preserveDataModel=true throws ClassCastException (with Trinidad)

When you have a datatable with preserveDataModel=true, it throws ClassClastException when you use commandSortHeader and try to sort
the data (click it twice).

I believe that the problem is that trinidad use a cache mechanism in its StateManager implementation. When you load first, it works well, but
when I click the sort header, throws the error, In the navigator, if I click back, and try again the error is not thrown.

The component assume that the method restoreState is called(and the Serialized model is restored) when there is a request, but this is not
true for trinidad StateManager Impl (If the tree exists trinidad takes it).

Solution: instead this line in method saveState of class org.apache.myfaces.component.html.ext.HtmlDataTable

if (isPreserveDataModel())

{ values[2] = saveAttachedState(context, getSerializableDataModel()); }

add these lines

if (isPreserveDataModel())

{ _preservedDataModel = getSerializableDataModel(); values[2] = saveAttachedState(context, _preservedDataModel); }

It's the same but note that when the method getDataModel() is called again, it checks _preservedDataModel, and
the model is restored.

I have probe this with and without trinidad (using myfaces tomahawk examples simple project) and works
without problems

I found a similar issue to this in TOMAHAWK-241, but in this issue I have not found anything about the environment
when the error is thrown.