Mapping ZonedDateTime or OffsetDateTime to LocalDateTime #4027

Expected behavior

This is very similar to:

• Mapping LocalDate to LocalDateTime and reverse #3304
• Support for implicit conversion between java.time.LocalDate and java.time.LocalDateTime #3199
  ...which was implemented in 1.6, so I expected all time-related conversions to behave the same.

However, given:

record Zoned(ZonedDateTime zonedDateTime) {}
record Local(LocalDateTime localDateTime) {}

@Mapper
interface ZonedToLocalMapper {
    @Mapping(target = "localDateTime", source = "zonedDateTime")
    Local toLocal(Zoned zoned);
}

I'd expect the mapper to just do

localDateTime = zonedDateTime.toLocalDateTime();

The reverse fails nicely, that's correct as converting LocalDateTime to ZonedDateTime requires a Zone.

Actual behavior

however, we see this monstrosity

localDateTime = xmlGregorianCalendarToLocalDateTime( zonedDateTimeToXmlGregorianCalendar( zonedDateTime ) );

with a lot of javax.xml.datatype classes. Those should be unnecessary.

Steps to reproduce the problem

record Zoned(ZonedDateTime zonedDateTime) {}
record Local(LocalDateTime localDateTime) {}

@Mapper
interface ZonedToLocalMapper {
    @Mapping(target = "localDateTime", source = "zonedDateTime")
    Local toLocal(Zoned zoned);
}

and the sane for OffsetDateTime on the left side and likely Instant and LocalTime and LocalDate on the right side etc.

MapStruct Version

1.6.3