Merge branch 'master' of github.com:src-d/go-git into commit

25 files changed, 663 insertions, 163 deletions

diff --git a/_examples/common_test.go b/_examples/common_test.go
index 5543eaf..ff01ba3 100644
--- a/_examples/common_test.go
+++ b/_examples/common_test.go
@@ -2,7 +2,6 @@ package examples
 
 import (
 	"flag"
-	"fmt"
 	"go/build"
 	"io/ioutil"
 	"os"
@@ -96,7 +95,7 @@ func createBareRepository(dir string) string {
 
 func setEmptyRemote(dir string) string {
 	remote := createBareRepository(tempFolder())
-	setRemote(dir, fmt.Sprintf("file://%s", remote))
+	setRemote(dir, remote)
 	return dir
 }
 
diff --git a/_examples/storage/README.md b/_examples/storage/README.md
index 02b68da..b7207ee 100644
--- a/_examples/storage/README.md
+++ b/_examples/storage/README.md
@@ -1,4 +1,4 @@
-#go-git + aerospike: a git repository backed by a database
+# go-git + aerospike: a git repository backed by a database
 
 <img src="https://upload.wikimedia.org/wikipedia/en/2/2b/Aerospike_logo.png" align="right"/> This is an example of a [go-git](https://github.com/src-d/go-git) repository backed by [Aerospike](http://www.aerospike.com/). 
 
diff --git a/common_test.go b/common_test.go
index bd60385..e1a2a0f 100644
--- a/common_test.go
+++ b/common_test.go
@@ -1,7 +1,6 @@
 package git
 
 import (
-	"fmt"
 	"testing"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
@@ -95,8 +94,7 @@ func (s *BaseSuite) GetBasicLocalRepositoryURL() string {
 }
 
 func (s *BaseSuite) GetLocalRepositoryURL(f *fixtures.Fixture) string {
-	path := f.DotGit().Base()
-	return fmt.Sprintf("file://%s", path)
+	return f.DotGit().Base()
 }
 
 type SuiteCommon struct{}
diff --git a/plumbing/transport/client/client.go b/plumbing/transport/client/client.go
index a398a74..76c1469 100644
--- a/plumbing/transport/client/client.go
+++ b/plumbing/transport/client/client.go
@@ -35,13 +35,13 @@ func InstallProtocol(scheme string, c transport.Transport) {
 // http://, https://, ssh:// and file://.
 // See `InstallProtocol` to add or modify protocols.
 func NewClient(endpoint transport.Endpoint) (transport.Transport, error) {
-	f, ok := Protocols[endpoint.Scheme]
+	f, ok := Protocols[endpoint.Protocol()]
 	if !ok {
-		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Scheme)
+		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Protocol())
 	}
 
 	if f == nil {
-		return nil, fmt.Errorf("malformed client for scheme %q, client is defined as nil", endpoint.Scheme)
+		return nil, fmt.Errorf("malformed client for scheme %q, client is defined as nil", endpoint.Protocol())
 	}
 
 	return f, nil
diff --git a/plumbing/transport/common.go b/plumbing/transport/common.go
index d3cfe21..d6594ca 100644
--- a/plumbing/transport/common.go
+++ b/plumbing/transport/common.go
@@ -18,6 +18,7 @@ import (
 	"io"
 	"net/url"
 	"regexp"
+	"strconv"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
@@ -28,7 +29,7 @@ var (
 	ErrRepositoryNotFound     = errors.New("repository not found")
 	ErrEmptyRemoteRepository  = errors.New("remote repository is empty")
 	ErrAuthenticationRequired = errors.New("authentication required")
-	ErrAuthorizationFailed	  = errors.New("authorization failed")
+	ErrAuthorizationFailed    = errors.New("authorization failed")
 	ErrEmptyUploadPackRequest = errors.New("empty git-upload-pack given")
 	ErrInvalidAuthMethod      = errors.New("invalid auth method")
 	ErrAlreadyConnected       = errors.New("session already established")
@@ -88,42 +89,159 @@ type ReceivePackSession interface {
 	ReceivePack(*packp.ReferenceUpdateRequest) (*packp.ReportStatus, error)
 }
 
-type Endpoint url.URL
-
-var (
-	isSchemeRegExp   = regexp.MustCompile("^[^:]+://")
-	scpLikeUrlRegExp = regexp.MustCompile("^(?P<user>[^@]+@)?(?P<host>[^:]+):/?(?P<path>.+)$")
-)
+// Endpoint represents a Git URL in any supported protocol.
+type Endpoint interface {
+	// Protocol returns the protocol (e.g. git, https, file). It should never
+	// return the empty string.
+	Protocol() string
+	// User returns the user or an empty string if none is given.
+	User() string
+	// Password returns the password or an empty string if none is given.
+	Password() string
+	// Host returns the host or an empty string if none is given.
+	Host() string
+	// Port returns the port or 0 if there is no port or a default should be
+	// used.
+	Port() int
+	// Path returns the repository path.
+	Path() string
+	// String returns a string representation of the Git URL.
+	String() string
+}
 
 func NewEndpoint(endpoint string) (Endpoint, error) {
-	endpoint = transformSCPLikeIfNeeded(endpoint)
+	if e, ok := parseSCPLike(endpoint); ok {
+		return e, nil
+	}
+
+	if e, ok := parseFile(endpoint); ok {
+		return e, nil
+	}
 
 	u, err := url.Parse(endpoint)
 	if err != nil {
-		return Endpoint{}, plumbing.NewPermanentError(err)
+		return nil, plumbing.NewPermanentError(err)
 	}
 
 	if !u.IsAbs() {
-		return Endpoint{}, plumbing.NewPermanentError(fmt.Errorf(
+		return nil, plumbing.NewPermanentError(fmt.Errorf(
 			"invalid endpoint: %s", endpoint,
 		))
 	}
 
-	return Endpoint(*u), nil
+	return urlEndpoint{u}, nil
+}
+
+type urlEndpoint struct {
+	*url.URL
+}
+
+func (e urlEndpoint) Protocol() string { return e.URL.Scheme }
+func (e urlEndpoint) Host() string     { return e.URL.Hostname() }
+
+func (e urlEndpoint) User() string {
+	if e.URL.User == nil {
+		return ""
+	}
+
+	return e.URL.User.Username()
+}
+
+func (e urlEndpoint) Password() string {
+	if e.URL.User == nil {
+		return ""
+	}
+
+	p, _ := e.URL.User.Password()
+	return p
+}
+
+func (e urlEndpoint) Port() int {
+	p := e.URL.Port()
+	if p == "" {
+		return 0
+	}
+
+	i, err := strconv.Atoi(e.URL.Port())
+	if err != nil {
+		return 0
+	}
+
+	return i
+}
+
+func (e urlEndpoint) Path() string {
+	var res string = e.URL.Path
+	if e.URL.RawQuery != "" {
+		res += "?" + e.URL.RawQuery
+	}
+
+	if e.URL.Fragment != "" {
+		res += "#" + e.URL.Fragment
+	}
+
+	return res
+}
+
+type scpEndpoint struct {
+	user string
+	host string
+	path string
 }
 
-func (e *Endpoint) String() string {
-	u := url.URL(*e)
-	return u.String()
+func (e *scpEndpoint) Protocol() string { return "ssh" }
+func (e *scpEndpoint) User() string     { return e.user }
+func (e *scpEndpoint) Password() string { return "" }
+func (e *scpEndpoint) Host() string     { return e.host }
+func (e *scpEndpoint) Port() int        { return 22 }
+func (e *scpEndpoint) Path() string     { return e.path }
+
+func (e *scpEndpoint) String() string {
+	var user string
+	if e.user != "" {
+		user = fmt.Sprintf("%s@", e.user)
+	}
+
+	return fmt.Sprintf("%s%s:%s", user, e.host, e.path)
+}
+
+type fileEndpoint struct {
+	path string
+}
+
+func (e *fileEndpoint) Protocol() string { return "file" }
+func (e *fileEndpoint) User() string     { return "" }
+func (e *fileEndpoint) Password() string { return "" }
+func (e *fileEndpoint) Host() string     { return "" }
+func (e *fileEndpoint) Port() int        { return 0 }
+func (e *fileEndpoint) Path() string     { return e.path }
+func (e *fileEndpoint) String() string   { return e.path }
+
+var (
+	isSchemeRegExp   = regexp.MustCompile(`^[^:]+://`)
+	scpLikeUrlRegExp = regexp.MustCompile(`^(?:(?P<user>[^@]+)@)?(?P<host>[^:\s]+):(?P<path>[^\\].*)$`)
+)
+
+func parseSCPLike(endpoint string) (Endpoint, bool) {
+	if isSchemeRegExp.MatchString(endpoint) || !scpLikeUrlRegExp.MatchString(endpoint) {
+		return nil, false
+	}
+
+	m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
+	return &scpEndpoint{
+		user: m[1],
+		host: m[2],
+		path: m[3],
+	}, true
 }
 
-func transformSCPLikeIfNeeded(endpoint string) string {
-	if !isSchemeRegExp.MatchString(endpoint) && scpLikeUrlRegExp.MatchString(endpoint) {
-		m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
-		return fmt.Sprintf("ssh://%s%s/%s", m[1], m[2], m[3])
+func parseFile(endpoint string) (Endpoint, bool) {
+	if isSchemeRegExp.MatchString(endpoint) {
+		return nil, false
 	}
 
-	return endpoint
+	path := endpoint
+	return &fileEndpoint{path}, true
 }
 
 // UnsupportedCapabilities are the capabilities not supported by any client
diff --git a/plumbing/transport/common_test.go b/plumbing/transport/common_test.go
index e9a5efa..ec617bd 100644
--- a/plumbing/transport/common_test.go
+++ b/plumbing/transport/common_test.go
@@ -14,22 +14,118 @@ type SuiteCommon struct{}
 
 var _ = Suite(&SuiteCommon{})
 
-func (s *SuiteCommon) TestNewEndpoint(c *C) {
+func (s *SuiteCommon) TestNewEndpointHTTP(c *C) {
+	e, err := NewEndpoint("http://git:pass@github.com/user/repository.git?foo#bar")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "http")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "pass")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git?foo#bar")
+	c.Assert(e.String(), Equals, "http://git:pass@github.com/user/repository.git?foo#bar")
+}
+
+func (s *SuiteCommon) TestNewEndpointSSH(c *C) {
 	e, err := NewEndpoint("ssh://git@github.com/user/repository.git")
 	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
 	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
 }
 
+func (s *SuiteCommon) TestNewEndpointSSHNoUser(c *C) {
+	e, err := NewEndpoint("ssh://github.com/user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
+	c.Assert(e.String(), Equals, "ssh://github.com/user/repository.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointSSHWithPort(c *C) {
+	e, err := NewEndpoint("ssh://git@github.com:777/user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 777)
+	c.Assert(e.Path(), Equals, "/user/repository.git")
+	c.Assert(e.String(), Equals, "ssh://git@github.com:777/user/repository.git")
+}
+
 func (s *SuiteCommon) TestNewEndpointSCPLike(c *C) {
 	e, err := NewEndpoint("git@github.com:user/repository.git")
 	c.Assert(err, IsNil)
-	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
+	c.Assert(e.Protocol(), Equals, "ssh")
+	c.Assert(e.User(), Equals, "git")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "github.com")
+	c.Assert(e.Port(), Equals, 22)
+	c.Assert(e.Path(), Equals, "user/repository.git")
+	c.Assert(e.String(), Equals, "git@github.com:user/repository.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointFileAbs(c *C) {
+	e, err := NewEndpoint("/foo.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "file")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/foo.git")
+	c.Assert(e.String(), Equals, "/foo.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointFileRel(c *C) {
+	e, err := NewEndpoint("foo.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "file")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "foo.git")
+	c.Assert(e.String(), Equals, "foo.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointFileWindows(c *C) {
+	e, err := NewEndpoint("C:\\foo.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "file")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "C:\\foo.git")
+	c.Assert(e.String(), Equals, "C:\\foo.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointFileURL(c *C) {
+	e, err := NewEndpoint("file:///foo.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.Protocol(), Equals, "file")
+	c.Assert(e.User(), Equals, "")
+	c.Assert(e.Password(), Equals, "")
+	c.Assert(e.Host(), Equals, "")
+	c.Assert(e.Port(), Equals, 0)
+	c.Assert(e.Path(), Equals, "/foo.git")
+	c.Assert(e.String(), Equals, "file:///foo.git")
 }
 
-func (s *SuiteCommon) TestNewEndpointWrongForgat(c *C) {
-	e, err := NewEndpoint("foo")
-	c.Assert(err, Not(IsNil))
-	c.Assert(e.Host, Equals, "")
+func (s *SuiteCommon) TestNewEndpointInvalidURL(c *C) {
+	e, err := NewEndpoint("http://\\")
+	c.Assert(err, NotNil)
+	c.Assert(e, IsNil)
 }
 
 func (s *SuiteCommon) TestFilterUnsupportedCapabilities(c *C) {
diff --git a/plumbing/transport/file/client.go b/plumbing/transport/file/client.go
index 58e60db..d2a57d0 100644
--- a/plumbing/transport/file/client.go
+++ b/plumbing/transport/file/client.go
@@ -41,7 +41,7 @@ func (r *runner) Command(cmd string, ep transport.Endpoint, auth transport.AuthM
 		return nil, err
 	}
 
-	return &command{cmd: exec.Command(cmd, ep.Path)}, nil
+	return &command{cmd: exec.Command(cmd, ep.Path())}, nil
 }
 
 type command struct {
diff --git a/plumbing/transport/file/client_test.go b/plumbing/transport/file/client_test.go
index 220df3d..030175e 100644
--- a/plumbing/transport/file/client_test.go
+++ b/plumbing/transport/file/client_test.go
@@ -1,9 +1,9 @@
 package file
 
 import (
-	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -20,13 +20,12 @@ filemode = true
 bare = true`
 
 func prepareRepo(c *C, path string) transport.Endpoint {
-	url := fmt.Sprintf("file://%s", path)
-	ep, err := transport.NewEndpoint(url)
+	ep, err := transport.NewEndpoint(path)
 	c.Assert(err, IsNil)
 
 	// git-receive-pack refuses to update refs/heads/master on non-bare repo
 	// so we ensure bare repo config.
-	config := fmt.Sprintf("%s/config", path)
+	config := filepath.Join(path, "config")
 	if _, err := os.Stat(config); err == nil {
 		f, err := os.OpenFile(config, os.O_TRUNC|os.O_WRONLY, 0)
 		c.Assert(err, IsNil)
diff --git a/plumbing/transport/file/server.go b/plumbing/transport/file/server.go
index 74085c2..61dd42d 100644
--- a/plumbing/transport/file/server.go
+++ b/plumbing/transport/file/server.go
@@ -14,7 +14,7 @@ import (
 // and error. This is meant to be used when implementing a git-upload-pack
 // command.
 func ServeUploadPack(path string) error {
-	ep, err := transport.NewEndpoint(fmt.Sprintf("file://%s", path))
+	ep, err := transport.NewEndpoint(path)
 	if err != nil {
 		return err
 	}
@@ -32,7 +32,7 @@ func ServeUploadPack(path string) error {
 // input and error. This is meant to be used when implementing a
 // git-receive-pack command.
 func ServeReceivePack(path string) error {
-	ep, err := transport.NewEndpoint(fmt.Sprintf("file://%s", path))
+	ep, err := transport.NewEndpoint(path)
 	if err != nil {
 		return err
 	}
diff --git a/plumbing/transport/file/server_test.go b/plumbing/transport/file/server_test.go
index a7b4e34..176d6ee 100644
--- a/plumbing/transport/file/server_test.go
+++ b/plumbing/transport/file/server_test.go
@@ -1,7 +1,6 @@
 package file
 
 import (
-	"fmt"
 	"os"
 	"os/exec"
 
@@ -15,7 +14,6 @@ type ServerSuite struct {
 	RemoteName string
 	SrcPath    string
 	DstPath    string
-	DstURL     string
 }
 
 var _ = Suite(&ServerSuite{})
@@ -30,9 +28,8 @@ func (s *ServerSuite) SetUpSuite(c *C) {
 
 	fixture = fixtures.ByTag("empty").One()
 	s.DstPath = fixture.DotGit().Base()
-	s.DstURL = fmt.Sprintf("file://%s", s.DstPath)
 
-	cmd := exec.Command("git", "remote", "add", s.RemoteName, s.DstURL)
+	cmd := exec.Command("git", "remote", "add", s.RemoteName, s.DstPath)
 	cmd.Dir = s.SrcPath
 	c.Assert(cmd.Run(), IsNil)
 }
diff --git a/plumbing/transport/file/upload_pack_test.go b/plumbing/transport/file/upload_pack_test.go
index e5915f0..f013683 100644
--- a/plumbing/transport/file/upload_pack_test.go
+++ b/plumbing/transport/file/upload_pack_test.go
@@ -1,8 +1,8 @@
 package file
 
 import (
-	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/src-d/go-git-fixtures"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
@@ -25,20 +25,18 @@ func (s *UploadPackSuite) SetUpSuite(c *C) {
 
 	fixture := fixtures.Basic().One()
 	path := fixture.DotGit().Base()
-	url := fmt.Sprintf("file://%s", path)
-	ep, err := transport.NewEndpoint(url)
+	ep, err := transport.NewEndpoint(path)
 	c.Assert(err, IsNil)
 	s.Endpoint = ep
 
 	fixture = fixtures.ByTag("empty").One()
 	path = fixture.DotGit().Base()
-	url = fmt.Sprintf("file://%s", path)
-	ep, err = transport.NewEndpoint(url)
+	ep, err = transport.NewEndpoint(path)
 	c.Assert(err, IsNil)
 	s.EmptyEndpoint = ep
 
-	url = fmt.Sprintf("file://%s/%s", fixtures.DataFolder, "non-existent")
-	ep, err = transport.NewEndpoint(url)
+	path = filepath.Join(fixtures.DataFolder, "non-existent")
+	ep, err = transport.NewEndpoint(path)
 	c.Assert(err, IsNil)
 	s.NonExistentEndpoint = ep
 }
diff --git a/plumbing/transport/git/common.go b/plumbing/transport/git/common.go
index 24134c1..753f125 100644
--- a/plumbing/transport/git/common.go
+++ b/plumbing/transport/git/common.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"strings"
 
 	"gopkg.in/src-d/go-git.v4/plumbing/format/pktline"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
@@ -16,6 +15,8 @@ import (
 // DefaultClient is the default git client.
 var DefaultClient = common.NewClient(&runner{})
 
+const DefaultPort = 9418
+
 type runner struct{}
 
 // Command returns a new Command for the given cmd in the given Endpoint
@@ -62,12 +63,13 @@ func (c *command) connect() error {
 }
 
 func (c *command) getHostWithPort() string {
-	host := c.endpoint.Host
-	if strings.Index(c.endpoint.Host, ":") == -1 {
-		host += ":9418"
+	host := c.endpoint.Host()
+	port := c.endpoint.Port()
+	if port <= 0 {
+		port = DefaultPort
 	}
 
-	return host
+	return fmt.Sprintf("%s:%d", host, port)
 }
 
 // StderrPipe git protocol doesn't have any dedicated error channel
@@ -88,7 +90,7 @@ func (c *command) StdoutPipe() (io.Reader, error) {
 }
 
 func endpointToCommand(cmd string, ep transport.Endpoint) string {
-	return fmt.Sprintf("%s %s%chost=%s%c", cmd, ep.Path, 0, ep.Host, 0)
+	return fmt.Sprintf("%s %s%chost=%s%c", cmd, ep.Path(), 0, ep.Host(), 0)
 }
 
 // Wait no-op function, required by the interface
diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go
index 930e8eb..04b6121 100644
--- a/plumbing/transport/http/common.go
+++ b/plumbing/transport/http/common.go
@@ -73,18 +73,12 @@ type AuthMethod interface {
 }
 
 func basicAuthFromEndpoint(ep transport.Endpoint) *BasicAuth {
-	info := ep.User
-	if info == nil {
+	u := ep.User()
+	if u == "" {
 		return nil
 	}
 
-	p, ok := info.Password()
-	if !ok {
-		return nil
-	}
-
-	u := info.Username()
-	return NewBasicAuth(u, p)
+	return NewBasicAuth(u, ep.Password())
 }
 
 // BasicAuth represent a HTTP basic auth
diff --git a/plumbing/transport/http/upload_pack.go b/plumbing/transport/http/upload_pack.go
index 8f73789..2d1ea45 100644
--- a/plumbing/transport/http/upload_pack.go
+++ b/plumbing/transport/http/upload_pack.go
@@ -150,7 +150,7 @@ func (s *upSession) doRequest(method, url string, content *bytes.Buffer) (*http.
 // it requires a bytes.Buffer, because we need to know the length
 func (s *upSession) applyHeadersToRequest(req *http.Request, content *bytes.Buffer) {
 	req.Header.Add("User-Agent", "git/1.0")
-	req.Header.Add("Host", s.endpoint.Host)
+	req.Header.Add("Host", s.endpoint.Host()) // host:port
 
 	if content == nil {
 		req.Header.Add("Accept", "*/*")
diff --git a/plumbing/transport/server/loader.go b/plumbing/transport/server/loader.go
index cfe9f04..b51a795 100644
--- a/plumbing/transport/server/loader.go
+++ b/plumbing/transport/server/loader.go
@@ -34,7 +34,7 @@ func NewFilesystemLoader(base billy.Filesystem) Loader {
 // storer for it. Returns transport.ErrRepositoryNotFound if a repository does
 // not exist in the given path.
 func (l *fsLoader) Load(ep transport.Endpoint) (storer.Storer, error) {
-	fs := l.base.Dir(ep.Path)
+	fs := l.base.Dir(ep.Path())
 	if _, err := fs.Stat("config"); err != nil {
 		return nil, transport.ErrRepositoryNotFound
 	}
diff --git a/plumbing/transport/server/loader_test.go b/plumbing/transport/server/loader_test.go
index b4a8c37..5f32cb0 100644
--- a/plumbing/transport/server/loader_test.go
+++ b/plumbing/transport/server/loader_test.go
@@ -1,7 +1,6 @@
 package server
 
 import (
-	"fmt"
 	"os/exec"
 	"path/filepath"
 
@@ -33,7 +32,7 @@ func (s *LoaderSuite) endpoint(c *C, url string) transport.Endpoint {
 }
 
 func (s *LoaderSuite) TestLoadNonExistent(c *C) {
-	sto, err := DefaultLoader.Load(s.endpoint(c, "file:///does-not-exist"))
+	sto, err := DefaultLoader.Load(s.endpoint(c, "does-not-exist"))
 	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
 	c.Assert(sto, IsNil)
 }
@@ -45,13 +44,13 @@ func (s *LoaderSuite) TestLoadNonExistentIgnoreHost(c *C) {
 }
 
 func (s *LoaderSuite) TestLoad(c *C) {
-	sto, err := DefaultLoader.Load(s.endpoint(c, fmt.Sprintf("file://%s", s.RepoPath)))
+	sto, err := DefaultLoader.Load(s.endpoint(c, s.RepoPath))
 	c.Assert(err, IsNil)
 	c.Assert(sto, NotNil)
 }
 
 func (s *LoaderSuite) TestLoadIgnoreHost(c *C) {
-	sto, err := DefaultLoader.Load(s.endpoint(c, fmt.Sprintf("file://%s", s.RepoPath)))
+	sto, err := DefaultLoader.Load(s.endpoint(c, s.RepoPath))
 	c.Assert(err, IsNil)
 	c.Assert(sto, NotNil)
 }
diff --git a/plumbing/transport/ssh/auth_method.go b/plumbing/transport/ssh/auth_method.go
index a3e1ad1..84dfe14 100644
--- a/plumbing/transport/ssh/auth_method.go
+++ b/plumbing/transport/ssh/auth_method.go
@@ -179,9 +179,14 @@ type PublicKeysCallback struct {
 // NewSSHAgentAuth returns a PublicKeysCallback based on a SSH agent, it opens
 // a pipe with the SSH agent and uses the pipe as the implementer of the public
 // key callback function.
-func NewSSHAgentAuth(user string) (AuthMethod, error) {
-	if user == "" {
-		user = DefaultUsername
+func NewSSHAgentAuth(u string) (AuthMethod, error) {
+	if u == "" {
+		usr, err := user.Current()
+		if err != nil {
+			return nil, fmt.Errorf("error getting current user: %q", err)
+		}
+
+		u = usr.Username
 	}
 
 	sshAgentAddr := os.Getenv("SSH_AUTH_SOCK")
@@ -195,7 +200,7 @@ func NewSSHAgentAuth(user string) (AuthMethod, error) {
 	}
 
 	return &PublicKeysCallback{
-		User:     user,
+		User:     u,
 		Callback: agent.NewClient(pipe).Signers,
 	}, nil
 }
diff --git a/plumbing/transport/ssh/common.go b/plumbing/transport/ssh/common.go
index 7b44a91..d53fc12 100644
--- a/plumbing/transport/ssh/common.go
+++ b/plumbing/transport/ssh/common.go
@@ -3,7 +3,6 @@ package ssh
 
 import (
 	"fmt"
-	"strings"
 
 	"gopkg.in/src-d/go-git.v4/plumbing/transport"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport/internal/common"
@@ -20,6 +19,8 @@ var DefaultAuthBuilder = func(user string) (AuthMethod, error) {
 	return NewSSHAgentAuth(user)
 }
 
+const DefaultPort = 22
+
 type runner struct{}
 
 func (r *runner) Command(cmd string, ep transport.Endpoint, auth transport.AuthMethod) (common.Command, error) {
@@ -110,25 +111,21 @@ func (c *command) connect() error {
 }
 
 func (c *command) getHostWithPort() string {
-	host := c.endpoint.Host
-	if strings.Index(c.endpoint.Host, ":") == -1 {
-		host += ":22"
+	host := c.endpoint.Host()
+	port := c.endpoint.Port()
+	if port <= 0 {
+		port = DefaultPort
 	}
 
-	return host
+	return fmt.Sprintf("%s:%d", host, port)
 }
 
 func (c *command) setAuthFromEndpoint() error {
-	var u string
-	if info := c.endpoint.User; info != nil {
-		u = info.Username()
-	}
-
 	var err error
-	c.auth, err = DefaultAuthBuilder(u)
+	c.auth, err = DefaultAuthBuilder(c.endpoint.User())
 	return err
 }
 
 func endpointToCommand(cmd string, ep transport.Endpoint) string {
-	return fmt.Sprintf("%s '%s'", cmd, ep.Path)
+	return fmt.Sprintf("%s '%s'", cmd, ep.Path())
 }
diff --git a/references_test.go b/references_test.go
index 3cd0b97..050f169 100644
--- a/references_test.go
+++ b/references_test.go
@@ -295,7 +295,7 @@ func (s *ReferencesSuite) TestObjectNotFoundError(c *C) {
 	url := fixtures.ByURL("https://github.com/git-fixtures/basic.git").One().DotGit().Base()
 	storer := memory.NewStorage()
 	r, err := Clone(storer, nil, &CloneOptions{
-		URL: "file://" + url,
+		URL: url,
 	})
 	c.Assert(err, IsNil)
 
diff --git a/remote.go b/remote.go
index ae8a544..592f7b6 100644
--- a/remote.go
+++ b/remote.go
@@ -8,6 +8,7 @@ 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/format/packfile"
+	"gopkg.in/src-d/go-git.v4/plumbing/object"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability"
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/sideband"
@@ -56,9 +57,7 @@ func (r *Remote) Fetch(o *FetchOptions) error {
 // remote was already up-to-date.
 func (r *Remote) Push(o *PushOptions) (err error) {
 	// TODO: Support deletes.
-	// TODO: Support pushing tags.
-	// TODO: Check if force update is given, otherwise reject non-fast forward.
-	// TODO: Sideband suppor
+	// TODO: Sideband support
 
 	if o.RemoteName == "" {
 		o.RemoteName = r.c.Name
@@ -196,12 +195,12 @@ func newSendPackSession(url string, auth transport.AuthMethod) (transport.Receiv
 func newClient(url string) (transport.Transport, transport.Endpoint, error) {
 	ep, err := transport.NewEndpoint(url)
 	if err != nil {
-		return nil, transport.Endpoint{}, err
+		return nil, nil, err
 	}
 
 	c, err := client.NewClient(ep)
 	if err != nil {
-		return nil, transport.Endpoint{}, err
+		return nil, nil, err
 	}
 
 	return c, ep, err
@@ -265,37 +264,35 @@ func (r *Remote) addReferenceIfRefSpecMatches(rs config.RefSpec,
 		return nil
 	}
 
-	dstName := rs.Dst(localRef.Name())
-	oldHash := plumbing.ZeroHash
-	newHash := localRef.Hash()
-
-	iter, err := remoteRefs.IterReferences()
-	if err != nil {
-		return err
+	cmd := &packp.Command{
+		Name: rs.Dst(localRef.Name()),
+		Old:  plumbing.ZeroHash,
+		New:  localRef.Hash(),
 	}
 
-	err = iter.ForEach(func(remoteRef *plumbing.Reference) error {
+	remoteRef, err := remoteRefs.Reference(cmd.Name)
+	if err == nil {
 		if remoteRef.Type() != plumbing.HashReference {
+			//TODO: check actual git behavior here
 			return nil
 		}
 
-		if dstName != remoteRef.Name() {
-			return nil
-		}
+		cmd.Old = remoteRef.Hash()
+	} else if err != plumbing.ErrReferenceNotFound {
+		return err
+	}
 
-		oldHash = remoteRef.Hash()
+	if cmd.Old == cmd.New {
 		return nil
-	})
+	}
 
-	if oldHash == newHash {
-		return nil
+	if !rs.IsForceUpdate() {
+		if err := checkFastForwardUpdate(r.s, remoteRefs, cmd); err != nil {
+			return err
+		}
 	}
 
-	req.Commands = append(req.Commands, &packp.Command{
-		Name: dstName,
-		Old:  oldHash,
-		New:  newHash,
-	})
+	req.Commands = append(req.Commands, cmd)
 	return nil
 }
 
@@ -390,6 +387,50 @@ func objectExists(s storer.EncodedObjectStorer, h plumbing.Hash) (bool, error) {
 	return true, err
 }
 
+func checkFastForwardUpdate(s storer.EncodedObjectStorer, remoteRefs storer.ReferenceStorer, cmd *packp.Command) error {
+	if cmd.Old == plumbing.ZeroHash {
+		_, err := remoteRefs.Reference(cmd.Name)
+		if err == plumbing.ErrReferenceNotFound {
+			return nil
+		}
+
+		if err != nil {
+			return err
+		}
+
+		return fmt.Errorf("non-fast-forward update: %s", cmd.Name.String())
+	}
+
+	ff, err := isFastForward(s, cmd.Old, cmd.New)
+	if err != nil {
+		return err
+	}
+
+	if !ff {
+		return fmt.Errorf("non-fast-forward update: %s", cmd.Name.String())
+	}
+
+	return nil
+}
+
+func isFastForward(s storer.EncodedObjectStorer, old, new plumbing.Hash) (bool, error) {
+	c, err := object.GetCommit(s, new)
+	if err != nil {
+		return false, err
+	}
+
+	found := false
+	iter := object.NewCommitPreIterator(c)
+	return found, iter.ForEach(func(c *object.Commit) error {
+		if c.Hash != old {
+			return nil
+		}
+
+		found = true
+		return storer.ErrStop
+	})
+}
+
 func (r *Remote) newUploadPackRequest(o *FetchOptions,
 	ar *packp.AdvRefs) (*packp.UploadPackRequest, error) {
 
diff --git a/remote_test.go b/remote_test.go
index 2cd80cf..8b2f71c 100644
--- a/remote_test.go
+++ b/remote_test.go
@@ -2,7 +2,6 @@ package git
 
 import (
 	"bytes"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -26,9 +25,9 @@ type RemoteSuite struct {
 var _ = Suite(&RemoteSuite{})
 
 func (s *RemoteSuite) TestFetchInvalidEndpoint(c *C) {
-	r := newRemote(nil, &config.RemoteConfig{Name: "foo", URL: "qux"})
-	err := r.Fetch(&FetchOptions{})
-	c.Assert(err, ErrorMatches, ".*invalid endpoint.*")
+	r := newRemote(nil, &config.RemoteConfig{Name: "foo", URL: "http://\\"})
+	err := r.Fetch(&FetchOptions{RemoteName: "foo"})
+	c.Assert(err, ErrorMatches, ".*invalid character.*")
 }
 
 func (s *RemoteSuite) TestFetchNonExistentEndpoint(c *C) {
@@ -215,7 +214,7 @@ func (s *RemoteSuite) TestPushToEmptyRepository(c *C) {
 	c.Assert(err, IsNil)
 
 	dstFs := fixtures.ByTag("empty").One().DotGit()
-	url := fmt.Sprintf("file://%s", dstFs.Base())
+	url := dstFs.Base()
 
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
@@ -249,11 +248,56 @@ func (s *RemoteSuite) TestPushToEmptyRepository(c *C) {
 	c.Assert(err, IsNil)
 }
 
+func (s *RemoteSuite) TestPushTags(c *C) {
+	srcFs := fixtures.ByURL("https://github.com/git-fixtures/tags.git").One().DotGit()
+	sto, err := filesystem.NewStorage(srcFs)
+	c.Assert(err, IsNil)
+
+	dstFs := fixtures.ByTag("empty").One().DotGit()
+	url := dstFs.Base()
+
+	r := newRemote(sto, &config.RemoteConfig{
+		Name: DefaultRemoteName,
+		URL:  url,
+	})
+
+	rs := config.RefSpec("refs/tags/*:refs/tags/*")
+	err = r.Push(&PushOptions{
+		RefSpecs: []config.RefSpec{rs},
+	})
+	c.Assert(err, IsNil)
+
+	dstSto, err := filesystem.NewStorage(dstFs)
+	c.Assert(err, IsNil)
+	dstRepo, err := Open(dstSto, nil)
+	c.Assert(err, IsNil)
+
+	ref, err := dstRepo.Storer.Reference(plumbing.ReferenceName("refs/tags/lightweight-tag"))
+	c.Assert(err, IsNil)
+	c.Assert(ref, DeepEquals, plumbing.NewReferenceFromStrings("refs/tags/lightweight-tag", "f7b877701fbf855b44c0a9e86f3fdce2c298b07f"))
+
+	ref, err = dstRepo.Storer.Reference(plumbing.ReferenceName("refs/tags/annotated-tag"))
+	c.Assert(err, IsNil)
+	c.Assert(ref, DeepEquals, plumbing.NewReferenceFromStrings("refs/tags/annotated-tag", "b742a2a9fa0afcfa9a6fad080980fbc26b007c69"))
+
+	ref, err = dstRepo.Storer.Reference(plumbing.ReferenceName("refs/tags/commit-tag"))
+	c.Assert(err, IsNil)
+	c.Assert(ref, DeepEquals, plumbing.NewReferenceFromStrings("refs/tags/commit-tag", "ad7897c0fb8e7d9a9ba41fa66072cf06095a6cfc"))
+
+	ref, err = dstRepo.Storer.Reference(plumbing.ReferenceName("refs/tags/blob-tag"))
+	c.Assert(err, IsNil)
+	c.Assert(ref, DeepEquals, plumbing.NewReferenceFromStrings("refs/tags/blob-tag", "fe6cb94756faa81e5ed9240f9191b833db5f40ae"))
+
+	ref, err = dstRepo.Storer.Reference(plumbing.ReferenceName("refs/tags/tree-tag"))
+	c.Assert(err, IsNil)
+	c.Assert(ref, DeepEquals, plumbing.NewReferenceFromStrings("refs/tags/tree-tag", "152175bf7e5580299fa1f0ba41ef6474cc043b70"))
+}
+
 func (s *RemoteSuite) TestPushNoErrAlreadyUpToDate(c *C) {
 	f := fixtures.Basic().One()
 	sto, err := filesystem.NewStorage(f.DotGit())
 	c.Assert(err, IsNil)
-	url := fmt.Sprintf("file://%s", f.DotGit().Base())
+	url := f.DotGit().Base()
 	r := newRemote(sto, &config.RemoteConfig{
 		Name: DefaultRemoteName,
 		URL:  url,
@@ -266,10 +310,97 @@ func (s *RemoteSuite) TestPushNoErrAlreadyUpToDate(c *C) {
 	c.Assert(err, Equals, NoErrAlreadyUpToDate)
 }
 
+func (s *RemoteSuite) TestPushRejectNonFastForward(c *C) {
+	f := fixtures.Basic().One()
+	sto, err := filesystem.NewStorage(f.DotGit())
+	c.Assert(err, IsNil)
+
+	dstFs := f.DotGit()
+	dstSto, err := filesystem.NewStorage(dstFs)
+	c.Assert(err, IsNil)
+
+	url := dstFs.Base()
+	r := newRemote(sto, &config.RemoteConfig{
+		Name: DefaultRemoteName,
+		URL:  url,
+	})
+
+	oldRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, IsNil)
+	c.Assert(oldRef, NotNil)
+
+	err = r.Push(&PushOptions{RefSpecs: []config.RefSpec{
+		config.RefSpec("refs/heads/master:refs/heads/branch"),
+	}})
+	c.Assert(err, ErrorMatches, "non-fast-forward update: refs/heads/branch")
+
+	newRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, IsNil)
+	c.Assert(newRef, DeepEquals, oldRef)
+}
+
+func (s *RemoteSuite) TestPushForce(c *C) {
+	f := fixtures.Basic().One()
+	sto, err := filesystem.NewStorage(f.DotGit())
+	c.Assert(err, IsNil)
+
+	dstFs := f.DotGit()
+	dstSto, err := filesystem.NewStorage(dstFs)
+	c.Assert(err, IsNil)
+
+	url := dstFs.Base()
+	r := newRemote(sto, &config.RemoteConfig{
+		Name: DefaultRemoteName,
+		URL:  url,
+	})
+
+	oldRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, IsNil)
+	c.Assert(oldRef, NotNil)
+
+	err = r.Push(&PushOptions{RefSpecs: []config.RefSpec{
+		config.RefSpec("+refs/heads/master:refs/heads/branch"),
+	}})
+	c.Assert(err, IsNil)
+
+	newRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, IsNil)
+	c.Assert(newRef, Not(DeepEquals), oldRef)
+}
+
+func (s *RemoteSuite) TestPushNewReference(c *C) {
+	f := fixtures.Basic().One()
+	sto, err := filesystem.NewStorage(f.DotGit())
+	c.Assert(err, IsNil)
+
+	dstFs := f.DotGit()
+	dstSto, err := filesystem.NewStorage(dstFs)
+	c.Assert(err, IsNil)
+
+	url := dstFs.Base()
+	r := newRemote(sto, &config.RemoteConfig{
+		Name: DefaultRemoteName,
+		URL:  url,
+	})
+
+	oldRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch"))
+	c.Assert(err, IsNil)
+	c.Assert(oldRef, NotNil)
+
+	err = r.Push(&PushOptions{RefSpecs: []config.RefSpec{
+		config.RefSpec("refs/heads/branch:refs/heads/branch2"),
+	}})
+	c.Assert(err, IsNil)
+
+	newRef, err := dstSto.Reference(plumbing.ReferenceName("refs/heads/branch2"))
+	c.Assert(err, IsNil)
+	c.Assert(newRef.Hash(), Equals, oldRef.Hash())
+}
+
 func (s *RemoteSuite) TestPushInvalidEndpoint(c *C) {
-	r := newRemote(nil, &config.RemoteConfig{Name: "foo", URL: "qux"})
-	err := r.Push(&PushOptions{})
-	c.Assert(err, ErrorMatches, ".*invalid endpoint.*")
+	r := newRemote(nil, &config.RemoteConfig{Name: "foo", URL: "http://\\"})
+	err := r.Push(&PushOptions{RemoteName: "foo"})
+	c.Assert(err, ErrorMatches, ".*invalid character.*")
 }
 
 func (s *RemoteSuite) TestPushNonExistentEndpoint(c *C) {
@@ -294,7 +425,7 @@ func (s *RemoteSuite) TestPushInvalidFetchOptions(c *C) {
 func (s *RemoteSuite) TestPushInvalidRefSpec(c *C) {
 	r := newRemote(nil, &config.RemoteConfig{
 		Name: DefaultRemoteName,
-		URL:  "file:///some-url",
+		URL:  "some-url",
 	})
 
 	rs := config.RefSpec("^*$**")
@@ -307,7 +438,7 @@ func (s *RemoteSuite) TestPushInvalidRefSpec(c *C) {
 func (s *RemoteSuite) TestPushWrongRemoteName(c *C) {
 	r := newRemote(nil, &config.RemoteConfig{
 		Name: DefaultRemoteName,
-		URL:  "file:///some-url",
+		URL:  "some-url",
 	})
 
 	err := r.Push(&PushOptions{
diff --git a/repository.go b/repository.go
index bb59afe..8a7b348 100644
--- a/repository.go
+++ b/repository.go
@@ -3,8 +3,10 @@ package git
 import (
 	"errors"
 	"fmt"
+	stdioutil "io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"gopkg.in/src-d/go-git.v4/config"
 	"gopkg.in/src-d/go-git.v4/internal/revision"
@@ -13,6 +15,7 @@ import (
 	"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"
+	"gopkg.in/src-d/go-git.v4/utils/ioutil"
 
 	"gopkg.in/src-d/go-billy.v2"
 	"gopkg.in/src-d/go-billy.v2/osfs"
@@ -193,26 +196,69 @@ func PlainInit(path string, isBare bool) (*Repository, error) {
 // repository is bare or a normal one. If the path doesn't contain a valid
 // repository ErrRepositoryNotExists is returned
 func PlainOpen(path string) (*Repository, error) {
-	var wt, dot billy.Filesystem
+	dot, wt, err := dotGitToFilesystems(path)
+	if err != nil {
+		return nil, err
+	}
+
+	s, err := filesystem.NewStorage(dot)
+	if err != nil {
+		return nil, err
+	}
 
+	return Open(s, wt)
+}
+
+func dotGitToFilesystems(path string) (dot, wt billy.Filesystem, err error) {
 	fs := osfs.New(path)
-	if _, err := fs.Stat(".git"); err != nil {
+	fi, err := fs.Stat(".git")
+	if err != nil {
 		if !os.IsNotExist(err) {
-			return nil, err
+			return nil, nil, err
 		}
 
-		dot = fs
-	} else {
-		wt = fs
-		dot = fs.Dir(".git")
+		return fs, nil, nil
 	}
 
-	s, err := filesystem.NewStorage(dot)
+	if fi.IsDir() {
+		return fs.Dir(".git"), fs, nil
+	}
+
+	dot, err = dotGitFileToFilesystem(fs)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return dot, fs, nil
+}
+
+func dotGitFileToFilesystem(fs billy.Filesystem) (billy.Filesystem, error) {
+	var err error
+
+	f, err := fs.Open(".git")
 	if err != nil {
 		return nil, err
 	}
+	defer ioutil.CheckClose(f, &err)
 
-	return Open(s, wt)
+	b, err := stdioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	line := string(b)
+	const prefix = "gitdir: "
+	if !strings.HasPrefix(line, prefix) {
+		return nil, fmt.Errorf(".git file has no %s prefix", prefix)
+	}
+
+	gitdir := line[len(prefix):]
+	gitdir = strings.TrimSpace(gitdir)
+	if filepath.IsAbs(gitdir) {
+		return osfs.New(gitdir), nil
+	}
+
+	return fs.Dir(gitdir), err
 }
 
 // PlainClone a repository into the path with the given options, isBare defines
diff --git a/repository_test.go b/repository_test.go
index 77bfde2..deb3f58 100644
--- a/repository_test.go
+++ b/repository_test.go
@@ -272,6 +272,93 @@ func (s *RepositorySuite) TestPlainOpenNotBare(c *C) {
 	c.Assert(r, IsNil)
 }
 
+func (s *RepositorySuite) testPlainOpenGitFile(c *C, f func(string, string) string) {
+	dir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(dir)
+
+	r, err := PlainInit(dir, true)
+	c.Assert(err, IsNil)
+	c.Assert(r, NotNil)
+
+	altDir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(altDir)
+
+	err = ioutil.WriteFile(filepath.Join(altDir, ".git"), []byte(f(dir, altDir)), 0644)
+	c.Assert(err, IsNil)
+
+	r, err = PlainOpen(altDir)
+	c.Assert(err, IsNil)
+	c.Assert(r, NotNil)
+}
+
+func (s *RepositorySuite) TestPlainOpenBareAbsoluteGitDirFile(c *C) {
+	s.testPlainOpenGitFile(c, func(dir, altDir string) string {
+		return fmt.Sprintf("gitdir: %s\n", dir)
+	})
+}
+
+func (s *RepositorySuite) TestPlainOpenBareAbsoluteGitDirFileNoEOL(c *C) {
+	s.testPlainOpenGitFile(c, func(dir, altDir string) string {
+		return fmt.Sprintf("gitdir: %s", dir)
+	})
+}
+
+func (s *RepositorySuite) TestPlainOpenBareRelativeGitDirFile(c *C) {
+	s.testPlainOpenGitFile(c, func(dir, altDir string) string {
+		dir, err := filepath.Rel(altDir, dir)
+		c.Assert(err, IsNil)
+		return fmt.Sprintf("gitdir: %s\n", dir)
+	})
+}
+
+func (s *RepositorySuite) TestPlainOpenBareRelativeGitDirFileNoEOL(c *C) {
+	s.testPlainOpenGitFile(c, func(dir, altDir string) string {
+		dir, err := filepath.Rel(altDir, dir)
+		c.Assert(err, IsNil)
+		return fmt.Sprintf("gitdir: %s\n", dir)
+	})
+}
+
+func (s *RepositorySuite) TestPlainOpenBareRelativeGitDirFileTrailingGarbage(c *C) {
+	dir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(dir)
+
+	r, err := PlainInit(dir, true)
+	c.Assert(err, IsNil)
+	c.Assert(r, NotNil)
+
+	altDir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	err = ioutil.WriteFile(filepath.Join(altDir, ".git"), []byte(fmt.Sprintf("gitdir: %s\nTRAILING", dir)), 0644)
+	c.Assert(err, IsNil)
+
+	r, err = PlainOpen(altDir)
+	c.Assert(err, Equals, ErrRepositoryNotExists)
+	c.Assert(r, IsNil)
+}
+
+func (s *RepositorySuite) TestPlainOpenBareRelativeGitDirFileBadPrefix(c *C) {
+	dir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(dir)
+
+	r, err := PlainInit(dir, true)
+	c.Assert(err, IsNil)
+	c.Assert(r, NotNil)
+
+	altDir, err := ioutil.TempDir("", "plain-open")
+	c.Assert(err, IsNil)
+	err = ioutil.WriteFile(filepath.Join(altDir, ".git"), []byte(fmt.Sprintf("xgitdir: %s\n", dir)), 0644)
+	c.Assert(err, IsNil)
+
+	r, err = PlainOpen(altDir)
+	c.Assert(err, ErrorMatches, ".*gitdir.*")
+	c.Assert(r, IsNil)
+}
+
 func (s *RepositorySuite) TestPlainOpenNotExists(c *C) {
 	r, err := PlainOpen("/not-exists/")
 	c.Assert(err, Equals, ErrRepositoryNotExists)
@@ -301,7 +388,7 @@ func (s *RepositorySuite) TestPlainCloneWithRecurseSubmodules(c *C) {
 
 	path := fixtures.ByTag("submodule").One().Worktree().Base()
 	r, err := PlainClone(dir, false, &CloneOptions{
-		URL:               fmt.Sprintf("file://%s", path),
+		URL:               path,
 		RecurseSubmodules: DefaultSubmoduleRecursionDepth,
 	})
 
@@ -591,7 +678,7 @@ func (s *RepositorySuite) TestPullProgressWithRecursion(c *C) {
 	r, _ := PlainInit(dir, false)
 	r.CreateRemote(&config.RemoteConfig{
 		Name: DefaultRemoteName,
-		URL:  fmt.Sprintf("file://%s", path),
+		URL:  path,
 	})
 
 	err = r.Pull(&PullOptions{
@@ -607,7 +694,7 @@ func (s *RepositorySuite) TestPullAdd(c *C) {
 	path := fixtures.Basic().ByTag("worktree").One().Worktree().Base()
 
 	r, err := Clone(memory.NewStorage(), nil, &CloneOptions{
-		URL: fmt.Sprintf("file://%s", filepath.Join(path, ".git")),
+		URL: filepath.Join(path, ".git"),
 	})
 
 	c.Assert(err, IsNil)
@@ -642,7 +729,7 @@ func (s *RepositorySuite) TestPushToEmptyRepository(c *C) {
 	c.Assert(err, IsNil)
 
 	dstFs := fixtures.ByTag("empty").One().DotGit()
-	url := fmt.Sprintf("file://%s", dstFs.Base())
+	url := dstFs.Base()
 
 	r, err := Open(sto, srcFs)
 	c.Assert(err, IsNil)
diff --git a/submodule_test.go b/submodule_test.go
index 6e06191..fdbe4a8 100644
--- a/submodule_test.go
+++ b/submodule_test.go
@@ -1,15 +1,14 @@
 package git
 
 import (
-	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 
 	"github.com/src-d/go-git-fixtures"
+	"gopkg.in/src-d/go-git.v4/plumbing"
 
 	. "gopkg.in/check.v1"
-	"gopkg.in/src-d/go-git.v4/plumbing"
 )
 
 type SubmoduleSuite struct {
@@ -27,7 +26,7 @@ func (s *SubmoduleSuite) SetUpTest(c *C) {
 	c.Assert(err, IsNil)
 
 	r, err := PlainClone(filepath.Join(dir, "worktree"), false, &CloneOptions{
-		URL: fmt.Sprintf("file://%s", path),
+		URL: path,
 	})
 
 	c.Assert(err, IsNil)
diff --git a/worktree_status.go b/worktree_status.go
index 46953c7..632f102 100644
--- a/worktree_status.go
+++ b/worktree_status.go
@@ -233,42 +233,36 @@ func (w *Worktree) addOrUpdateFileToIndex(filename string, h plumbing.Hash) erro
 		return err
 	}
 
-	_, err = idx.Entry(filename)
-	if err == index.ErrEntryNotFound {
-		err = w.doAddFileToIndex(idx, filename)
-	}
-
-	if err != nil {
+	e, err := idx.Entry(filename)
+	if err != nil && err != index.ErrEntryNotFound {
 		return err
 	}
 
-	err = w.doUpdateFileToIndex(idx, filename, h)
-	if err != nil {
-		return err
+	if err == index.ErrEntryNotFound {
+		if err := w.doAddFileToIndex(idx, filename, h); err != nil {
+			return err
+		}
+	} else {
+		if err := w.doUpdateFileToIndex(e, filename, h); err != nil {
+			return err
+		}
 	}
-
 	return w.r.Storer.SetIndex(idx)
 }
 
-func (w *Worktree) doAddFileToIndex(idx *index.Index, filename string) error {
-	idx.Entries = append(idx.Entries, &index.Entry{
-		Name: filename,
-	})
+func (w *Worktree) doAddFileToIndex(idx *index.Index, filename string, h plumbing.Hash) error {
+	e := &index.Entry{Name: filename}
+	idx.Entries = append(idx.Entries, e)
 
-	return nil
+	return w.doUpdateFileToIndex(e, filename, h)
 }
 
-func (w *Worktree) doUpdateFileToIndex(idx *index.Index, filename string, h plumbing.Hash) error {
+func (w *Worktree) doUpdateFileToIndex(e *index.Entry, filename string, h plumbing.Hash) error {
 	info, err := w.fs.Stat(filename)
 	if err != nil {
 		return err
 	}
 
-	e, err := idx.Entry(filename)
-	if err != nil {
-		return err
-	}
-
 	e.Hash = h
 	e.ModifiedAt = info.ModTime()
 	e.Mode, err = filemode.NewFromOSFileMode(info.Mode())