Error 400 with no error description if visit request receives no location, but location has seats defined

[pbek]

Follow up of #34...

You will get an error 400 (log says io.ktor.features.BadRequestException: No seat provided but location has seats defined) if a visit POST request without the seat number is made, but the location has seats defined.

e.g.

• https://server/location/c65200af79517a925d44/visit results in error 500
• https://server/location/c65200af79517a925d44-1/visit results in ok

In order to be able to show the user what the reason for the error 400 is it would be good to also return (at least) an actual error message.

There also is an error 400 if a seat is defined in the request but the location has no seats (io.ktor.features.BadRequestException: Seat provided but location has no seats defined).

(@euneuber, in case you want to watch)

[pbek]

The same issue is with other exceptions like io.ktor.features.BadRequestException: Seat must be <= location.seatCount, there is no way to know what happened on the frontend if there is no error message in the API.