Wrong type in relationships section when using lookup by id and resource is a subtype.

[lgringo]

Issue

Given a resource named main having one related resource named related of type a, and a have a sub-type b, and using @JsonApiRelation(lookup=AUTOMATICALLY_WHEN_NULL) and @JsonApiRelationId
When requesting main using include=related and repository implementation of main fills the id of related, but this id matches an instance of b (which extends a).
Result the type of related in relationships section is a, the type of related in included section is b
Expected Same type, ideally b into the 2 sections.

Example :

Resources

@JsonApiResource(type = "main")
public class MainResource {

	@JsonApiId
	private String id;

	@JsonApiRelationId
	private String relatedId

	@JsonApiRelation(lookUp = LookupIncludeBehavior.AUTOMATICALLY_WHEN_NULL)
	private A related;
}

@JsonApiResource(type = "a", subTypes = RelatedResourceB.class)
public class RelatedResourceA {
	@JsonApiId
	private String id;

	private String data;
}

@JsonApiResource(type = "b", resourcePath="a")
public class RelatedResourceB extends RelatedResourceA {

	private String otherData;
}

NB: Getters and setters are omitted for brevity.

Requests

NB: requests are written with httpie, for these examples, you just have to know that 'x==y' means add a request parameter x with value y.

• http :8080/main/mainId include==related

{
    "data": {
        "id": "mainId",
        "links": " [...] "
        "relationships": {
            "related": {
                "data": {
                    "id": "mainId.B",
                    "type": "a"
                },
                "links": " [...] "
            }
        },
        "type": "main"
    },
    "included": [
        {
            "attributes": {
                "data": "Label from resource B",
                "otherData": "Other"
            },
            "id": "mainId.B",
            "links": " [...] ",
            "type": "b"
        }
    ],
    "links": " [...] "
}

data.relationships.related.data.type should match included[0].type

Remark

I know that having Crnk returning type b if included=related is not specified is not possible. But when included is present, types should match.