bluetooth DUN silently discarding "invalid" APNs

[Marc Herbert <Marc Herbert gmail com>]

Hi,

  I wasted a number of hours when trying to tether using
bluetooth... it seems any APN containing an underscore "_" causes the
DUN configuration entered into the gnome bluetooth wizard to be
*SILENTLY* discarded.

Can anyone reproduce this? Only a bluetooth phone is needed, plus
deleting the bluetooth configuration for this phone if you already
have one (sorry), so you can run the wizard on it again. You do not
even need a valid network subscription to reproduce this problem.

I am using NetworkManager 0.8.4 in Fedora 14.

Since the APN is the hostname of the GGSN or PDN gateway, I guess this
"validation" tries to apply the restrictions of RFC 1123 concerning
hostnames (note that, as opposed to a common misconception, the DNS
itself does not have any such restriction, see section 11 in RFC
2181. DNS is not just for hostnames.)

I see extremely little value in this validation. There are millions of
other and more likely typos that it will never catch. Since it does
not even issue an error message but silently discard the user input
instead, the little value that ever was intended is completely
gone. This validation "feature" has now become a severe bug since it
hides the next and proper error message (i.e., "connection failed,
check your settings"). And wastes hours.

Even worse, wvdial is perfectly able to get me online using an APN
that includes an underscore. So whatever the standards say, this
validation prevents some configurations to work.

By the way it is not possible to enter a blank APN either (asking the
network use the default APN). This again works perfectly with wvdial.
And this is valid.

Cheers,

Marc