static void spl_filesystem_tree_it_move_forward(zend_object_iterator *iter TSRMLS_DC)
{
	spl_filesystem_iterator *iterator = (spl_filesystem_iterator *)iter;
	spl_filesystem_object   *object   = spl_filesystem_iterator_to_object(iterator);

	object->u.dir.index++;
	do {
		spl_filesystem_dir_read(object TSRMLS_CC);
	} while (spl_filesystem_is_dot(object->u.dir.entry.d_name));
	if (object->file_name) {
		efree(object->file_name);
		object->file_name = NULL;
	}
	if (iterator->current) {
		zval_ptr_dtor(&iterator->current);
		iterator->current = NULL;
	}
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.