Commit 80aafdd3 authored by jimw@mysql.com's avatar jimw@mysql.com
Browse files

Bug #17043: Casting trimmed string to decimal loses precision 

  Results of string functions were being converted to decimals by first
  being converted to integers, resulting in a loss of precision.
parent 819b629c

mysql-test/r/func_str.result

+10 −0
Original line number Diff line number Diff line
@@ -1030,3 +1030,13 @@ c res 
y,abc	abc

y,abc	abc

drop table t1;

select cast(rtrim('  20.06 ') as decimal(19,2));

cast(rtrim('  20.06 ') as decimal(19,2))

20.06

select cast(ltrim('  20.06 ') as decimal(19,2));

cast(ltrim('  20.06 ') as decimal(19,2))

20.06

select cast(rtrim(ltrim('  20.06 ')) as decimal(19,2));

cast(rtrim(ltrim('  20.06 ')) as decimal(19,2))

20.06

End of 5.0 tests

mysql-test/t/func_str.test

+8 −1
Original line number Diff line number Diff line
@@ -684,4 +684,11 @@ insert into t1 values ('y,abc'),('y,abc'); 
select c, substring_index(lcase(c), @q:=',', -1) as res from t1;

drop table t1;



# End of 5.0 tests
 
#

# Bug #17043: Casting trimmed string to decimal loses precision

#

select cast(rtrim('  20.06 ') as decimal(19,2));

select cast(ltrim('  20.06 ') as decimal(19,2));

select cast(rtrim(ltrim('  20.06 ')) as decimal(19,2));



--echo End of 5.0 tests

sql/item_strfunc.cc

+14 −0
Original line number Diff line number Diff line
@@ -80,6 +80,20 @@ String *Item_str_func::check_well_formed_result(String *str) 
}





my_decimal *Item_str_func::val_decimal(my_decimal *decimal_value)

{

  DBUG_ASSERT(fixed == 1);

  char buff[64];

  String *res, tmp(buff,sizeof(buff), &my_charset_bin);

  res= val_str(&tmp);

  if (!res)

    return 0;

  (void)str2my_decimal(E_DEC_FATAL_ERROR, (char*) res->ptr(),

                       res->length(), res->charset(), decimal_value);

  return decimal_value;

}





double Item_str_func::val_real()

{

  DBUG_ASSERT(fixed == 1);

sql/item_strfunc.h

+1 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ class Item_str_func :public Item_func 
  Item_str_func(List<Item> &list) :Item_func(list) {decimals=NOT_FIXED_DEC; }

  longlong val_int();

  double val_real();

  my_decimal *val_decimal(my_decimal *);

  enum Item_result result_type () const { return STRING_RESULT; }

  void left_right_max_length();

  String *check_well_formed_result(String *str);