Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 38159)
+++ wp-includes/taxonomy.php	(working copy)
@@ -2846,7 +2846,7 @@
 	$parsed_args['description'] = $description;
 
 	if ( '' == trim($name) )
-		return new WP_Error('empty_term_name', __('A name is required for this term'));
+		return new WP_Error( 'empty_term_name', __( 'A name is required for this term.' ) );
 
 	if ( $parsed_args['parent'] > 0 && ! term_exists( (int) $parsed_args['parent'] ) ) {
 		return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );