Description:
------------
I am using the latest stable PHP version 5.2.4 on Windows XP (SP2) and Linux (Kernel 2.6.16) and a MySQL Database version 5.0.45.

In both cases mysqli_free_result doesn't seem to free the allocated memory.

Reproduce code:
---------------
$db = new mysqli("localhost", "username", "password", "database");

for ($i = 1; $i <= 100; $i++)
{
    echo 'turn '.$i.'<br />';

    echo "before query: ".memory_get_usage(false).'<br />';

    $dbResult = $db->query("SELECT * FROM example LIMIT $i, $i");

    $row = $dbResult->fetch_assoc();

    echo "before close: ".memory_get_usage(false).'<br />';

    $dbResult->free();
    unset($dbResult);

    echo "after close: ".memory_get_usage(false).'<br /><br />';
}

Expected result:
----------------
turn 1
before query: 75624
before close: 79736
after close: 75624

turn 2
before query: 75624
before close: 79834
after close: 75624

turn 3
before query: 75624
before close: 79976
after close: 75624

[...]

turn 100
before query: 75624
before close: 79858
after close: 75624

Actual result:
--------------
turn 1
before query: 75624
before close: 79736
after close: 79872

turn 2
before query: 79872
before close: 84184
after close: 84184

turn 3
before query: 84184
before close: 84200
after close: 84240

[...]

turn 100
before query: 85360
before close: 85360
after close: 85360