commit 7e7be29f8f44f4e883c44b4cf2ec68c486442afe
Author: Ingo Korb <ingo@akana.de>
Date:   Wed Jan 18 22:11:20 2023 +0100

    Turn on -Wextra and fix the fallout
    
    Enable even more compiler warnings with -Wextra and fix all of the
    fallout caused by it - most of them about unused function parameters.