Description:
------------
On win32, the function escapeshellarg() replaces percent characters (%) with spaces. Instead, the function should escape the percent character, perhaps using the ^% construct, so that the percent sign can be safely used as a an argument to an application executed through exec().

Reproduce code:
---------------
<?

  // .... This creates a directory called "Test dir"  (without the quotes)
  // .... which is unexpected.
  $cmd = 'md';
  $arg = 'test%dir';
  $fullcmd = $cmd.' '.escapeshellarg($arg);

  // .... This creates a directory called "Test%dir"  (without the quotes)
  // .... which is the expected result of the above.
  // $fullcmd = 'md test^%dir';

  exec($fullcmd);
  system("dir /B");

?>

Expected result:
----------------
test%dir


Actual result:
--------------
test dir