From 70760b8b1021e6d558ba7446c89c4776df3c200c Mon Sep 17 00:00:00 2001
From: time-and-fate <25057648+time-and-fate@users.noreply.github.com>
Date: Wed, 4 Jan 2023 14:57:55 +0800
Subject: [PATCH] add nil check

---
 executor/adapter.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/executor/adapter.go b/executor/adapter.go
index afbee5c989a8e..ed2c0566e0f81 100644
--- a/executor/adapter.go
+++ b/executor/adapter.go
@@ -1611,8 +1611,10 @@ func (a *ExecStmt) LogSlowQuery(txnTS uint64, succ bool, hasMoreResults bool) {
 }
 
 func extractMsgFromSQLWarn(SQLWarn *stmtctx.SQLWarn) string {
+	// Currently, this function is only used in extractMsgFromSQLWarn().
+	// extractMsgFromSQLWarn() can make sure SQLWarn is not nil so no need to add a nil check here.
 	warn := errors.Cause(SQLWarn.Err)
-	if x, ok := warn.(*terror.Error); ok {
+	if x, ok := warn.(*terror.Error); ok && x != nil {
 		sqlErr := terror.ToSQLError(x)
 		return sqlErr.Message
 	}