@@ -87,8 +87,6 @@ func (d *driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, startCallba

 		return execdriver.ExitStatus{ExitCode: -1}, err

 	}

-	var term execdriver.Terminal

-

 	p := &libcontainer.Process{

 		Args: append([]string{c.ProcessConfig.Entrypoint}, c.ProcessConfig.Arguments...),

 		Env:  c.ProcessConfig.Env,

@@ -96,36 +94,9 @@ func (d *driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, startCallba

 		User: c.ProcessConfig.User,

 	}

-	if c.ProcessConfig.Tty {

-		rootuid, err := container.HostUID()

-		if err != nil {

-			return execdriver.ExitStatus{ExitCode: -1}, err

-		}

-		cons, err := p.NewConsole(rootuid)

-		if err != nil {

-			return execdriver.ExitStatus{ExitCode: -1}, err

-		}

-		term, err = NewTtyConsole(cons, pipes, rootuid)

-	} else {

-		p.Stdout = pipes.Stdout

-		p.Stderr = pipes.Stderr

-		r, w, err := os.Pipe()

-		if err != nil {

-			return execdriver.ExitStatus{ExitCode: -1}, err

-		}

-		if pipes.Stdin != nil {

-			go func() {

-				io.Copy(w, pipes.Stdin)

-				w.Close()

-			}()

-			p.Stdin = r

-		}

-		term = &execdriver.StdConsole{}

-	}

-	if err != nil {

+	if err := setupPipes(container, &c.ProcessConfig, p, pipes); err != nil {

 		return execdriver.ExitStatus{ExitCode: -1}, err

 	}

-	c.ProcessConfig.Terminal = term

 	cont, err := d.factory.Create(c.ID, container)

 	if err != nil {

@@ -398,3 +369,40 @@ func (t *TtyConsole) AttachPipes(pipes *execdriver.Pipes) error {

 func (t *TtyConsole) Close() error {

 	return t.console.Close()

 }

+

+func setupPipes(container *configs.Config, processConfig *execdriver.ProcessConfig, p *libcontainer.Process, pipes *execdriver.Pipes) error {

+	var term execdriver.Terminal

+	var err error

+

+	if processConfig.Tty {

+		rootuid, err := container.HostUID()

+		if err != nil {

+			return err

+		}

+		cons, err := p.NewConsole(rootuid)

+		if err != nil {

+			return err

+		}

+		term, err = NewTtyConsole(cons, pipes, rootuid)

+	} else {

+		p.Stdout = pipes.Stdout

+		p.Stderr = pipes.Stderr

+		r, w, err := os.Pipe()

+		if err != nil {

+			return err

+		}

+		if pipes.Stdin != nil {

+			go func() {

+				io.Copy(w, pipes.Stdin)

+				w.Close()

+			}()

+			p.Stdin = r

+		}

+		term = &execdriver.StdConsole{}

+	}

+	if err != nil {

+		return err

+	}

+	processConfig.Terminal = term

+	return nil

+}

@@ -20,9 +20,6 @@ func (d *driver) Exec(c *execdriver.Command, processConfig *execdriver.ProcessCo

 		return -1, fmt.Errorf("No active container exists with ID %s", c.ID)

 	}

-	var term execdriver.Terminal

-	var err error

-

 	p := &libcontainer.Process{

 		Args: append([]string{processConfig.Entrypoint}, processConfig.Arguments...),

 		Env:  c.ProcessConfig.Env,

@@ -34,29 +31,11 @@ func (d *driver) Exec(c *execdriver.Command, processConfig *execdriver.ProcessCo

 		p.Capabilities = execdriver.GetAllCapabilities()

 	}

-	if processConfig.Tty {

-		config := active.Config()

-		rootuid, err := config.HostUID()

-		if err != nil {

-			return -1, err

-		}

-		cons, err := p.NewConsole(rootuid)

-		if err != nil {

-			return -1, err

-		}

-		term, err = NewTtyConsole(cons, pipes, rootuid)

-	} else {

-		p.Stdout = pipes.Stdout

-		p.Stderr = pipes.Stderr

-		p.Stdin = pipes.Stdin

-		term = &execdriver.StdConsole{}

-	}

-	if err != nil {

+	config := active.Config()

+	if err := setupPipes(&config, processConfig, p, pipes); err != nil {

 		return -1, err

 	}

-	processConfig.Terminal = term

-

 	if err := active.Start(p); err != nil {

 		return -1, err

 	}

@@ -38,44 +38,6 @@ func (s *DockerSuite) TestExec(c *check.C) {

 }

-func (s *DockerSuite) TestExecInteractiveStdinClose(c *check.C) {

-	out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-itd", "busybox", "/bin/cat"))

-	if err != nil {

-		c.Fatal(err)

-	}

-

-	contId := strings.TrimSpace(out)

-

-	returnchan := make(chan struct{})

-

-	go func() {

-		var err error

-		cmd := exec.Command(dockerBinary, "exec", "-i", contId, "/bin/ls", "/")

-		cmd.Stdin = os.Stdin

-		if err != nil {

-			c.Fatal(err)

-		}

-

-		out, err := cmd.CombinedOutput()

-		if err != nil {

-			c.Fatal(err, string(out))

-		}

-

-		if string(out) == "" {

-			c.Fatalf("Output was empty, likely blocked by standard input")

-		}

-

-		returnchan <- struct{}{}

-	}()

-

-	select {

-	case <-returnchan:

-	case <-time.After(10 * time.Second):

-		c.Fatal("timed out running docker exec")

-	}

-

-}

-

 func (s *DockerSuite) TestExecInteractive(c *check.C) {

 	runCmd := exec.Command(dockerBinary, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && top")

new file mode 100644

@@ -0,0 +1,47 @@

+// +build !windows,!test_no_exec

+

+package main

+

+import (

+	"bytes"

+	"io"

+	"os/exec"

+	"strings"

+	"time"

+

+	"github.com/go-check/check"

+	"github.com/kr/pty"

+)

+

+// regression test for #12546

+func (s *DockerSuite) TestExecInteractiveStdinClose(c *check.C) {

+	out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-itd", "busybox", "/bin/cat"))

+	if err != nil {

+		c.Fatal(err)

+	}

+	contId := strings.TrimSpace(out)

+

+	cmd := exec.Command(dockerBinary, "exec", "-i", contId, "echo", "-n", "hello")

+	p, err := pty.Start(cmd)

+	if err != nil {

+		c.Fatal(err)

+	}

+

+	b := bytes.NewBuffer(nil)

+	go io.Copy(b, p)

+

+	ch := make(chan error)

+	go func() { ch <- cmd.Wait() }()

+

+	select {

+	case err := <-ch:

+		if err != nil {

+			c.Errorf("cmd finished with error %v", err)

+		}

+		if output := b.String(); strings.TrimSpace(output) != "hello" {

+			c.Fatalf("Unexpected output %s", output)

+		}

+	case <-time.After(1 * time.Second):

+		c.Fatal("timed out running docker exec")

+	}

+}