[fix][libexpr] Fix float/double cast to decimal issue.

Author: nokiaMS

src/expr/calc/casting.cc

@@ -188,14 +188,12 @@ DecimalP Cast(bool v) {
 
 template <>
 DecimalP Cast(float v) {
-  String const f2s = CastFloat(v);
-  return DecimalP(*f2s.GetPtr());
+  return DecimalP(v);
 }
 
 template <>
 DecimalP Cast(double v) {
-  String const d2s = CastDouble(v);
-  return DecimalP(*d2s.GetPtr());
+  return DecimalP(v);
 }
 
 template <>

test/types/test_type_decimal.cc

@@ -385,6 +385,10 @@ TEST(TestTypeDecimal, DecimalTest) {
   //Test -dec 0.
   ASSERT_EQ((-Decimal(std::string("0"))).toLong(), 0);
 
+  //Test decimal to double
+  DecimalP dp = DecimalP((double)32.91);
+  ASSERT_EQ(dp.GetPtr()->toString(), std::string("32.9099999999999965894"));
+
   //DecimalP p = DecimalP((float)12.34);
   ASSERT_EQ(DecimalP((long)12).GetPtr()->toString(10,4), std::string("12.0000"));
   ASSERT_EQ(DecimalP((float)12.34).GetPtr()->toString(10,4), std::string("12.3400"));