@@ -2027,12 +2027,7 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc

 		containerValues.Set("name", name)

 	}

-	var data interface{}

-	if hostConfig != nil {

-		data = runconfig.MergeConfigs(config, hostConfig)

-	} else {

-		data = config

-	}

+	mergedConfig := runconfig.MergeConfigs(config, hostConfig)

 	var containerIDFile *cidFile

 	if cidfile != "" {

@@ -2044,7 +2039,7 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc

 	}

 	//create the container

-	stream, statusCode, err := cli.call("POST", "/containers/create?"+containerValues.Encode(), data, false)

+	stream, statusCode, err := cli.call("POST", "/containers/create?"+containerValues.Encode(), mergedConfig, false)

 	//if image not found try to pull it

 	if statusCode == 404 {

 		fmt.Fprintf(cli.err, "Unable to find image '%s' locally\n", config.Image)

@@ -2053,7 +2048,7 @@ func (cli *DockerCli) createContainer(config *runconfig.Config, hostConfig *runc

 			return nil, err

 		}

 		// Retry

-		if stream, _, err = cli.call("POST", "/containers/create?"+containerValues.Encode(), data, false); err != nil {

+		if stream, _, err = cli.call("POST", "/containers/create?"+containerValues.Encode(), mergedConfig, false); err != nil {

 			return nil, err

 		}

 	} else if err != nil {

@@ -2155,7 +2150,7 @@ func (cli *DockerCli) CmdRun(args ...string) error {

 		sigProxy = false

 	}

-	runResult, err := cli.createContainer(config, nil, hostConfig.ContainerIDFile, *flName)

+	runResult, err := cli.createContainer(config, hostConfig, hostConfig.ContainerIDFile, *flName)

 	if err != nil {

 		return err

 	}

@@ -173,7 +173,7 @@ func (b *Builder) runContextCommand(args []string, allowRemote bool, allowDecomp

 		return nil

 	}

-	container, _, err := b.Daemon.Create(b.Config, "")

+	container, _, err := b.Daemon.Create(b.Config, nil, "")

 	if err != nil {

 		return err

 	}

@@ -442,7 +442,7 @@ func (b *Builder) create() (*daemon.Container, error) {

 	config := *b.Config

 	// Create the container

-	c, warnings, err := b.Daemon.Create(b.Config, "")

+	c, warnings, err := b.Daemon.Create(b.Config, nil, "")

 	if err != nil {

 		return nil, err

 	}

@@ -26,7 +26,16 @@ func (daemon *Daemon) ContainerCreate(job *engine.Job) engine.Status {

 		job.Errorf("Your kernel does not support swap limit capabilities. Limitation discarded.\n")

 		config.MemorySwap = -1

 	}

-	container, buildWarnings, err := daemon.Create(config, name)

+

+	var hostConfig *runconfig.HostConfig

+	if job.EnvExists("HostConfig") {

+		hostConfig = runconfig.ContainerHostConfigFromJob(job)

+	} else {

+		// Older versions of the API don't provide a HostConfig.

+		hostConfig = nil

+	}

+

+	container, buildWarnings, err := daemon.Create(config, hostConfig, name)

 	if err != nil {

 		if daemon.Graph().IsNotExist(err) {

 			_, tag := parsers.ParseRepositoryTag(config.Image)

@@ -51,18 +60,11 @@ func (daemon *Daemon) ContainerCreate(job *engine.Job) engine.Status {

 		job.Errorf("%s\n", warning)

 	}

-	if job.EnvExists("HostConfig") {

-		hostConfig := runconfig.ContainerHostConfigFromJob(job)

-		if err := daemon.setHostConfig(container, hostConfig); err != nil {

-			return job.Error(err)

-		}

-	}

-

 	return engine.StatusOK

 }

 // Create creates a new container from the given configuration with a given name.

-func (daemon *Daemon) Create(config *runconfig.Config, name string) (*Container, []string, error) {

+func (daemon *Daemon) Create(config *runconfig.Config, hostConfig *runconfig.HostConfig, name string) (*Container, []string, error) {

 	var (

 		container *Container

 		warnings  []string

@@ -84,6 +86,11 @@ func (daemon *Daemon) Create(config *runconfig.Config, name string) (*Container,

 	if err := daemon.createRootfs(container, img); err != nil {

 		return nil, nil, err

 	}

+	if hostConfig != nil {

+		if err := daemon.setHostConfig(container, hostConfig); err != nil {

+			return nil, nil, err

+		}

+	}

 	if err := container.ToDisk(); err != nil {

 		return nil, nil, err

 	}

@@ -27,6 +27,8 @@ func (daemon *Daemon) ContainerStart(job *engine.Job) engine.Status {

 	}

 	// If no environment was set, then no hostconfig was passed.

+	// This is kept for backward compatibility - hostconfig should be passed when

+	// creating a container, not during start.

 	if len(job.Environ()) > 0 {

 		hostConfig := runconfig.ContainerHostConfigFromJob(job)

 		if err := daemon.setHostConfig(container, hostConfig); err != nil {

@@ -18,6 +18,7 @@ func TestRestartStdin(t *testing.T) {

 		OpenStdin: true,

 	},

+		&runconfig.HostConfig{},

 		"",

 	)

 	if err != nil {

@@ -94,6 +95,7 @@ func TestStdin(t *testing.T) {

 		OpenStdin: true,

 	},

+		&runconfig.HostConfig{},

 		"",

 	)

 	if err != nil {

@@ -139,6 +141,7 @@ func TestTty(t *testing.T) {

 		OpenStdin: true,

 	},

+		&runconfig.HostConfig{},

 		"",

 	)

 	if err != nil {

@@ -183,6 +186,7 @@ func BenchmarkRunSequential(b *testing.B) {

 			Image: GetTestImage(daemon).ID,

 			Cmd:   []string{"echo", "-n", "foo"},

 		},

+			&runconfig.HostConfig{},

 			"",

 		)

 		if err != nil {

@@ -216,6 +220,7 @@ func BenchmarkRunParallel(b *testing.B) {

 				Image: GetTestImage(daemon).ID,

 				Cmd:   []string{"echo", "-n", "foo"},

 			},

+				&runconfig.HostConfig{},

 				"",

 			)

 			if err != nil {

@@ -266,6 +266,7 @@ func TestDaemonCreate(t *testing.T) {

 		Image: GetTestImage(daemon).ID,

 		Cmd:   []string{"ls", "-al"},

 	},

+		&runconfig.HostConfig{},

 		"",

 	)

 	if err != nil {

@@ -309,14 +310,15 @@ func TestDaemonCreate(t *testing.T) {

 			Image: GetTestImage(daemon).ID,

 			Cmd:   []string{"ls", "-al"},

 		},

+		&runconfig.HostConfig{},

 		"conflictname",

 	)

-	if _, _, err := daemon.Create(&runconfig.Config{Image: GetTestImage(daemon).ID, Cmd: []string{"ls", "-al"}}, testContainer.Name); err == nil || !strings.Contains(err.Error(), utils.TruncateID(testContainer.ID)) {

+	if _, _, err := daemon.Create(&runconfig.Config{Image: GetTestImage(daemon).ID, Cmd: []string{"ls", "-al"}}, &runconfig.HostConfig{}, testContainer.Name); err == nil || !strings.Contains(err.Error(), utils.TruncateID(testContainer.ID)) {

 		t.Fatalf("Name conflict error doesn't include the correct short id. Message was: %s", err.Error())

 	}

 	// Make sure create with bad parameters returns an error

-	if _, _, err = daemon.Create(&runconfig.Config{Image: GetTestImage(daemon).ID}, ""); err == nil {

+	if _, _, err = daemon.Create(&runconfig.Config{Image: GetTestImage(daemon).ID}, &runconfig.HostConfig{}, ""); err == nil {

 		t.Fatal("Builder.Create should throw an error when Cmd is missing")

 	}

@@ -325,6 +327,7 @@ func TestDaemonCreate(t *testing.T) {

 			Image: GetTestImage(daemon).ID,

 			Cmd:   []string{},

 		},

+		&runconfig.HostConfig{},

 		"",

 	); err == nil {

 		t.Fatal("Builder.Create should throw an error when Cmd is empty")

@@ -335,7 +338,7 @@ func TestDaemonCreate(t *testing.T) {

 		Cmd:       []string{"/bin/ls"},

 		PortSpecs: []string{"80"},

 	}

-	container, _, err = daemon.Create(config, "")

+	container, _, err = daemon.Create(config, &runconfig.HostConfig{}, "")

 	_, err = daemon.Commit(container, "testrepo", "testtag", "", "", true, config)

 	if err != nil {

@@ -348,6 +351,7 @@ func TestDaemonCreate(t *testing.T) {

 		Cmd:       []string{"ls", "-al"},

 		PortSpecs: []string{"80:8000"},

 	},

+		&runconfig.HostConfig{},

 		"",

 	)

 	if err != nil {

@@ -365,7 +369,9 @@ func TestDestroy(t *testing.T) {

 	container, _, err := daemon.Create(&runconfig.Config{

 		Image: GetTestImage(daemon).ID,

 		Cmd:   []string{"ls", "-al"},

-	}, "")

+	},

+		&runconfig.HostConfig{},

+		"")

 	if err != nil {

 		t.Fatal(err)

 	}

@@ -857,7 +863,9 @@ func TestDestroyWithInitLayer(t *testing.T) {

 	container, _, err := daemon.Create(&runconfig.Config{

 		Image: GetTestImage(daemon).ID,

 		Cmd:   []string{"ls", "-al"},

-	}, "")

+	},

+		&runconfig.HostConfig{},

+		"")

 	if err != nil {

 		t.Fatal(err)

@@ -263,7 +263,7 @@ func mkContainer(r *daemon.Daemon, args []string, t *testing.T) (*daemon.Contain

 	if config.Image == "_" {

 		config.Image = GetTestImage(r).ID

 	}

-	c, _, err := r.Create(config, "")

+	c, _, err := r.Create(config, nil, "")

 	if err != nil {

 		return nil, nil, err

 	}