mariadb/mysql-test/t/func_if.test
Alexey Kopytov df389d0135 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.
2010-08-25 19:57:53 +04:00

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4.4 KiB
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#
# Init section
#
--disable_warnings
drop table if exists t1;
--enable_warnings
#
# Simple IF tests
#
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 ;
#
# Test of IF and case-sensitiveness
#
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;
select if(u=1,st,st) s from t1 order by s;
select if(u=1,binary st,st) s from t1 order by s;
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
#
# NULLIF test
#
select nullif(u, 1) from t1;
explain extended select nullif(u, 1) from t1;
drop table t1;
select nullif(1,'test');
#
# Bug 2629
#
select NULLIF(NULL,NULL), NULLIF(NULL,1), NULLIF(NULL,1.0), NULLIF(NULL,"test");
select NULLIF(1,NULL), NULLIF(1.0, NULL), NULLIF("test", NULL);
#
# Problem with IF()
#
create table t1 (num double(12,2));
insert into t1 values (144.54);
select sum(if(num is null,0.00,num)) from t1;
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;
drop table t1;
#
# BUG#3987
#
create table t1 (a int);
insert t1 values (1),(2);
select if(1>2,a,avg(a)) from t1;
drop table t1;
#
# Bug #5595 NULLIF() IS NULL returns false if NULLIF() returns NULL
#
SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
#
# Bug #9669 Ordering on IF function with FROM_UNIXTIME function fails
#
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;
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord DESC;
DROP TABLE t1;
#
# Test for bug #11142: evaluation of NULLIF when the first argument is NULL
#
CREATE TABLE t1 (a CHAR(10));
INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
SELECT a, NULLIF(a,'') FROM t1;
SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
DROP TABLE t1;
# End of 4.1 tests
#
# Bug #16272 IF function with decimal args can produce wrong result
#
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;
drop table t1;
#
# Bug#24532 (The return data type of IS TRUE is different from similar
# operations)
#
# IF(x, unsigned, unsigned) should be unsigned.
#
select if(0, 18446744073709551610, 18446744073709551610);
#
# Bug #37662: nested if() inside sum() is parsed in exponential time
#
CREATE TABLE t1(a DECIMAL(10,3));
# check : should be fast. more than few secs means failure.
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;
DROP TABLE t1;
#
# Bug #40761: Assert on sum func on IF(..., CAST(longtext AS UNSIGNED), signed)
# (was: LEFT JOIN on inline view crashes server)
#
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;
SELECT * FROM (SELECT MAX(IFNULL(CAST(c AS UNSIGNED), 0)) FROM t1) AS te;
DROP TABLE t1;
--echo End of 5.0 tests
--echo #
--echo # Bug#55077: Assertion failed: width > 0 && to != ((void *)0), file .\dtoa.c
--echo #
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;
DROP TABLE t1;