expression: fix infinity loop in timestampadd (#54916)

close #54908
pingcap · Jul 26, 2024 · a8d29c2 · a8d29c2
1 parent 0abf3ae
commit a8d29c2
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Showing 2 changed files with 45 additions and 7 deletions.
diff --git a/pkg/expression/builtin_time.go b/pkg/expression/builtin_time.go
@@ -6231,13 +6231,11 @@ func addUnitToTime(unit string, t time.Time, v float64) (time.Time, bool, error)
 		if !validAddMonth(v, t.Year(), int(t.Month())) {
 			return tb, true, nil
 		}
-		tb = t.AddDate(0, int(v), 0)
 
-		// For corner case: timestampadd(month,1,date '2024-01-31') = "2024-02-29", timestampadd(month,1,date '2024-01-30') = "2024-02-29"
-		// `tb.Month()` refers to the actual result, `t.Month()+v` refers to the expect result.
-		// Actual result may be greater than expect result, we need to judge and modify it.
-		for int(tb.Month())%12 != (int(t.Month())+int(v))%12 {
-			tb = tb.AddDate(0, 0, -1)
+		var err error
+		tb, err = types.AddDate(0, int64(v), 0, t)
+		if err != nil {
+			return tb, false, err
 		}
 	case "QUARTER":
 		if !validAddMonth(v*3, t.Year(), int(t.Month())) {

diff --git a/pkg/expression/builtin_time_test.go b/pkg/expression/builtin_time_test.go
@@ -2581,7 +2581,7 @@ func TestTimestampAdd(t *testing.T) {
 		{"MINUTE", 1.5, "1995-05-01 00:00:00.000000", "1995-05-01 00:02:00"},
 		{"MICROSECOND", -100, "1995-05-01 00:00:00.0001", "1995-05-01 00:00:00"},
 
-		// issue41052
+		// issue 41052
 		{"MONTH", 1, "2024-01-31", "2024-02-29 00:00:00"},
 		{"MONTH", 1, "2024-01-30", "2024-02-29 00:00:00"},
 		{"MONTH", 1, "2024-01-29", "2024-02-29 00:00:00"},
@@ -2592,6 +2592,46 @@ func TestTimestampAdd(t *testing.T) {
 		{"MONTH", 10, "2024-10-31", "2025-08-31 00:00:00"},
 		{"MONTH", 1, "2024-11-30", "2024-12-30 00:00:00"},
 		{"MONTH", 13, "2024-11-30", "2025-12-30 00:00:00"},
+
+		// issue 54908
+		{"MONTH", 0, "2024-09-01", "2024-09-01 00:00:00"},
+		{"MONTH", -10, "2024-09-01", "2023-11-01 00:00:00"},
+		{"MONTH", -2, "2024-04-28", "2024-02-28 00:00:00"},
+		{"MONTH", -2, "2024-04-29", "2024-02-29 00:00:00"},
+		{"MONTH", -2, "2024-04-30", "2024-02-29 00:00:00"},
+		{"MONTH", -1, "2024-03-28", "2024-02-28 00:00:00"},
+		{"MONTH", -1, "2024-03-29", "2024-02-29 00:00:00"},
+		{"MONTH", -1, "2024-03-30", "2024-02-29 00:00:00"},
+		{"MONTH", -1, "2024-03-31", "2024-02-29 00:00:00"},
+		{"MONTH", -1, "2024-03-25", "2024-02-25 00:00:00"},
+		{"MONTH", -12, "2024-03-31", "2023-03-31 00:00:00"},
+		{"MONTH", -13, "2024-03-31", "2023-02-28 00:00:00"},
+		{"MONTH", -14, "2024-03-31", "2023-01-31 00:00:00"},
+		{"MONTH", -24, "2024-03-31", "2022-03-31 00:00:00"},
+		{"MONTH", -25, "2024-03-31", "2022-02-28 00:00:00"},
+		{"MONTH", -26, "2024-03-31", "2022-01-31 00:00:00"},
+		{"MONTH", -1, "2024-02-25", "2024-01-25 00:00:00"},
+		{"MONTH", -11, "2025-02-28", "2024-03-28 00:00:00"},
+		{"MONTH", -12, "2025-02-28", "2024-02-28 00:00:00"},
+		{"MONTH", -13, "2025-02-28", "2024-01-28 00:00:00"},
+		{"MONTH", -11, "2024-02-29", "2023-03-29 00:00:00"},
+		{"MONTH", -12, "2024-02-29", "2023-02-28 00:00:00"},
+		{"MONTH", -13, "2024-02-29", "2023-01-29 00:00:00"},
+		{"MONTH", -11, "2023-02-28", "2022-03-28 00:00:00"},
+		{"MONTH", -12, "2023-02-28", "2022-02-28 00:00:00"},
+		{"MONTH", -13, "2023-02-28", "2022-01-28 00:00:00"},
+		{"MONTH", -2, "2023-02-28", "2022-12-28 00:00:00"},
+		{"MONTH", -14, "2023-02-28", "2021-12-28 00:00:00"},
+		{"MONTH", -3, "2023-03-20", "2022-12-20 00:00:00"},
+		{"MONTH", -3, "2023-03-31", "2022-12-31 00:00:00"},
+		{"MONTH", -15, "2023-03-20", "2021-12-20 00:00:00"},
+		{"MONTH", -15, "2023-03-31", "2021-12-31 00:00:00"},
+		{"MONTH", 12, "2020-02-29", "2021-02-28 00:00:00"},
+		{"MONTH", -12, "2020-02-29", "2019-02-28 00:00:00"},
+		{"MONTH", 10000*365 + 1, "2024-10-29", ""},
+		{"MONTH", -10000*365 - 1, "2024-10-29", ""},
+		{"MONTH", 3, "9999-10-29", ""},
+		{"MONTH", -3, "0001-01-29", ""},
 	}
 
 	fc := funcs[ast.TimestampAdd]