Simple test case showing flush() wrecking PHP and Apache

library.php:
------------
<?php

function foo() {
}

?>


error.php:
----------
<?php

error_reporting(E_ALL);
require_once 'library.php';

echo 'I will deal with a 500 error and show a pretty error message';

?>


test.php:
---------
<?php

error_reporting(E_ALL);
require_once 'library.php';

$test = 1; // Try all 3 tests

if ($test == 1) {
    header('Foo: Bar');
    flush();
    echo 'I worked absolutely fine';
}

if ($test == 2) {
    header('Foo : Bar'); // Only change
    echo 'I went wrong but did so gracefully';
}


if ($test == 3) {
    header('Foo : Bar');
    flush(); // Only change
    echo 'I fell to pieces in a horrendous and nonsensical way';
}

?>