From b7e32bcf9994f0fc916c59e6d5f573a39127d105 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Mon, 20 May 2024 17:47:46 +0800
Subject: [PATCH] planner: fix the wrong result caused by `year_col cmp
 out-of-range-uint` (#53395)

close pingcap/tidb#50235
---
 pkg/planner/core/integration_test.go | 9 +++++++++
 pkg/util/ranger/points.go            | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/pkg/planner/core/integration_test.go b/pkg/planner/core/integration_test.go
index 5c06840c2d4b0..01d8ccd2511b9 100644
--- a/pkg/planner/core/integration_test.go
+++ b/pkg/planner/core/integration_test.go
@@ -1218,6 +1218,15 @@ func TestRepeatPushDownToTiFlash(t *testing.T) {
 	tk.MustQuery("explain select repeat(a,b) from t;").CheckAt([]int{0, 2, 4}, rows)
 }
 
+func TestIssue50235(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table tt (c year(4) NOT NULL DEFAULT '2016', primary key(c));`)
+	tk.MustExec(`insert into tt values (2016);`)
+	tk.MustQuery(`select * from tt where c < 16212511333665770580`).Check(testkit.Rows("2016"))
+}
+
 func TestIssue36194(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
diff --git a/pkg/util/ranger/points.go b/pkg/util/ranger/points.go
index 7f015e3f0385e..f01bfa89d97cf 100644
--- a/pkg/util/ranger/points.go
+++ b/pkg/util/ranger/points.go
@@ -330,6 +330,12 @@ func (r *builder) buildFromBinOp(
 		}
 		// If nulleq with null value, values.ToInt64 will return err
 		if col.GetType().GetType() == mysql.TypeYear && !value.IsNull() {
+			// Convert the out-of-range uint number to int and then let the following logic can handle it correctly.
+			// Since the max value of year is 2155, `col op MaxUint` should have the same result with `col op MaxInt`.
+			if value.Kind() == types.KindUint64 && value.GetUint64() > math.MaxInt64 {
+				value.SetInt64(math.MaxInt64)
+			}
+
 			// If the original value is adjusted, we need to change the condition.
 			// For example, col < 2156. Since the max year is 2155, 2156 is changed to 2155.
 			// col < 2155 is wrong. It should be col <= 2155.