Commit 56dc6b2e authored by Alexey Botchkov's avatar Alexey Botchkov
Browse files

Bug#31616 div_precision_increment description looks wrong 

Item_func_div didn't calculate the precision of the result properly.
  The result of 5/0.0001 is 5000 so we have to add decimals of the divisor
  to the planned precision.

per-file comments:
  mysql-test/r/type_newdecimal.result
Bug#31616 div_precision_increment description looks wrong
    test result fixed

  mysql-test/t/type_newdecimal.test
Bug#31616 div_precision_increment description looks wrong
    test case

  sql/item_func.cc
Bug#31616 div_precision_increment description looks wrong
    precision must be increased with args[1]->decimals parameter
parent b82094a0

mysql-test/r/type_newdecimal.result

+15 −0
Original line number Diff line number Diff line
@@ -1524,4 +1524,19 @@ select (1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 * 
(1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 *

1.01500000 * 1.01500000 * 0.99500000)

0.812988073953673124592306939480

create table t1 as select 5.05 / 0.014;

Warnings:

Note	1265	Data truncated for column '5.05 / 0.014' at row 1

show warnings;

Level	Code	Message

Note	1265	Data truncated for column '5.05 / 0.014' at row 1

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `5.05 / 0.014` decimal(10,6) default NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

select * from t1;

5.05 / 0.014

360.714286

DROP TABLE t1;

End of 5.0 tests

mysql-test/t/type_newdecimal.test

+10 −0
Original line number Diff line number Diff line
@@ -1225,4 +1225,14 @@ DROP TABLE t1; 
select (1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 *

        1.01500000 * 1.01500000 * 0.99500000);



#

# Bug #31616 div_precision_increment description looks wrong 

#



create table t1 as select 5.05 / 0.014;

show warnings;

show create table t1;

select * from t1;

DROP TABLE t1;



--echo End of 5.0 tests

sql/item_func.cc

+4 −2
Original line number Diff line number Diff line
@@ -1316,8 +1316,10 @@ my_decimal *Item_func_div::decimal_op(my_decimal *decimal_value) 


void Item_func_div::result_precision()

{

  uint arg_prec= args[0]->decimal_precision() + prec_increment;

  uint precision=min(arg_prec, DECIMAL_MAX_PRECISION);

  uint precision=min(args[0]->decimal_precision() + 

                     args[1]->decimals + prec_increment,

                     DECIMAL_MAX_PRECISION);



  /* Integer operations keep unsigned_flag if one of arguments is unsigned */

  if (result_type() == INT_RESULT)

    unsigned_flag= args[0]->unsigned_flag | args[1]->unsigned_flag;