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Bug #79025 Assigning superglobals by reference in functions are reset to null
Submitted: 2019-12-24 05:19 UTC Modified: 2019-12-24 13:57 UTC
From: ssigwart at yahoo dot com Assigned:
Status: Not a bug Package: *General Issues
PHP Version: 7.4.1 OS: Any
Private report: No CVE-ID: None
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From: ssigwart at yahoo dot com
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 [2019-12-24 05:19 UTC] ssigwart at yahoo dot com 
Description:
------------
When you assign a variable to a superglobal ($_SESSION, $_GET, etc) by reference within a function, the variable is reset to null once you exit the function.

Test script:
---------------
$_SESSION['var'] = 1;
function func1()
{
	global $ref;
	global $nonRef;
	$ref = &$_SESSION['var'];
	$nonRef = $_SESSION['var'];
}
func1();
var_dump($_SESSION['var']);
var_dump($ref);
var_dump($nonRef);

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

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

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 [2019-12-24 05:46 UTC] thedinosaurmail at gmail dot com 
https://3v4l.org/WGsD9

it seems  same at ervery version
 [2019-12-24 06:49 UTC] requinix@php.net
-Status: Open +Status: Not a bug
 [2019-12-24 06:49 UTC] requinix@php.net 
When you
  global $ref;
PHP created a local variable inside the function named "ref" which acts as a reference to the global variable outside the function also named "ref". Since it didn't exist yet, it was given the value of null.

When you
  $ref = &$_SESSION['var'];
you severed the connection between the local and global $refs and instead gave the local $ref a new reference to $_SESSION['var'].

The global $ref started with a value of NULL and never changed from that.
 [2019-12-24 13:57 UTC] ssigwart at yahoo dot com 
Thanks for the quick response and details.  That makes sense.
 
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