From 7b8f3763b24b1f448c2ab47507f82d8c301b1e49 Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Wed, 5 Jun 2024 16:37:37 +0900
Subject: [PATCH] fix some write error handling

---
 connection.go | 6 ++++--
 packets.go    | 2 ++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/connection.go b/connection.go
index a3dc09d2c..bf102cdf9 100644
--- a/connection.go
+++ b/connection.go
@@ -230,8 +230,10 @@ func (mc *mysqlConn) interpolateParams(query string, args []driver.Value) (strin
 	buf, err := mc.buf.takeCompleteBuffer()
 	if err != nil {
 		// can not take the buffer. Something must be wrong with the connection
-		mc.log(err)
-		return "", ErrInvalidConn
+		mc.cleanup()
+		// interpolateParams would be called before sending any query.
+		// So its safe to retry.
+		return "", driver.ErrBadConn
 	}
 	buf = buf[:0]
 	argPos := 0
diff --git a/packets.go b/packets.go
index cf3412ff6..033ef201e 100644
--- a/packets.go
+++ b/packets.go
@@ -117,6 +117,8 @@ func (mc *mysqlConn) writePacket(data []byte) error {
 		// Write packet
 		if mc.writeTimeout > 0 {
 			if err := mc.netConn.SetWriteDeadline(time.Now().Add(mc.writeTimeout)); err != nil {
+				mc.cleanup()
+				mc.log(err)
 				return err
 			}
 		}