Description:
------------
exec does not remove the first char in a line of output, if it is whitespace
if the line only contains " \n" the " " isn't striped

Test script:
---------------
<?php
$output = array();
exec('/bin/echo -n -e "abc\f\n \n"',$output);
var_dump($output);


Expected result:
----------------
array(2) {
  [0]=>
  string(3) "abc"
  [1]=>
  string(0) ""
}


Actual result:
--------------
array(2) {
  [0]=>
  string(3) "abc"
  [1]=>
  string(1) " "
}