Description:
------------
By Operator Precedence on 
http://php.net/manual/en/language.operators.precedence.php, logical operator '||' 
is higher than assignment operator '=', so the script below should cause a syntax 
error. 

Test script:
---------------
$a = $b = 0;
if ($a = 1 || $b = 1) {
    echo $a;
}


Expected result:
----------------
execute as:
if ($a = (1 || $b) = 1) {

output:
syntax error, unexpected '='

Actual result:
--------------
execute as:
if ($a = (1 || ($b = 1))) {

output:
1