From a3d57fde34e80527da2c2ae194367bf56b09490a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=92=9F=E8=92=BB?= <mlpmmy@gmail.com>
Date: Wed, 18 Jun 2025 08:47:58 +0800
Subject: [PATCH] more util types

---
 net/packet/util.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/packet/util.go b/net/packet/util.go
index 0336d92..8c8c2cf 100644
--- a/net/packet/util.go
+++ b/net/packet/util.go
@@ -313,7 +313,10 @@ func (o OptID[T, P]) WriteTo(w io.Writer) (n int64, err error) {
 		o.ID++
 	}
 	n1, err := (*VarInt)(&o.ID).WriteTo(w)
-	if err != nil || o.ID > 0 {
+	if err != nil {
+		return n1, err
+	}
+	if o.Has {
 		return n1, err
 	}
 	n2, err := o.Val.WriteTo(w)
@@ -323,6 +326,7 @@ func (o OptID[T, P]) WriteTo(w io.Writer) (n int64, err error) {
 func (o *OptID[T, P]) ReadFrom(r io.Reader) (n int64, err error) {
 	n1, err := (*VarInt)(&o.ID).ReadFrom(r)
 	if o.ID > 0 {
+		o.Has = true
 		o.ID--
 		return n1, err
 	}