Index: includes/menu.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/menu.inc,v
retrieving revision 1.333
diff -u -p -r1.333 menu.inc
--- includes/menu.inc	11 Aug 2009 17:26:33 -0000	1.333
+++ includes/menu.inc	16 Aug 2009 16:42:41 -0000
@@ -2085,7 +2085,9 @@ function _menu_delete_item($item, $force
  *   saved.
  */
 function menu_link_save(&$item) {
-
+  // Get the router if it is already in memory. $menu will be NULL, unless this
+  // is during a menu rebuild
+  $menu = _menu_router_cache();
   drupal_alter('menu_link', $item);
 
   // This is the easiest way to handle the unique internal path '<front>',
@@ -2111,14 +2113,13 @@ function menu_link_save(&$item) {
     }
   }
 
-  if (isset($item['plid'])) {
-    if ($item['plid']) {
-      $parent = db_query("SELECT * FROM {menu_links} WHERE mlid = :mlid", array(':mlid' => $item['plid']))->fetchAssoc();
-    }
-    else {
-      // Don't bother with the query - mlid can never equal zero..
-      $parent = FALSE;
-    }
+  // If no explicit plid is defined as parent, then the the re-parenting process
+  // is always invoked, since there is no guarantee that a plid of 0 is not
+  // caused by a re-parenting process that went wrong previously. For example,
+  // local tasks may be re-parented to the top-level (0) when tab_root points to
+  // an item of type MENU_CALLBACK.
+  if (!empty($item['plid'])) {
+    $parent = db_query("SELECT * FROM {menu_links} WHERE mlid = :mlid", array(':mlid' => $item['plid']))->fetchAssoc();
   }
   else {
     $query = db_select('menu_links');
@@ -2146,7 +2147,16 @@ function menu_link_save(&$item) {
     } while ($parent === FALSE && $parent_path);
   }
   if ($parent !== FALSE) {
+    // If a parent link was found, derive its menu.
     $item['menu_name'] = $parent['menu_name'];
+
+    // Whenever we retrieve a parent link for a router item from the database,
+    // we need to update the parent link's properties according to the new
+    // router item. Otherwise, the re-parenting process gets stuck on the menu
+    // router data that was stored in {menu_links} in a previous menu rebuild.
+    if (isset($menu) && !empty($parent['router_path']) && isset($menu[$parent['router_path']])) {
+      $parent = array_merge($parent, _menu_link_build($menu[$parent['router_path']]));
+    }
   }
   $menu_name = $item['menu_name'];
   // Menu callbacks need to be in the links table for breadcrumbs, but can't