Close stdin after execution with `docker exec -i`

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)

daemon/exec.go

@@ -203,7 +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, cStdout, cStderr)
+	attachErr := d.attach(&execConfig.StreamConfig, execConfig.OpenStdin, true, execConfig.ProcessConfig.Tty, cStdin, cStdout, cStderr)
 
 	execErr := make(chan error)
 

integration-cli/docker_cli_exec_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bufio"
+	"os"
 	"os/exec"
 	"strings"
 	"testing"
@@ -31,6 +32,47 @@ func TestExec(t *testing.T) {
 	logDone("exec - basic test")
 }
 
+func TestExecInteractiveStdinClose(t *testing.T) {
+	defer deleteAllContainers()
+	out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-itd", "busybox", "/bin/cat"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	contId := strings.TrimSpace(out)
+	println(contId)
+
+	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 {
+			t.Fatal(err)
+		}
+
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			t.Fatal(err, out)
+		}
+
+		if string(out) == "" {
+			t.Fatalf("Output was empty, likely blocked by standard input")
+		}
+
+		returnchan <- struct{}{}
+	}()
+
+	select {
+	case <-returnchan:
+	case <-time.After(10 * time.Second):
+		t.Fatal("timed out running docker exec")
+	}
+
+	logDone("exec - interactive mode closes stdin after execution")
+}
+
 func TestExecInteractive(t *testing.T) {
 	runCmd := exec.Command(dockerBinary, "run", "-d", "--name", "testing", "busybox", "sh", "-c", "echo test > /tmp/file && sleep 100")
 	if out, _, _, err := runCommandWithStdoutStderr(runCmd); err != nil {