Description:
------------
Hash pointer should be reset at the end of function : php_taint_mark_strings

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

$str = 'a,' . 'b';
taint($str);
$a = explode(',', $str);
while (list($key, $val) = each($a)) {
    echo $val;
}

?>

Expected result:
----------------
Warning: main(): Attempt to echo a string that might be tainted in /data/taint-
1.0.0/tests/012.php on line 7
a
Warning: main(): Attempt to echo a string that might be tainted in /data/taint-
1.0.0/tests/012.php on line 7
b

Actual result:
--------------
empty