Description:
------------
---
From manual page: http://www.php.net/function.isset#Description
---

if valid variable $var with NULL value passed to isset(), result is FALSE.

There should be language reserved word/language construct that behaves exactly 
like isset() except for NULL value.

behavior of isset should be changed in future major release, optionally 
configurable by ini setting.

If I create patch, do you include it? 
Note that if I'll go implement this, compatible behavior will be preserved.

Test script:
---------------
if(isset($var))
    die('ERROR');
else
    echo "OK\n";

$var = null;
if(!isset($var)) 
    die('NOT GOOD. THIS IS UNCLEAR AND STRANGE');
else
    echo "THIS IS BETTER\n";

unset($var);
if(isset($var)) 
    die('ERROR');
else
    echo "OK\n";


Expected result:
----------------
OK
THIS IS BETTER
OK


Actual result:
--------------
OK
NOT GOOD. THIS IS UNCLEAR AND STRANGE