mariadb/mysql-test/r/func_if.result
Alexey Kopytov 04ae1aa954 Bug#55077: Assertion failed: width > 0 && to != ((void *)0),
file .\dtoa.c

The assertion failure was correct because the 'width' argument
of my_gcvt() has the signed integer type, whereas the unsigned
value UINT_MAX32 was being passed by the caller
(Field_double::val_str()) leading to a negative width in
my_gcvt().

The following chain of problems was found by further analysis:

1. The display width for a floating point number is calculated
in Field_double::val_str() as either field_length or the
maximum possible length of string representation of a floating
point number, whichever is greater. Since in the bug's test
case field_length is UINT_MAX32, we get the same value as the
display width. This does not make any sense because for numeric
values field_length only matters for ZEROFILL columns,
otherwise it does not make sense to allocate that much memory
just to print a number. Field_float::val_str() has a similar
problem.

2. Even if the above wasn't the case, we would still get a
crash on a slightly different test case when trying to allocate
UINT_MAX32 bytes with String::alloc() because the latter does
not handle such large input values correctly due to alignment
overflows.

3. Even when String::alloc() is fixed to return an error when
an alignment overflow occurs, there is still a problem because
almost no callers check its return value, and
Field_double::val_str() is not an exception (same for
Field_float::val_str()).

4. Even if all of the above wasn't the case, creating a
Field_double object with UINT_MAX32 as its field_length does
not make much sense either, since the .frm code limits it to
MAX_FIELD_CHARLENGTH (255) bytes. Such a beast can only be
created by create_tmp_field_from_item() from an Item with
REAL_RESULT as its result_type() and UINT_MAX32 as its
max_length.

5. For the bug's test case, the above condition (REAL_RESULT
Item with max_length = UINT_MAX32) was a result of
Item_func_if::fix_length_and_dec() "shortcutting" aggregation
of argument types when one of the arguments was a constant
NULL. In this case, the attributes of the aggregated type were
simply copied from the other, non-NULL argument, but max_length
was still calculated as per the general, non-shortcut case, by
choosing the greatest of argument's max_length, which is
obviously not correct.

The patch addresses all of the above problems, even though
fixing the assertion failure for the particular test case would
require only a subset of the above problems to be solved.


client/sql_string.cc:
  Return an error in case of uint32 overflow in alignment.
  Also assert there was no overflow to help find such conditions
  in debug builds, since almost no callers check the return value
  of String::alloc().
mysql-test/r/func_if.result:
  Add a test case for bug #55077.
mysql-test/t/func_if.test:
  Add a test case for bug #55077.
sql/field.cc:
  - Assert we don't operate with fields wider than 255 
  (MAX_FIELD_CHARLENGTH) bytes in both Field_float and  
  Field_double. 
  - Don't take field_length into account when calculating the 
  output buffer length.
  - Check the return value of String::alloc()
sql/item_cmpfunc.cc:
  When shortcutting type aggregation, don't take the NULL 
  argument's max_length into account.
sql/sql_string.cc:
  Return an error in case of uint32 overflow in alignment.
  Also assert there was no overflow to help find such conditions
  in debug builds, since almost no callers check the return value
  of String::alloc().
2010-08-25 19:57:53 +04:00

198 lines
5.4 KiB
Text

drop table if exists t1;
select IF(0,"ERROR","this"),IF(1,"is","ERROR"),IF(NULL,"ERROR","a"),IF(1,2,3)|0,IF(1,2.0,3.0)+0 ;
IF(0,"ERROR","this") IF(1,"is","ERROR") IF(NULL,"ERROR","a") IF(1,2,3)|0 IF(1,2.0,3.0)+0
this is a 2 2.0
CREATE TABLE t1 (st varchar(255) NOT NULL, u int(11) NOT NULL) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('a',1),('A',1),('aa',1),('AA',1),('a',1),('aaa',0),('BBB',0);
select if(1,st,st) s from t1 order by s;
s
a
A
a
aa
AA
aaa
BBB
select if(u=1,st,st) s from t1 order by s;
s
a
A
a
aa
AA
aaa
BBB
select if(u=1,binary st,st) s from t1 order by s;
s
A
AA
BBB
a
a
aa
aaa
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
s
A
AA
a
a
aa
aaa
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00 Using where; Using filesort
Warnings:
Note 1003 select if((`test`.`t1`.`u` = 1),`test`.`t1`.`st`,cast(`test`.`t1`.`st` as char charset binary)) AS `s` from `test`.`t1` where (`test`.`t1`.`st` like '%a%') order by if((`test`.`t1`.`u` = 1),`test`.`t1`.`st`,cast(`test`.`t1`.`st` as char charset binary))
select nullif(u, 1) from t1;
nullif(u, 1)
NULL
NULL
NULL
NULL
NULL
0
0
explain extended select nullif(u, 1) from t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 7 100.00
Warnings:
Note 1003 select nullif(`test`.`t1`.`u`,1) AS `nullif(u, 1)` from `test`.`t1`
drop table t1;
select nullif(1,'test');
nullif(1,'test')
1
Warnings:
Warning 1292 Truncated incorrect DOUBLE value: 'test'
select NULLIF(NULL,NULL), NULLIF(NULL,1), NULLIF(NULL,1.0), NULLIF(NULL,"test");
NULLIF(NULL,NULL) NULLIF(NULL,1) NULLIF(NULL,1.0) NULLIF(NULL,"test")
NULL NULL NULL NULL
select NULLIF(1,NULL), NULLIF(1.0, NULL), NULLIF("test", NULL);
NULLIF(1,NULL) NULLIF(1.0, NULL) NULLIF("test", NULL)
1 1.0 test
create table t1 (num double(12,2));
insert into t1 values (144.54);
select sum(if(num is null,0.00,num)) from t1;
sum(if(num is null,0.00,num))
144.54
drop table t1;
create table t1 (x int, y int);
insert into t1 values (0,6),(10,16),(20,26),(30,10),(40,46),(50,56);
select min(if(y -x > 5,y,NULL)), max(if(y - x > 5,y,NULL)) from t1;
min(if(y -x > 5,y,NULL)) max(if(y - x > 5,y,NULL))
6 56
drop table t1;
create table t1 (a int);
insert t1 values (1),(2);
select if(1>2,a,avg(a)) from t1;
if(1>2,a,avg(a))
1.5000
drop table t1;
SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
NULLIF(5,5) IS NULL NULLIF(5,5) IS NOT NULL
1 0
CREATE TABLE `t1` (
`id` int(11) NOT NULL ,
`date` int(10) default NULL,
`text` varchar(32) NOT NULL
);
INSERT INTO t1 VALUES (1,1110000000,'Day 1'),(2,1111000000,'Day 2'),(3,1112000000,'Day 3');
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord ASC;
id date_ord text
1 05-03-2005 Day 1
2 16-03-2005 Day 2
3 28-03-2005 Day 3
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord DESC;
id date_ord text
3 28-03-2005 Day 3
2 16-03-2005 Day 2
1 05-03-2005 Day 1
DROP TABLE t1;
CREATE TABLE t1 (a CHAR(10));
INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
SELECT a, NULLIF(a,'') FROM t1;
a NULLIF(a,'')
aaa aaa
NULL NULL
NULL
bbb bbb
SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
a NULLIF(a,'')
NULL NULL
NULL
DROP TABLE t1;
create table t1 (f1 int, f2 int);
insert into t1 values(1,1),(0,0);
select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
f1 f2 if(f1, 40.0, 5.00)
0 0 5.00
1 1 40.00
drop table t1;
select if(0, 18446744073709551610, 18446744073709551610);
if(0, 18446744073709551610, 18446744073709551610)
18446744073709551610
CREATE TABLE t1(a DECIMAL(10,3));
SELECT t1.a,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,0)))))))))))))))))))))))))))))) + 1
FROM t1;
a IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((R
DROP TABLE t1;
CREATE TABLE t1 (c LONGTEXT);
INSERT INTO t1 VALUES(1), (2), (3), (4), ('12345678901234567890');
SELECT * FROM (SELECT MAX(IF(1, CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IF(1, CAST(c AS UNSIGNED), 0))
12345678901234567890
SELECT * FROM (SELECT MAX(IFNULL(CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
MAX(IFNULL(CAST(c AS UNSIGNED), 0))
12345678901234567890
DROP TABLE t1;
End of 5.0 tests
#
# Bug#55077: Assertion failed: width > 0 && to != ((void *)0), file .\dtoa.c
#
CREATE TABLE t1 (a LONGBLOB, b DOUBLE);
INSERT INTO t1 VALUES (NULL, 0), (NULL, 1);
SELECT IF(b, (SELECT a FROM t1 LIMIT 1), b) c FROM t1 GROUP BY c;
c
NULL
0
DROP TABLE t1;