Merge pull request #147 from gabriel-samfira/fix-follow-symlinks

Fix follow symlinkResolver on Windows

followlinks.go

@@ -19,7 +19,7 @@ func FollowLinks(root string, paths []string) ([]string, error) {
 	}
 	res := make([]string, 0, len(r.resolved))
 	for r := range r.resolved {
-		res = append(res, r)
+		res = append(res, filepath.ToSlash(r))
 	}
 	sort.Strings(res)
 	return dedupePaths(res), nil
@@ -31,6 +31,12 @@ type symlinkResolver struct {
 }
 
 func (r *symlinkResolver) append(p string) error {
+	if runtime.GOOS == "windows" && filepath.IsAbs(filepath.FromSlash(p)) {
+		absParts := strings.SplitN(p, ":", 2)
+		if len(absParts) == 2 {
+			p = absParts[1]
+		}
+	}
 	p = filepath.Join(".", p)
 	current := "."
 	for {
@@ -41,7 +47,6 @@ func (r *symlinkResolver) append(p string) error {
 		if err != nil {
 			return err
 		}
-
 		p = ""
 		if len(parts) == 2 {
 			p = parts[1]
@@ -76,7 +81,7 @@ func (r *symlinkResolver) readSymlink(p string, allowWildcard bool) ([]string, e
 	if allowWildcard && containsWildcards(base) {
 		fis, err := os.ReadDir(filepath.Dir(realPath))
 		if err != nil {
-			if errors.Is(err, os.ErrNotExist) {
+			if isNotFound(err) {
 				return nil, nil
 			}
 			return nil, errors.Wrap(err, "readdir")
@@ -96,7 +101,7 @@ func (r *symlinkResolver) readSymlink(p string, allowWildcard bool) ([]string, e
 
 	fi, err := os.Lstat(realPath)
 	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
+		if isNotFound(err) {
 			return nil, nil
 		}
 		return nil, errors.WithStack(err)
@@ -139,7 +144,7 @@ func dedupePaths(in []string) []string {
 		if s == "." {
 			return nil
 		}
-		if strings.HasPrefix(s, last+string(filepath.Separator)) {
+		if strings.HasPrefix(s, last+"/") {
 			continue
 		}
 		out = append(out, s)

followlinks_test.go

@@ -1,6 +1,8 @@
 package fsutil
 
 import (
+	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/containerd/continuity/fs/fstest"
@@ -46,9 +48,14 @@ func TestFollowLinksLoop(t *testing.T) {
 func TestFollowLinksAbsolute(t *testing.T) {
 	tmpDir := t.TempDir()
 
+	abslutePathForBaz := "/foo/bar/baz"
+	if runtime.GOOS == "windows" {
+		abslutePathForBaz = "C:/foo/bar/baz"
+	}
+
 	apply := fstest.Apply(
 		fstest.CreateDir("dir", 0700),
-		fstest.Symlink("/foo/bar/baz", "dir/l1"),
+		fstest.Symlink(abslutePathForBaz, "dir/l1"),
 		fstest.CreateDir("foo", 0700),
 		fstest.Symlink("../", "foo/bar"),
 		fstest.CreateFile("baz", nil, 0600),
@@ -58,14 +65,14 @@ func TestFollowLinksAbsolute(t *testing.T) {
 	out, err := FollowLinks(tmpDir, []string{"dir/l1"})
 	require.NoError(t, err)
 
-	require.Equal(t, out, []string{"baz", "dir/l1", "foo/bar"})
+	require.Equal(t, []string{"baz", "dir/l1", "foo/bar"}, out)
 
 	// same but a link outside root
 	tmpDir = t.TempDir()
 
 	apply = fstest.Apply(
 		fstest.CreateDir("dir", 0700),
-		fstest.Symlink("/foo/bar/baz", "dir/l1"),
+		fstest.Symlink(abslutePathForBaz, "dir/l1"),
 		fstest.CreateDir("foo", 0700),
 		fstest.Symlink("../../../", "foo/bar"),
 		fstest.CreateFile("baz", nil, 0600),
@@ -75,7 +82,7 @@ func TestFollowLinksAbsolute(t *testing.T) {
 	out, err = FollowLinks(tmpDir, []string{"dir/l1"})
 	require.NoError(t, err)
 
-	require.Equal(t, out, []string{"baz", "dir/l1", "foo/bar"})
+	require.Equal(t, []string{"baz", "dir/l1", "foo/bar"}, out)
 }
 
 func TestFollowLinksNotExists(t *testing.T) {
@@ -95,7 +102,7 @@ func TestFollowLinksNotExists(t *testing.T) {
 	out, err = FollowLinks(tmpDir, []string{"f*/foo/t*"})
 	require.NoError(t, err)
 
-	require.Equal(t, out, []string{"f*/foo/t*"})
+	require.Equal(t, []string{"f*/foo/t*"}, out)
 }
 
 func TestFollowLinksNormalized(t *testing.T) {
@@ -106,10 +113,15 @@ func TestFollowLinksNormalized(t *testing.T) {
 
 	require.Equal(t, out, []string{"foo/bar"})
 
+	rootPath := "/"
+	if runtime.GOOS == "windows" {
+		rootPath = "C:/"
+	}
+
 	apply := fstest.Apply(
 		fstest.CreateDir("dir", 0700),
-		fstest.Symlink("/foo", "dir/l1"),
-		fstest.Symlink("/", "dir/l2"),
+		fstest.Symlink(filepath.Join(rootPath, "foo"), "dir/l1"),
+		fstest.Symlink(rootPath, "dir/l2"),
 		fstest.CreateDir("foo", 0700),
 		fstest.CreateFile("foo/bar", nil, 0600),
 	)
@@ -129,12 +141,17 @@ func TestFollowLinksNormalized(t *testing.T) {
 func TestFollowLinksWildcard(t *testing.T) {
 	tmpDir := t.TempDir()
 
+	absolutePathForFoo := "/foo"
+	if runtime.GOOS == "windows" {
+		absolutePathForFoo = "C:/foo"
+	}
+
 	apply := fstest.Apply(
 		fstest.CreateDir("dir", 0700),
 		fstest.CreateDir("foo", 0700),
-		fstest.Symlink("/foo/bar1", "dir/l1"),
-		fstest.Symlink("/foo/bar2", "dir/l2"),
-		fstest.Symlink("/foo/bar3", "dir/anotherlink"),
+		fstest.Symlink(filepath.Join(absolutePathForFoo, "bar1"), "dir/l1"),
+		fstest.Symlink(filepath.Join(absolutePathForFoo, "bar2"), "dir/l2"),
+		fstest.Symlink(filepath.Join(absolutePathForFoo, "bar3"), "dir/anotherlink"),
 		fstest.Symlink("../baz", "foo/bar2"),
 		fstest.CreateFile("foo/bar1", nil, 0600),
 		fstest.CreateFile("foo/bar3", nil, 0600),
@@ -145,7 +162,7 @@ func TestFollowLinksWildcard(t *testing.T) {
 	out, err := FollowLinks(tmpDir, []string{"dir/l*"})
 	require.NoError(t, err)
 
-	require.Equal(t, out, []string{"baz", "dir/l*", "foo/bar1", "foo/bar2"})
+	require.Equal(t, []string{"baz", "dir/l*", "foo/bar1", "foo/bar2"}, out)
 
 	out, err = FollowLinks(tmpDir, []string{"dir"})
 	require.NoError(t, err)

followlinks_unix.go

@@ -0,0 +1,14 @@
+//go:build !windows
+// +build !windows
+
+package fsutil
+
+import (
+	"os"
+
+	"github.com/pkg/errors"
+)
+
+func isNotFound(err error) bool {
+	return errors.Is(err, os.ErrNotExist)
+}

followlinks_windows.go

@@ -0,0 +1,15 @@
+package fsutil
+
+import (
+	"os"
+
+	"github.com/pkg/errors"
+	"golang.org/x/sys/windows"
+)
+
+func isNotFound(err error) bool {
+	if errors.Is(err, os.ErrNotExist) || errors.Is(err, windows.ERROR_INVALID_NAME) {
+		return true
+	}
+	return false
+}