Description:
------------
When assigning an array by-value into itself PHP will insert a self-referencing Array into the new entry

Reproduce code:
---------------
$a = array();
$a[] =& $a;
print_r($a);

$b = array();
$b[] = $b;
print_r($b);

Expected result:
----------------
array(1) {
  [0]=>
  array(1) {
    [0]=>
    array(1) {
      [0]=>
      *RECURSION*
    }
  }
}
array(1) {
  [0]=>
  array(0) {
  }
}
$b[0] should contain an empty array because $b was assigned by-value, i.e. should get copied.

Actual result:
--------------
array(1) {
  [0]=>
  array(1) {
    [0]=>
    array(1) {
      [0]=>
      *RECURSION*
    }
  }
}
array(1) {
  [0]=>
  array(1) {
    [0]=>
    array(1) {
      [0]=>
      *RECURSION*
    }
  }
}

Comparing the references (see my entry regarding Spotting References) you find that $b and $b[0] are different pointers and $b[0] is an array like the one created in $a.