@@ -760,8 +760,13 @@ func postContainersStart(eng *engine.Engine, version version.Version, w http.Res

 		job  = eng.Job("start", name)

 	)

+	// If contentLength is -1, we can assumed chunked encoding

+	// or more technically that the length is unknown

+	// http://golang.org/src/pkg/net/http/request.go#L139

+	// net/http otherwise seems to swallow any headers related to chunked encoding

+	// including r.TransferEncoding

 	// allow a nil body for backwards compatibility

-	if r.Body != nil && r.ContentLength > 0 {

+	if r.Body != nil && (r.ContentLength > 0 || r.ContentLength == -1) {

 		if err := checkForJson(r); err != nil {

 			return err

 		}

@@ -1072,6 +1072,86 @@ func TestPostContainersCopyWhenContainerNotFound(t *testing.T) {

 	}

 }

+// Regression test for https://github.com/docker/docker/issues/6231

+func TestConstainersStartChunkedEncodingHostConfig(t *testing.T) {

+	eng := NewTestEngine(t)

+	defer mkDaemonFromEngine(eng, t).Nuke()

+

+	r := httptest.NewRecorder()

+

+	var testData engine.Env

+	testData.Set("Image", "docker-test-image")

+	testData.SetAuto("Volumes", map[string]struct{}{"/foo": {}})

+	testData.Set("Cmd", "true")

+	jsonData := bytes.NewBuffer(nil)

+	if err := testData.Encode(jsonData); err != nil {

+		t.Fatal(err)

+	}

+

+	req, err := http.NewRequest("POST", "/containers/create?name=chunk_test", jsonData)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	req.Header.Add("Content-Type", "application/json")

+	if err := server.ServeRequest(eng, api.APIVERSION, r, req); err != nil {

+		t.Fatal(err)

+	}

+	assertHttpNotError(r, t)

+

+	var testData2 engine.Env

+	testData2.SetAuto("Binds", []string{"/tmp:/foo"})

+	jsonData = bytes.NewBuffer(nil)

+	if err := testData2.Encode(jsonData); err != nil {

+		t.Fatal(err)

+	}

+

+	req, err = http.NewRequest("POST", "/containers/chunk_test/start", jsonData)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	req.Header.Add("Content-Type", "application/json")

+	// This is a cheat to make the http request do chunked encoding

+	// Otherwise (just setting the Content-Encoding to chunked) net/http will overwrite

+	// http://golang.org/src/pkg/net/http/request.go?s=11980:12172

+	req.ContentLength = -1

+	if err := server.ServeRequest(eng, api.APIVERSION, r, req); err != nil {

+		t.Fatal(err)

+	}

+	assertHttpNotError(r, t)

+

+	type config struct {

+		HostConfig struct {

+			Binds []string

+		}

+	}

+

+	req, err = http.NewRequest("GET", "/containers/chunk_test/json", nil)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	r2 := httptest.NewRecorder()

+	req.Header.Add("Content-Type", "application/json")

+	if err := server.ServeRequest(eng, api.APIVERSION, r2, req); err != nil {

+		t.Fatal(err)

+	}

+	assertHttpNotError(r, t)

+

+	c := config{}

+

+	json.Unmarshal(r2.Body.Bytes(), &c)

+

+	if len(c.HostConfig.Binds) == 0 {

+		t.Fatal("Chunked Encoding not handled")

+	}

+

+	if c.HostConfig.Binds[0] != "/tmp:/foo" {

+		t.Fatal("Chunked encoding not properly handled, execpted binds to be /tmp:/foo, got:", c.HostConfig.Binds[0])

+	}

+}

+

 // Mocked types for tests

 type NopConn struct {

 	io.ReadCloser