Description:
------------
When a class is expecting an array as in the example, it's waiting for $vars['var'], and a string is given, $vars['var'] still returns true. It picks up the first character of the string. isset($vars['var']) should return false if a string is passed.

Normal arrays given to the class work fine. if the key is there, it returns true, if not then it returns false. But a string always returns true and it picks up the first character.

Reproduce code:
---------------
URL = http://www.legaciesleft.net/php/temp/source.php

Script.php ---- 
<?  include 'class.php';

    echo "test 1: ";
    $class_one = new problem(array('var'=>'good')); 
    echo "<BR>test 2: ";
    $class_two = new problem(array('novar'=>'bad')); 
    echo "<BR>test 3: ";
    $class_three = new problem('string');
?>

Class.php ---- 
<?
class problem{
    function problem($vars) {
        if (isset($vars['var'])) echo $vars['var'];
        else echo 'array is not set';
    }
}
?>

Expected result:
----------------
test 1: good
test 2: array is not set
test 3: array is not set

Actual result:
--------------
test 1: good
test 2: array is not set
test 3: s