Description:
------------
In the Simple::$var property the reference to a variable instead of a copy is located, depending on many conditions.

If lines 6 and 8 of bug.php to change places the expected result is received.

If to remove a line 7 of bug.php the expected result is received.

If remove a line 1 of bug.php and to place contents of a Simple.php in a bug.php the expected result is received.

Reproduce code:
---------------
<file Simple.php>
1 class Simple
2 {
3     protected static $var;
4 
5     public static function setVar($value)
6     {
7         self::$var = $value;
8     }
9 }

<file bug.php>
1 require_once('Simple.php');
2
3 $var1 = 'value1';
4 $var2 = 'value2';
5 
6 Simple::setVar($var1);
7 
8 class VerySimple extends Simple {}
9 
10 Simple::setVar($var2);
11 
12 print $var1;

Expected result:
----------------
value1


Actual result:
--------------
value2