From:             robin_fernandes at uk dot ibm dot com
Operating system: Windows
PHP version:      5.3CVS-2007-12-03 (snap)
PHP Bug Type:     Scripting Engine problem
Bug description:  call_user_func_array(): questionable pass-by-val/pass-by-ref 
behaviour.

Description:
------------
This issue was originally raised as documentation bug 43079. Raising as
Scripting Engine problem as suggested by vrana at php dot net.

The pass-by-value/pass-by-ref behaviour of call_user_func_array() is not
intuitive (see the user contributed notes on the documentation page:
http://php.net/call_user_func_array ).

It appears that the way in which an argument is passed depends not on the
target function signature, but rather on whether its entry in $param_arr is
referenced or not.

Specifically, it is possible to force an argument to be passed by
reference to a function which expects a pass-by-value argument, even
with call time pass by reference DISABLED in php.ini.

Reproduced on php5.3 and php6 snaps on Windows.

Reproduce code:
---------------
<?php
 function byRef(&$a, &$b) {
        $a = 'changed.a';
        $b = 'changed.b';
 }
 
 function byVal($a, $b) {
        $a = 'changed.a';
        $b = 'changed.b';
 }

 //Currently, this forces a pass-by-ref function to take args by val:
 $args = array('original.a', 'original.b');
 call_user_func_array('byRef', $args);
 var_dump($args);

 //Currently, this forces a pass-by-val function to take 1 arg by ref.
 //This works even with call-time pass-by-ref DISABLED in php.ini.
 $args = array('original.a', 'original.b');
 $ref = &$args[0];
 call_user_func_array('byVal', $args);
 var_dump($args); 
?>

Expected result:
----------------
array(2) {
  [0]=>
  string(9) "changed.a"
  [1]=>
  string(9) "changed.b"
}
array(2) {
  [0]=>
  &string(10) "original.a"
  [1]=>
  string(10) "original.b"
}

Actual result:
--------------
array(2) {
  [0]=>
  string(10) "original.a"
  [1]=>
  string(10) "original.b"
}
array(2) {
  [0]=>
  &string(9) "changed.a"
  [1]=>
  string(10) "original.b"
}

-- 
Edit bug report at http://bugs.php.net/?id=43484&edit=1
-- 
Try a CVS snapshot (PHP 4.4): 
http://bugs.php.net/fix.php?id=43484&r=trysnapshot44
Try a CVS snapshot (PHP 5.2): 
http://bugs.php.net/fix.php?id=43484&r=trysnapshot52
Try a CVS snapshot (PHP 5.3): 
http://bugs.php.net/fix.php?id=43484&r=trysnapshot53
Try a CVS snapshot (PHP 6.0): 
http://bugs.php.net/fix.php?id=43484&r=trysnapshot60
Fixed in CVS:                 http://bugs.php.net/fix.php?id=43484&r=fixedcvs
Fixed in release:             
http://bugs.php.net/fix.php?id=43484&r=alreadyfixed
Need backtrace:               http://bugs.php.net/fix.php?id=43484&r=needtrace
Need Reproduce Script:        http://bugs.php.net/fix.php?id=43484&r=needscript
Try newer version:            http://bugs.php.net/fix.php?id=43484&r=oldversion
Not developer issue:          http://bugs.php.net/fix.php?id=43484&r=support
Expected behavior:            http://bugs.php.net/fix.php?id=43484&r=notwrong
Not enough info:              
http://bugs.php.net/fix.php?id=43484&r=notenoughinfo
Submitted twice:              
http://bugs.php.net/fix.php?id=43484&r=submittedtwice
register_globals:             http://bugs.php.net/fix.php?id=43484&r=globals
PHP 3 support discontinued:   http://bugs.php.net/fix.php?id=43484&r=php3
Daylight Savings:             http://bugs.php.net/fix.php?id=43484&r=dst
IIS Stability:                http://bugs.php.net/fix.php?id=43484&r=isapi
Install GNU Sed:              http://bugs.php.net/fix.php?id=43484&r=gnused
Floating point limitations:   http://bugs.php.net/fix.php?id=43484&r=float
No Zend Extensions:           http://bugs.php.net/fix.php?id=43484&r=nozend
MySQL Configuration Error:    http://bugs.php.net/fix.php?id=43484&r=mysqlcfg

Reply via email to