evalengine: Fix week overflow (#14859)

Signed-off-by: Manan Gupta <[email protected]>

go/mysql/datetime/types.go

@@ -314,12 +314,16 @@ func (d Date) Week(mode int) int {
 		year, week := d.SundayWeek()
 		if year < d.Year() {
 			return 0
+		} else if year > d.Year() {
+			return 53
 		}
 		return week
 	case 1:
 		year, week := d.ISOWeek()
 		if year < d.Year() {
 			return 0
+		} else if year > d.Year() {
+			return 53
 		}
 		return week
 	case 2:
@@ -332,12 +336,16 @@ func (d Date) Week(mode int) int {
 		year, week := d.Sunday4DayWeek()
 		if year < d.Year() {
 			return 0
+		} else if year > d.Year() {
+			return 53
 		}
 		return week
 	case 5:
 		year, week := d.MondayWeek()
 		if year < d.Year() {
 			return 0
+		} else if year > d.Year() {
+			return 53
 		}
 		return week
 	case 6:

go/vt/vtgate/evalengine/compiler_test.go

@@ -476,6 +476,22 @@ func TestCompilerSingle(t *testing.T) {
 			expression: `case when null is null then 23 else null end`,
 			result:     `INT64(23)`,
 		},
+		{
+			expression: `week('2023-12-31', 4)`,
+			result:     `INT64(53)`,
+		},
+		{
+			expression: `week('2023-12-31', 2)`,
+			result:     `INT64(53)`,
+		},
+		{
+			expression: `week('2024-12-31', 1)`,
+			result:     `INT64(53)`,
+		},
+		{
+			expression: `week('2024-12-31', 5)`,
+			result:     `INT64(53)`,
+		},
 	}
 
 	for _, tc := range testCases {