Index: book.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/book.module,v
retrieving revision 1.301
diff -u -F^f -r1.301 book.module
--- book.module	7 Jun 2005 19:20:20 -0000	1.301
+++ book.module	12 Jun 2005 21:13:19 -0000
@@ -881,7 +881,7 @@ function book_node_visitor_xml_pre($node
   $content .= "</literallayout>\n";
 
   if ($depth == 1) {
-      $output .= "<book>\n";
+      $output .= "<book id=\"node-".$node->nid ."\">\n";
       $output .= $title;
       $output .= "<bookinfo>\n$releaseinfo</bookinfo>\n";
       $output .= "<preface>\n";