Bug #5877 server crashes when field in cursor is fetched into the variable with same name

• Submitted: 4 Oct 2004 12:47
• Modified: 4 Oct 2004 21:02
• Reporter: Levap Aretnyd
• Status: Can't repeat
• Category: MySQL Server
• Severity: S1 (Critical)
• Version: 5.0.1-alpha-nt
• OS: Windows (Windows 2003 web)
• CPU Architecture: Any

[4 Oct 2004 12:47] Levap Aretnyd

Description:
When the CURSOR in stored procedure with select and some filelds is fetched into a variable(s) that has a same name as the source field - server crashes.

How to repeat:
This slightly modifed example from manual crashes the server:
mysql> delimiter //
mysql> CREATE PROCEDURE `cdklubcz3`.`curdemo`()
    -> BEGIN
    ->   DECLARE done INT DEFAULT 0;
    ->   DECLARE jmeno VARCHAR(64) DEFAULT '';
    ->   DECLARE cur CURSOR FOR SELECT `jmeno` FROM `fjmena` LIMIT 10;
    ->   DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;
    ->   OPEN cur;
    ->   REPEAT
    ->     FETCH cur INTO jmeno;
    ->   UNTIL done END REPEAT;
    ->   CLOSE cur;
    -> END//
mysql> call curdemo()//
ERROR 2013 (HY000): Lost connection to MySQL server during query

When the local variable 'jmeno' is changed to something else, no problem occures. No problem occures also, when an another field (instead of `jmeno` from `fjmena`) is selected.

Definiton of `fjmena` table is as follows:
CREATE TABLE `fjmena` (
 `id` int(10) unsigned NOT NULL auto_increment,
 `jmeno` varchar(64) collate utf8_czech_ci NOT NULL default '',
 `jmenosort` varchar(64) collate utf8_czech_ci NOT NULL default '',
 PRIMARY KEY  (`id`),
 UNIQUE KEY `jmeno` (`jmeno`),
 KEY `jmenosort` (`jmenosort`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_czech_ci

[4 Oct 2004 21:02] MySQL Verification Team

Hi,

Thank you for the report, but I can't repeat it on the 5.0.2-debug-log:

mysql> delimiter //
mysql> CREATE PROCEDURE `curdemo`()
    -> BEGIN
    -> DECLARE done INT DEFAULT 0;
    -> DECLARE jmeno VARCHAR(64) DEFAULT '';
    -> DECLARE cur CURSOR FOR SELECT `jmeno` FROM `fjmena` LIMIT 10;
    -> DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;
    -> OPEN cur;
    -> REPEAT
    -> FETCH cur INTO jmeno;
    -> UNTIL done END REPEAT;
    -> CLOSE cur;
    -> END//
Query OK, 0 rows affected (0.00 sec)

mysql> call curdemo()//
Query OK, 0 rows affected (0.00 sec)

[4 Oct 2004 23:28] Levap Aretnyd

I've built lastest 5.0.2 snapshot and problem is gone. Sorry about not using lastest snapshot.