False alarm, something else is going on here. Revert [14780], restore [14695]. see #13317.

git-svn-id: https://develop.svn.wordpress.org/trunk@14781 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/pluggable.php

@@ -102,6 +102,9 @@ if ( !function_exists('get_userdata') ) :
  */
 function get_userdata( $user_id ) {
 	global $wpdb;
+
+	if ( ! is_numeric( $user_id ) )
+		return false;
 		
 	$user_id = absint( $user_id );
 	if ( ! $user_id )