Description:
------------
When "Iconv" and "Multibyte String" library classes operate on "SimpleXML" object a memory leak occures while processing "SimpleXML" string objects.
If "SimpleXML" string object is converted into an "ordinal" string before the control is being passed to routines from "Iconv" and "Multibyte String" libraries the memory leak doesn't occur. 
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System Linux 2.6.24-23-xen #1 SMP Mon Jan 26 03:09:12 UTC 2009 x86_64
Apache Version Apache/2.2.8 (Ubuntu)
PHP Version 5.2.4-2ubuntu5.5 with Suhosin-Patch
Server API Apache 2.0 Handler
Zend Engine v2.2.0

phpinfo():
http://79.170.152.11/phpinf.php

Reproduce code:
---------------
<?php
mb_Internal_Encoding('UTF-8');
Header('Content-Type: text/plain; charset=UTF-8');

$sxml = SimpleXML_Load_String('<main><el>some string</el></main>');

For($i = 0; $i < 1000; $i++)
{
	$tmp = IConv('UTF-8', 'UTF-8//TRANSLIT', $sxml->el);				# v1
	//$tmp = mb_StrToLower($sxml->el);									# v2
	//$tmp = IConv('UTF-8', 'UTF-8//TRANSLIT', (string)$sxml->el);		# v3
	//$tmp = mb_StrToLower((string)$sxml->el);							# v4
	UnSet($tmp);
	If(!($i % 100))
	{
		Echo $i . ' - ' . Number_Format(Memory_Get_Usage()) . "\n";
	}
}
?>

Expected result:
----------------
In example the first and the second variants demonstrate memory leak. The third and the fourth variants show that some extra conversions help to avoid the memory leak.

The results of the script execution.

v1:
0 - 103,352
100 - 185,816
200 - 268,232
300 - 350,632
400 - 433,032
500 - 515,432
600 - 646,984
700 - 729,384
800 - 811,800
900 - 894,200

v2:
0 - 103,080
100 - 185,584
200 - 268,016
300 - 350,416
400 - 432,816
500 - 515,216
600 - 646,800
700 - 729,200
800 - 811,600
900 - 894,000

v3:
0 - 103,400
100 - 103,456
200 - 103,456
300 - 103,456
400 - 103,456
500 - 103,456
600 - 103,456
700 - 103,456
800 - 103,456
900 - 103,456

v4:
0 - 103,128
100 - 103,184
200 - 103,184
300 - 103,184
400 - 103,184
500 - 103,184
600 - 103,184
700 - 103,184
800 - 103,184
900 - 103,184