Bug #67348 [NEW]: Reading $dbc->stat modifies $dbc->affected_rows

From: Date: Tue, 27 May 2014 22:31:59 +0000
Subject: Bug #67348 [NEW]: Reading $dbc->stat modifies $dbc->affected_rows
Groups: php.bugs 
Request: Send a blank email to php-bugs+get-185940@lists.php.net to get a copy of this message 
From:             derick
Operating system: Linux
PHP version:      5.6Git-2014-05-27 (Git)
Package:          MySQLi related
Bug Type:         Bug
Bug description:Reading $dbc->stat modifies $dbc->affected_rows

Description:
------------
When a script reads $dbc->stat, subsequent reads of $dbc->affected_rows
return a different result. 

This was first reported to me as Xdebug bug #1053:
http://bugs.xdebug.org/view.php?id=1053. I
traced this back to the
reading of ->stat as follows:

- Xdebug's debugging command "context_get" reads all the variables in
the local scope
- For each object variable, the debug handlers are called (through
Z_OBJDEBUG_PP):
https://github.com/derickr/xdebug/blob/master/xdebug_var.c#L1725
- MySQLi debug handler loops over a list of properties:
https://github.com/php/php-src/blob/master/ext/mysqli/mysqli_prop.c#L449
- The debug handler for affected_rows is at
https://github.com/php/php-src/blob/master/ext/mysqli/mysqli_prop.c#L158
- The debug handler for stat is at
https://github.com/php/php-src/blob/master/ext/mysqli/mysqli_prop.c#L256
- The debug handler for stat is defined at
https://github.com/php/php-src/blob/master/ext/mysqlnd/mysqlnd.h#L212
- When I do *not* call "$foo = $dbc->stat", everything works.
- I can not created a work around, because the debug handler loops over
all properties, and I have no chance to prevent ->stat from being read
from the Xdebug side.


Test script:
---------------
<?php
$dbc = mysqli_connect('localhost', 'root', 'passwd',
'test');

$q = "INSERT INTO test1053 VALUES(7)";
$r = mysqli_query($dbc, $q);

var_dump($dbc->affected_rows);

$foo = $dbc->stat;

var_dump($dbc->affected_rows);
?>


Expected result:
----------------
int(1)
int(1)

Actual result:
--------------
int(1)
int(-1)

-- 
Edit bug report at https://bugs.php.net/bug.php?id=67348&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=67348&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=67348&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=67348&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=67348&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=67348&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=67348&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=67348&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=67348&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=67348&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=67348&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=67348&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=67348&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=67348&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=67348&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=67348&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=67348&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=67348&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=67348&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=67348&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=67348&r=mysqlcfg

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