hhvm/hphp/test/quick/nullbranch.php

<?php
error_reporting(0);
$a = null;
if ($a) {
  echo "a evaluates to true\n";
} else {
  echo "a evaluates to false\n";
}
if ($b) {
  echo "b evaluates to true\n";
} else {
  echo "b evaluates to false\n";
}