@@ -83,7 +83,6 @@ func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status {

 		var (

 			cStdin           io.ReadCloser

 			cStdout, cStderr io.Writer

-			cStdinCloser     io.Closer

 		)

 		if stdin {

@@ -94,7 +93,6 @@ func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status {

 				io.Copy(w, job.Stdin)

 			}()

 			cStdin = r

-			cStdinCloser = job.Stdin

 		}

 		if stdout {

 			cStdout = job.Stdout

@@ -103,7 +101,7 @@ func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status {

 			cStderr = job.Stderr

 		}

-		<-daemon.attach(&container.StreamConfig, container.Config.OpenStdin, container.Config.StdinOnce, container.Config.Tty, cStdin, cStdinCloser, cStdout, cStderr)

+		<-daemon.attach(&container.StreamConfig, container.Config.OpenStdin, container.Config.StdinOnce, container.Config.Tty, cStdin, cStdout, cStderr)

 		// If we are in stdinonce mode, wait for the process to end

 		// otherwise, simply return

 		if container.Config.StdinOnce && !container.Config.Tty {

@@ -113,7 +111,7 @@ func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status {

 	return engine.StatusOK

 }

-func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, tty bool, stdin io.ReadCloser, stdinCloser io.Closer, stdout io.Writer, stderr io.Writer) chan error {

+func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, tty bool, stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) chan error {

 	var (

 		cStdout, cStderr io.ReadCloser

 		nJobs            int

@@ -130,10 +128,10 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 			go func() {

 				log.Debugf("attach: stdin: begin")

 				defer log.Debugf("attach: stdin: end")

-				// No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr

 				if stdinOnce && !tty {

 					defer cStdin.Close()

 				} else {

+					// No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr

 					defer func() {

 						if cStdout != nil {

 							cStdout.Close()

@@ -173,9 +171,6 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 				if stdinOnce && stdin != nil {

 					defer stdin.Close()

 				}

-				if stdinCloser != nil {

-					defer stdinCloser.Close()

-				}

 				_, err := io.Copy(stdout, cStdout)

 				if err == io.ErrClosedPipe {

 					err = nil

@@ -189,9 +184,6 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 	} else {

 		// Point stdout of container to a no-op writer.

 		go func() {

-			if stdinCloser != nil {

-				defer stdinCloser.Close()

-			}

 			if cStdout, err := streamConfig.StdoutPipe(); err != nil {

 				log.Errorf("attach: stdout pipe: %s", err)

 			} else {

@@ -213,9 +205,6 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 				if stdinOnce && stdin != nil {

 					defer stdin.Close()

 				}

-				if stdinCloser != nil {

-					defer stdinCloser.Close()

-				}

 				_, err := io.Copy(stderr, cStderr)

 				if err == io.ErrClosedPipe {

 					err = nil

@@ -229,10 +218,6 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 	} else {

 		// Point stderr at a no-op writer.

 		go func() {

-			if stdinCloser != nil {

-				defer stdinCloser.Close()

-			}

-

 			if cStderr, err := streamConfig.StderrPipe(); err != nil {

 				log.Errorf("attach: stdout pipe: %s", err)

 			} else {

@@ -251,8 +236,6 @@ func (daemon *Daemon) attach(streamConfig *StreamConfig, openStdin, stdinOnce, t

 			}

 		}()

-		// FIXME: how to clean up the stdin goroutine without the unwanted side effect

-		// of closing the passed stdin? Add an intermediary io.Pipe?

 		for i := 0; i < nJobs; i++ {

 			log.Debugf("attach: waiting for job %d/%d", i+1, nJobs)

 			if err := <-errors; err != nil {

@@ -155,7 +155,6 @@ func (d *Daemon) ContainerExecStart(job *engine.Job) engine.Status {

 	var (

 		cStdin           io.ReadCloser

 		cStdout, cStderr io.Writer

-		cStdinCloser     io.Closer

 		execName         = job.Args[0]

 	)

@@ -183,10 +182,10 @@ func (d *Daemon) ContainerExecStart(job *engine.Job) engine.Status {

 		r, w := io.Pipe()

 		go func() {

 			defer w.Close()

+			defer log.Debugf("Closing buffered stdin pipe")

 			io.Copy(w, job.Stdin)

 		}()

 		cStdin = r

-		cStdinCloser = job.Stdin

 	}

 	if execConfig.OpenStdout {

 		cStdout = job.Stdout

@@ -204,7 +203,7 @@ func (d *Daemon) ContainerExecStart(job *engine.Job) engine.Status {

 		execConfig.StreamConfig.stdinPipe = ioutils.NopWriteCloser(ioutil.Discard) // Silently drop stdin

 	}

-	attachErr := d.attach(&execConfig.StreamConfig, execConfig.OpenStdin, false, execConfig.ProcessConfig.Tty, cStdin, cStdinCloser, cStdout, cStderr)

+	attachErr := d.attach(&execConfig.StreamConfig, execConfig.OpenStdin, false, execConfig.ProcessConfig.Tty, cStdin, cStdout, cStderr)

 	execErr := make(chan error)

@@ -4,6 +4,7 @@ import (

 	"bufio"

 	"bytes"

 	"fmt"

+	"io"

 	"io/ioutil"

 	"net"

 	"os"

@@ -2446,3 +2447,46 @@ func TestRunVolumesCleanPaths(t *testing.T) {

 	logDone("run - volume paths are cleaned")

 }

+

+// Regression test for #3631

+func TestRunSlowStdoutConsumer(t *testing.T) {

+	defer deleteAllContainers()

+

+	c := exec.Command("/bin/bash", "-c", dockerBinary+` run --rm -i busybox /bin/sh -c "dd if=/dev/zero of=/foo bs=1024 count=2000 &>/dev/null; catv /foo"`)

+

+	stdout, err := c.StdoutPipe()

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if err := c.Start(); err != nil {

+		t.Fatal(err)

+	}

+	n, err := consumeSlow(stdout, 10000, 5*time.Millisecond)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	expected := 2 * 1024 * 2000

+	if n != expected {

+		t.Fatalf("Expected %d, got %d", expected, n)

+	}

+

+	logDone("run - slow consumer")

+}

+

+func consumeSlow(reader io.Reader, chunkSize int, interval time.Duration) (n int, err error) {

+	buffer := make([]byte, chunkSize)

+	for {

+		var readBytes int

+		readBytes, err = reader.Read(buffer)

+		n += readBytes

+		if err != nil {

+			if err == io.EOF {

+				err = nil

+			}

+			return

+		}

+		time.Sleep(interval)

+	}

+}