ID: 40610
User updated by: Webbed dot Pete at gmail dot com
Reported By: Webbed dot Pete at gmail dot com
Status: Open
Bug Type: Arrays related
Operating System: Windows, Linux
PHP Version: 5.2.1
New Comment:
Even simpler:
$x=&$aEmpty['wheat'];
Adds element 'wheat' to the array.
This creates a nasty side effect for a couple of valuable and common
functions, which basically extend isset() for default values and so
forth:
function varset(&$val,$default='') {
if (isset($val)) return $val;
return $default;
}
function varsettrue(&$val,$default='') {
if (isset($val) && $val) return $val;
return $default;
}
$myVal = varset($pref['maxsize'],1000); // set myVal to pref or
default
NOTE: all of the following leave $aEmpty alone. I understand why this
might be the case, yet it still is wrong to break references IMHO, not
least because of losing ability to create functions like those above.
$aEmpty['wheat']; // simple reference
isset($aEmpty['wheat']); // built-in function
myFunc($aEmpty['wheat']); // pass-by-value to user func
Previous Comments:
------------------------------------------------------------------------
[2007-02-23 17:59:06] Webbed dot Pete at gmail dot com
Description:
------------
Pass an unset array element by reference, without doing anything at
all.
The passed array will gain an element.
(Note: We use isset() in our real function, which is what pointed us to
the bug, but it is not necessary for demoing the defect.)
Reproduce code:
---------------
<?php
// NOP function with pass-by-reference (PBR) parameter
function refTest( &$param ) { }
// Do test with empty and non-empty arrays
$aEmpty = array(); $aOne = array( 'corn' );
// Initial state is fine
echo "<pre>BEFORE\n";
echo "aEmpty contains ".count($aEmpty)." element(s)\n",print_r(
$aEmpty, TRUE ); echo "aOne contains ".count($aOne)."
element(s)\n",print_r( $aOne, TRUE );
// Pass by reference modifies the arrays. (we use with 'isset()' and
saw this; I've reduced to basic issue.)
$aEmpty = array(); $aOne = array( 'corn' );
refTest( $aEmpty['wheat'] ); refTest( $aOne['wheat'] );
echo "\nAFTER PASS BY REFERENCE\n";
echo "aEmpty contains ".count($aEmpty)." element(s)\n",print_r(
$aEmpty, TRUE ); echo "aOne contains ".count($aOne)."
element(s)\n",print_r( $aOne, TRUE );
?>
Expected result:
----------------
BEFORE
aEmpty contains 0 element(s)
Array
(
)
aOne contains 1 element(s)
Array
(
[0] => corn
)
[Same if you directly reference, or use isset() outside of a function,
etc etc]
[If you don't pass by reference you get notice error so that is not a
solution]
Actual result:
--------------
AFTER PASS BY REFERENCE
aEmpty contains 1 element(s)
Array
(
[wheat] =>
)
aOne contains 2 element(s)
Array
(
[0] => corn
[wheat] =>
)
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=40610&edit=1
