Bug #78475 [Opn->Csd]: Unsetting or assigning a value to $GLOBALS makes it stop working
Edit report at https://bugs.php.net/bug.php?id=78475&edit=1
ID: 78475
Updated by: nikic@php.net
Reported by: ayg at aryeh dot name
Summary: Unsetting or assigning a value to $GLOBALS makes it
stop working
-Status: Open
+Status: Closed
Type: Bug
Package: Scripting Engine problem
PHP Version: 7.3.9
-Assigned To:
+Assigned To: nikic
Block user comment: N
Private report: N
New Comment:
unset($GLOBALS) results in a compile-time error in PHP 8.1, as part of https://wiki.php.net/rfc/restrict_globals_usage.
Previous Comments:
------------------------------------------------------------------------
[2019-08-29 18:14:51] ayg at aryeh dot name
Description:
------------
$GLOBALS contains a reference to a magical array that has all the globals in it. Unsetting or
assigning a value to it seems to forevermore lose the reference to this magical array, making
$GLOBALS a regular old variable that has no connection to defined globals (although it's still
a superglobal).
Unsetting or assigning to $GLOBALS probably should fail, just like $this does. I spent some time
today trying to debug a scenario where $GLOBALS['someVar'] did not equal $someVar after I
had written "global $someVar". It turned out to be because someone had unset $GLOBALS
somewhere (they were trying to clear all global variables and restore them to an earlier state).
This is really confusing and should be disallowed. Or at least produce a notice or something.
Test script:
---------------
$a = 1;
unset( $GLOBALS );
function f() {
global $a;
unset( $GLOBALS ); // $GLOBALS = []; is the same
var_dump( $a );
var_dump( isset( $GLOBALS['a' ) );
}
f();
Expected result:
----------------
Either:
int(1)
bool(true)
Or:
NULL
bool(false)
Actual result:
--------------
int(1)
bool(false)
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=78475&edit=1
Thread (4 messages)