feedTree: amend previous to check that nodes are actually there (2)

js/FeedTree.js

@@ -273,13 +273,15 @@ define(["dojo/_base/declare", "dojo/dom-construct", "dijit/Tree", "dijit/Menu"],
 				setTimeout(() => {
 					$("headlines-frame").focus();
 
-					const node = treeNode.rowNode;
-					const tree = this.domNode;
-
-					if (node && tree) {
-						// scroll tree to selection if needed
-						if (node.offsetTop < tree.scrollTop || node.offsetTop > tree.scrollTop + tree.clientHeight) {
-							$("feedTree").scrollTop = node.offsetTop;
+					if (treeNode) {
+						const node = treeNode.rowNode;
+						const tree = this.domNode;
+
+						if (node && tree) {
+							// scroll tree to selection if needed
+							if (node.offsetTop < tree.scrollTop || node.offsetTop > tree.scrollTop + tree.clientHeight) {
+								$("feedTree").scrollTop = node.offsetTop;
+							}
 						}
 					}