Commit ac82a2d5 authored by unknown's avatar unknown
Browse files

Setting a variable to CAST(NULL as X) set the result type of the variable to X. (Bug #6598) 


mysql-test/r/bigint.result:
  Test to show show that the parser threats big longlong values as unsigned
mysql-test/r/user_var.result:
  Test of CAST(NULL as SIGNED/UNSIGNED)
mysql-test/t/bigint.test:
  Test to show show that the parser threats big longlong values as unsigned
mysql-test/t/user_var.test:
  Test of CAST(NULL as SIGNED/UNSIGNED)
sql/item_func.cc:
  Setting a variable to CAST(NULL as X) set the result type of the variable to X. (Bug #6598)
  Setting a variable to NULL doesn't change the old result type.
sql/item_func.h:
  Detect setting a variable to NULL
sql/unireg.cc:
  Safety fix
parent 8b5b3652

mysql-test/r/bigint.result

+17 −0
Original line number Diff line number Diff line
@@ -128,3 +128,20 @@ t2.value64=t1.value64; 
value64	value32	value64	value32

9223372036854775807	2	9223372036854775807	4

drop table t1, t2;

create table t1 select 1 as 'a';

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `a` bigint(1) NOT NULL default '0'

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

create table t1 select 9223372036854775809 as 'a';

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `a` bigint(19) unsigned NOT NULL default '0'

) ENGINE=MyISAM DEFAULT CHARSET=latin1

select * from t1;

a

9223372036854775809

drop table t1;

mysql-test/r/user_var.result

+41 −0
Original line number Diff line number Diff line
@@ -182,3 +182,44 @@ coercibility(@v1) coercibility(@v2) coercibility(@v3) coercibility(@v4) 
set session @honk=99;

set one_shot @honk=99;

ERROR HY000: The 'SET ONE_SHOT' syntax is reserved for purposes internal to the MySQL server

set @first_var= NULL;

create table t1 select @first_var;

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `@first_var` longblob

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

set @first_var= cast(NULL as signed integer);

create table t1 select @first_var;

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `@first_var` bigint(20) default NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

set @first_var= NULL;

create table t1 select @first_var;

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `@first_var` bigint(20) default NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

set @first_var= concat(NULL);

create table t1 select @first_var;

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `@first_var` longblob

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

set @first_var=1;

set @first_var= cast(NULL as CHAR);

create table t1 select @first_var;

show create table t1;

Table	Create Table

t1	CREATE TABLE `t1` (

  `@first_var` longtext

) ENGINE=MyISAM DEFAULT CHARSET=latin1

drop table t1;

mysql-test/t/bigint.test

+10 −0
Original line number Diff line number Diff line
@@ -104,3 +104,13 @@ t2.value64=t1.value64; 


drop table t1, t2;



#

# Test of CREATE ... SELECT and unsigned integers

#

create table t1 select 1 as 'a';

show create table t1;

drop table t1;

create table t1 select 9223372036854775809 as 'a';

show create table t1;

select * from t1;

drop table t1;

mysql-test/t/user_var.test

+26 −0
Original line number Diff line number Diff line
@@ -119,3 +119,29 @@ select coercibility(@v1),coercibility(@v2),coercibility(@v3),coercibility(@v4); 
set session @honk=99;

--error 1382

set one_shot @honk=99;



#

# Bug #6598: problem with cast(NULL as signed integer);

#



set @first_var= NULL;

create table t1 select @first_var;

show create table t1;

drop table t1;

set @first_var= cast(NULL as signed integer);

create table t1 select @first_var;

show create table t1;

drop table t1;

set @first_var= NULL;

create table t1 select @first_var;

show create table t1;

drop table t1;

set @first_var= concat(NULL);

create table t1 select @first_var;

show create table t1;

drop table t1;

set @first_var=1;

set @first_var= cast(NULL as CHAR);

create table t1 select @first_var;

show create table t1;

drop table t1;

sql/item_func.cc

+11 −4
Original line number Diff line number Diff line
@@ -3271,7 +3271,8 @@ bool Item_func_set_user_var::fix_fields(THD *thd, TABLE_LIST *tables, 
    from the argument if the argument is NULL

    and the variable has previously been initialized.

  */

  if (!entry->collation.collation || !args[0]->null_value)

  null_item= (args[0]->type() == NULL_ITEM);

  if (!entry->collation.collation || !null_item)

    entry->collation.set(args[0]->collation.collation, DERIVATION_IMPLICIT);

  collation.set(entry->collation.collation, DERIVATION_IMPLICIT);

  cached_result_type= args[0]->result_type();
@@ -3355,9 +3356,9 @@ update_hash(user_var_entry *entry, bool set_null, void *ptr, uint length, 
    if (type == DECIMAL_RESULT)

      ((my_decimal*)entry->value)->fix_buffer_pointer();

    entry->length= length;

    entry->type=type;

    entry->collation.set(cs, dv);

  }

  entry->type=type;

  return 0;

}
@@ -3366,6 +3367,12 @@ bool 
Item_func_set_user_var::update_hash(void *ptr, uint length, Item_result type,

                                    CHARSET_INFO *cs, Derivation dv)

{

  /*

    If we set a variable explicitely to NULL then keep the old

    result type of the variable

  */

  if ((null_value= args[0]->null_value) && null_item)

    type= entry->type;                          // Don't change type of item

  if (::update_hash(entry, (null_value= args[0]->null_value),

                    ptr, length, type, cs, dv))

  {