Support SymlinkNoFollow on Windows

Fixes #41

at/at_other.go

@@ -106,13 +106,6 @@ func (d Dir) stat(path string, flag int) (fs.FileInfo, error) {
 	return os.Stat(d.join(path))
 }
 
-func (d Dir) utimes(path string, atime, mtime time.Time, flag int) error {
-	if flag == SymlinkNoFollow {
-		return &Error{Op: "utimes", Err: ErrUnsupportedFlag}
-	}
-	return chtimes(d.join(path), atime, mtime)
-}
-
 func futimes(f *os.File, atime, mtime time.Time) error {
 	return os.Chtimes(f.Name(), atime, mtime)
 }
@@ -123,13 +116,3 @@ func (d Dir) join(path string) string {
 	}
 	return filepath.Join(d.path, path)
 }
-
-func chtimes(path string, atime, mtime time.Time) error {
-	if mtime == UtimeOmit {
-		return &Error{Op: "chtimes", Err: ErrMtimeOmitted}
-	}
-	if atime == UtimeOmit {
-		atime = time.Now()
-	}
-	return os.Chtimes(path, atime, mtime)
-}

at/utimes_other.go

@@ -0,0 +1,35 @@
+// Copyright (c) 2023 Tim van der Molen <[email protected]>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+//go:build !(unix || aix || android || darwin || dragonfly || freebsd || hurd || illumos || ios || linux || netbsd || openbsd || solaris || windows)
+
+package at
+
+import (
+	"os"
+	"time"
+)
+
+func (d Dir) utimes(path string, atime, mtime time.Time, flag int) error {
+	if flag == SymlinkNoFollow {
+		return &Error{Op: "utimes", Err: ErrUnsupportedFlag}
+	}
+	if mtime == UtimeOmit {
+		return &Error{Op: "utimes", Err: ErrMtimeOmitted}
+	}
+	if atime == UtimeOmit {
+		atime = time.Now()
+	}
+	return os.Chtimes(d.join(path), atime, mtime)
+}

at/utimes_windows.go

@@ -0,0 +1,59 @@
+// Copyright (c) 2024 Tim van der Molen <[email protected]>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+package at
+
+import (
+	"os"
+	"time"
+
+	"golang.org/x/sys/windows"
+)
+
+func (d Dir) utimes(path string, atime, mtime time.Time, flag int) error {
+	upath, err := windows.UTF16PtrFromString(path)
+	if err != nil {
+		return &os.PathError{Op: "utimes", Path: path, Err: err}
+	}
+
+	var fileFlags uint32 = windows.FILE_FLAG_BACKUP_SEMANTICS
+	if flag == SymlinkNoFollow {
+		fileFlags |= windows.FILE_FLAG_OPEN_REPARSE_POINT
+	}
+
+	h, err := windows.CreateFile(upath, windows.FILE_WRITE_ATTRIBUTES, windows.FILE_SHARE_WRITE, nil, windows.OPEN_EXISTING, fileFlags, 0)
+	if err != nil {
+		return &os.PathError{Op: "utimes", Path: path, Err: err}
+	}
+
+	aft := timeToFiletime(atime)
+	mft := timeToFiletime(mtime)
+	if err := windows.SetFileTime(h, nil, &aft, &mft); err != nil {
+		windows.CloseHandle(h)
+		return &os.PathError{Op: "utimes", Path: path, Err: err}
+	}
+
+	if err := windows.CloseHandle(h); err != nil {
+		return &os.PathError{Op: "utimes", Path: path, Err: err}
+	}
+
+	return nil
+}
+
+func timeToFiletime(t time.Time) windows.Filetime {
+	if t == UtimeOmit {
+		return windows.Filetime{LowDateTime: 0, HighDateTime: 0}
+	}
+	return windows.NsecToFiletime(t.UnixNano())
+}