Description:
------------
Hi

We are getting an odd result when submitting a query to a mysql server (4.1.10), we get a different result when performing the query through php (an incorrect result) as opposed to straight in to a mysql client.

It seems to have performed the sub-query twice, so the variable @j has been incremented twice.

A simplified version of our code is shown below and reproduces the problem, I have also included a sample table.  I have seen it on both windows and linux.

Reproduce code:
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mysql_query("SET @j=0;");
$sql = "select offset from (select @j:=@j+1 as offset, if(element_id=2,1,0) as result from element) as t1 WHERE t1.result=1 ";
$result = mysql_query($sql);
$row = mysql_fetch_row($result);
echo $row[0];


/******************DATABASE****************/

CREATE TABLE `element` (
  `element_id` int(10) unsigned NOT NULL auto_increment,
  `element_type_id` int(10) unsigned NOT NULL default '0',
  `lock_level` int(10) unsigned NOT NULL default '0',
  PRIMARY KEY  (`element_id`),
  KEY `new_index` (`element_type_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

/*Data for the table `element` */

insert  into `element`(`element_id`,`element_type_id`,`lock_level`) values (1,1,0);
insert  into `element`(`element_id`,`element_type_id`,`lock_level`) values (2,10,0);
insert  into `element`(`element_id`,`element_type_id`,`lock_level`) values (3,2,0);
insert  into `element`(`element_id`,`element_type_id`,`lock_level`) values (4,10,1);
insert  into `element`(`element_id`,`element_type_id`,`lock_level`) values (5,2,0);


Expected result:
----------------
2

Actual result:
--------------
7