hexl buffer of DOS file strange length

[john]

This bug report will be sent to the Free Software Foundation,
 not to your local site managers!!
Please write in English, because the Emacs maintainers do not have
translators to read other languages for them.

In GNU Emacs 20.7.1 (i586-pc-linux-gnulibc1, X toolkit)
 of Wed Oct 11 2000 on arrows

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:


I create a buffer containing

abc
def
ghi

Do
M-x set-buffer-file-coding-system dos
M-x hexl-mode

to find
00000000: 6162 630d 0a64 6566 0d0a 670d 690d 0a    abc..def..g.i..

I then find I cannot move the cursor beyond the 12th byte.

OK, I know it might be a slightly daft thing to do, but I did
actually encounter it for real on a Windows machine.

John