Bug #52576 [NEW]: Variable variables can create invalid variables.
From: rquadling
Operating system: Windows XP SP3
PHP version: 5.3.3
Package: Scripting Engine problem
Bug Type: Bug
Bug description:Variable variables can create invalid variables.
Description:
------------
It seems you can create a variable in $GLOBALS that is not accessible as a
normal variable.
I found this because I wanted to use variable variables to populate a
nested
array.
Jim Lucas, in http://news.php.net/php.general/307392, comments
that the use
of
eval() may be appropriate in the case.
That aside, the entry that is created in $GLOBALS doesn't follow the rules
for
variable naming in
http://docs.php.net/manual/en/language.variables.basics.php,
namely that '[' and ']' are not valid variable names. I think this should
have t
least produced an E_WARNING.
So, with all of that, I'm not sure if this is a bug or a documentation
problem.
I certainly think it is an edge case.
Regards,
Richard Quadling.
Test script:
---------------
<?php
// Show all errors.
error_reporting(-1);
ini_set('display_errors', 1);
// Expectation was to be able to create a deep array using variable
variables.
$a = 'b[1][2][3]';
$$a = 'Inaccessible?';
print_r($b);
// Hide superglobals
unset($_POST);
unset($_GET);
unset($_SESSION);
unset($_FILES);
unset($_COOKIE);
unset($_SERVER);
unset($argv);
unset($argc);
// Reveals inaccessible variable.
var_dump($GLOBALS);
Expected result:
----------------
Array
(
[1] => Array
(
[2] => Array
(
[3] => Inaccessible?
)
)
)
array(3) {
["GLOBALS"]=>
*RECURSION*
["a"]=>
string(10) "b[1][2][3]"
["b"]=>
array(1) {
[1]=>
array(1) {
[2]=>
array(1) {
[3]=>
string(13) "Inaccessible?"
}
}
}
}
Actual result:
--------------
Notice: Undefined variable: b in - on line 5
array(4) {
["GLOBALS"]=>
*RECURSION*
["a"]=>
string(10) "b[1][2][3]"
["b[1][2][3]"]=>
string(13) "Inaccessible?"
["php_errormsg"]=>
string(21) "Undefined variable: b"
}
--
Edit bug report at http://bugs.php.net/bug.php?id=52576&edit=1
--
Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=52576&r=trysnapshot52
Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=52576&r=trysnapshot53
Try a snapshot (trunk): http://bugs.php.net/fix.php?id=52576&r=trysnapshottrunk
Fixed in SVN: http://bugs.php.net/fix.php?id=52576&r=fixed
Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=52576&r=needdocs
Fixed in release: http://bugs.php.net/fix.php?id=52576&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=52576&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=52576&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=52576&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=52576&r=support
Expected behavior: http://bugs.php.net/fix.php?id=52576&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=52576&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=52576&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=52576&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=52576&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=52576&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=52576&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=52576&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=52576&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=52576&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=52576&r=mysqlcfg
Thread (2 messages)
- rquadling@php.net