From b0c9d19c5ebe2849a3cf9820cfcbdb3905ad239c Mon Sep 17 00:00:00 2001
From: wjHuang <huangwenjun1997@gmail.com>
Date: Wed, 1 Sep 2021 19:36:13 +0800
Subject: [PATCH] expression: remove useless code (#27700)

---
 expression/builtin_arithmetic.go      | 11 -----------
 expression/builtin_arithmetic_test.go | 25 -------------------------
 2 files changed, 36 deletions(-)

diff --git a/expression/builtin_arithmetic.go b/expression/builtin_arithmetic.go
index 06a7f07d0ce99..9711f585ca0f4 100644
--- a/expression/builtin_arithmetic.go
+++ b/expression/builtin_arithmetic.go
@@ -86,13 +86,6 @@ func numericContextResultType(ft *types.FieldType) types.EvalType {
 	return evalTp4Ft
 }
 
-// setFlenDecimal4Int is called to set proper `Flen` and `Decimal` of return
-// type according to the two input parameter's types.
-func setFlenDecimal4Int(retTp, a, b *types.FieldType) {
-	retTp.Decimal = 0
-	retTp.Flen = mysql.MaxIntWidth
-}
-
 // setFlenDecimal4RealOrDecimal is called to set proper `Flen` and `Decimal` of return
 // type according to the two input parameter's types.
 func setFlenDecimal4RealOrDecimal(retTp, a, b *types.FieldType, isReal bool, isMultiply bool) {
@@ -190,7 +183,6 @@ func (c *arithmeticPlusFunctionClass) getFunction(ctx sessionctx.Context, args [
 		if mysql.HasUnsignedFlag(args[0].GetType().Flag) || mysql.HasUnsignedFlag(args[1].GetType().Flag) {
 			bf.tp.Flag |= mysql.UnsignedFlag
 		}
-		setFlenDecimal4Int(bf.tp, args[0].GetType(), args[1].GetType())
 		sig := &builtinArithmeticPlusIntSig{bf}
 		sig.setPbCode(tipb.ScalarFuncSig_PlusInt)
 		return sig, nil
@@ -338,7 +330,6 @@ func (c *arithmeticMinusFunctionClass) getFunction(ctx sessionctx.Context, args
 		if err != nil {
 			return nil, err
 		}
-		setFlenDecimal4Int(bf.tp, args[0].GetType(), args[1].GetType())
 		if (mysql.HasUnsignedFlag(args[0].GetType().Flag) || mysql.HasUnsignedFlag(args[1].GetType().Flag)) && !ctx.GetSessionVars().SQLMode.HasNoUnsignedSubtractionMode() {
 			bf.tp.Flag |= mysql.UnsignedFlag
 		}
@@ -523,12 +514,10 @@ func (c *arithmeticMultiplyFunctionClass) getFunction(ctx sessionctx.Context, ar
 		}
 		if mysql.HasUnsignedFlag(lhsTp.Flag) || mysql.HasUnsignedFlag(rhsTp.Flag) {
 			bf.tp.Flag |= mysql.UnsignedFlag
-			setFlenDecimal4Int(bf.tp, args[0].GetType(), args[1].GetType())
 			sig := &builtinArithmeticMultiplyIntUnsignedSig{bf}
 			sig.setPbCode(tipb.ScalarFuncSig_MultiplyIntUnsigned)
 			return sig, nil
 		}
-		setFlenDecimal4Int(bf.tp, args[0].GetType(), args[1].GetType())
 		sig := &builtinArithmeticMultiplyIntSig{bf}
 		sig.setPbCode(tipb.ScalarFuncSig_MultiplyInt)
 		return sig, nil
diff --git a/expression/builtin_arithmetic_test.go b/expression/builtin_arithmetic_test.go
index e9c7ab959bce8..af0e0d27970d1 100644
--- a/expression/builtin_arithmetic_test.go
+++ b/expression/builtin_arithmetic_test.go
@@ -91,31 +91,6 @@ func (s *testEvaluatorSuite) TestSetFlenDecimal4RealOrDecimal(c *C) {
 	c.Assert(ret.Flen, Equals, types.UnspecifiedLength)
 }
 
-func (s *testEvaluatorSuite) TestSetFlenDecimal4Int(c *C) {
-	ret := &types.FieldType{}
-	a := &types.FieldType{
-		Decimal: 1,
-		Flen:    3,
-	}
-	b := &types.FieldType{
-		Decimal: 0,
-		Flen:    2,
-	}
-	setFlenDecimal4Int(ret, a, b)
-	c.Assert(ret.Decimal, Equals, 0)
-	c.Assert(ret.Flen, Equals, mysql.MaxIntWidth)
-
-	b.Flen = mysql.MaxIntWidth + 1
-	setFlenDecimal4Int(ret, a, b)
-	c.Assert(ret.Decimal, Equals, 0)
-	c.Assert(ret.Flen, Equals, mysql.MaxIntWidth)
-
-	b.Flen = types.UnspecifiedLength
-	setFlenDecimal4Int(ret, a, b)
-	c.Assert(ret.Decimal, Equals, 0)
-	c.Assert(ret.Flen, Equals, mysql.MaxIntWidth)
-}
-
 func (s *testEvaluatorSuite) TestArithmeticPlus(c *C) {
 	// case: 1
 	args := []interface{}{int64(12), int64(1)}