DOM-less stocks app shouldn't crash on touch

sky/sdk/lib/framework/components2/scaffold.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import '../fn2.dart';
 import '../layout2.dart';
 import '../theme/typography.dart' as typography;
 
 // RenderNode
 class RenderScaffold extends RenderDecoratedBox {
@@ skipping 130 matching lines @@
     if (toolbar != null)
       canvas.paintChild(toolbar, (toolbar.parentData as BoxParentData).x, (toolbar.parentData as BoxParentData).y);
     if (floatingActionButton != null)
       canvas.paintChild(floatingActionButton, (floatingActionButton.parentData as BoxParentData).x, (floatingActionButton.parentData as BoxParentData).y);
     if (drawer != null)
       canvas.paintChild(drawer, (drawer.parentData as BoxParentData).x, (drawer.parentData as BoxParentData).y);
   }
 
   void hitTestChildren(HitTestResult result, { double x, double y }) {
     assert(floatingActionButton == null || floatingActionButton.parentData is BoxParentData);
-    assert(statusBar == null || statusBar.parentData is BoxParentData);
+    assert(statusbar == null || statusbar.parentData is BoxParentData);
     if ((drawer != null) && (x < drawer.width)) {
       drawer.hitTest(result, x: x, y: y);
     } else if ((floatingActionButton != null) && (x >= floatingActionButton.parentData.x) && (x < floatingActionButton.parentData.x + floatingActionButton.width)
                                               && (y >= floatingActionButton.parentData.y) && (y < floatingActionButton.parentData.y + floatingActionButton.height)) {
       floatingActionButton.hitTest(result, x: x-floatingActionButton.parentData.x, y: y-floatingActionButton.parentData.y);
     } else if ((toolbar != null) && (y < toolbar.height)) {
       toolbar.hitTest(result, x: x, y: y);
     } else if ((statusbar != null) && (y > statusbar.parentData.y)) {
       statusbar.hitTest(result, x: x, y: y-statusbar.parentData.y);
-    } else {
+    } else if (body != null) {
       body.hitTest(result, x: x, y: y-body.parentData.y);
     }
   }
 
 }
 
 class Scaffold extends RenderNodeWrapper {
 
   // static final Style _style = new Style('''
   //   ${typography.typeface};
@@ skipping 50 matching lines @@
   void syncRenderNode(UINode old) {
     super.syncRenderNode(old);
     syncChild(toolbar, old is Scaffold ? old.toolbar : null, #toolbar);
     syncChild(body, old is Scaffold ? old.body : null, #body);
     syncChild(statusbar, old is Scaffold ? old.statusbar : null, #statusbar);
     syncChild(drawer, old is Scaffold ? old.drawer : null, #drawer);
     syncChild(floatingActionButton, old is Scaffold ? old.floatingActionButton : null, #floatingActionButton);
   }
 
 }