[FIX] list paginator's 'last page' button: not all state was transferred between datasets during paginator configuration

lp bug: https://launchpad.net/bugs/939614 fixed

bzr revid: xmo@openerp.com-20120228101200-atisgrb2fb0eqi1g

addons/web/static/src/js/view_list.js

@@ -291,6 +291,10 @@ openerp.web.ListView = openerp.web.View.extend( /** @lends openerp.web.ListView#
      */
     configure_pager: function (dataset) {
         this.dataset.ids = dataset.ids;
+        // Not exactly clean
+        if (dataset._length) {
+            this.dataset._length = dataset._length;
+        }
 
         var limit = this.limit(),
             total = dataset.size(),