--TEST--
Implicit initialisation when passing by reference
--FILE--
<?php
function passbyVal($val) {
    echo "\nInside passbyVal call:\n";
    var_dump($val);
}

function passbyRef(&$ref) {
    echo "\nInside passbyRef call:\n";
    var_dump($ref);
}

echo "\nPassing undefined by value\n";
passbyVal($undef1[0]);
echo "\nAfter call\n";
var_dump($undef1);

echo "\nPassing undefined by reference\n";
passbyRef($undef2[0]);
echo "\nAfter call\n";
var_dump($undef2)
?>
--EXPECTF--
Passing undefined by value

Warning: Undefined variable $undef1 in %s on line %d

Warning: Trying to access array offset on value of type null in %s on line %d

Inside passbyVal call:
NULL

After call

Warning: Undefined variable $undef1 in %s on line %d
NULL

Passing undefined by reference

Inside passbyRef call:
NULL

After call
array(1) {
  [0]=>
  NULL
}