Description:
------------
array_merge_recursive seems to modify the arrays which are passed, 
except for the first one.
it turns all first-level non-array elements, into arrays.
the code will explain it better :)

Reproduce code:
---------------
$array1 = array(
	'friends' => 5,
	'children' => array(
		'dogs' => 0,
	),
);

$array2 = array(
	'friends' => 10,
	'children' => array(
		'cats' => 5,
	),
);

echo sprintf("Second array before: %s\n", print_r($array2, true));
$merged = array_merge_recursive($array1, $array2);
echo sprintf("Second array after: %s\n", print_r($array2, true));

Expected result:
----------------
to have $array2 untouched after array_merge_recursive:

Array
(
    [friends] => 10
    [children] => Array
        (
            [cats] => 5
        )

)

Actual result:
--------------
$array2 gets modified after array_merge_recursive, and every first-
level no-array element, gets turned into an array (in this case 
'friends')...

Array
(
    [friends] => Array
        (
            [0] => 10
        )

    [children] => Array
        (
            [cats] => 5
        )

)