Fix issues that broke editing on browsers without Shadow DOM support.

dart/site/try/src/decoration.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library trydart.decoration;
 
 import 'dart:html';
 
 import 'shadow_root.dart' show
     setShadowRoot;
@@ skipping 50 matching lines @@
     var element = super.applyTo(text);
     var nodes = new List.from(element.nodes);
     element.nodes.clear();
     var tip = new Text('');
     if (kind == 'error') {
       tip = error(message);
     }
     return element..append(
         new AnchorElement()
             ..classes.add('diagnostic')
-            ..nodes.addAll(nodes)
-            ..append(tip));
+            ..append(tip)

[ahe, 2014/06/27 11:23:27]

Assume the user have written "foo" and we want to show a diagnostic around
"foo".  We have two options:

1. <a class="diagnostic">foo<span>tip</span></a>

2. <a class="diagnostic"><span>tip</span>foo</a>

Turns out that option 1 doesn't work well with backspace in Firefox. So option 2
it is :-)

[Johnni Winther, 2014/07/02 08:40:53]

Put this explanation as comment in the code.

[ahe, 2014/07/04 13:52:00]

Done.

+            ..nodes.addAll(nodes));
   }
 }
 
 createAlert(text, [String cls]) {
   var classes = ['alert'];
   if (cls != null) {
     classes.add(cls);
   }
   SpanElement result = new SpanElement()
       ..classes.addAll(classes)
@@ skipping 29 matching lines @@
 
   Element applyTo(text) {
     var codeCompletion = new DivElement()
         ..contentEditable = 'false'
         ..classes.add('dart-code-completion');
     return super.applyTo(text)
         ..classes.add('dart-code-completion-holder')
         ..nodes.add(codeCompletion);
   }
 }