windows: fix exutable replacement

adopt workaround that simply hides it

see https://github.com/minio/selfupdate
see https://github.com/sanbornm/go-selfupdate

selfupdate.go

@@ -230,12 +230,7 @@ func (c config) Install(tag, asset string) error {
 		}
 	}
 
-	c.Printf("moving to %#v\n", target)
-	if err = os.Rename(fExecutable.Name(), target); err != nil {
-		return err
-	}
-
-	return nil
+	return c.swap(fExecutable.Name(), target)
 }
 
 func (c config) verify(executable string) error {

swap.go

@@ -0,0 +1,14 @@
+//go:build !windows
+
+package selfupdate
+
+import (
+	"os"
+)
+
+// swap replaces the running executable.
+// On most systems this simply renames the source file.
+func (c config) swap(source, target string) error {
+	c.Printf("moving to %#v\n", target)
+	return os.Rename(source, target)
+}

swap_windows.go

@@ -0,0 +1,52 @@
+package selfupdate
+
+import (
+	"os"
+	"syscall"
+)
+
+// swap replaces the running executable.
+// On windows it cannot be overwritten/deleted.
+// It is thus renamed to an intermediate file (`{target}.old`) and simply hidden.
+//
+// see https://github.com/minio/selfupdate
+// see https://github.com/sanbornm/go-selfupdate
+func (c config) swap(source, target string) error {
+	old := target + ".old"
+	if _, err := os.Stat(old); err == nil {
+		if err := c.confirm("remove %#v", old); err != nil {
+			return err
+		}
+		if err := os.Remove(old); err != nil {
+			return err
+		}
+	}
+
+	c.Printf("moving current executable to %#v\n", old)
+	if err := os.Rename(target, old); err != nil {
+		return err
+	}
+
+	c.Printf("moving new executable to %#v\n", target)
+	if err := os.Rename(source, target); err != nil {
+		_ = os.Rename(old, target) // try to restore old executable
+		return err
+	}
+
+	c.Printf("hiding %#v\n", old)
+	return hide(old)
+}
+
+func hide(path string) error {
+	p, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	err = syscall.SetFileAttributes(p, syscall.FILE_ATTRIBUTE_HIDDEN)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}