Merge pull request #1308 in VISUAL/fineui from ~WINDY/fineui:master to master

* commit 'a05ef147a25355053defc42df3a2d831a6570332':
  无JIRA任务 assert

src/base/tree/ztree/treetrender.page.service.js

@@ -56,8 +56,8 @@
         },
 
         removeNodeList: function (tId) {
-            this.nodeLists[tId].loadWidget.destroy();
-            this.nodeLists[tId].loadWidget = null;
+            this.nodeLists[tId] && this.nodeLists[tId].loadWidget.destroy();
+            this.nodeLists[tId] && (this.nodeLists[tId].loadWidget = null);
             delete this.nodeLists[tId];
             if (BI.size(this.nodeLists) === 0) {
                 this.clear();