src/Pure/Tools/spell_checker.scala

 
   def current_word(rendering: Rendering, range: Text.Range): Option[Text.Info[String]] =
   {
     for {
       spell_range <- rendering.spell_checker_point(range)
-      text <- rendering.model.get_text(spell_range)
+      text <- rendering.get_text(spell_range)
       info <- marked_words(spell_range.start, text, info => info.range.overlaps(range)).headOption
     } yield info
   }