiveAccess means that the filesystem is not modified externally
+	// while the repo is open.
+	ExclusiveAccess bool
+	// KeepDescriptors makes the file descriptors to be reused but they will
+	// need to be manually closed calling Close().
+	KeepDescriptors bool
+}
+
 // The DotGit type represents a local git repository on disk. This
 // type is not zero-value-safe, use the New function to initialize it.
 type DotGit struct {
-	fs billy.Filesystem
+	options Options
+	fs      billy.Filesystem
+
+	// incoming object directory information
+	incomingChecked bool
+	incomingDirName string
+
+	objectList []plumbing.Hash
+	objectMap  map[plumbing.Hash]struct{}
+	packList   []plumbing.Hash
+	packMap    map[plumbing.Hash]struct{}
+
+	files map[string]billy.File
 }
 
 // New returns a DotGit value ready to be used. The path argument must
 // be the absolute path of a git repository directory (e.g.
 // "/foo/bar/.git").
 func New(fs billy.Filesystem) *DotGit {
-	return &DotGit{fs: fs}
+	return NewWithOptions(fs, Options{})
+}
+
+// NewWithOptions sets non default configuration options.
+// See New for complete help.
+func NewWithOptions(fs billy.Filesystem, o Options) *DotGit {
+	return &DotGit{
+		options: o,
+		fs:      fs,
+	}
 }
 
 // Initialize creates all the folder scaffolding.
@@ -97,6 +128,28 @@ func (d *DotGit) Initialize() error {
 	return nil
 }
 
+// Close closes all opened files.
+func (d *DotGit) Close() error {
+	var firstError error
+	if d.files != nil {
+		for _, f := range d.files {
+			err := f.Close()
+			if err != nil && firstError == nil {
+				firstError = err
+				continue
+			}
+		}
+
+		d.files = nil
+	}
+
+	if firstError != nil {
+		return firstError
+	}
+
+	return nil
+}
+
 // ConfigWriter returns a file pointer for write to the config file
 func (d *DotGit) ConfigWriter() (billy.File, error) {
 	return d.fs.Create(configPath)
@@ -139,11 +192,25 @@ func (d *DotGit) Shallow() (billy.File, error) {
 // NewObjectPack return a writer for a new packfile, it saves the packfile to
 // disk and also generates and save the index for the given packfile.
 func (d *DotGit) NewObjectPack() (*PackWriter, error) {
+	d.cleanPackList()
 	return newPackWrite(d.fs)
 }
 
 // ObjectPacks returns the list of availables packfiles
 func (d *DotGit) ObjectPacks() ([]plumbing.Hash, error) {
+	if !d.options.ExclusiveAccess {
+		return d.objectPacks()
+	}
+
+	err := d.genPackList()
+	if err != nil {
+		return nil, err
+	}
+
+	return d.packList, nil
+}
+
+func (d *DotGit) objectPacks() ([]plumbing.Hash, error) {
 	packDir := d.fs.Join(objectsPath, packPath)
 	files, err := d.fs.ReadDir(packDir)
 	if err != nil {
@@ -177,7 +244,22 @@ func (d *DotGit) objectPackPath(hash plumbing.Hash, extension string) string {
 }
 
 func (d *DotGit) objectPackOpen(hash plumbing.Hash, extension string) (billy.File, error) {
-	pack, err := d.fs.Open(d.objectPackPath(hash, extension))
+	if d.files == nil {
+		d.files = make(map[string]billy.File)
+	}
+
+	err := d.hasPack(hash)
+	if err != nil {
+		return nil, err
+	}
+
+	path := d.objectPackPath(hash, extension)
+	f, ok := d.files[path]
+	if ok {
+		return f, nil
+	}
+
+	pack, err := d.fs.Open(path)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, ErrPackfileNotFound
@@ -186,20 +268,36 @@ func (d *DotGit) objectPackOpen(hash plumbing.Hash, extension string) (billy.Fil
 		return nil, err
 	}
 
+	if d.options.KeepDescriptors && extension == "pack" {
+		d.files[path] = pack
+	}
+
 	return pack, nil
 }
 
 // ObjectPack returns a fs.File of the given packfile
 func (d *DotGit) ObjectPack(hash plumbing.Hash) (billy.File, error) {
+	err := d.hasPack(hash)
+	if err != nil {
+		return nil, err
+	}
+
 	return d.objectPackOpen(hash, `pack`)
 }
 
 // ObjectPackIdx returns a fs.File of the index file for a given packfile
 func (d *DotGit) ObjectPackIdx(hash plumbing.Hash) (billy.File, error) {
+	err := d.hasPack(hash)
+	if err != nil {
+		return nil, err
+	}
+
 	return d.objectPackOpen(hash, `idx`)
 }
 
 func (d *DotGit) DeleteOldObjectPackAndIndex(hash plumbing.Hash, t time.Time) error {
+	d.cleanPackList()
+
 	path := d.objectPackPath(hash, `pack`)
 	if !t.IsZero() {
 		fi, err := d.fs.Stat(path)
@@ -220,12 +318,23 @@ func (d *DotGit) DeleteOldObjectPackAndIndex(hash plumbing.Hash, t time.Time) er
 
 // NewObject return a writer for a new object file.
 func (d *DotGit) NewObject() (*ObjectWriter, error) {
+	d.cleanObjectList()
+
 	return newObjectWriter(d.fs)
 }
 
 // Objects returns a slice with the hashes of objects found under the
 // .git/objects/ directory.
 func (d *DotGit) Objects() ([]plumbing.Hash, error) {
+	if d.options.ExclusiveAccess {
+		err := d.genObjectList()
+		if err != nil {
+			return nil, err
+		}
+
+		return d.objectList, nil
+	}
+
 	var objects []plumbing.Hash
 	err := d.ForEachObjectHash(func(hash plumbing.Hash) error {
 		objects = append(objects, hash)
@@ -237,9 +346,29 @@ func (d *DotGit) Objects() ([]plumbing.Hash, error) {
 	return objects, nil
 }
 
-// Objects returns a slice with the hashes of objects found under the
-// .git/objects/ directory.
+// ForEachObjectHash iterates over the hashes of objects found under the
+// .git/objects/ directory and executes the provided function.
 func (d *DotGit) ForEachObjectHash(fun func(plumbing.Hash) error) error {
+	if !d.options.ExclusiveAccess {
+		return d.forEachObjectHash(fun)
+	}
+
+	err := d.genObjectList()
+	if err != nil {
+		return err
+	}
+
+	for _, h := range d.objectList {
+		err := fun(h)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DotGit) forEachObjectHash(fun func(plumbing.Hash) error) error {
 	files, err := d.fs.ReadDir(objectsPath)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -274,24 +403,178 @@ func (d *DotGit) ForEachObjectHash(fun func(plumbing.Hash) error) error {
 	return nil
 }
 
+func (d *DotGit) cleanObjectList() {
+	d.objectMap = nil
+	d.objectList = nil
+}
+
+func (d *DotGit) genObjectList() error {
+	if d.objectMap != nil {
+		return nil
+	}
+
+	d.objectMap = make(map[plumbing.Hash]struct{})
+	return d.forEachObjectHash(func(h plumbing.Hash) error {
+		d.objectList = append(d.objectList, h)
+		d.objectMap[h] = struct{}{}
+
+		return nil
+	})
+}
+
+func (d *DotGit) hasObject(h plumbing.Hash) error {
+	if !d.options.ExclusiveAccess {
+		return nil
+	}
+
+	err := d.genObjectList()
+	if err != nil {
+		return err
+	}
+
+	_, ok := d.objectMap[h]
+	if !ok {
+		return plumbing.ErrObjectNotFound
+	}
+
+	return nil
+}
+
+func (d *DotGit) cleanPackList() {
+	d.packMap = nil
+	d.packList = nil
+}
+
+func (d *DotGit) genPackList() error {
+	if d.packMap != nil {
+		return nil
+	}
+
+	op, err := d.objectPacks()
+	if err != nil {
+		return err
+	}
+
+	d.packMap = make(map[plumbing.Hash]struct{})
+	d.packList = nil
+
+	for _, h := range op {
+		d.packList = append(d.packList, h)
+		d.packMap[h] = struct{}{}
+	}
+
+	return nil
+}
+
+func (d *DotGit) hasPack(h plumbing.Hash) error {
+	if !d.options.ExclusiveAccess {
+		return nil
+	}
+
+	err := d.genPackList()
+	if err != nil {
+		return err
+	}
+
+	_, ok := d.packMap[h]
+	if !ok {
+		return ErrPackfileNotFound
+	}
+
+	return nil
+}
+
 func (d *DotGit) objectPath(h plumbing.Hash) string {
 	hash := h.String()
 	return d.fs.Join(objectsPath, hash[0:2], hash[2:40])
 }
 
+// incomingObjectPath is intended to add support for a git pre-receive hook
+// to be written it adds support for go-git to find objects in an "incoming"
+// directory, so that the library can be used to write a pre-receive hook
+// that deals with the incoming objects.
+//
+// More on git hooks found here : https://git-scm.com/docs/githooks
+// More on 'quarantine'/incoming directory here:
+//     https://git-scm.com/docs/git-receive-pack
+func (d *DotGit) incomingObjectPath(h plumbing.Hash) string {
+	hString := h.String()
+
+	if d.incomingDirName == "" {
+		return d.fs.Join(objectsPath, hString[0:2], hString[2:40])
+	}
+
+	return d.fs.Join(objectsPath, d.incomingDirName, hString[0:2], hString[2:40])
+}
+
+// hasIncomingObjects searches for an incoming directory and keeps its name
+// so it doesn't have to be found each time an object is accessed.
+func (d *DotGit) hasIncomingObjects() bool {
+	if !d.incomingChecked {
+		directoryContents, err := d.fs.ReadDir(objectsPath)
+		if err == nil {
+			for _, file := range directoryContents {
+				if strings.HasPrefix(file.Name(), "incoming-") && file.IsDir() {
+					d.incomingDirName = file.Name()
+				}
+			}
+		}
+
+		d.incomingChecked = true
+	}
+
+	return d.incomingDirName != ""
+}
+
 // Object returns a fs.File pointing the object file, if exists
 func (d *DotGit) Object(h plumbing.Hash) (billy.File, error) {
-	return d.fs.Open(d.objectPath(h))
+	err := d.hasObject(h)
+	if err != nil {
+		return nil, err
+	}
+
+	obj1, err1 := d.fs.Open(d.objectPath(h))
+	if os.IsNotExist(err1) && d.hasIncomingObjects() {
+		obj2, err2 := d.fs.Open(d.incomingObjectPath(h))
+		if err2 != nil {
+			return obj1, err1
+		}
+		return obj2, err2
+	}
+	return obj1, err1
 }
 
 // ObjectStat returns a os.FileInfo pointing the object file, if exists
 func (d *DotGit) ObjectStat(h plumbing.Hash) (os.FileInfo, error) {
-	return d.fs.Stat(d.objectPath(h))
+	err := d.hasObject(h)
+	if err != nil {
+		return nil, err
+	}
+
+	obj1, err1 := d.fs.Stat(d.objectPath(h))
+	if os.IsNotExist(err1) && d.hasIncomingObjects() {
+		obj2, err2 := d.fs.Stat(d.incomingObjectPath(h))
+		if err2 != nil {
+			return obj1, err1
+		}
+		return obj2, err2
+	}
+	return obj1, err1
 }
 
 // ObjectDelete removes the object file, if exists
 func (d *DotGit) ObjectDelete(h plumbing.Hash) error {
-	return d.fs.Remove(d.objectPath(h))
+	d.cleanObjectList()
+
+	err1 := d.fs.Remove(d.objectPath(h))
+	if os.IsNotExist(err1) && d.hasIncomingObjects() {
+		err2 := d.fs.Remove(d.incomingObjectPath(h))
+		if err2 != nil {
+			return err1
+		}
+		return err2
+	}
+	return err1
 }
 
 func (d *DotGit) readReferenceFrom(rd io.Reader, name string) (ref *plumbing.Reference, err error) {
diff --git a/storage/filesystem/dotgit/dotgit_test.go b/storage/filesystem/dotgit/dotgit_test.go
index 7733eef..308c6b7 100644
--- a/storage/filesystem/dotgit/dotgit_test.go
+++ b/storage/filesystem/dotgit/dotgit_test.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"testing"
 
+	"gopkg.in/src-d/go-billy.v4"
 	"gopkg.in/src-d/go-git.v4/plumbing"
 
 	. "gopkg.in/check.v1"
@@ -424,6 +425,18 @@ func (s *SuiteDotGit) TestObjectPacks(c *C) {
 	fs := f.DotGit()
 	dir := New(fs)
 
+	testObjectPacks(c, fs, dir, f)
+}
+
+func (s *SuiteDotGit) TestObjectPacksExclusive(c *C) {
+	f := fixtures.Basic().ByTag(".git").One()
+	fs := f.DotGit()
+	dir := NewWithOptions(fs, Options{ExclusiveAccess: true})
+
+	testObjectPacks(c, fs, dir, f)
+}
+
+func testObjectPacks(c *C, fs billy.Filesystem, dir *DotGit, f *fixtures.Fixture) {
 	hashes, err := dir.ObjectPacks()
 	c.Assert(err, IsNil)
 	c.Assert(hashes, HasLen, 1)
@@ -452,6 +465,45 @@ func (s *SuiteDotGit) TestObjectPack(c *C) {
 	c.Assert(filepath.Ext(pack.Name()), Equals, ".pack")
 }
 
+func (s *SuiteDotGit) TestObjectPackWithKeepDescriptors(c *C) {
+	f := fixtures.Basic().ByTag(".git").One()
+	fs := f.DotGit()
+	dir := NewWithOptions(fs, Options{KeepDescriptors: true})
+
+	pack, err := dir.ObjectPack(f.PackfileHash)
+	c.Assert(err, IsNil)
+	c.Assert(filepath.Ext(pack.Name()), Equals, ".pack")
+
+	// Move to an specific offset
+	pack.Seek(42, os.SEEK_SET)
+
+	pack2, err := dir.ObjectPack(f.PackfileHash)
+	c.Assert(err, IsNil)
+
+	// If the file is the same the offset should be the same
+	offset, err := pack2.Seek(0, os.SEEK_CUR)
+	c.Assert(err, IsNil)
+	c.Assert(offset, Equals, int64(42))
+
+	err = dir.Close()
+	c.Assert(err, IsNil)
+
+	pack2, err = dir.ObjectPack(f.PackfileHash)
+	c.Assert(err, IsNil)
+
+	// If the file is opened again its offset should be 0
+	offset, err = pack2.Seek(0, os.SEEK_CUR)
+	c.Assert(err, IsNil)
+	c.Assert(offset, Equals, int64(0))
+
+	err = pack2.Close()
+	c.Assert(err, IsNil)
+
+	err = dir.Close()
+	c.Assert(err, NotNil)
+
+}
+
 func (s *SuiteDotGit) TestObjectPackIdx(c *C) {
 	f := fixtures.Basic().ByTag(".git").One()
 	fs := f.DotGit()
@@ -506,6 +558,17 @@ func (s *SuiteDotGit) TestObjects(c *C) {
 	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
 	dir := New(fs)
 
+	testObjects(c, fs, dir)
+}
+
+func (s *SuiteDotGit) TestObjectsExclusive(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := NewWithOptions(fs, Options{ExclusiveAccess: true})
+
+	testObjects(c, fs, dir)
+}
+
+func testObjects(c *C, fs billy.Filesystem, dir *DotGit) {
 	hashes, err := dir.Objects()
 	c.Assert(err, IsNil)
 	c.Assert(hashes, HasLen, 187)
@@ -537,6 +600,57 @@ func (s *SuiteDotGit) TestObject(c *C) {
 		file.Name(), fs.Join("objects", "03", "db8e1fbe133a480f2867aac478fd866686d69e")),
 		Equals, true,
 	)
+	incomingHash := "9d25e0f9bde9f82882b49fe29117b9411cb157b7" //made up hash
+	incomingDirPath := fs.Join("objects", "incoming-123456")
+	incomingFilePath := fs.Join(incomingDirPath, incomingHash[0:2], incomingHash[2:40])
+	fs.MkdirAll(incomingDirPath, os.FileMode(0755))
+	fs.Create(incomingFilePath)
+
+	file, err = dir.Object(plumbing.NewHash(incomingHash))
+	c.Assert(err, IsNil)
+}
+
+func (s *SuiteDotGit) TestObjectStat(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := New(fs)
+
+	hash := plumbing.NewHash("03db8e1fbe133a480f2867aac478fd866686d69e")
+	_, err := dir.ObjectStat(hash)
+	c.Assert(err, IsNil)
+	incomingHash := "9d25e0f9bde9f82882b49fe29117b9411cb157b7" //made up hash
+	incomingDirPath := fs.Join("objects", "incoming-123456")
+	incomingFilePath := fs.Join(incomingDirPath, incomingHash[0:2], incomingHash[2:40])
+	fs.MkdirAll(incomingDirPath, os.FileMode(0755))
+	fs.Create(incomingFilePath)
+
+	_, err = dir.ObjectStat(plumbing.NewHash(incomingHash))
+	c.Assert(err, IsNil)
+}
+
+func (s *SuiteDotGit) TestObjectDelete(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := New(fs)
+
+	hash := plumbing.NewHash("03db8e1fbe133a480f2867aac478fd866686d69e")
+	err := dir.ObjectDelete(hash)
+	c.Assert(err, IsNil)
+
+	incomingHash := "9d25e0f9bde9f82882b49fe29117b9411cb157b7" //made up hash
+	incomingDirPath := fs.Join("objects", "incoming-123456")
+	incomingSubDirPath := fs.Join(incomingDirPath, incomingHash[0:2])
+	incomingFilePath := fs.Join(incomingSubDirPath, incomingHash[2:40])
+
+	err = fs.MkdirAll(incomingSubDirPath, os.FileMode(0755))
+	c.Assert(err, IsNil)
+
+	f, err := fs.Create(incomingFilePath)
+	c.Assert(err, IsNil)
+
+	err = f.Close()
+	c.Assert(err, IsNil)
+
+	err = dir.ObjectDelete(plumbing.NewHash(incomingHash))
+	c.Assert(err, IsNil)
 }
 
 func (s *SuiteDotGit) TestObjectNotFound(c *C) {
diff --git a/storage/filesystem/module.go b/storage/filesystem/module.go
index 7c8c8d8..9272206 100644
--- a/storage/filesystem/module.go
+++ b/storage/filesystem/module.go
@@ -1,6 +1,7 @@
 package filesystem
 
 import (
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/storage"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem/dotgit"
 )
@@ -15,5 +16,5 @@ func (s *ModuleStorage) Module(name string) (storage.Storer, error) {
 		return nil, err
 	}
 
-	return NewStorage(fs)
+	return NewStorage(fs, cache.NewObjectLRUDefault()), nil
 }
diff --git a/storage/filesystem/object.go b/storage/filesystem/object.go
index 6958e32..9eb085f 100644
--- a/storage/filesystem/object.go
+++ b/storage/filesystem/object.go
@@ -18,6 +18,8 @@ import (
 )
 
 type ObjectStorage struct {
+	options Options
+
 	// deltaBaseCache is an object cache uses to cache delta's bases when
 	deltaBaseCache cache.Object
 
@@ -25,14 +27,18 @@ type ObjectStorage struct {
 	index map[plumbing.Hash]idxfile.Index
 }
 
-// NewObjectStorage creates a new ObjectStorage with the given .git directory.
-func NewObjectStorage(dir *dotgit.DotGit) (ObjectStorage, error) {
-	s := ObjectStorage{
-		deltaBaseCache: cache.NewObjectLRUDefault(),
+// NewObjectStorage creates a new ObjectStorage with the given .git directory and cache.
+func NewObjectStorage(dir *dotgit.DotGit, cache cache.Object) *ObjectStorage {
+	return NewObjectStorageWithOptions(dir, cache, Options{})
+}
+
+// NewObjectStorageWithOptions creates a new ObjectStorage with the given .git directory, cache and extra options
+func NewObjectStorageWithOptions(dir *dotgit.DotGit, cache cache.Object, ops Options) *ObjectStorage {
+	return &ObjectStorage{
+		options:        ops,
+		deltaBaseCache: cache,
 		dir:            dir,
 	}
-
-	return s, nil
 }
 
 func (s *ObjectStorage) requireIndex() error {
@@ -62,6 +68,7 @@ func (s *ObjectStorage) loadIdxFile(h plumbing.Hash) (err error) {
 	}
 
 	defer ioutil.CheckClose(f, &err)
+
 	idxf := idxfile.NewMemoryIndex()
 	d := idxfile.NewDecoder(f)
 	if err = d.Decode(idxf); err != nil {
@@ -169,10 +176,7 @@ func (s *ObjectStorage) EncodedObject(t plumbing.ObjectType, h plumbing.Hash) (p
 			// Create a new object storage with the DotGit(s) and check for the
 			// required hash object. Skip when not found.
 			for _, dg := range dotgits {
-				o, oe := NewObjectStorage(dg)
-				if oe != nil {
-					continue
-				}
+				o := NewObjectStorage(dg, s.deltaBaseCache)
 				enobj, enerr := o.EncodedObject(t, h)
 				if enerr != nil {
 					continue
@@ -268,7 +272,9 @@ func (s *ObjectStorage) getFromPackfile(h plumbing.Hash, canBeDelta bool) (
 		return nil, err
 	}
 
-	defer ioutil.CheckClose(f, &err)
+	if !s.options.KeepDescriptors {
+		defer ioutil.CheckClose(f, &err)
+	}
 
 	idx := s.index[pack]
 	if canBeDelta {
@@ -295,7 +301,14 @@ func (s *ObjectStorage) decodeObjectAt(
 		return nil, err
 	}
 
-	return packfile.NewPackfile(idx, s.dir.Fs(), f).GetByOffset(offset)
+	var p *packfile.Packfile
+	if s.deltaBaseCache != nil {
+		p = packfile.NewPackfileWithCache(idx, s.dir.Fs(), f, s.deltaBaseCache)
+	} else {
+		p = packfile.NewPackfile(idx, s.dir.Fs(), f)
+	}
+
+	return p.GetByOffset(offset)
 }
 
 func (s *ObjectStorage) decodeDeltaObjectAt(
@@ -404,6 +417,11 @@ func (s *ObjectStorage) buildPackfileIters(t plumbing.ObjectType, seen map[plumb
 	}, nil
 }
 
+// Close closes all opened files.
+func (s *ObjectStorage) Close() error {
+	return s.dir.Close()
+}
+
 type lazyPackfilesIter struct {
 	hashes []plumbing.Hash
 	open   func(h plumbing.Hash) (storer.EncodedObjectIter, error)
@@ -486,7 +504,14 @@ func newPackfileIter(
 	index idxfile.Index,
 	cache cache.Object,
 ) (storer.EncodedObjectIter, error) {
-	iter, err := packfile.NewPackfile(index, fs, f).GetByType(t)
+	var p *packfile.Packfile
+	if cache != nil {
+		p = packfile.NewPackfileWithCache(index, fs, f, cache)
+	} else {
+		p = packfile.NewPackfile(index, fs, f)
+	}
+
+	iter, err := p.GetByType(t)
 	if err != nil {
 		return nil, err
 	}
diff --git a/storage/filesystem/object_test.go b/storage/filesystem/object_test.go
index b1408b7..bd4a94b 100644
--- a/storage/filesystem/object_test.go
+++ b/storage/filesystem/object_test.go
@@ -2,9 +2,11 @@ package filesystem
 
 import (
 	"io/ioutil"
+	"os"
 	"testing"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem/dotgit"
 
 	. "gopkg.in/check.v1"
@@ -26,8 +28,7 @@ var _ = Suite(&FsSuite{})
 
 func (s *FsSuite) TestGetFromObjectFile(c *C) {
 	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
-	o, err := NewObjectStorage(dotgit.New(fs))
-	c.Assert(err, IsNil)
+	o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
 
 	expected := plumbing.NewHash("f3dfe29d268303fc6e1bbce268605fc99573406e")
 	obj, err := o.EncodedObject(plumbing.AnyObject, expected)
@@ -38,20 +39,53 @@ func (s *FsSuite) TestGetFromObjectFile(c *C) {
 func (s *FsSuite) TestGetFromPackfile(c *C) {
 	fixtures.Basic().ByTag(".git").Test(c, func(f *fixtures.Fixture) {
 		fs := f.DotGit()
-		o, err := NewObjectStorage(dotgit.New(fs))
+		o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
+
+		expected := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+		obj, err := o.EncodedObject(plumbing.AnyObject, expected)
 		c.Assert(err, IsNil)
+		c.Assert(obj.Hash(), Equals, expected)
+	})
+}
+
+func (s *FsSuite) TestGetFromPackfileKeepDescriptors(c *C) {
+	fixtures.Basic().ByTag(".git").Test(c, func(f *fixtures.Fixture) {
+		fs := f.DotGit()
+		dg := dotgit.NewWithOptions(fs, dotgit.Options{KeepDescriptors: true})
+		o := NewObjectStorageWithOptions(dg, cache.NewObjectLRUDefault(), Options{KeepDescriptors: true})
 
 		expected := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
 		obj, err := o.EncodedObject(plumbing.AnyObject, expected)
 		c.Assert(err, IsNil)
 		c.Assert(obj.Hash(), Equals, expected)
+
+		packfiles, err := dg.ObjectPacks()
+		c.Assert(err, IsNil)
+
+		pack1, err := dg.ObjectPack(packfiles[0])
+		c.Assert(err, IsNil)
+
+		pack1.Seek(42, os.SEEK_SET)
+
+		err = o.Close()
+		c.Assert(err, IsNil)
+
+		pack2, err := dg.ObjectPack(packfiles[0])
+		c.Assert(err, IsNil)
+
+		offset, err := pack2.Seek(0, os.SEEK_CUR)
+		c.Assert(err, IsNil)
+		c.Assert(offset, Equals, int64(0))
+
+		err = o.Close()
+		c.Assert(err, IsNil)
+
 	})
 }
 
 func (s *FsSuite) TestGetFromPackfileMultiplePackfiles(c *C) {
 	fs := fixtures.ByTag(".git").ByTag("multi-packfile").One().DotGit()
-	o, err := NewObjectStorage(dotgit.New(fs))
-	c.Assert(err, IsNil)
+	o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
 
 	expected := plumbing.NewHash("8d45a34641d73851e01d3754320b33bb5be3c4d3")
 	obj, err := o.getFromPackfile(expected, false)
@@ -67,8 +101,7 @@ func (s *FsSuite) TestGetFromPackfileMultiplePackfiles(c *C) {
 func (s *FsSuite) TestIter(c *C) {
 	fixtures.ByTag(".git").ByTag("packfile").Test(c, func(f *fixtures.Fixture) {
 		fs := f.DotGit()
-		o, err := NewObjectStorage(dotgit.New(fs))
-		c.Assert(err, IsNil)
+		o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
 
 		iter, err := o.IterEncodedObjects(plumbing.AnyObject)
 		c.Assert(err, IsNil)
@@ -88,8 +121,7 @@ func (s *FsSuite) TestIterWithType(c *C) {
 	fixtures.ByTag(".git").Test(c, func(f *fixtures.Fixture) {
 		for _, t := range objectTypes {
 			fs := f.DotGit()
-			o, err := NewObjectStorage(dotgit.New(fs))
-			c.Assert(err, IsNil)
+			o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
 
 			iter, err := o.IterEncodedObjects(t)
 			c.Assert(err, IsNil)
@@ -271,11 +303,7 @@ func BenchmarkGetObjectFromPackfile(b *testing.B) {
 	for _, f := range fixtures.Basic() {
 		b.Run(f.URL, func(b *testing.B) {
 			fs := f.DotGit()
-			o, err := NewObjectStorage(dotgit.New(fs))
-			if err != nil {
-				b.Fatal(err)
-			}
-
+			o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
 			for i := 0; i < b.N; i++ {
 				expected := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
 				obj, err := o.EncodedObject(plumbing.AnyObject, expected)
diff --git a/storage/filesystem/storage.go b/storage/filesystem/storage.go
index 622bb4a..14a772a 100644
--- a/storage/filesystem/storage.go
+++ b/storage/filesystem/storage.go
@@ -2,6 +2,7 @@
 package filesystem
 
 import (
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/storage/filesystem/dotgit"
 
 	"gopkg.in/src-d/go-billy.v4"
@@ -22,25 +23,45 @@ type Storage struct {
 	ModuleStorage
 }
 
-// NewStorage returns a new Storage backed by a given `fs.Filesystem`
-func NewStorage(fs billy.Filesystem) (*Storage, error) {
-	dir := dotgit.New(fs)
-	o, err := NewObjectStorage(dir)
-	if err != nil {
-		return nil, err
+// Options holds configuration for the storage.
+type Options struct {
+	// ExclusiveAccess means that the filesystem is not modified externally
+	// while the repo is open.
+	ExclusiveAccess bool
+	// KeepDescriptors makes the file descriptors to be reused but they will
+	// need to be manually closed calling Close().
+	KeepDescriptors bool
+}
+
+// NewStorage returns a new Storage backed by a given `fs.Filesystem` and cache.
+func NewStorage(fs billy.Filesystem, cache cache.Object) *Storage {
+	return NewStorageWithOptions(fs, cache, Options{})
+}
+
+// NewStorageWithOptions returns a new Storage with extra options,
+// backed by a given `fs.Filesystem` and cache.
+func NewStorageWithOptions(fs billy.Filesystem, cache cache.Object, ops Options) *Storage {
+	dirOps := dotgit.Options{
+		ExclusiveAccess: ops.ExclusiveAccess,
+		KeepDescriptors: ops.KeepDescriptors,
 	}
+	dir := dotgit.NewWithOptions(fs, dirOps)
 
 	return &Storage{
 		fs:  fs,
 		dir: dir,
 
-		ObjectStorage:    o,
+		ObjectStorage: ObjectStorage{
+			options:        ops,
+			deltaBaseCache: cache,
+			dir:            dir,
+		},
 		ReferenceStorage: ReferenceStorage{dir: dir},
 		IndexStorage:     IndexStorage{dir: dir},
 		ShallowStorage:   ShallowStorage{dir: dir},
 		ConfigStorage:    ConfigStorage{dir: dir},
 		ModuleStorage:    ModuleStorage{dir: dir},
-	}, nil
+	}
 }
 
 // Filesystem returns the underlying filesystem
@@ -48,6 +69,7 @@ func (s *Storage) Filesystem() billy.Filesystem {
 	return s.fs
 }
 
+// Init initializes .git directory
 func (s *Storage) Init() error {
 	return s.dir.Initialize()
 }
diff --git a/storage/filesystem/storage_test.go b/storage/filesystem/storage_test.go
index 4d9ba6f..6fa0d90 100644
--- a/storage/filesystem/storage_test.go
+++ b/storage/filesystem/storage_test.go
@@ -4,6 +4,7 @@ import (
 	"io/ioutil"
 	"testing"
 
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage/test"
 
@@ -23,9 +24,12 @@ var _ = Suite(&StorageSuite{})
 
 func (s *StorageSuite) SetUpTest(c *C) {
 	s.dir = c.MkDir()
-	storage, err := NewStorage(osfs.New(s.dir))
-	c.Assert(err, IsNil)
+	storage := NewStorage(osfs.New(s.dir), cache.NewObjectLRUDefault())
+
+	setUpTest(s, c, storage)
+}
 
+func setUpTest(s *StorageSuite, c *C, storage *Storage) {
 	// ensure that right interfaces are implemented
 	var _ storer.EncodedObjectStorer = storage
 	var _ storer.IndexStorer = storage
@@ -40,8 +44,7 @@ func (s *StorageSuite) SetUpTest(c *C) {
 
 func (s *StorageSuite) TestFilesystem(c *C) {
 	fs := memfs.New()
-	storage, err := NewStorage(fs)
-	c.Assert(err, IsNil)
+	storage := NewStorage(fs, cache.NewObjectLRUDefault())
 
 	c.Assert(storage.Filesystem(), Equals, fs)
 }
@@ -51,3 +54,19 @@ func (s *StorageSuite) TestNewStorageShouldNotAddAnyContentsToDir(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(fis, HasLen, 0)
 }
+
+type StorageExclusiveSuite struct {
+	StorageSuite
+}
+
+var _ = Suite(&StorageExclusiveSuite{})
+
+func (s *StorageExclusiveSuite) SetUpTest(c *C) {
+	s.dir = c.MkDir()
+	storage := NewStorageWithOptions(
+		osfs.New(s.dir),
+		cache.NewObjectLRUDefault(),
+		Options{ExclusiveAccess: true})
+
+	setUpTest(&s.StorageSuite, c, storage)
+}
diff --git a/worktree.go b/worktree.go
index 99b2cd1..e45d815 100644
--- a/worktree.go
+++ b/worktree.go
@@ -713,29 +713,54 @@ func (w *Worktree) readGitmodulesFile() (*config.Modules, error) {
 }
 
 // Clean the worktree by removing untracked files.
+// An empty dir could be removed - this is what  `git clean -f -d .` does.
 func (w *Worktree) Clean(opts *CleanOptions) error {
 	s, err := w.Status()
 	if err != nil {
 		return err
 	}
 
-	// Check Worktree status to be Untracked, obtain absolute path and delete.
-	for relativePath, status := range s {
-		// Check if the path contains a directory and if Dir options is false,
-		// skip the path.
-		if relativePath != filepath.Base(relativePath) && !opts.Dir {
+	root := ""
+	files, err := w.Filesystem.ReadDir(root)
+	if err != nil {
+		return err
+	}
+	return w.doClean(s, opts, root, files)
+}
+
+func (w *Worktree) doClean(status Status, opts *CleanOptions, dir string, files []os.FileInfo) error {
+	for _, fi := range files {
+		if fi.Name() == ".git" {
 			continue
 		}
 
-		// Remove the file only if it's an untracked file.
-		if status.Worktree == Untracked {
-			absPath := filepath.Join(w.Filesystem.Root(), relativePath)
-			if err := os.Remove(absPath); err != nil {
+		// relative path under the root
+		path := filepath.Join(dir, fi.Name())
+		if fi.IsDir() {
+			if !opts.Dir {
+				continue
+			}
+
+			subfiles, err := w.Filesystem.ReadDir(path)
+			if err != nil {
+				return err
+			}
+			err = w.doClean(status, opts, path, subfiles)
+			if err != nil {
 				return err
 			}
+		} else {
+			if status.IsUntracked(path) {
+				if err := w.Filesystem.Remove(path); err != nil {
+					return err
+				}
+			}
 		}
 	}
 
+	if opts.Dir {
+		return doCleanDirectories(w.Filesystem, dir)
+	}
 	return nil
 }
 
@@ -881,15 +906,18 @@ func rmFileAndDirIfEmpty(fs billy.Filesystem, name string) error {
 		return err
 	}
 
-	path := filepath.Dir(name)
-	files, err := fs.ReadDir(path)
+	dir := filepath.Dir(name)
+	return doCleanDirectories(fs, dir)
+}
+
+// doCleanDirectories removes empty subdirs (without files)
+func doCleanDirectories(fs billy.Filesystem, dir string) error {
+	files, err := fs.ReadDir(dir)
 	if err != nil {
 		return err
 	}
-
 	if len(files) == 0 {
-		fs.Remove(path)
+		return fs.Remove(dir)
 	}
-
 	return nil
 }
diff --git a/worktree_commit.go b/worktree_commit.go
index b83bf0c..673eb16 100644
--- a/worktree_commit.go
+++ b/worktree_commit.go
@@ -3,6 +3,7 @@ package git
 import (
 	"bytes"
 	"path"
+	"sort"
 	"strings"
 
 	"golang.org/x/crypto/openpgp"
@@ -188,7 +189,20 @@ func (h *buildTreeHelper) doBuildTree(e *index.Entry, parent, fullpath string) {
 	h.trees[parent].Entries = append(h.trees[parent].Entries, te)
 }
 
+type sortableEntries []object.TreeEntry
+
+func (sortableEntries) sortName(te object.TreeEntry) string {
+	if te.Mode == filemode.Dir {
+		return te.Name + "/"
+	}
+	return te.Name
+}
+func (se sortableEntries) Len() int               { return len(se) }
+func (se sortableEntries) Less(i int, j int) bool { return se.sortName(se[i]) < se.sortName(se[j]) }
+func (se sortableEntries) Swap(i int, j int)      { se[i], se[j] = se[j], se[i] }
+
 func (h *buildTreeHelper) copyTreeToStorageRecursive(parent string, t *object.Tree) (plumbing.Hash, error) {
+	sort.Sort(sortableEntries(t.Entries))
 	for i, e := range t.Entries {
 		if e.Mode != filemode.Dir && !e.Hash.IsZero() {
 			continue
diff --git a/worktree_commit_test.go b/worktree_commit_test.go
index fdeaec0..da377c6 100644
--- a/worktree_commit_test.go
+++ b/worktree_commit_test.go
@@ -2,19 +2,25 @@ package git
 
 import (
 	"bytes"
+	"io/ioutil"
+	"os"
+	"os/exec"
 	"strings"
 	"time"
 
-	"golang.org/x/crypto/openpgp"
-	"golang.org/x/crypto/openpgp/armor"
-	"golang.org/x/crypto/openpgp/errors"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
 	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+	"gopkg.in/src-d/go-git.v4/storage/filesystem"
 	"gopkg.in/src-d/go-git.v4/storage/memory"
 
+	"golang.org/x/crypto/openpgp"
+	"golang.org/x/crypto/openpgp/armor"
+	"golang.org/x/crypto/openpgp/errors"
 	. "gopkg.in/check.v1"
 	"gopkg.in/src-d/go-billy.v4/memfs"
+	"gopkg.in/src-d/go-billy.v4/osfs"
 	"gopkg.in/src-d/go-billy.v4/util"
 )
 
@@ -196,6 +202,53 @@ func (s *WorktreeSuite) TestCommitSignBadKey(c *C) {
 	c.Assert(err, Equals, errors.InvalidArgumentError("signing key is encrypted"))
 }
 
+func (s *WorktreeSuite) TestCommitTreeSort(c *C) {
+	path, err := ioutil.TempDir(os.TempDir(), "test-commit-tree-sort")
+	c.Assert(err, IsNil)
+	fs := osfs.New(path)
+	st := filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
+	r, err := Init(st, nil)
+	c.Assert(err, IsNil)
+
+	r, err = Clone(memory.NewStorage(), memfs.New(), &CloneOptions{
+		URL: path,
+	})
+
+	w, err := r.Worktree()
+	c.Assert(err, IsNil)
+
+	mfs := w.Filesystem
+
+	err = mfs.MkdirAll("delta", 0755)
+	c.Assert(err, IsNil)
+
+	for _, p := range []string{"delta_last", "Gamma", "delta/middle", "Beta", "delta-first", "alpha"} {
+		util.WriteFile(mfs, p, []byte("foo"), 0644)
+		_, err = w.Add(p)
+		c.Assert(err, IsNil)
+	}
+
+	_, err = w.Commit("foo\n", &CommitOptions{
+		All:    true,
+		Author: defaultSignature(),
+	})
+	c.Assert(err, IsNil)
+
+	err = r.Push(&PushOptions{})
+	c.Assert(err, IsNil)
+
+	cmd := exec.Command("git", "fsck")
+	cmd.Dir = path
+	cmd.Env = os.Environ()
+	buf := &bytes.Buffer{}
+	cmd.Stderr = buf
+	cmd.Stdout = buf
+
+	err = cmd.Run()
+
+	c.Assert(err, IsNil, Commentf("%s", buf.Bytes()))
+}
+
 func assertStorageStatus(
 	c *C, r *Repository,
 	treesCount, blobCount, commitCount int, head plumbing.Hash,
diff --git a/worktree_test.go b/worktree_test.go
index df191b0..c714011 100644
--- a/worktree_test.go
+++ b/worktree_test.go
@@ -1591,6 +1591,10 @@ func (s *WorktreeSuite) TestClean(c *C) {
 
 	c.Assert(len(status), Equals, 1)
 
+	fi, err := fs.Lstat("pkgA")
+	c.Assert(err, IsNil)
+	c.Assert(fi.IsDir(), Equals, true)
+
 	// Clean with Dir: true.
 	err = wt.Clean(&CleanOptions{Dir: true})
 	c.Assert(err, IsNil)
@@ -1599,6 +1603,11 @@ func (s *WorktreeSuite) TestClean(c *C) {
 	c.Assert(err, IsNil)
 
 	c.Assert(len(status), Equals, 0)
+
+	// An empty dir should be deleted, as well.
+	_, err = fs.Lstat("pkgA")
+	c.Assert(err, ErrorMatches, ".*(no such file or directory.*|.*file does not exist)*.")
+
 }
 
 func (s *WorktreeSuite) TestAlternatesRepo(c *C) {