[PHP-BUG] Bug #79192 [NEW]: unset does not unset uninitialized typed properties completely

From:             raincomplain at outlook dot com
Operating system: Linux
PHP version:      7.4.2
Package:          Testing related
Bug Type:         Bug
Bug description:unset does not unset uninitialized typed properties completely 

Description:
------------
After unsetting an uninitialized typed property any attempt to modify
that property will still generate a fatal error an unset seems to set
that property to null which is another issue. The later can be
illustrated after adding the magic method __get.





 

Test script:
---------------
**Without __get**
<?php
class Foo
{
    public int $bar;

    public function __set($prop, $val) {
        throw new Exception('Dynamic properties are not allowed');
    }

}

$f = new Foo();
unset($f->bar);
echo $f->bar

?>

**With __get**

class Foo
{
    public int $bar;

    public function __set($prop, $val) {
        throw new Exception('Dynamic properties are not allowed');
    }

    public function __get($name)
    {
        echo 'works'.PHP_EOL;
    }
}

$f = new Foo();
unset($f->bar);
echo $f->bar

Expected result:
----------------
The expected behavior is to emit a notice (PHP Notice:  Undefined
property: Foo::$bar) or prevent unsetting uninitialized typed properties
in the first place.

Actual result:
--------------
**Without __get**

Typed property Foo::$bar must not be accessed before initialization


**With __get**

works
PHP Fatal error:  Uncaught TypeError: Typed property Foo::$bar must be
int, null used

-- 
Edit bug report at https://bugs.php.net/bug.php?id=79192&edit=1
-- 
Fix committed:                    https://bugs.php.net/fix.php?id=79192&r=fixed
Fixed in release:                 https://bugs.php.net/fix.php?id=79192&r=alreadyfixed
Need backtrace:                   https://bugs.php.net/fix.php?id=79192&r=needtrace
Need Reproduce Script:            https://bugs.php.net/fix.php?id=79192&r=needscript
Try newer version:                https://bugs.php.net/fix.php?id=79192&r=oldversion
Not developer issue:              https://bugs.php.net/fix.php?id=79192&r=support
Expected behavior:                https://bugs.php.net/fix.php?id=79192&r=notwrong
Not enough info:                  https://bugs.php.net/fix.php?id=79192&r=notenoughinfo
Submitted twice:                  https://bugs.php.net/fix.php?id=79192&r=submittedtwice
register_globals:                 https://bugs.php.net/fix.php?id=79192&r=globals
PHP version support discontinued: https://bugs.php.net/fix.php?id=79192&r=phptooold
Daylight Savings:                 https://bugs.php.net/fix.php?id=79192&r=dst
IIS Stability:                    https://bugs.php.net/fix.php?id=79192&r=isapi
Install GNU Sed:                  https://bugs.php.net/fix.php?id=79192&r=gnused
Floating point limitations:       https://bugs.php.net/fix.php?id=79192&r=float
No Zend Extensions:               https://bugs.php.net/fix.php?id=79192&r=nozend
MySQL Configuration Error:        https://bugs.php.net/fix.php?id=79192&r=mysqlcfg