misc/174436: Jails with numbers as names don't work

[Ian Smith]

On Fri, 14 Dec 2012, Glen Barber wrote:
 > The following reply was made to PR misc/174436; it has been noted by GNATS.
 > 
 > From: Glen Barber <gjb at FreeBSD.org>
 > To: Eitan Adler <lists at eitanadler.com>
 > Cc: Robert Schulze <rs at bytecamp.net>,
 > 	bug-followup <bug-followup at freebsd.org>
 > Subject: Re: misc/174436: Jails with numbers as names don't work
 > Date: Fri, 14 Dec 2012 10:58:15 -0500
 > 
 >  --xgyAXRrhYN0wYx8y
 >  Content-Type: text/plain; charset=us-ascii
 >  Content-Disposition: inline
 >  Content-Transfer-Encoding: quoted-printable
 >  
 >  On Fri, Dec 14, 2012 at 10:51:48AM -0500, Eitan Adler wrote:
 >  > On 14 December 2012 10:13, Robert Schulze <rs at bytecamp.net> wrote:
 >  >=20
 >  > >>Description:
 >  > > When configuring jails with numbers as their names, one can't start a j=
 >  ail named "0" (system panics)
 >  >=20
 >  > This is not just a documentation bug.  I'm concerned about the system
 >  > panic here.
 >  >=20
 >  
 >  So am I, but I am the one that added the rc.conf(5) note about jail
 >  names containing only alphanumeric characters.

Back in my day, '0' was an alphanumeric character :)

Should it be that jail names should begin with an alphabetic character?  
Or just not parse as numeric?  Or is only '0' problematic?  ie, is this 
just an rc.d parsing issue with substitution, or something deeper?

/etc/defaults/rc.conf also has room for a half-line qualification:
  # NOTES:
- # - replace 'example' with the jail's name.
+ # - replace 'example' with the jail's name, which must be $whatever

Consulting Parameter 'name' in jail(8) leaves me none the wiser: if name 
defaults to jid if not supplied, are jids alphanumeric?

confused, Ian