Description:
------------
In the below example, the foreach in the global scope doesn't use any extra memory, but the memory usage almost doubles from doing the foreach inside test_function.  Is there a reason that so much extra memory is used?  I was expecting it not to use any extra memory as the foreach is done using a reference for each array element.


Test script:
---------------
<?php
function test_function($rows)
{
	echo memory_get_usage(true)."\n";

	foreach ($rows as &$row)
	{

	}

	unset($row);

	echo memory_get_usage(true)."\n";
};

$rows = range(1, 10000);

echo memory_get_usage(true)."\n";

foreach ($rows as &$row)
{

}

unset($row);

echo memory_get_usage(true)."\n";

test_function($rows);


Expected result:
----------------
1835008
1835008
1835008
1835008


Actual result:
--------------
1835008
1835008
1835008
3407872