@@ -169,13 +169,13 @@ func (b *Builder) dispatch(stepN int, stepTotal int, ast *parser.Node) error {

 			var words []string

 			if allowWordExpansion[cmd] {

-				words, err = ProcessWords(str, envs)

+				words, err = ProcessWords(str, envs, b.directive.EscapeToken)

 				if err != nil {

 					return err

 				}

 				strList = append(strList, words...)

 			} else {

-				str, err = ProcessWord(str, envs)

+				str, err = ProcessWord(str, envs, b.directive.EscapeToken)

 				if err != nil {

 					return err

 				}

@@ -14,19 +14,21 @@ import (

 )

 type shellWord struct {

-	word    string

-	scanner scanner.Scanner

-	envs    []string

-	pos     int

+	word        string

+	scanner     scanner.Scanner

+	envs        []string

+	pos         int

+	escapeToken rune

 }

 // ProcessWord will use the 'env' list of environment variables,

 // and replace any env var references in 'word'.

-func ProcessWord(word string, env []string) (string, error) {

+func ProcessWord(word string, env []string, escapeToken rune) (string, error) {

 	sw := &shellWord{

-		word: word,

-		envs: env,

-		pos:  0,

+		word:        word,

+		envs:        env,

+		pos:         0,

+		escapeToken: escapeToken,

 	}

 	sw.scanner.Init(strings.NewReader(word))

 	word, _, err := sw.process()

@@ -40,11 +42,12 @@ func ProcessWord(word string, env []string) (string, error) {

 // this splitting is done **after** the env var substitutions are done.

 // Note, each one is trimmed to remove leading and trailing spaces (unless

 // they are quoted", but ProcessWord retains spaces between words.

-func ProcessWords(word string, env []string) ([]string, error) {

+func ProcessWords(word string, env []string, escapeToken rune) ([]string, error) {

 	sw := &shellWord{

-		word: word,

-		envs: env,

-		pos:  0,

+		word:        word,

+		envs:        env,

+		pos:         0,

+		escapeToken: escapeToken,

 	}

 	sw.scanner.Init(strings.NewReader(word))

 	_, words, err := sw.process()

@@ -138,8 +141,8 @@ func (sw *shellWord) processStopOn(stopChar rune) (string, []string, error) {

 			// Not special, just add it to the result

 			ch = sw.scanner.Next()

-			if ch == '\\' {

-				// '\' escapes, except end of line

+			if ch == sw.escapeToken {

+				// '\' (default escape token, but ` allowed) escapes, except end of line

 				ch = sw.scanner.Next()

@@ -179,7 +182,7 @@ func (sw *shellWord) processSingleQuote() (string, error) {

 func (sw *shellWord) processDoubleQuote() (string, error) {

 	// All chars up to the next " are taken as-is, even ', except any $ chars

-	// But you can escape " with a \

+	// But you can escape " with a \ (or ` if escape token set accordingly)

 	var result string

 	sw.scanner.Next()

@@ -198,7 +201,7 @@ func (sw *shellWord) processDoubleQuote() (string, error) {

 			result += tmp

 		} else {

 			ch = sw.scanner.Next()

-			if ch == '\\' {

+			if ch == sw.escapeToken {

 				chNext := sw.scanner.Peek()

 				if chNext == scanner.EOF {

@@ -40,7 +40,7 @@ func TestShellParser4EnvVars(t *testing.T) {

 		words[0] = strings.TrimSpace(words[0])

 		words[1] = strings.TrimSpace(words[1])

-		newWord, err := ProcessWord(words[0], envs)

+		newWord, err := ProcessWord(words[0], envs, '\\')

 		if err != nil {

 			newWord = "error"

@@ -83,7 +83,7 @@ func TestShellParser4Words(t *testing.T) {

 		test := strings.TrimSpace(words[0])

 		expected := strings.Split(strings.TrimLeft(words[1], " "), ",")

-		result, err := ProcessWords(test, envs)

+		result, err := ProcessWords(test, envs, '\\')

 		if err != nil {

 			result = []string{"error"}

@@ -6884,6 +6884,42 @@ func (s *DockerSuite) TestBuildShellWindowsPowershell(c *check.C) {

 	}

 }

+// Verify that escape is being correctly applied to words when escape directive is not \.

+// Tests WORKDIR, ADD

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

+	testRequires(c, DaemonIsWindows)

+	name := "testbuildescapenotbackslashwordtesta"

+	_, out, err := buildImageWithOut(name,

+		`# escape= `+"`"+`

+		FROM `+minimalBaseImage()+`

+        WORKDIR c:\windows

+		RUN dir /w`,

+		true)

+	if err != nil {

+		c.Fatal(err)

+	}

+	if !strings.Contains(strings.ToLower(out), "[system32]") {

+		c.Fatalf("Line with '[windows]' not found in output %q", out)

+	}

+

+	name = "testbuildescapenotbackslashwordtestb"

+	_, out, err = buildImageWithOut(name,

+		`# escape= `+"`"+`

+		FROM `+minimalBaseImage()+`

+		SHELL ["powershell.exe"]

+        WORKDIR c:\foo

+		ADD Dockerfile c:\foo\

+		RUN dir Dockerfile`,

+		true)

+	if err != nil {

+		c.Fatal(err)

+	}

+	if !strings.Contains(strings.ToLower(out), "-a----") {

+		c.Fatalf("Line with '-a----' not found in output %q", out)

+	}

+

+}

+

 // #22868. Make sure shell-form CMD is marked as escaped in the config of the image

 func (s *DockerSuite) TestBuildCmdShellArgsEscaped(c *check.C) {

 	testRequires(c, DaemonIsWindows)