@@ -387,7 +387,7 @@ func workdir(req dispatchRequest) error {

 	runConfig := req.state.runConfig

 	// This is from the Dockerfile and will not necessarily be in platform

 	// specific semantics, hence ensure it is converted.

-	runConfig.WorkingDir, err = normaliseWorkdir(runConfig.WorkingDir, req.args[0])

+	runConfig.WorkingDir, err = normaliseWorkdir(req.builder.platform, runConfig.WorkingDir, req.args[0])

 	if err != nil {

 		return err

 	}

@@ -11,7 +11,7 @@ import (

 // normaliseWorkdir normalises a user requested working directory in a

 // platform semantically consistent way.

-func normaliseWorkdir(current string, requested string) (string, error) {

+func normaliseWorkdir(_ string, current string, requested string) (string, error) {

 	if requested == "" {

 		return "", errors.New("cannot normalise nothing")

 	}

@@ -3,6 +3,7 @@

 package dockerfile

 import (

+	"runtime"

 	"testing"

 )

@@ -16,7 +17,7 @@ func TestNormaliseWorkdir(t *testing.T) {

 	}

 	for _, test := range testCases {

-		normalised, err := normaliseWorkdir(test.current, test.requested)

+		normalised, err := normaliseWorkdir(runtime.GOOS, test.current, test.requested)

 		if test.expectedError != "" && err == nil {

 			t.Fatalf("NormaliseWorkdir should return an error %s, got nil", test.expectedError)

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

 	"errors"

 	"fmt"

 	"os"

+	"path"

 	"path/filepath"

 	"regexp"

 	"strings"

@@ -15,7 +16,33 @@ var pattern = regexp.MustCompile(`^[a-zA-Z]:\.$`)

 // normaliseWorkdir normalises a user requested working directory in a

 // platform semantically consistent way.

-func normaliseWorkdir(current string, requested string) (string, error) {

+func normaliseWorkdir(platform string, current string, requested string) (string, error) {

+	if platform == "" {

+		platform = "windows"

+	}

+	if platform == "windows" {

+		return normaliseWorkdirWindows(current, requested)

+	}

+	return normaliseWorkdirUnix(current, requested)

+}

+

+// normaliseWorkdirUnix normalises a user requested working directory in a

+// platform semantically consistent way.

+func normaliseWorkdirUnix(current string, requested string) (string, error) {

+	if requested == "" {

+		return "", errors.New("cannot normalise nothing")

+	}

+	current = strings.Replace(current, string(os.PathSeparator), "/", -1)

+	requested = strings.Replace(requested, string(os.PathSeparator), "/", -1)

+	if !path.IsAbs(requested) {

+		return path.Join(`/`, current, requested), nil

+	}

+	return requested, nil

+}

+

+// normaliseWorkdirWindows normalises a user requested working directory in a

+// platform semantically consistent way.

+func normaliseWorkdirWindows(current string, requested string) (string, error) {

 	if requested == "" {

 		return "", errors.New("cannot normalise nothing")

 	}

@@ -5,25 +5,31 @@ package dockerfile

 import "testing"

 func TestNormaliseWorkdir(t *testing.T) {

-	tests := []struct{ current, requested, expected, etext string }{

-		{``, ``, ``, `cannot normalise nothing`},

-		{``, `C:`, ``, `C:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

-		{``, `C:.`, ``, `C:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

-		{`c:`, `\a`, ``, `c:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

-		{`c:.`, `\a`, ``, `c:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

-		{``, `a`, `C:\a`, ``},

-		{``, `c:\foo`, `C:\foo`, ``},

-		{``, `c:\\foo`, `C:\foo`, ``},

-		{``, `\foo`, `C:\foo`, ``},

-		{``, `\\foo`, `C:\foo`, ``},

-		{``, `/foo`, `C:\foo`, ``},

-		{``, `C:/foo`, `C:\foo`, ``},

-		{`C:\foo`, `bar`, `C:\foo\bar`, ``},

-		{`C:\foo`, `/bar`, `C:\bar`, ``},

-		{`C:\foo`, `\bar`, `C:\bar`, ``},

+	tests := []struct{ platform, current, requested, expected, etext string }{

+		{"windows", ``, ``, ``, `cannot normalise nothing`},

+		{"windows", ``, `C:`, ``, `C:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

+		{"windows", ``, `C:.`, ``, `C:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

+		{"windows", `c:`, `\a`, ``, `c:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

+		{"windows", `c:.`, `\a`, ``, `c:. is not a directory. If you are specifying a drive letter, please add a trailing '\'`},

+		{"windows", ``, `a`, `C:\a`, ``},

+		{"windows", ``, `c:\foo`, `C:\foo`, ``},

+		{"windows", ``, `c:\\foo`, `C:\foo`, ``},

+		{"windows", ``, `\foo`, `C:\foo`, ``},

+		{"windows", ``, `\\foo`, `C:\foo`, ``},

+		{"windows", ``, `/foo`, `C:\foo`, ``},

+		{"windows", ``, `C:/foo`, `C:\foo`, ``},

+		{"windows", `C:\foo`, `bar`, `C:\foo\bar`, ``},

+		{"windows", `C:\foo`, `/bar`, `C:\bar`, ``},

+		{"windows", `C:\foo`, `\bar`, `C:\bar`, ``},

+		{"linux", ``, ``, ``, `cannot normalise nothing`},

+		{"linux", ``, `foo`, `/foo`, ``},

+		{"linux", ``, `/foo`, `/foo`, ``},

+		{"linux", `/foo`, `bar`, `/foo/bar`, ``},

+		{"linux", `/foo`, `/bar`, `/bar`, ``},

+		{"linux", `\a`, `b\c`, `/a/b/c`, ``},

 	}

 	for _, i := range tests {

-		r, e := normaliseWorkdir(i.current, i.requested)

+		r, e := normaliseWorkdir(i.platform, i.current, i.requested)

 		if i.etext != "" && e == nil {

 			t.Fatalf("TestNormaliseWorkingDir Expected error %s for '%s' '%s', got no error", i.etext, i.current, i.requested)

@@ -261,12 +261,17 @@ func (container *Container) WriteHostConfig() (*containertypes.HostConfig, error

 // SetupWorkingDirectory sets up the container's working directory as set in container.Config.WorkingDir

 func (container *Container) SetupWorkingDirectory(rootIDs idtools.IDPair) error {

+	// TODO @jhowardmsft, @gupta-ak LCOW Support. This will need revisiting.

+	// We will need to do remote filesystem operations here.

+	if container.Platform != runtime.GOOS {

+		return nil

+	}

+

 	if container.Config.WorkingDir == "" {

 		return nil

 	}

 	container.Config.WorkingDir = filepath.Clean(container.Config.WorkingDir)

-

 	pth, err := container.GetResourcePath(container.Config.WorkingDir)

 	if err != nil {

 		return err

@@ -3,7 +3,10 @@ package daemon

 import (

 	"fmt"

 	"os"

+	"path"

 	"path/filepath"

+	"runtime"

+	"strings"

 	"time"

 	containertypes "github.com/docker/docker/api/types/container"

@@ -226,13 +229,24 @@ func (daemon *Daemon) setHostConfig(container *container.Container, hostConfig *

 // verifyContainerSettings performs validation of the hostconfig and config

 // structures.

-func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {

-

+func (daemon *Daemon) verifyContainerSettings(platform string, hostConfig *containertypes.HostConfig, config *containertypes.Config, update bool) ([]string, error) {

 	// First perform verification of settings common across all platforms.

 	if config != nil {

 		if config.WorkingDir != "" {

-			config.WorkingDir = filepath.FromSlash(config.WorkingDir) // Ensure in platform semantics

-			if !system.IsAbs(config.WorkingDir) {

+			wdInvalid := false

+			if runtime.GOOS == platform {

+				config.WorkingDir = filepath.FromSlash(config.WorkingDir) // Ensure in platform semantics

+				if !system.IsAbs(config.WorkingDir) {

+					wdInvalid = true

+				}

+			} else {

+				// LCOW. Force Unix semantics

+				config.WorkingDir = strings.Replace(config.WorkingDir, string(os.PathSeparator), "/", -1)

+				if !path.IsAbs(config.WorkingDir) {

+					wdInvalid = true

+				}

+			}

+			if wdInvalid {

 				return nil, fmt.Errorf("the working directory '%s' is invalid, it needs to be an absolute path", config.WorkingDir)

 			}

 		}

@@ -39,7 +39,17 @@ func (daemon *Daemon) containerCreate(params types.ContainerCreateConfig, manage

 		return containertypes.ContainerCreateCreatedBody{}, validationError{errors.New("Config cannot be empty in order to create a container")}

 	}

-	warnings, err := daemon.verifyContainerSettings(params.HostConfig, params.Config, false)

+	// TODO: @jhowardmsft LCOW support - at a later point, can remove the hard-coding

+	// to force the platform to be linux.

+	// Default the platform if not supplied

+	if params.Platform == "" {

+		params.Platform = runtime.GOOS

+	}

+	if system.LCOWSupported() {

+		params.Platform = "linux"

+	}

+

+	warnings, err := daemon.verifyContainerSettings(params.Platform, params.HostConfig, params.Config, false)

 	if err != nil {

 		return containertypes.ContainerCreateCreatedBody{Warnings: warnings}, validationError{err}

 	}

@@ -75,16 +85,6 @@ func (daemon *Daemon) create(params types.ContainerCreateConfig, managed bool) (

 		err       error

 	)

-	// TODO: @jhowardmsft LCOW support - at a later point, can remove the hard-coding

-	// to force the platform to be linux.

-	// Default the platform if not supplied

-	if params.Platform == "" {

-		params.Platform = runtime.GOOS

-	}

-	if system.LCOWSupported() {

-		params.Platform = "linux"

-	}

-

 	if params.Config.Image != "" {

 		img, err = daemon.GetImage(params.Config.Image)

 		if err != nil {

@@ -79,7 +79,7 @@ func (daemon *Daemon) ContainerStart(name string, hostConfig *containertypes.Hos

 	// check if hostConfig is in line with the current system settings.

 	// It may happen cgroups are umounted or the like.

-	if _, err = daemon.verifyContainerSettings(container.HostConfig, nil, false); err != nil {

+	if _, err = daemon.verifyContainerSettings(container.Platform, container.HostConfig, nil, false); err != nil {

 		return validationError{err}

 	}

 	// Adapt for old containers in case we have updates in this function and

@@ -11,7 +11,12 @@ import (

 func (daemon *Daemon) ContainerUpdate(name string, hostConfig *container.HostConfig) (container.ContainerUpdateOKBody, error) {

 	var warnings []string

-	warnings, err := daemon.verifyContainerSettings(hostConfig, nil, true)

+	c, err := daemon.GetContainer(name)

+	if err != nil {

+		return container.ContainerUpdateOKBody{Warnings: warnings}, err

+	}

+

+	warnings, err = daemon.verifyContainerSettings(c.Platform, hostConfig, nil, true)

 	if err != nil {

 		return container.ContainerUpdateOKBody{Warnings: warnings}, validationError{err}

 	}