Description:
------------
PHP engine doesn?t throw the expected parsing error (which is according to doc) with the ?input string given in ?parse.ini file? containing ?@? char and which is not included in double quotes (??). 
Documentation says -
?Note: If a value in the ini file contains any non-alphanumeric characters it needs to be enclosed in double-quotes (") in ?http://in2.php.net/manual/en/function.parse-ini-file.php.
And it is happening with many other Non-alpha numeric chars like #, %, &, +, -, `, ^, <, >, :, ?, _, ?, etc. 
For some of chars like ?!?, ?~?, ?()?, etc php throws parsing error which is expected according to doc.


Environment:
Operating System: Linux, Windows XP
PHP Version:PHP 5.2.4-dev (cli) (built: Jul 21 2007 19:21:35)
Copyright (c) 1997-2007 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2007 Zend Technologies
Configure Setup: ./configure


Reproduce code:
---------------
Parse_ini_file.php:
<?php
$ini_array = parse_ini_file(dirname(__FILE__)."/parse.ini");
print_r($ini_array);
?>



parse.ini:
;start of ini file

[Strings with non-alpha numeric values]
;without quotes
;Expected a parse error
Non-alpha_string1 = Hello@world 
;Throws an error, which is according to doc
;Non-alpha_string2 = Hello!world 

;with quotes
;Works fine, which is according to doc
Non-alpha_string1_quotes = "Hello@world"
Non-alpha_string2_quotes = "Hello!world"

;end of ini file


Expected result:
----------------
PHP Warning:  Error parsing %s/parse.ini on line %d in %s\parse_ini_file.php on line %d
Array
(
    [Non-alpha_string2] => Hello
)


Actual result:
--------------
Array
(
    [Non-alpha_string1] => Hello@world
    [Non-alpha_string1_quotes] => Hello@world
    [Non-alpha_string2_quotes] => Hello!world
)