`configureAbsentsAsNulls` not working for primitive Optionals like `OptionalInt`

[lrpg]

type.isTypeOrSubTypeOf(Optional.class)

is evaluated to true with Optional<Integer> while
it is evaluated to false with OptionalInt because OptionalInt is not a type or subtype of Optional<>

Same goes for OptionalDouble and OptionalLong

https://github.com/FasterXML/jackson-modules-java8/blob/master/datatypes/src/main/java/com/fasterxml/jackson/datatype/jdk8/Jdk8BeanSerializerModifier.java#L26

[cowtowncoder]

What is the bug here? Optionalnt is indeed not a sub-type of Optional in Java world. You may think of them as related, but from Java (JVM) type system perspective they are not related.

But perhaps you have an actual problem, and above is just explaining why you think that might occur? If so, please describe the problem first.

[lrpg]

Jdk8Module.configureAbsentsAsNulls has an effect on Optional<> but not OptionalInt, OptionalLong and OptionalDouble, which is confusing and contradictory according to the javadoc of the Jdk8Module.configureAbsentsAsNulls:
Configuration setting that determines whether Optional.empty() is considered "same as null" for serialization purposes; that is, to be filtered same as nulls are. If enabled, absent values are treated like nulls; if disabled, they are not. In either case, absent values are always considered "empty".

The logic around Optional happens in Jdk8BeanSerializerModifier at type.isTypeOrSubTypeOf(Optional.class) as specified above.

[cowtowncoder]

@lrpg thank you for clarification, makes sense. I updated title to reflect what I think is the issue.

[cowtowncoder]

Ok required bit bigger changes but works now, for 2.9.0(.pr2).