[9fans] frogs and osx

["Steve Simon" <steve@quintile.net>]

Hi,

Using u9fs to access my mac I find I cannot see directories (folders)
that have their own specific icon.

This turns out to be because these directories contain a file
Icon<cr> whiel <cr> is ASCII 13, and /sys/src/9/port/chan.c:1656
defines the frogs illegal in filenames to include carriage return.

Why does frogs contain these latters, My feeling is that only <nul>
should be illegal, perhaps these are a hangover from pre utf-8
days?

Perhaps there is a good reason for not allowing such characters,
I can see that creating such files should be discouraged but
failing a read(2) of a directory containing such files seems extreme.

Is it historic or there for a very good reason™ ?

-Steve