lib/file: check if windows long paths are enabled

lib/file/file_windows.go

@@ -9,6 +9,8 @@ import (
 	"path/filepath"
 	"regexp"
 	"syscall"
+
+	"golang.org/x/sys/windows/registry"
 )
 
 // OpenFile is the generalized open call; most users will use Open or Create
@@ -28,9 +30,11 @@ func OpenFile(path string, mode int, perm os.FileMode) (*os.File, error) {
 	if len(path) == 0 {
 		return nil, syscall.ERROR_FILE_NOT_FOUND
 	}
+
 	// For windows the max path length is 260 characters
+	// if the LongPathsEnabled is not set
 	// https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
-	if len(path) >= 260 {
+	if !IsLongPathsEnabled() && len(path) >= 260 {
 		return nil, &os.PathError{Path: path, Op: "open", Err: errors.New("path length higher than 260")}
 	}
 
@@ -107,3 +111,24 @@ func IsReserved(path string) error {
 	}
 	return nil
 }
+
+// IsLongPathsEnabled checks if the current have the LongPathsEnabled enabled
+func IsLongPathsEnabled() bool {
+	// Read registry
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SYSTEM\CurrentControlSet\Control\FileSystem`, registry.QUERY_VALUE)
+	if err != nil {
+		return false
+	}
+	defer k.Close()
+
+	s, _, err := k.GetIntegerValue("LongPathsEnabled")
+	if err != nil {
+		return false
+	}
+
+	if s == 0x00000001 {
+		return true
+	} else {
+		return false
+	}
+}

lib/file/file_windows_test.go

@@ -10,6 +10,11 @@ import (
 )
 
 func TestFileOpenMaxPathLength(t *testing.T) {
+	// Skip if the long path is enabled
+	if IsLongPathsEnabled() {
+		t.Skip()
+	}
+
 	path := `C:\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path`
 	_, err := OpenFile(path, 0644, 0644)
 	assert.Error(t, err, "mkdir: Max path length can't exceed 260")

lib/file/mkdir_windows.go

@@ -19,8 +19,9 @@ import (
 // (https://github.com/golang/go/blob/master/src/os/path.go)
 func MkdirAll(path string, perm os.FileMode) error {
 	// For windows the max path length is 260 characters
+	// if the LongPathsEnabled is not set
 	// https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
-	if len(path) >= 260 {
+	if !IsLongPathsEnabled() && len(path) >= 260 {
 		return &os.PathError{Path: path, Op: "open", Err: errors.New("path length higher than 260")}
 	}
 

lib/file/mkdir_windows_test.go

@@ -132,6 +132,11 @@ func TestMkdirAllOnUnusedDrive(t *testing.T) {
 }
 
 func TestMkdirMaxPathLength(t *testing.T) {
+	// Skip if the long path is enabled
+	if IsLongPathsEnabled() {
+		t.Skip()
+	}
+
 	path := `C:\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path\my\path`
 	err := MkdirAll(path, 0777)
 	assert.Error(t, err, "mkdir: Max path length can't exceed 260")