handle unsigned hour overflow (#10074)

Author: AndrewDi

expression/builtin_time.go

@@ -4682,6 +4682,10 @@ func (b *builtinMakeTimeSig) evalDuration(row chunk.Row) (types.Duration, bool,
 	var overflow bool
 	// MySQL TIME datatype: https://dev.mysql.com/doc/refman/5.7/en/time.html
 	// ranges from '-838:59:59.000000' to '838:59:59.000000'
+	if hour < 0 && mysql.HasUnsignedFlag(b.args[0].GetType().Flag) {
+		hour = 838
+		overflow = true
+	}
 	if hour < -838 {
 		hour = -838
 		overflow = true

expression/builtin_time_test.go

@@ -1939,6 +1939,23 @@ func (s *testEvaluatorSuite) TestMakeTime(c *C) {
 		}
 	}
 
+	// MAKETIME(CAST(-1 AS UNSIGNED),0,0);
+	tp1 := &types.FieldType{
+		Tp:      mysql.TypeLonglong,
+		Flag:    mysql.UnsignedFlag,
+		Charset: charset.CharsetBin,
+		Collate: charset.CollationBin,
+		Flen:    mysql.MaxIntWidth,
+	}
+	f := BuildCastFunction(s.ctx, &Constant{Value: types.NewDatum("-1"), RetType: types.NewFieldType(mysql.TypeString)}, tp1)
+	res, err := f.Eval(chunk.Row{})
+	c.Assert(err, IsNil)
+	f1, err := maketime.getFunction(s.ctx, s.datumsToConstants([]types.Datum{res, makeDatums(0)[0], makeDatums(0)[0]}))
+	c.Assert(err, IsNil)
+	got, err := evalBuiltinFunc(f1, chunk.Row{})
+	c.Assert(err, IsNil)
+	c.Assert(got.GetMysqlDuration().String(), Equals, "838:59:59")
+
 	tbl = []struct {
 		Args []interface{}
 		Want interface{}