Description:
------------
When trying to iterate the ArrayIterator of an empty ArrayObject, it throws a very misleading notice complaining about how the array was modified. In a complicated system, this will likely lead to a long wild goose chase of trying to find all the possible places where the object could have been accessed through some other iterator, when in reality the error is of a completely different nature.

Test script:
---------------
error_reporting(E_ALL);
$ao = new ArrayObject(array());
$ai = $ao->getIterator();
$ai->next();

Expected result:
----------------
$ai->next() returns null; no errors. (Or maybe a notice saying you reached the end of the array.)

Actual result:
--------------
$ai->next() returns null and throws a notice saying "ArrayIterator::next(): Array was modified outside object and internal position is no longer valid".