Bug #54973 [Bgs->Ana]: SimpleXML casts intergers wrong.

Edit report at http://bugs.php.net/bug.php?id=54973&edit=1 ID: 54973 Updated by: felipe@php.net Reported by: bphelpsen at gmail dot com Summary: SimpleXML casts intergers wrong. -Status: Bogus +Status: Analyzed Type: Bug Package: SimpleXML related Operating System: Linux PHP Version: 5.3.6 Block user comment: N Private report: N Previous Comments: ------------------------------------------------------------------------ [2011-06-02 22:14:14] dtajchreber@php.net This looks like a bug... SimpleXML's cast_object handler doesn't check for overflow when trying to convert a node value to a long. $xml->value goes through Zend's add_function and gets passed to zendi_convert_scalar_to_number which calls SimpleXML's cast_object handler because $xml->number is an object. It then gets chopped into LONG_MAX by strtol. An overflow check could fix this... but it might break some BC.... [1] http://lxr.php.net/xref/PHP_5_3/Zend/zend_operators.c#758 [2] http://lxr.php.net/xref/PHP_5_3/ext/simplexml/simplexml.c#1722 [3] http://lxr.php.net/xref/PHP_5_3/Zend/zend_operators.c#355 [4] http://lxr.php.net/xref/PHP_5_3/Zend/zend_operators.c#768 [5] http://www.gnu.org/s/hello/manual/libc/Parsing-of-Integers.html ------------------------------------------------------------------------ [2011-06-02 20:05:07] bphelpsen at gmail dot com Then why do I get different results when I run this code: <?php echo "214748364800" / 1024 / 1024 / 1024; ?> than when I run the example code. Shouldn't they return the same value? Here is an example, with the same results as my local test: http://codepad.org/KICl3xHw ------------------------------------------------------------------------ [2011-06-02 20:00:54] iliaa@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php This has nothing to do with SimpleXML, but rather the fact that a numeric string in PHP by default would converted to an integer. ------------------------------------------------------------------------ [2011-06-01 22:18:27] bphelpsen at gmail dot com Description: ------------ When an XML node value is an integer SimpleXML always casts it to an int, even if its a float or double. Test script: --------------- <?php $xml = simplexml_load_string("<xml><number>214748364800</number></xml>"); echo $xml->number . "\n"; // the proper number $int = $xml->number / 1024 / 1024 / 1024; // initial cast to an int causes problems echo $int . "\n"; $double = (double) $xml->number / 1024 / 1024 / 1024; // hard cast to a double fixes it echo $double . "\n"; ?> Expected result: ---------------- 214748364800 200 200 Actual result: -------------- 214748364800 1.9999999990687 200 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=54973&edit=1