#45311 [NEW]: substr works incorrect with binary data

From: Date: Thu, 19 Jun 2008 07:53:32 +0000
Subject: #45311 [NEW]: substr works incorrect with binary data
Groups: php.bugs 
Request: Send a blank email to php-bugs+get-125872@lists.php.net to get a copy of this message 
From:             yar_helg at mail dot ru
Operating system: 
PHP version:      5.2.6
PHP Bug Type:     Strings related
Bug description:  substr works incorrect with binary data

Description:
------------
When trying to operate with binary data using substr and
mb_internal_encoding is set to UTF-8 (but no function overloading is set)
substr works wrong - wrong number of bytes is returned after function call

P.S. emptyfile.xls used in example is an empty MS Excel 2003 file. It can
be downloaded at http://an-best.ru/empty_file.xls
(13/5 Kbytes)

P.P.S. IDENTIFIER_OLE constant is taken from Spreadsheet_excel_reader
class.

Reproduce code:
---------------
<?php

echo "function overload = ".ini_get('mbstring.func_overload')."<br
/>\n";

// Uncomment this for demonstration of wrong behaviour
//mb_internal_encoding('UTF-8');


echo "MB_INTERNAL_ENCODING =".mb_internal_encoding()."<br />\n";

define('IDENTIFIER_OLE',
pack("CCCCCCCC",0xd0,0xcf,0x11,0xe0,0xa1,0xb1,0x1a,0xe1));

$data =
file_get_contents($_SERVER['DOCUMENT_ROOT'].'/substr_bug/emptyfile.xls');

echo "Data length = ".strlen($data)."<br />\n";
echo "First 8 symbols  ==>".var_export(substr($data,0,8),1)."<== <br
/>\n";
echo "Compare result (substr(\$data,0,8)==IDENTIFIER_OLE) -
".var_export(substr($data,0,8)==IDENTIFIER_OLE,1)."<br />\n";
echo "Substring length (substr(\$data,0,8)) -
".strlen(substr($data,0,8))."<br />\n";

?>

Expected result:
----------------
function overload = 0
MB_INTERNAL_ENCODING =ISO-8859-1
Data length = 13824
First 8 symbols
==>'&#1087;&#1086;&#1070;&#9553;&#9568;&#1040;'<==
Compare result (substr($data,0,8)==IDENTIFIER_OLE) - true
Substring length (substr($data,0,8)) - 8


Actual result:
--------------
// This result can be seen if mb_internal_encoding is set to UTF-8

function overload = 0
MB_INTERNAL_ENCODING =UTF-8
Data length = 13824
First 8 symbols
==>'&#1087;&#1086;&#1070;&#9553;&#9568;&#1040;' .
"\0"
. '' . "\0" . '' . "\0" . '' . "\0" .
'' . "\0" . ''<==
Compare result (substr($data,0,8)==IDENTIFIER_OLE) - false
Substring length (substr($data,0,8)) - 13


-- 
Edit bug report at http://bugs.php.net/?id=45311&edit=1
-- 
Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=45311&r=trysnapshot52
Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=45311&r=trysnapshot53
Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=45311&r=trysnapshot60
Fixed in CVS:                 http://bugs.php.net/fix.php?id=45311&r=fixedcvs
Fixed in release:             http://bugs.php.net/fix.php?id=45311&r=alreadyfixed
Need backtrace:               http://bugs.php.net/fix.php?id=45311&r=needtrace
Need Reproduce Script:        http://bugs.php.net/fix.php?id=45311&r=needscript
Try newer version:            http://bugs.php.net/fix.php?id=45311&r=oldversion
Not developer issue:          http://bugs.php.net/fix.php?id=45311&r=support
Expected behavior:            http://bugs.php.net/fix.php?id=45311&r=notwrong
Not enough info:              http://bugs.php.net/fix.php?id=45311&r=notenoughinfo
Submitted twice:              http://bugs.php.net/fix.php?id=45311&r=submittedtwice
register_globals:             http://bugs.php.net/fix.php?id=45311&r=globals
PHP 4 support discontinued:   http://bugs.php.net/fix.php?id=45311&r=php4
Daylight Savings:             http://bugs.php.net/fix.php?id=45311&r=dst
IIS Stability:                http://bugs.php.net/fix.php?id=45311&r=isapi
Install GNU Sed:              http://bugs.php.net/fix.php?id=45311&r=gnused
Floating point limitations:   http://bugs.php.net/fix.php?id=45311&r=float
No Zend Extensions:           http://bugs.php.net/fix.php?id=45311&r=nozend
MySQL Configuration Error:    http://bugs.php.net/fix.php?id=45311&r=mysqlcfg

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