@@ -1349,6 +1349,9 @@ func (s *Server) postContainerExecCreate(version version.Version, w http.Respons

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

 		return err

 	}

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

+		return err

+	}

 	name := vars["name"]

 	execConfig := &runconfig.ExecConfig{}

@@ -4,6 +4,7 @@ package main

 import (

 	"bytes"

+	"encoding/json"

 	"fmt"

 	"net/http"

 	"os/exec"

@@ -27,3 +28,24 @@ func (s *DockerSuite) TestExecApiCreateNoCmd(c *check.C) {

 		c.Fatalf("Expected message when creating exec command with no Cmd specified")

 	}

 }

+

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

+	name := "exec_test"

+	dockerCmd(c, "run", "-d", "-t", "--name", name, "busybox", "/bin/sh")

+

+	jsonData := bytes.NewBuffer(nil)

+	if err := json.NewEncoder(jsonData).Encode(map[string]interface{}{"Cmd": nil}); err != nil {

+		c.Fatalf("Can not encode data to json %s", err)

+	}

+

+	res, body, err := sockRequestRaw("POST", fmt.Sprintf("/containers/%s/exec", name), jsonData, "text/plain")

+	c.Assert(err, check.IsNil)

+	c.Assert(res.StatusCode, check.Equals, http.StatusInternalServerError)

+

+	b, err := readBody(body)

+	c.Assert(err, check.IsNil)

+

+	if !bytes.Contains(b, []byte("Content-Type specified")) {

+		c.Fatalf("Expected message when creating exec command with invalid Content-Type specified")

+	}

+}