Description:
------------
what I want to do: left-padding a string with spaces.
In this example, up to 30 charachters.

code snippet:
<?php
$mystring = 'Luca Nanetti';
$formatstring = "[%30s]";
$fstring = sprintf($formatstring, $mystring);
echo $fstring;
?>

expected:
[                  Luca Nanetti]

what I get is instead a one-charachter padding, i.e. the string
is left padded with only one space:
[ Luca Nanetti]

it successfully works with the number 0:
using "[%030s]" I get [000000000000000000Luca Nanetti]

it successfully works with custom padding, "[%'#30s]"

Additional informations:
- Abyss web server, accessed locally on 127.0.0.1:8000
- modules: PDO, PDO_SQLITE, MCRYPT

Reproduce code:
---------------
<?php
$mystring = 'Luca Nanetti';
$formatstring = "[%30s]";
$fstring = sprintf($formatstring, $mystring);
echo $fstring;
?>

Expected result:
----------------
[                  Luca Nanetti]

Actual result:
--------------
[ Luca Nanetti]