@@ -15,6 +15,7 @@ import (

 	Cli "github.com/docker/docker/cli"

 	"github.com/docker/docker/pkg/archive"

 	flag "github.com/docker/docker/pkg/mflag"

+	"github.com/docker/docker/pkg/system"

 )

 type copyDirection int

@@ -101,7 +102,7 @@ func (cli *DockerCli) CmdCp(args ...string) error {

 // client, a `:` could be part of an absolute Windows path, in which case it

 // is immediately proceeded by a backslash.

 func splitCpArg(arg string) (container, path string) {

-	if filepath.IsAbs(arg) {

+	if system.IsAbs(arg) {

 		// Explicit local absolute path, e.g., `C:\foo` or `/foo`.

 		return "", arg

 	}

@@ -236,7 +237,7 @@ func (cli *DockerCli) copyToContainer(srcPath, dstContainer, dstPath string) (er

 	// If the destination is a symbolic link, we should evaluate it.

 	if err == nil && dstStat.Mode&os.ModeSymlink != 0 {

 		linkTarget := dstStat.LinkTarget

-		if !filepath.IsAbs(linkTarget) {

+		if !system.IsAbs(linkTarget) {

 			// Join with the parent directory.

 			dstParent, _ := archive.SplitPathDirEntry(dstPath)

 			linkTarget = filepath.Join(dstParent, linkTarget)

@@ -10,7 +10,7 @@ package builder

 import (

 	"fmt"

 	"io/ioutil"

-	"path"

+	"os"

 	"path/filepath"

 	"regexp"

 	"runtime"

@@ -21,6 +21,7 @@ import (

 	flag "github.com/docker/docker/pkg/mflag"

 	"github.com/docker/docker/pkg/nat"

 	"github.com/docker/docker/pkg/stringutils"

+	"github.com/docker/docker/pkg/system"

 	"github.com/docker/docker/runconfig"

 )

@@ -272,39 +273,15 @@ func workdir(b *builder, args []string, attributes map[string]bool, original str

 		return err

 	}

-	// Note that workdir passed comes from the Dockerfile. Hence it is in

-	// Linux format using forward-slashes, even on Windows. However,

-	// b.Config.WorkingDir is in platform-specific notation (in other words

-	// on Windows will use `\`

-	workdir := args[0]

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

+	// specific semantics, hence ensure it is converted.

+	workdir := filepath.FromSlash(args[0])

-	isAbs := false

-	if runtime.GOOS == "windows" {

-		// Alternate processing for Windows here is necessary as we can't call

-		// filepath.IsAbs(workDir) as that would verify Windows style paths,

-		// along with drive-letters (eg c:\pathto\file.txt). We (arguably

-		// correctly or not) check for both forward and back slashes as this

-		// is what the 1.4.2 GoLang implementation of IsAbs() does in the

-		// isSlash() function.

-		isAbs = workdir[0] == '\\' || workdir[0] == '/'

-	} else {

-		isAbs = filepath.IsAbs(workdir)

-	}

-

-	if !isAbs {

-		current := b.Config.WorkingDir

-		if runtime.GOOS == "windows" {

-			// Convert to Linux format before join

-			current = strings.Replace(current, "\\", "/", -1)

-		}

-		// Must use path.Join so works correctly on Windows, not filepath

-		workdir = path.Join("/", current, workdir)

+	if !system.IsAbs(workdir) {

+		current := filepath.FromSlash(b.Config.WorkingDir)

+		workdir = filepath.Join(string(os.PathSeparator), current, workdir)

 	}

-	// Convert to platform specific format

-	if runtime.GOOS == "windows" {

-		workdir = strings.Replace(workdir, "/", "\\", -1)

-	}

 	b.Config.WorkingDir = workdir

 	return b.commit("", b.Config.Cmd, fmt.Sprintf("WORKDIR %v", workdir))

@@ -270,7 +270,7 @@ func calcCopyInfo(b *builder, cmdName string, cInfos *[]*copyInfo, origPath stri

 	// Twiddle the destPath when its a relative path - meaning, make it

 	// relative to the WORKINGDIR

-	if !filepath.IsAbs(destPath) {

+	if !system.IsAbs(destPath) {

 		hasSlash := strings.HasSuffix(destPath, string(os.PathSeparator))

 		destPath = filepath.Join(string(os.PathSeparator), filepath.FromSlash(b.Config.WorkingDir), destPath)

@@ -10,6 +10,7 @@ import (

 	"strings"

 	"github.com/Sirupsen/logrus"

+	"github.com/docker/docker/pkg/system"

 )

 // Errors used or returned by this file.

@@ -210,7 +211,7 @@ func CopyInfoDestinationPath(path string) (info CopyInfo, err error) {

 			return CopyInfo{}, err

 		}

-		if !filepath.IsAbs(linkTarget) {

+		if !system.IsAbs(linkTarget) {

 			// Join with the parent directory.

 			dstParent, _ := SplitPathDirEntry(path)

 			linkTarget = filepath.Join(dstParent, linkTarget)

@@ -12,6 +12,8 @@ import (

 	"os"

 	"path/filepath"

 	"strings"

+

+	"github.com/docker/docker/pkg/system"

 )

 // FollowSymlinkInScope is a wrapper around evalSymlinksInScope that returns an

@@ -120,7 +122,7 @@ func evalSymlinksInScope(path, root string) (string, error) {

 		if err != nil {

 			return "", err

 		}

-		if filepath.IsAbs(dest) {

+		if system.IsAbs(dest) {

 			b.Reset()

 		}

 		path = dest + string(filepath.Separator) + path