func (b *builder) addContext(container *daemon.Container, orig, dest string, decompress bool) error {
	var (
		err        error
		destExists = true
		origPath   = filepath.Join(b.contextPath, orig)
		destPath   string
	)

	// Work in daemon-local OS specific file paths
	dest = filepath.FromSlash(dest)

	destPath, err = container.GetResourcePath(dest)
	if err != nil {
		return err
	}

	// Preserve the trailing slash
	if strings.HasSuffix(dest, string(os.PathSeparator)) || dest == "." {
		destPath = destPath + string(os.PathSeparator)
	}

	destStat, err := os.Stat(destPath)
	if err != nil {
		if !os.IsNotExist(err) {
			logrus.Errorf("Error performing os.Stat on %s. %s", destPath, err)
			return err
		}
		destExists = false
	}

	fi, err := os.Stat(origPath)
	if err != nil {
		if os.IsNotExist(err) {
			return fmt.Errorf("%s: no such file or directory", orig)
		}
		return err
	}

	if fi.IsDir() {
		return copyAsDirectory(origPath, destPath, destExists)
	}

	// If we are adding a remote file (or we've been told not to decompress), do not try to untar it
	if decompress {
		// First try to unpack the source as an archive
		// to support the untar feature we need to clean up the path a little bit
		// because tar is very forgiving.  First we need to strip off the archive's
		// filename from the path but this is only added if it does not end in slash
		tarDest := destPath
		if strings.HasSuffix(tarDest, string(os.PathSeparator)) {
			tarDest = filepath.Dir(destPath)
		}

		// try to successfully untar the orig
		if err := chrootarchive.UntarPath(origPath, tarDest); err == nil {
			return nil
		} else if err != io.EOF {
			logrus.Debugf("Couldn't untar %s to %s: %s", origPath, tarDest, err)
		}
	}

	if err := system.MkdirAll(filepath.Dir(destPath), 0755); err != nil {
		return err
	}
	if err := chrootarchive.CopyWithTar(origPath, destPath); err != nil {
		return err
	}

	resPath := destPath
	if destExists && destStat.IsDir() {
		resPath = filepath.Join(destPath, filepath.Base(origPath))
	}

	return fixPermissions(origPath, resPath, 0, 0, destExists)
}

func (b *Builder) addContext(container *daemon.Container, orig, dest string, decompress bool) error {
	var (
		err        error
		destExists = true
		origPath   = path.Join(b.contextPath, orig)
		destPath   = path.Join(container.RootfsPath(), dest)
	)

	if destPath != container.RootfsPath() {
		destPath, err = symlink.FollowSymlinkInScope(destPath, container.RootfsPath())
		if err != nil {
			return err
		}
	}

	// Preserve the trailing '/'
	if strings.HasSuffix(dest, "/") || dest == "." {
		destPath = destPath + "/"
	}

	destStat, err := os.Stat(destPath)
	if err != nil {
		if !os.IsNotExist(err) {
			return err
		}
		destExists = false
	}

	fi, err := os.Stat(origPath)
	if err != nil {
		if os.IsNotExist(err) {
			return fmt.Errorf("%s: no such file or directory", orig)
		}
		return err
	}

	if fi.IsDir() {
		return copyAsDirectory(origPath, destPath, destExists)
	}

	// If we are adding a remote file (or we've been told not to decompress), do not try to untar it
	if decompress {
		// First try to unpack the source as an archive
		// to support the untar feature we need to clean up the path a little bit
		// because tar is very forgiving.  First we need to strip off the archive's
		// filename from the path but this is only added if it does not end in / .
		tarDest := destPath
		if strings.HasSuffix(tarDest, "/") {
			tarDest = filepath.Dir(destPath)
		}

		// try to successfully untar the orig
		if err := chrootarchive.UntarPath(origPath, tarDest); err == nil {
			return nil
		} else if err != io.EOF {
			log.Debugf("Couldn't untar %s to %s: %s", origPath, tarDest, err)
		}
	}

	if err := os.MkdirAll(path.Dir(destPath), 0755); err != nil {
		return err
	}
	if err := chrootarchive.CopyWithTar(origPath, destPath); err != nil {
		return err
	}

	resPath := destPath
	if destExists && destStat.IsDir() {
		resPath = path.Join(destPath, path.Base(origPath))
	}

	return fixPermissions(origPath, resPath, 0, 0, destExists)
}

// Copy copies/extracts a source FileInfo to a destination path inside a container
// specified by a container object.
// TODO: make sure callers don't unnecessarily convert destPath with filepath.FromSlash (Copy does it already).
// Copy should take in abstract paths (with slashes) and the implementation should convert it to OS-specific paths.
func (d Docker) Copy(c *daemon.Container, destPath string, src builder.FileInfo, decompress bool) error {
	srcPath := src.Path()
	destExists := true

	// Work in daemon-local OS specific file paths
	destPath = filepath.FromSlash(destPath)

	dest, err := c.GetResourcePath(destPath)
	if err != nil {
		return err
	}

	// Preserve the trailing slash
	// TODO: why are we appending another path separator if there was already one?
	if strings.HasSuffix(destPath, string(os.PathSeparator)) || destPath == "." {
		dest += string(os.PathSeparator)
	}

	destPath = dest

	destStat, err := os.Stat(destPath)
	if err != nil {
		if !os.IsNotExist(err) {
			logrus.Errorf("Error performing os.Stat on %s. %s", destPath, err)
			return err
		}
		destExists = false
	}

	if src.IsDir() {
		// copy as directory
		if err := chrootarchive.CopyWithTar(srcPath, destPath); err != nil {
			return err
		}
		return fixPermissions(srcPath, destPath, 0, 0, destExists)
	}
	if decompress {
		// Only try to untar if it is a file and that we've been told to decompress (when ADD-ing a remote file)

		// First try to unpack the source as an archive
		// to support the untar feature we need to clean up the path a little bit
		// because tar is very forgiving.  First we need to strip off the archive's
		// filename from the path but this is only added if it does not end in slash
		tarDest := destPath
		if strings.HasSuffix(tarDest, string(os.PathSeparator)) {
			tarDest = filepath.Dir(destPath)
		}

		// try to successfully untar the orig
		if err := chrootarchive.UntarPath(srcPath, tarDest); err == nil {
			return nil
		} else if err != io.EOF {
			logrus.Debugf("Couldn't untar to %s: %v", tarDest, err)
		}
	}

	// only needed for fixPermissions, but might as well put it before CopyFileWithTar
	if destExists && destStat.IsDir() {
		destPath = filepath.Join(destPath, filepath.Base(srcPath))
	}

	if err := system.MkdirAll(filepath.Dir(destPath), 0755); err != nil {
		return err
	}
	if err := chrootarchive.CopyFileWithTar(srcPath, destPath); err != nil {
		return err
	}

	return fixPermissions(srcPath, destPath, 0, 0, destExists)
}