まつもと ゆきひろです

In message "[ruby-dev:10109] bit fix for net/protocol.rb"
    on 00/06/23, Toshiro Kuwabara <toshirok / yb3.so-net.ne.jp> writes:

|-      @buffer = @buffer[ len, bsi - len ]
|+      if bsi - len > 0
|+	@buffer = @buffer[ len, bsi - len ]
|+      else
|+	@buffer = ""
|+      end

        @buffer = @buffer[ len, bsi - len ] || ""

なんて感じでどうでしょう?