* Fixed bug when using AddChild to add nodes, that was preventing a node to be selected

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@175 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/virtualtreeview-unstable/VirtualTrees.pas

@@ -23975,7 +23975,13 @@ begin
         Sort(Parent, FHeader.FSortColumn, FHeader.FSortDirection, True);
 
       InvalidateToBottom(Parent);
-      UpdateScrollbars(True);
+
+      //Calling UpdateHorizontalScrollBar without a header leads to a
+      //wrong NodeWidth because the node is not initialized at this time.
+      //As result the horizontal scrollbar is not correctly
+      //sized and the node can not be selected by a click.
+      if HandleAllocated then
+        UpdateVerticalScrollBar(True)
     end;
   end
   else