From d6f24e13d73d0db78ec19842ac2b90dfb7eec287 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=99=BD=E6=97=A5=E6=A2=A6=E4=B8=BB=E4=B9=89?=
 <me@cherr.cc>
Date: Fri, 22 May 2026 04:11:40 +0800
Subject: [PATCH] Merge commit from fork

Signed-off-by: Cherrling <me@cherr.cc>
---
 core/internal/frag/frag.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/internal/frag/frag.go b/core/internal/frag/frag.go
index 237ba06..de21f90 100644
--- a/core/internal/frag/frag.go
+++ b/core/internal/frag/frag.go
@@ -10,6 +10,9 @@ func FragUDPMessage(m *protocol.UDPMessage, maxSize int) []protocol.UDPMessage {
 	}
 	fullPayload := m.Data
 	maxPayloadSize := maxSize - m.HeaderSize()
+	if maxPayloadSize <= 0 {
+		return nil
+	}
 	off := 0
 	fragID := uint8(0)
 	fragCount := uint8((len(fullPayload) + maxPayloadSize - 1) / maxPayloadSize) // round up