Description:
------------
It appears that the require and require_once functions raise an E_WARNING before raising an E_ERROR. This is inconsistent with the documentation which implies that only an E_ERROR is raised when require fails.

"The two constructs are identical in every way except how they handle failure. include() produces a Warning while require()  results in a Fatal Error."

Code below tested with PHP versions 4.4.2 on RedHat Linux and 5.1.4 on Ubuntu Linux. Same result.

Reproduce code:
---------------
function default_error_handler($code, $error, $file, $line) {
   switch ($code) {
   case E_WARNING:
      echo "Warning: $error";
      break;
   default:
      echo "Something Else: $error";
   }
}
set_error_handler('default_error_handler');
require('This file does not exist. At least not here!');


Expected result:
----------------
Fatal error: require(): Failed opening required 'This file does not exist. At least not here!' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/kermode/test.php on line 12

Actual result:
--------------
Warning: require(This file does not exist. At least not here!): failed to open stream: No such file or directory
Fatal error: require(): Failed opening required 'This file does not exist. At least not here!' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/kermode/test.php on line 12