Thanks for your answer Pavel.
This is expected - it is side effect of PostgreSQL implementation of
> function overloading and type conversions
>
> after installation citext, you will have more instances of function strpos
>
> strpos(citext, citext)
> strpos(text, text)
>
Do you think it would be appropriate to simply add an strpos(citext, text)
overload to the extension to make sure this behaves more as expected? If so
I can try to submit a patch at some point.