From c763eb94f4d8b47a4806e8ecb1ec24ada973c5d1 Mon Sep 17 00:00:00 2001
From: zyguan <zhongyangguan@gmail.com>
Date: Fri, 16 Dec 2022 20:30:52 +0800
Subject: [PATCH] planner: fix pessimistic-auto-commit not working for point
 plans (#39993)

close pingcap/tidb#39928
---
 planner/core/point_get_plan.go                   |  3 ++-
 .../pessimistictest/pessimistic_test.go          | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/planner/core/point_get_plan.go b/planner/core/point_get_plan.go
index 4ff2a319c2d12..f0dff0a18a9f8 100644
--- a/planner/core/point_get_plan.go
+++ b/planner/core/point_get_plan.go
@@ -22,6 +22,7 @@ import (
 	"unsafe"
 
 	"github.com/pingcap/errors"
+	"github.com/pingcap/tidb/config"
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/kv"
@@ -608,7 +609,7 @@ func getLockWaitTime(ctx sessionctx.Context, lockInfo *ast.SelectLockInfo) (lock
 			// autocommit to 0. If autocommit is enabled, the rows matching the specification are not locked.
 			// See https://dev.mysql.com/doc/refman/5.7/en/innodb-locking-reads.html
 			sessVars := ctx.GetSessionVars()
-			if !sessVars.IsAutocommit() || sessVars.InTxn() {
+			if !sessVars.IsAutocommit() || sessVars.InTxn() || config.GetGlobalConfig().PessimisticTxn.PessimisticAutoCommit.Load() {
 				lock = true
 				waitTime = sessVars.LockWaitTimeout
 				if lockInfo.LockType == ast.SelectLockForUpdateWaitN {
diff --git a/tests/realtikvtest/pessimistictest/pessimistic_test.go b/tests/realtikvtest/pessimistictest/pessimistic_test.go
index 0383272f8b1ed..ae7545e0e91f6 100644
--- a/tests/realtikvtest/pessimistictest/pessimistic_test.go
+++ b/tests/realtikvtest/pessimistictest/pessimistic_test.go
@@ -3074,13 +3074,21 @@ func TestPessimisticAutoCommitTxn(t *testing.T) {
 
 	tk.MustExec("set tidb_txn_mode = 'pessimistic'")
 	tk.MustExec("drop table if exists t")
-	tk.MustExec("create table t (i int)")
+	tk.MustExec("create table t (i int primary key)")
 	tk.MustExec("insert into t values (1)")
 	tk.MustExec("set autocommit = on")
 
 	rows := tk.MustQuery("explain update t set i = -i").Rows()
 	explain := fmt.Sprintf("%v", rows[1])
 	require.NotRegexp(t, ".*SelectLock.*", explain)
+	rows = tk.MustQuery("explain update t set i = -i where i = -1").Rows()
+	explain = fmt.Sprintf("%v", rows[1])
+	require.Regexp(t, ".*handle:-1.*", explain)
+	require.NotRegexp(t, ".*handle:-1, lock.*", explain)
+	rows = tk.MustQuery("explain update t set i = -i where i in (-1, 1)").Rows()
+	explain = fmt.Sprintf("%v", rows[1])
+	require.Regexp(t, ".*handle:\\[-1 1\\].*", explain)
+	require.NotRegexp(t, ".*handle:\\[-1 1\\].*, lock.*", explain)
 
 	originCfg := config.GetGlobalConfig()
 	defer config.StoreGlobalConfig(originCfg)
@@ -3091,6 +3099,12 @@ func TestPessimisticAutoCommitTxn(t *testing.T) {
 	rows = tk.MustQuery("explain update t set i = -i").Rows()
 	explain = fmt.Sprintf("%v", rows[1])
 	require.Regexp(t, ".*SelectLock.*", explain)
+	rows = tk.MustQuery("explain update t set i = -i where i = -1").Rows()
+	explain = fmt.Sprintf("%v", rows[1])
+	require.Regexp(t, ".*handle:-1, lock.*", explain)
+	rows = tk.MustQuery("explain update t set i = -i where i in (-1, 1)").Rows()
+	explain = fmt.Sprintf("%v", rows[1])
+	require.Regexp(t, ".*handle:\\[-1 1\\].*, lock.*", explain)
 }
 
 func TestPessimisticLockOnPartition(t *testing.T) {