Description:
------------
A class that extends mysqli, if passing its own members directly to the parent constructor, will have those members mangled after the call.

Assigning member values to local variables and then passing those to the parent solves the problem on for the user, but the above behaviour shouldn't happen...?

(Replacing the line "parent::__construct($this->p_host, $this->p_uname, $this->p_password);" with "parent::__construct($host, $username, $password);" produces the expected result.)

This same problem is reported on the comment by hans at lintoo dot dk on http://www.php.net/manual/en/ref.mysqli.php

Reproduce code:
---------------
<?php

class db_mysql extends mysqli
{
    private $p_host;
    private $p_uname = '';
    private $p_password = '';

    public function __construct($host, $username = '', $password = '')
    {
        $this->p_host     = $host;
        $this->p_uname    = $username;
        $this->p_password = $password;

        parent::__construct($this->p_host, $this->p_uname, $this->p_password);
    }
}

var_dump(new db_mysql('localhost', 'username', 'password'));
?>

Expected result:
----------------
object(db_mysql)#1 (3) {
  ["p_host:private"]=>
  string(9) "localhost"
  ["p_uname:private"]=>
  string(8) "username"
  ["p_password:private"]=>
  string(8) "password"
}

Actual result:
--------------
object(db_mysql)#1 (3) {
  ["p_host:private"]=>
  string(9) "localhost"
  ["p_uname:private"]=>
  string(8) "username"
  ["p_password:private"]=>
  NULL
}