Description:
------------
When writing to a non-seekable stream, the stream position is not
properly updated, what can be whitnessed by ftell().

The seemingly strange expected output is due to bug #81345.

Test script:
---------------
<?php
$s = fopen("compress.bzip2://file.bz2", "w");
fwrite($s, str_repeat("hello world", 100));
fflush($s);
var_dump(ftell($s));
?>

Expected result:
----------------
int(1100)

Actual result:
--------------
int(0)