[Tcsh] [PATCH] REMOTEHOST causes hang with IPv6 addresses

[Jamie Landeg-Jones]

Kimmo Suominen <kim at netbsd.org> wrote:

> Hi Chuck,
>
> Which version of tcsh are you having the issue with, and on which
> operating system?

For what it's worth, I just replicated the problem on a FreeBSD 13.1
machine that I've recently installed, but not yet had a chance to setup
(so it's pretty much stock)

I didn't have the delay, though - it turns out that no DNS lookups are
done on startup here. (though even when I tested the DNS lookup manually,
it was always less than a second, so that appears to be a local DNS problem)

(I never noticed this before, because all my IPv6 addresses normally
have PTR entries)

| jamie at catwalk:~ % w
|  9:51a.m.  up 4 days,  5:49, 1 user, load averages: 0.32, 0.29, 0.22
| USER       TTY      FROM                      LOGIN@  IDLE WHAT
| jamie      pts/0    2001:19f0:300:2185::4:3   9:48a.     - w
| jamie at catwalk:~ %
| jamie at catwalk:~ % echo $REMOTEHOST
| 2001
| jamie at catwalk:~ % echo $version
| tcsh 6.22.04 (Astron) 2021-04-26 (x86_64-amd-FreeBSD) options wide,nls,dl,al,kan,sm,rh,color,filec
| jamie at catwalk:~ % uname -a
| FreeBSD catwalk.dyslexicfish.net 13.1-RELEASE FreeBSD 13.1-RELEASE releng/13.1-n250148-fc952ac2212 GENERIC amd64

| 10:01 (28) "/tmp" root at catflap# time gethost 2001::
| 2001:: = 2001::
| 0.000u 0.001s 0:00.68 0.0%      0+0k 0+0io 0pf+0w
| 10:01 (29) "/tmp" root at catflap# time gethost fdd1::
| fdd1:: = fdd1::
| 0.000u 0.001s 0:00.00 0.0%      0+0k 0+0io 0pf+0w
| 10:01 (30) "/tmp" root at catflap# time gethost 2001:19f0:300:2185::1:1
| 2001:19f0:300:2185::1:1 = catflap.dyslexicfish.net
| 0.000u 0.002s 0:00.00 0.0%      0+0k 0+0io 0pf+0w

Cheers, Jamie