`CsvParser.Feature.ALLOW_TRAILING_COMMA` doesn't work with header columns

[bjmi]

When reading given CSV with jackson-dataformat-csv 2.9.9

name,age,
Roger,27,
Chris,53,

using following lines

List<Person> persons = new CsvMapper()
    .enable(CsvParser.Feature.ALLOW_TRAILING_COMMA)
    .readerFor(Person.class)
    .with(CsvSchema.emptySchema().withHeader())
    .<Person> readValues(csvAsString)
    .readAll();
...
class Person {
    public String name;
    public int age;
}

results in

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "" (class Person), not marked as ignorable (2 known properties: "name", "age"])
 at [Source: (StringReader); line: 2, column: 10] (through reference chain: Person[""])
	at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:61)
	at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:823)
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1153)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1589)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownVanilla(BeanDeserializerBase.java:1567)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:294)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
	at com.fasterxml.jackson.databind.MappingIterator.nextValue(MappingIterator.java:277)
	at com.fasterxml.jackson.databind.MappingIterator.readAll(MappingIterator.java:317)
	at com.fasterxml.jackson.databind.MappingIterator.readAll(MappingIterator.java:303)

The single trailing comma should be allowed in header columns too and should not raise an exception.

[cowtowncoder]

Sounds like a problem: thank you for reporting this.

[bjmi]

Are there any chances this can go to 2.10 too?

[cowtowncoder]

Was about to say no, due to risk, but looking at changes sure I can backport this I think.