Cached Optional serializer does not apply annotations for POJO properties

[codicusmaximus]

Simple test case:

public class JsonObjectTest {
    
    @JsonFormat(shape=JsonFormat.Shape.STRING, pattern="yyyy-MM-dd")
    private Optional<Date> date1;
    @JsonFormat(shape=JsonFormat.Shape.STRING, pattern="yyyy-MM")
    private Optional<Date> date2;
    
    public JsonObjectTest () {}

    public Optional<Date> getDate1() {
        return date1;
    }
    public void setDate1(Optional<Date> date1) {
        this.date1 = date1;
    }
    public Optional<Date> getDate2() {
        return date2;
    }
    public void setDate2(Optional<Date> date2) {
        this.date2 = date2;
    }
    
}

public class Main {
    public static void main(String[] args) throws JsonProcessingException {
        JsonObjectTest t = new JsonObjectTest();
        t.setDate1(Optional.ofNullable(new Date()));
        t.setDate2(Optional.ofNullable(new Date()));
        ObjectMapper mapper = new ObjectMapper().registerModule(new Jdk8Module());
        System.out.println(mapper.writeValueAsString(t));
    }
}

produces the output:
{"date1":"2017-03-10","date2":"2017-03-10"}

changing the order of the members to:

    @JsonFormat(shape=JsonFormat.Shape.STRING, pattern="yyyy-MM")
    private Optional<Date> date2;
    @JsonFormat(shape=JsonFormat.Shape.STRING, pattern="yyyy-MM-dd")
    private Optional<Date> date1;

produces the output:
{"date2":"2017-03","date1":"2017-03"}

I have found that the issue lies in OptionalSerializer.java on the ser = _findCachedSerializer(provider, value.getClass()); line. The first time a Date is encountered, a new serializer is constructed which observes the relevant annotation; however, every time a Date is encountered afterwards the cached serializer is used without any consideration regarding annotation differences.

[codicusmaximus]

I believe all that's needed is
ser = (JsonSerializer<Object>)provider.handlePrimaryContextualization(ser, _property);
after the _findCachedSerializer line. I will test this and submit a pull request.

[cowtowncoder]

Appears to affect 2.8 at least. Due to repo refactoring needs to be applied in 2 places, which is fine, I can handle the other one.
Added some notes on suggested patch, but when I get a chance I can have better look at changes.

[cowtowncoder]

Ok, found a simpler fix which I think is proper; different call to SerializerProvider that handles contextualization call as expected.

[codicusmaximus]

Sounds good, thank you very much!