Commit 98a4d999 authored by ramil/ram@mysql.com/ramil.myoffice.izhnet.ru's avatar ramil/ram@mysql.com/ramil.myoffice.izhnet.ru
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Fix for bug #30782: Truncated UNSIGNED BIGINT columns only in SELECT w/ CASE, 

JOIN, and ORDER BY

Problem: improper maximum length calculation of the CASE function leads to 
decimal value truncation (storing/retrieving decimal field values).

Fix: accurately calculate maximum length/unsigned flag/decimals parameters 
of the CASE function.
parent 3d203e55

mysql-test/r/case.result

+19 −1
Original line number Diff line number Diff line 
drop table if exists t1;

drop table if exists t1, t2;

select CASE "b" when "a" then 1 when "b" then 2 END;

CASE "b" when "a" then 1 when "b" then 2 END

2
@@ -200,3 +200,21 @@ CEMPNUM EMPMUM1 EMPNUM2 
0.00	0	0.00

2.00	2	NULL

DROP TABLE t1,t2;

End of 4.1 tests

create table t1 (a int, b bigint unsigned);

create table t2 (c int);

insert into t1 (a, b) values (1,4572794622775114594), (2,18196094287899841997),

(3,11120436154190595086);

insert into t2 (c) values (1), (2), (3);

select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1 

join t2 on t1.a=t2.c order by d;

a	d

1	4572794622775114594

3	11120436154190595086

2	18196094287899841997

select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1 

join t2 on t1.a=t2.c where b=11120436154190595086 order by d;

a	d

3	11120436154190595086

drop table t1, t2;

End of 5.0 tests

mysql-test/t/case.test

+19 −2
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ 
#



--disable_warnings

drop table if exists t1;

drop table if exists t1, t2;

--enable_warnings



select CASE "b" when "a" then 1 when "b" then 2 END;
@@ -152,4 +152,21 @@ SELECT IFNULL(t2.EMPNUM,t1.EMPNUM) AS CEMPNUM, 
  FROM t1 LEFT JOIN t2 ON t1.EMPNUM=t2.EMPNUM;



DROP TABLE t1,t2;

# End of 4.1 tests
 


--echo End of 4.1 tests



#

# #30782: Truncated UNSIGNED BIGINT columns 

#

create table t1 (a int, b bigint unsigned);

create table t2 (c int);

insert into t1 (a, b) values (1,4572794622775114594), (2,18196094287899841997),

  (3,11120436154190595086);

insert into t2 (c) values (1), (2), (3);

select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1 

  join t2 on t1.a=t2.c order by d;

select t1.a, (case t1.a when 0 then 0 else t1.b end) d from t1 

  join t2 on t1.a=t2.c where b=11120436154190595086 order by d;

drop table t1, t2;



--echo End of 5.0 tests

sql/item_cmpfunc.cc

+30 −6
Original line number Diff line number Diff line
@@ -2530,6 +2530,23 @@ bool Item_func_case::fix_fields(THD *thd, Item **ref) 
}





void Item_func_case::agg_str_lengths(Item* arg)

{

  set_if_bigger(max_length, arg->max_length);

  set_if_bigger(decimals, arg->decimals);

  unsigned_flag= unsigned_flag && arg->unsigned_flag;

}





void Item_func_case::agg_num_lengths(Item *arg)

{

  uint len= my_decimal_length_to_precision(arg->max_length, arg->decimals,

                                           arg->unsigned_flag) - arg->decimals;

  set_if_bigger(max_length, len); 

  set_if_bigger(decimals, arg->decimals);

  unsigned_flag= unsigned_flag && arg->unsigned_flag; 

}





void Item_func_case::fix_length_and_dec()

{
@@ -2579,15 +2596,22 @@ void Item_func_case::fix_length_and_dec() 
  

  max_length=0;

  decimals=0;

  for (uint i=0 ; i < ncases ; i+=2)

  unsigned_flag= TRUE;

  if (cached_result_type == STRING_RESULT)

  {

    set_if_bigger(max_length,args[i+1]->max_length);

    set_if_bigger(decimals,args[i+1]->decimals);

  }

    for (uint i= 0; i < ncases; i+= 2)

      agg_str_lengths(args[i + 1]);

    if (else_expr_num != -1)

      agg_str_lengths(args[else_expr_num]);

  }

  else

  {

    set_if_bigger(max_length,args[else_expr_num]->max_length);

    set_if_bigger(decimals,args[else_expr_num]->decimals);

    for (uint i= 0; i < ncases; i+= 2)

      agg_num_lengths(args[i + 1]);

    if (else_expr_num != -1) 

      agg_num_lengths(args[else_expr_num]);

    max_length= my_decimal_precision_to_length(max_length + decimals, decimals,

                                               unsigned_flag);

  }

}

sql/item_cmpfunc.h

+2 −0
Original line number Diff line number Diff line
@@ -753,6 +753,8 @@ class Item_func_case :public Item_func 
  void print(String *str);

  Item *find_item(String *str);

  CHARSET_INFO *compare_collation() { return cmp_collation.collation; }

  void agg_str_lengths(Item *arg);

  void agg_num_lengths(Item *arg);

};