Fixing a bug in CellTree where the Show More button doesn't work for the root node.

Issue: 5547

Review at http://gwt-code-reviews.appspot.com/1420801

Review by: rchandia@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9997 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/cellview/client/CellTree.java b/user/src/com/google/gwt/user/cellview/client/CellTree.java
index 160aaa9..de7f6ae 100644
--- a/user/src/com/google/gwt/user/cellview/client/CellTree.java
+++ b/user/src/com/google/gwt/user/cellview/client/CellTree.java
@@ -682,7 +682,7 @@
     final boolean isMouseDown = "mousedown".equals(eventType);
     final boolean isClick = "click".equals(eventType);
     final CellTreeNodeView<?> nodeView = findItemByChain(chain, 0, rootNode);
-    if (nodeView != null && nodeView != rootNode) {
+    if (nodeView != null) {
       if (isMouseDown) {
         Element showMoreElem = nodeView.getShowMoreElement();
         if (nodeView.getImageElement().isOrHasChild(target)) {
@@ -697,7 +697,7 @@
       }
 
       // Forward the event to the cell
-      if (nodeView.getSelectionElement().isOrHasChild(target)) {
+      if (nodeView != rootNode && nodeView.getSelectionElement().isOrHasChild(target)) {
         // Move the keyboard focus to the clicked item.
         if (isClick) {
           /*