Description:
------------
While trying to iterate SimpleXML's object property (array) with next(), memory exhausted.

Reproduce code:
---------------
$classes=new SimpleXMLElement("<?xml version=\"1.0\" encoding=\"utf-8\"?>
<classes>
	<class>
		<name>GenericClass</name>
		<path>somepath</path>
	</class>
	<class>
		<name>GenericClass2</name>
		<path>somepath2</path>
	</class>
	<class>
		<name>GenericClass3</name>
		<path>somepath3</path>
	</class>
</classes>
");
for ($classEntry=current($classes->class); $classEntry!==false; $classEntry=next($classes->class))
{
	print_r($classEntry);
	echo "\n";
}
echo 'Done smth.';

Expected result:
----------------
Expected: <class> elements of <classes> xml entry being printed.

Actual result:
--------------
Lot's of output and than "Allowed memory size of 134217728 bytes exhausted (tried to allocate 16 bytes)". Output may be ommited, but problem persists.