Ticket #14910: key-instead-of-user-in-ms-functions.patch

wp-includes/ms-functions.php

@@ -843 +843 @@
 }
 
 function wpmu_create_blog($domain, $path, $title, $user_id, $meta = '', $site_id = 1) {
-        $domain = preg_replace( '/\s+/', '', sanitize_user( $domain, true ) );
+        $domain = preg_replace( '/\s+/', '', sanitize_key( $domain ) );
 
         if ( is_subdomain_install() )
                 $domain = str_replace( '@', '', $domain );