readline

# File lib/rexml/source.rb, line 264
    def readline
      str = @source.readline(@line_break)
      if @pending_buffer
        if str.nil?
          str = @pending_buffer
        else
          str = @pending_buffer + str
        end
        @pending_buffer = nil
      end
      return nil if str.nil?

      if @to_utf
        decode(str)
      else
        str.force_encoding(::Encoding::UTF_8) if @force_utf8
        str
      end
    end