Restore original selection problem

Type ab in realtime wysiwyg editor, select "a" and apply bold => "a" is bold
Select all text "ab", apply italic.
Expected: "a" bold+italic, "b" italic and "ab" is selected
Actual: "a" bold+italic, "b" italic but only"b" is selected.

The original local selection which was "ab" it should be restored.
The Tree model is properly synched.