Description:
------------
Special characters, when exec() return duplicated last line:
( ) [ ] { }


Reproduce code:
---------------
unset($output);
exec('echo "("', $output, $retval);
var_dump($output);


Expected result:
----------------
array(1) {
  [0]=>
  string(1) "("
}


Actual result:
--------------
array(2) {
  [0]=>
  string(1) "("
  [1]=>
  string(1) "("
}