From ab181ce55707de6f47d662dcdf6eab9c6c040906 Mon Sep 17 00:00:00 2001
From: Iavael <iavaelooeyt@gmail.com>
Date: Mon, 2 Mar 2015 02:55:28 +0300
Subject: [PATCH] Fixed handling hardlinks to symlinks in tar stream

Signed-off-by: Iavael <iavaelooeyt@gmail.com>
---
 pkg/archive/archive.go      | 16 ++++++++++++++--
 pkg/archive/archive_test.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/pkg/archive/archive.go b/pkg/archive/archive.go
index bce66a505a..9e43d28cb1 100644
--- a/pkg/archive/archive.go
+++ b/pkg/archive/archive.go
@@ -349,7 +349,13 @@ func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, L
 
 	// There is no LChmod, so ignore mode for symlink. Also, this
 	// must happen after chown, as that can modify the file mode
-	if hdr.Typeflag != tar.TypeSymlink {
+	if hdr.Typeflag == tar.TypeLink {
+		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
+			if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+				return err
+			}
+		}
+	} else if hdr.Typeflag != tar.TypeSymlink {
 		if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
 			return err
 		}
@@ -357,7 +363,13 @@ func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, L
 
 	ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}
 	// syscall.UtimesNano doesn't support a NOFOLLOW flag atm, and
-	if hdr.Typeflag != tar.TypeSymlink {
+	if hdr.Typeflag == tar.TypeLink {
+		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
+			if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
+				return err
+			}
+		}
+	} else if hdr.Typeflag != tar.TypeSymlink {
 		if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform {
 			return err
 		}
diff --git a/pkg/archive/archive_test.go b/pkg/archive/archive_test.go
index 6cd95d5ad5..c127b307e2 100644
--- a/pkg/archive/archive_test.go
+++ b/pkg/archive/archive_test.go
@@ -435,6 +435,34 @@ func TestUntarInvalidFilenames(t *testing.T) {
 	}
 }
 
+func TestUntarHardlinkToSymlink(t *testing.T) {
+	for i, headers := range [][]*tar.Header{
+		{
+			{
+				Name:     "symlink1",
+				Typeflag: tar.TypeSymlink,
+				Linkname: "regfile",
+				Mode:     0644,
+			},
+			{
+				Name:     "symlink2",
+				Typeflag: tar.TypeLink,
+				Linkname: "symlink1",
+				Mode:     0644,
+			},
+			{
+				Name:     "regfile",
+				Typeflag: tar.TypeReg,
+				Mode:     0644,
+			},
+		},
+	} {
+		if err := testBreakout("untar", "docker-TestUntarHardlinkToSymlink", headers); err != nil {
+			t.Fatalf("i=%d. %v", i, err)
+		}
+	}
+}
+
 func TestUntarInvalidHardlink(t *testing.T) {
 	for i, headers := range [][]*tar.Header{
 		{ // try reading victim/hello (../)