host, dig and nslookup don't resolve IDN domains when not used in a tty

Summary

When calling the tools host, dig or nslookup getting data for a IDN domain only works in a tty environment. That's an extremely non-obvious bug.

Calling host stöcker.eu works, while host stöcker.eu |cat cannot resolve the domain.

See also my initial bug report to perl (https://github.com/Perl/perl5/issues/22080) which points to the exact code location for this bug.

BIND version affected

I'm using bind-utils-9.18.24-1.1.x86_64 on openSUSE Tumbleweed. Same happens on older version (Ubuntu LTS).

Steps to reproduce

See description above

1. Call host stöcker.eu |cat in Linux shell

What is the current bug behavior?

Does not resolve a correct name

What is the expected correct behavior?

Does resolve the name whether it's a tty or not.

Relevant configuration files

none

Relevant logs

none