Index: modules/user/user.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/user/user.module,v
retrieving revision 1.1188
diff -u -r1.1188 user.module
--- modules/user/user.module	30 Jul 2010 02:47:28 -0000	1.1188
+++ modules/user/user.module	2 Aug 2010 02:14:06 -0000
@@ -574,9 +574,6 @@
  * Verify the syntax of the given name.
  */
 function user_validate_name($name) {
-  if (!$name) {
-    return t('You must enter a username.');
-  }
   if (substr($name, 0, 1) == ' ') {
     return t('The username cannot begin with a space.');
   }