Description:
------------
 When i put a direct number or variable in a for block, it works fine, but if i do an equation it fails. Even if it is very simple. 

Test script:
---------------
<?php

error_reporting(0);

$index = "0"; 
$a = "0"; 
$b = "0"; 

//As you can see variable returns 1.
echo ">" . ($a==$b) . "<" . "<br>";

// So... this should go from 1 to 10.
// replace "($a==$b)" with 1 and everything works as it should.
for ($index=($a==$b); $index<=10; $index++)
  {
    // this always prints 1. An endless loop.
    echo $index . "<br>";
  }

?>

Expected result:
----------------
>1<
1
2
3
4
5
6
7
8
9
10

Actual result:
--------------
>1<
1
1
1
1
1
1
1
1
1
1
1
1
(infinite)