Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:56432
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain nebm.ist.utl.pt from 193.136.128.22 cause and error)
Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes
To: internals@lists.php.net
References: <CAKxcST_h4eHEnWnRqLJgdcOR9_+OsOYDNrC96MpXLJLfNB+z+w@mail.gmail.com>
Date: Sat, 19 Nov 2011 14:46:30 -0000
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Organization: =?utf-8?Q?N=C3=BAcleo_de_Eng=2E_Biom=C3=A9di?=
 =?utf-8?Q?ca_do_IST?=
Message-ID: <op.v467bsunidpuyk@cataphract.cata.lo.geleia.net>
In-Reply-To: <CAKxcST_h4eHEnWnRqLJgdcOR9_+OsOYDNrC96MpXLJLfNB+z+w@mail.gmail.com>
User-Agent: Opera Mail/11.52 (Win32)
Subject: Re: [PHP-DEV] PHP Integer Bug
From: glopes@nebm.ist.utl.pt ("Gustavo Lopes")

On Sat, 19 Nov 2011 13:46:35 -0000, Paul Dragoonis <dragoonis@gmail.com>  
wrote:

> [...]
>
> ---- CODE ---
> $s = "2433078805";
> var_dump($s);
> var_dump((int) $s); exit;
>
> ----- EXPECTED -----
> string(10) "2433078805" int(2433078805)
>
> ----- ACTUAL -----
> string(10) "2433078805" int(2147483647)
>
>

Anthony has already explained the problem, but I can't find this  
documented anywhere. The manual says a conversion from a float outside the  
integer boundaries results in undefined behavior (  
http://php.net/manual/en/language.types.integer.php#language.types.integer.casting  
) and that "if the string does not contain any of the characters '.', 'e',  
or 'E' and the numeric value fits into integer type limits (as defined by  
PHP_INT_MAX), the string will be evaluated as an integer. In all other  
cases it will be evaluated as a float." (  
http://php.net/manual/en/language.types.string.php#language.types.string.conversion  
). None of these seems to apply here, though perhaps from combining the  
two we could conclude the behavior is undefined.

Internally, the behavior is also not explicitly laid out; it follows from  
the behavior of strol. This adds a notice:

Index: Zend/zend_operators.c
===================================================================
--- Zend/zend_operators.c       (revision 319548)
+++ Zend/zend_operators.c       (working copy)
@@ -353,7 +353,11 @@
                         {
                                 char *strval = Z_STRVAL_P(op);

+                               errno = 0;
                                 Z_LVAL_P(op) = strtol(strval, NULL, base);
+                               if (errno == ERANGE) {
+                                       zend_error(E_NOTICE, "Value  
outside integer bounds");
+                               }
                                 STR_FREE(strval);
                         }
                         break;



-- 
Gustavo Lopes