I regret to have distracted your attention. All the above applies to a terminal window (KDE's konsole) in my GUI KDE. On the bare FreeBSD console, everything is fine. So this is a bug in some KDE library or konsole. I'm sorry I did not have the idea to test that on the bare console right away. I'll close this bug here.

Hello Mr. Niibe,

in your test, which you did on Linux I guess, utf-8 is written downcase, whereas on my system, it is written uppercase 'UTF-8, conforming to what I find elsewhere (e.g. Wikipedia and RFC 3629). I do not know though, if there is a recommended way to spell it. So the bug might be: gpg does not compare the RFC spelling uppercase, but the linuxism: utf-8 witten downcase. Then the correct fix would be to compare uppercase UTF-8 only, and let Linux fix their system to use the correct uppercase throughout the system... ;)
2nd, I know that FreeBSD has some issues with internationalization: it does not support charsets in their POSIX meaning, but emulates them by combining all available locales and (matching) CODESETs. Usually, this is not a problem, and most translations and handling of UTF-8 works as expected. Maybe this has some subtle effect causing this issue.

Hello Werner,