nsupdate -t timeout does not work

Summary

nsupdate option -t is broken and does not have any effect in v9.18 and v9.19 branches. It works in v9.16.

BIND version used

Versions affected:

• Affects v9.18: 9.18.10-dev 59cb6fa5
• Affects v9.19: 9.19.8-dev 48a92653

Not affected:

• v9.16: 9.16.36-dev 0fcec7a2

Steps to reproduce

Setup "something" which accepts UDP packets or TCP connections and does not respond.

In short, use nsupdate -t, either using TCP or TCP.

TCP

socat tcp6-listen:5301 -
time nsupdate -L 99 -p 5301 -v -t 1 /tmp/n/upd

• observe time to timeout - 30+ seconds

UDP

socat udp6-listen:5353 - &
time /tmp/main/bin/nsupdate -p 5353 -L 99 -t 1 /tmp/n/upd

nsupdate input file (content is not important): upd

What is the current bug behavior?

• Explicitly specified timeout value 1 is ignored.
• Default timeout 300 seconds (specified in man page) is also ignored.

What is the expected correct behavior?

Timeouts work.

Relevant logs and/or screenshots

• main-tcp.log
• main-udp.log

Please note the TCP is also suspicious because it seems it retries over the same connection? Huh?

Based on man page description of -u I would expect retries to apply only to UDP.