# File ../lib/fox/undolist.rb, line 132
    def add(command, doit=false)
      # Cut redo list
      cut

      # No command given?
      return true if (command == nil)

      # Add it to the end of the undo list
      @undolist.push(command)

      # Execute it right now?
      command.redo if doit

      # Update size
      @size += command.size     # measured after redo

      # Update the mark distance
      @marker = @marker + 1 if (@marker != nil)

      # Done
      return true
    end