src/Pure/Thy/thy_syntax.scala

   @tailrec def edit_text(eds: List[Text.Edit], commands: Linear_Set[Command]): Linear_Set[Command] =
   {
     eds match {
       case e :: es =>
         def insert_text(cmd: Option[Command], text: String): Linear_Set[Command] =
-          if (text == "") commands else commands.insert_after(cmd, Command.unparsed(text))
+          if (text == "") commands else commands.insert_after(cmd, Command.text(text))
 
         Document.Node.Commands.starts(commands.iterator).find {
           case (cmd, cmd_start) =>
             e.can_edit(cmd.source, cmd_start) ||
               e.is_insert && e.start == cmd_start + cmd.length