Merge pull request #4954 from MichaelEischer/improve-windows-path-handling

Improve windows path handling

changelog/unreleased/issue-4953

@@ -0,0 +1,7 @@
+Bugfix: Correctly handle long paths on older Windows versions
+
+When using older Windows versions, like Windows Server 2012, restic 0.17.0
+failed to back up files with long paths. This has been fixed.
+
+https://github.com/restic/restic/issues/4953
+https://github.com/restic/restic/pull/4954

internal/fs/file.go

@@ -134,7 +134,7 @@ func IsAccessDenied(err error) bool {
 // ResetPermissions resets the permissions of the file at the specified path
 func ResetPermissions(path string) error {
 	// Set the default file permissions
-	if err := os.Chmod(path, 0600); err != nil {
+	if err := os.Chmod(fixpath(path), 0600); err != nil {
 		return err
 	}
 	return nil

internal/fs/file_windows.go

@@ -85,7 +85,7 @@ func ClearSystem(path string) error {
 
 // ClearAttribute removes the specified attribute from the file.
 func ClearAttribute(path string, attribute uint32) error {
-	ptr, err := windows.UTF16PtrFromString(path)
+	ptr, err := windows.UTF16PtrFromString(fixpath(path))
 	if err != nil {
 		return err
 	}

internal/fs/sd_windows.go

@@ -129,22 +129,22 @@ func SetSecurityDescriptor(filePath string, securityDescriptor *[]byte) error {
 
 // getNamedSecurityInfoHigh gets the higher level SecurityDescriptor which requires admin permissions.
 func getNamedSecurityInfoHigh(filePath string) (*windows.SECURITY_DESCRIPTOR, error) {
-	return windows.GetNamedSecurityInfo(filePath, windows.SE_FILE_OBJECT, highSecurityFlags)
+	return windows.GetNamedSecurityInfo(fixpath(filePath), windows.SE_FILE_OBJECT, highSecurityFlags)
 }
 
 // getNamedSecurityInfoLow gets the lower level SecurityDescriptor which requires no admin permissions.
 func getNamedSecurityInfoLow(filePath string) (*windows.SECURITY_DESCRIPTOR, error) {
-	return windows.GetNamedSecurityInfo(filePath, windows.SE_FILE_OBJECT, lowBackupSecurityFlags)
+	return windows.GetNamedSecurityInfo(fixpath(filePath), windows.SE_FILE_OBJECT, lowBackupSecurityFlags)
 }
 
 // setNamedSecurityInfoHigh sets the higher level SecurityDescriptor which requires admin permissions.
 func setNamedSecurityInfoHigh(filePath string, owner *windows.SID, group *windows.SID, dacl *windows.ACL, sacl *windows.ACL) error {
-	return windows.SetNamedSecurityInfo(filePath, windows.SE_FILE_OBJECT, highSecurityFlags, owner, group, dacl, sacl)
+	return windows.SetNamedSecurityInfo(fixpath(filePath), windows.SE_FILE_OBJECT, highSecurityFlags, owner, group, dacl, sacl)
 }
 
 // setNamedSecurityInfoLow sets the lower level SecurityDescriptor which requires no admin permissions.
 func setNamedSecurityInfoLow(filePath string, dacl *windows.ACL) error {
-	return windows.SetNamedSecurityInfo(filePath, windows.SE_FILE_OBJECT, lowRestoreSecurityFlags, nil, nil, dacl, nil)
+	return windows.SetNamedSecurityInfo(fixpath(filePath), windows.SE_FILE_OBJECT, lowRestoreSecurityFlags, nil, nil, dacl, nil)
 }
 
 // enableBackupPrivilege enables privilege for backing up security descriptors

internal/restorer/restorer_test.go

@@ -1506,3 +1506,36 @@ func TestRestoreToFile(t *testing.T) {
 	err := res.RestoreTo(ctx, tempdir)
 	rtest.Assert(t, strings.Contains(err.Error(), "cannot create target directory"), "unexpected error %v", err)
 }
+
+func TestRestorerLongPath(t *testing.T) {
+	tmp := t.TempDir()
+
+	longPath := tmp
+	for i := 0; i < 20; i++ {
+		longPath = filepath.Join(longPath, "aaaaaaaaaaaaaaaaaaaa")
+	}
+
+	rtest.OK(t, os.MkdirAll(longPath, 0o700))
+	f, err := fs.OpenFile(filepath.Join(longPath, "file"), fs.O_CREATE|fs.O_RDWR, 0o600)
+	rtest.OK(t, err)
+	_, err = f.WriteString("Hello, World!")
+	rtest.OK(t, err)
+	rtest.OK(t, f.Close())
+
+	repo := repository.TestRepository(t)
+
+	local := &fs.Local{}
+	sc := archiver.NewScanner(local)
+	rtest.OK(t, sc.Scan(context.TODO(), []string{tmp}))
+	arch := archiver.New(repo, local, archiver.Options{})
+	sn, _, _, err := arch.Snapshot(context.Background(), []string{tmp}, archiver.SnapshotOptions{})
+	rtest.OK(t, err)
+
+	res := NewRestorer(repo, sn, Options{})
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	rtest.OK(t, res.RestoreTo(ctx, tmp))
+	_, err = res.VerifyFiles(ctx, tmp)
+	rtest.OK(t, err)
+}