builder/dockerfile: make normalizeDest() platform-specific again

Removing various bits that were added in https://github.com/moby/moby/commit/7a7357dae1bcccb17e9b2d4c7c8f5c025fce56ca

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

builder/dockerfile/copy_unix.go

@@ -4,7 +4,9 @@ package dockerfile // import "github.com/docker/docker/builder/dockerfile"
 
 import (
 	"os"
+	"path"
 	"path/filepath"
+	"strings"
 
 	"github.com/docker/docker/pkg/containerfs"
 	"github.com/docker/docker/pkg/idtools"
@@ -43,6 +45,22 @@ func fixPermissions(source, destination string, identity idtools.Identity, overr
 	})
 }
 
+// normalizeDest normalises the destination of a COPY/ADD command in a
+// platform semantically consistent way.
+func normalizeDest(workingDir, requested string) (string, error) {
+	dest := filepath.FromSlash(requested)
+	endsInSlash := strings.HasSuffix(dest, string(os.PathSeparator))
+
+	if !path.IsAbs(requested) {
+		dest = path.Join("/", filepath.ToSlash(workingDir), dest)
+		// Make sure we preserve any trailing slash
+		if endsInSlash {
+			dest += "/"
+		}
+	}
+	return dest, nil
+}
+
 func containsWildcards(name string) bool {
 	for i := 0; i < len(name); i++ {
 		ch := name[i]

builder/dockerfile/copy_windows.go

@@ -79,6 +79,52 @@ func fixPermissionsWindows(source, destination, SID string) error {
 	return windows.SetNamedSecurityInfo(destination, windows.SE_FILE_OBJECT, windows.OWNER_SECURITY_INFORMATION|windows.DACL_SECURITY_INFORMATION, sid, nil, dacl, nil)
 }
 
+// normalizeDest normalises the destination of a COPY/ADD command in a
+// platform semantically consistent way.
+func normalizeDest(workingDir, requested string) (string, error) {
+	dest := filepath.FromSlash(requested)
+	endsInSlash := strings.HasSuffix(dest, string(os.PathSeparator))
+
+	// We are guaranteed that the working directory is already consistent,
+	// However, Windows also has, for now, the limitation that ADD/COPY can
+	// only be done to the system drive, not any drives that might be present
+	// as a result of a bind mount.
+	//
+	// So... if the path requested is Linux-style absolute (/foo or \\foo),
+	// we assume it is the system drive. If it is a Windows-style absolute
+	// (DRIVE:\\foo), error if DRIVE is not C. And finally, ensure we
+	// strip any configured working directories drive letter so that it
+	// can be subsequently legitimately converted to a Windows volume-style
+	// pathname.
+
+	// Not a typo - filepath.IsAbs, not system.IsAbs on this next check as
+	// we only want to validate where the DriveColon part has been supplied.
+	if filepath.IsAbs(dest) {
+		if strings.ToUpper(string(dest[0])) != "C" {
+			return "", fmt.Errorf("Windows does not support destinations not on the system drive (C:)")
+		}
+		dest = dest[2:] // Strip the drive letter
+	}
+
+	// Cannot handle relative where WorkingDir is not the system drive.
+	if len(workingDir) > 0 {
+		if ((len(workingDir) > 1) && !system.IsAbs(workingDir[2:])) || (len(workingDir) == 1) {
+			return "", fmt.Errorf("Current WorkingDir %s is not platform consistent", workingDir)
+		}
+		if !system.IsAbs(dest) {
+			if string(workingDir[0]) != "C" {
+				return "", fmt.Errorf("Windows does not support relative paths when WORKDIR is not the system drive")
+			}
+			dest = filepath.Join(string(os.PathSeparator), workingDir[2:], dest)
+			// Make sure we preserve any trailing slash
+			if endsInSlash {
+				dest += string(os.PathSeparator)
+			}
+		}
+	}
+	return dest, nil
+}
+
 func containsWildcards(name string) bool {
 	for i := 0; i < len(name); i++ {
 		ch := name[i]

builder/dockerfile/internals.go

@@ -8,9 +8,6 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"os"
-	"path"
-	"path/filepath"
 	"strings"
 
 	"github.com/docker/docker/api/types"
@@ -23,7 +20,6 @@ import (
 	"github.com/docker/docker/pkg/containerfs"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/docker/docker/pkg/stringid"
-	"github.com/docker/docker/pkg/system"
 	"github.com/docker/go-connections/nat"
 	specs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
@@ -224,7 +220,7 @@ func (b *Builder) performCopy(req dispatchRequest, inst copyInstruction) error {
 func createDestInfo(workingDir string, inst copyInstruction, rwLayer builder.RWLayer, platform string) (copyInfo, error) {
 	// Twiddle the destination when it's a relative path - meaning, make it
 	// relative to the WORKINGDIR
-	dest, err := normalizeDest(workingDir, inst.dest, platform)
+	dest, err := normalizeDest(workingDir, inst.dest)
 	if err != nil {
 		return copyInfo{}, errors.Wrapf(err, "invalid %s", inst.cmdName)
 	}
@@ -232,63 +228,6 @@ func createDestInfo(workingDir string, inst copyInstruction, rwLayer builder.RWL
 	return copyInfo{root: rwLayer.Root(), path: dest}, nil
 }
 
-// normalizeDest normalises the destination of a COPY/ADD command in a
-// platform semantically consistent way.
-func normalizeDest(workingDir, requested string, platform string) (string, error) {
-	dest := filepath.FromSlash(requested)
-	endsInSlash := strings.HasSuffix(dest, string(os.PathSeparator))
-
-	if platform != "windows" {
-		if !path.IsAbs(requested) {
-			dest = path.Join("/", filepath.ToSlash(workingDir), dest)
-			// Make sure we preserve any trailing slash
-			if endsInSlash {
-				dest += "/"
-			}
-		}
-		return dest, nil
-	}
-
-	// We are guaranteed that the working directory is already consistent,
-	// However, Windows also has, for now, the limitation that ADD/COPY can
-	// only be done to the system drive, not any drives that might be present
-	// as a result of a bind mount.
-	//
-	// So... if the path requested is Linux-style absolute (/foo or \\foo),
-	// we assume it is the system drive. If it is a Windows-style absolute
-	// (DRIVE:\\foo), error if DRIVE is not C. And finally, ensure we
-	// strip any configured working directories drive letter so that it
-	// can be subsequently legitimately converted to a Windows volume-style
-	// pathname.
-
-	// Not a typo - filepath.IsAbs, not system.IsAbs on this next check as
-	// we only want to validate where the DriveColon part has been supplied.
-	if filepath.IsAbs(dest) {
-		if strings.ToUpper(string(dest[0])) != "C" {
-			return "", fmt.Errorf("Windows does not support destinations not on the system drive (C:)")
-		}
-		dest = dest[2:] // Strip the drive letter
-	}
-
-	// Cannot handle relative where WorkingDir is not the system drive.
-	if len(workingDir) > 0 {
-		if ((len(workingDir) > 1) && !system.IsAbs(workingDir[2:])) || (len(workingDir) == 1) {
-			return "", fmt.Errorf("Current WorkingDir %s is not platform consistent", workingDir)
-		}
-		if !system.IsAbs(dest) {
-			if string(workingDir[0]) != "C" {
-				return "", fmt.Errorf("Windows does not support relative paths when WORKDIR is not the system drive")
-			}
-			dest = filepath.Join(string(os.PathSeparator), workingDir[2:], dest)
-			// Make sure we preserve any trailing slash
-			if endsInSlash {
-				dest += string(os.PathSeparator)
-			}
-		}
-	}
-	return dest, nil
-}
-
 // For backwards compat, if there's just one info then use it as the
 // cache look-up string, otherwise hash 'em all into one
 func getSourceHashFromInfos(infos []copyInfo) string {

builder/dockerfile/internals_windows_test.go

@@ -40,7 +40,7 @@ func TestNormalizeDest(t *testing.T) {
 	}
 	for _, testcase := range tests {
 		msg := fmt.Sprintf("Input: %s, %s", testcase.current, testcase.requested)
-		actual, err := normalizeDest(testcase.current, testcase.requested, "windows")
+		actual, err := normalizeDest(testcase.current, testcase.requested)
 		if testcase.etext == "" {
 			if !assert.Check(t, err, msg) {
 				continue