From 9a2140519af4fa77998ad2298a44637de0932053 Mon Sep 17 00:00:00 2001
From: Kenjiro Nakayama <nakayamakenjiro@gmail.com>
Date: Wed, 8 Nov 2023 21:00:20 +0900
Subject: [PATCH] Do not handle network error in SetCloseHandler()

The 666c197 added an error handling in `SetCloseHandler()` and peer
stops getting `CloseError` when network issue like `write: broken
pipe` happens because the close handle returns the error.

Hence this patch changes to skip network error handling.
---
 conn.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/conn.go b/conn.go
index a19e5c4..a992825 100644
--- a/conn.go
+++ b/conn.go
@@ -1159,8 +1159,12 @@ func (c *Conn) SetCloseHandler(h func(code int, text string) error) {
 		h = func(code int, text string) error {
 			message := FormatCloseMessage(code, "")
 			err := c.WriteControl(CloseMessage, message, time.Now().Add(writeWait))
-			if err != nil && err != ErrCloseSent {
-				return err
+			if err != nil {
+				if _, ok := err.(net.Error); ok {
+					return nil
+				} else if err != ErrCloseSent {
+					return err
+				}
 			}
 			return nil
 		}