Commit 06736ab4 authored by unknown's avatar unknown

Fix for BUG#10095: {wrong query results because of incorrect constant propagation}

The problem: base_list::remove didn't modify base_list::last when removing 
the last list element.
The fix: If we remove the last element, find the element before it (by walking
from the beginning of the list) and set base_list::last accordingly.

The list gets corrupted in both 4.0 and 4.1. There are no visible problems in 
current 4.1 because current 4.1 doesn't call where_cond->fix_fields() after 
constant propagation step.


mysql-test/r/select.result:
  Testcase for BUG#10095
mysql-test/t/select.test:
  Testcase for BUG#10095
sql/sql_list.h:
  Fix for BUG#10095: {wrong query results because of incorrect constant propagation} 
  The problem: base_list::remove didn't modify base_list::last when removing 
  the last list element.
  The fix: If we remove the last element, find the element before it (by walking
  from the beginning of the list) and set base_list::last accordingly.
parent ce41e0de
......@@ -2377,3 +2377,57 @@ table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 5
t2 ref a a 23 t1.a 5
DROP TABLE t1, t2;
CREATE TABLE t1 (
kunde_intern_id int(10) unsigned NOT NULL default '0',
kunde_id int(10) unsigned NOT NULL default '0',
FK_firma_id int(10) unsigned NOT NULL default '0',
aktuell enum('Ja','Nein') NOT NULL default 'Ja',
vorname varchar(128) NOT NULL default '',
nachname varchar(128) NOT NULL default '',
geloescht enum('Ja','Nein') NOT NULL default 'Nein',
firma varchar(128) NOT NULL default ''
);
INSERT INTO t1 VALUES
(3964,3051,1,'Ja','Vorname1','1Nachname','Nein','Print Schau XXXX'),
(3965,3051111,1,'Ja','Vorname1111','1111Nachname','Nein','Print Schau XXXX');
SELECT kunde_id ,FK_firma_id ,aktuell, vorname, nachname, geloescht FROM t1
WHERE
(
(
( '' != '' AND firma LIKE CONCAT('%', '', '%'))
OR
(vorname LIKE CONCAT('%', 'Vorname1', '%') AND
nachname LIKE CONCAT('%', '1Nachname', '%') AND
'Vorname1' != '' AND 'xxxx' != '')
)
AND
(
aktuell = 'Ja' AND geloescht = 'Nein' AND FK_firma_id = 2
)
)
;
kunde_id FK_firma_id aktuell vorname nachname geloescht
SELECT kunde_id ,FK_firma_id ,aktuell, vorname, nachname,
geloescht FROM t1
WHERE
(
(
aktuell = 'Ja' AND geloescht = 'Nein' AND FK_firma_id = 2
)
AND
(
( '' != '' AND firma LIKE CONCAT('%', '', '%') )
OR
( vorname LIKE CONCAT('%', 'Vorname1', '%') AND
nachname LIKE CONCAT('%', '1Nachname', '%') AND 'Vorname1' != '' AND
'xxxx' != '')
)
)
;
kunde_id FK_firma_id aktuell vorname nachname geloescht
SELECT COUNT(*) FROM t1 WHERE
( 0 OR (vorname LIKE '%Vorname1%' AND nachname LIKE '%1Nachname%' AND 1))
AND FK_firma_id = 2;
COUNT(*)
0
drop table t1;
......@@ -1924,3 +1924,62 @@ EXPLAIN SELECT * FROM t1 LEFT JOIN t2 USE INDEX (a) ON t1.a=t2.a;
EXPLAIN SELECT * FROM t1 LEFT JOIN t2 FORCE INDEX (a) ON t1.a=t2.a;
DROP TABLE t1, t2;
# Test for BUG#10095
CREATE TABLE t1 (
kunde_intern_id int(10) unsigned NOT NULL default '0',
kunde_id int(10) unsigned NOT NULL default '0',
FK_firma_id int(10) unsigned NOT NULL default '0',
aktuell enum('Ja','Nein') NOT NULL default 'Ja',
vorname varchar(128) NOT NULL default '',
nachname varchar(128) NOT NULL default '',
geloescht enum('Ja','Nein') NOT NULL default 'Nein',
firma varchar(128) NOT NULL default ''
);
INSERT INTO t1 VALUES
(3964,3051,1,'Ja','Vorname1','1Nachname','Nein','Print Schau XXXX'),
(3965,3051111,1,'Ja','Vorname1111','1111Nachname','Nein','Print Schau XXXX');
SELECT kunde_id ,FK_firma_id ,aktuell, vorname, nachname, geloescht FROM t1
WHERE
(
(
( '' != '' AND firma LIKE CONCAT('%', '', '%'))
OR
(vorname LIKE CONCAT('%', 'Vorname1', '%') AND
nachname LIKE CONCAT('%', '1Nachname', '%') AND
'Vorname1' != '' AND 'xxxx' != '')
)
AND
(
aktuell = 'Ja' AND geloescht = 'Nein' AND FK_firma_id = 2
)
)
;
SELECT kunde_id ,FK_firma_id ,aktuell, vorname, nachname,
geloescht FROM t1
WHERE
(
(
aktuell = 'Ja' AND geloescht = 'Nein' AND FK_firma_id = 2
)
AND
(
( '' != '' AND firma LIKE CONCAT('%', '', '%') )
OR
( vorname LIKE CONCAT('%', 'Vorname1', '%') AND
nachname LIKE CONCAT('%', '1Nachname', '%') AND 'Vorname1' != '' AND
'xxxx' != '')
)
)
;
SELECT COUNT(*) FROM t1 WHERE
( 0 OR (vorname LIKE '%Vorname1%' AND nachname LIKE '%1Nachname%' AND 1))
AND FK_firma_id = 2;
drop table t1;
......@@ -110,10 +110,32 @@ public:
void remove(list_node **prev)
{
list_node *node=(*prev)->next;
if (&(*prev)->next == last)
{
/*
We're removing the last element from the list. Adjust "last" to point
to the previous element.
The other way to fix this would be to change this function to
remove_next() and have base_list_iterator save ptr to previous node
(one extra assignment in iterator++) but as the remove() of the last
element isn't a common operation it's faster to just walk through the
list from the beginning here.
*/
list_node *cur= first;
if (cur == *prev)
{
last= &first;
}
else
{
while (cur->next != *prev)
cur= cur->next;
last= &(cur->next);
}
}
delete *prev;
*prev=node;
if (!--elements)
last= &first;
elements--;
}
inline void *pop(void)
{
......@@ -130,6 +152,54 @@ public:
inline list_node *last_ref() { return &end_of_list; }
friend class base_list_iterator;
#ifdef LIST_EXTRA_DEBUG
/*
Check list invariants and print results into trace. Invariants are:
- (*last) points to end_of_list
- There are no NULLs in the list.
- base_list::elements is the number of elements in the list.
SYNOPSIS
check_list()
name Name to print to trace file
RETURN
1 The list is Ok.
0 List invariants are not met.
*/
bool check_list(const char *name)
{
base_list *list= this;
list_node *node= first;
uint cnt= 0;
while (node->next != &end_of_list)
{
if (!node->info)
{
DBUG_PRINT("list_invariants",("%s: error: NULL element in the list",
name));
return FALSE;
}
node= node->next;
cnt++;
}
if (last != &(node->next))
{
DBUG_PRINT("list_invariants", ("%s: error: wrong last pointer", name));
return FALSE;
}
if (cnt+1 != elements)
{
DBUG_PRINT("list_invariants", ("%s: error: wrong element count", name));
return FALSE;
}
DBUG_PRINT("list_invariants", ("%s: list is ok", name));
return TRUE;
}
#endif // LIST_EXTRA_DEBUG
protected:
void after(void *info,list_node *node)
{
......
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