jackson-dataformat-xml: `XmlMapper` 2.12 regression: no default no-arg ctor found

As described first in FasterXML/jackson-module-kotlin#396, 2.12.0 has introduced a regression to the XmlMapper. I have managed to reproduce the regression in the below Java snippet, which works on 2.11.4, but fails on 2.12.{0…4}:

package com.vlkan.jackson;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonRootName;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import org.junit.jupiter.api.Test;

import java.io.IOException;
import java.nio.charset.StandardCharsets;

import static org.junit.jupiter.api.Assertions.assertEquals;

class MixinTest {

    interface Problem {

        String DEFAULT_TYPE = "about:blank";

        int DEFAULT_STATUS = 500;

        String getType();

        int getStatus();

    }

    static class DefaultProblem implements Problem {

        private final String type;

        private final int status;

        /**
         * This is required to workaround Jackson's missing support for static
         * {@link JsonCreator}s in mix-ins. That is, we need to define the
         * creator on a constructor in the mix-in that is matching with a
         * constructor here too.
         *
         * @see <a href="https://github.com/FasterXML/jackson-databind/issues/1820">jackson-databind issue 1820</a>
         */
        DefaultProblem(String type, Integer status) {
            this.type = type != null ? type : Problem.DEFAULT_TYPE;
            this.status = status != null ? status : Problem.DEFAULT_STATUS;
        }

        @Override
        public String getType() {
            return type;
        }

        @Override
        public int getStatus() {
            return status;
        }

    }

    @JsonTypeInfo(
            use = JsonTypeInfo.Id.NAME,
            include = JsonTypeInfo.As.EXISTING_PROPERTY,
            property = "type",
            defaultImpl = DefaultProblem.class,
            visible = true)
    @JsonInclude(JsonInclude.Include.NON_EMPTY)
    @JsonRootName("problem")
    interface ProblemMixIn extends Problem {

        @Override
        @JsonProperty("type")
        String getType();

        @Override
        @JsonProperty("status")
        int getStatus();

    }

    abstract static class DefaultProblemMixIn extends DefaultProblem {

        @JsonCreator
        DefaultProblemMixIn(
                @JsonProperty("type") String type,
                @JsonProperty("status") Integer status) {
            super(type, status);
            throw new IllegalStateException(
                    "mix-in constructor is there only for extracting the JSON mapping, " +
                            "it should not have been called");
        }

    }

    static class ProblemModule extends SimpleModule {

        @Override
        public void setupModule(SetupContext context) {
            super.setupModule(context);
            registerMixIns(context);
        }

        private static void registerMixIns(SetupContext context) {
            context.setMixInAnnotations(DefaultProblem.class, DefaultProblemMixIn.class);
            context.setMixInAnnotations(Problem.class, ProblemMixIn.class);
        }

    }

    private static final ProblemModule MODULE = new ProblemModule();

    private static final ObjectMapper JSON_MAPPER = new ObjectMapper().registerModule(MODULE);

    private static final XmlMapper XML_MAPPER = (XmlMapper) new XmlMapper().registerModule(MODULE);

    @Test
    void test_empty_Problem_JSON_deserialization() throws IOException {
        byte[] problemJsonBytes = "{}".getBytes(StandardCharsets.UTF_8);
        Problem problem = JSON_MAPPER.readValue(problemJsonBytes, Problem.class);
        assertEquals(Problem.DEFAULT_TYPE, problem.getType());
        assertEquals(Problem.DEFAULT_STATUS, problem.getStatus());
    }

    @Test
    void test_empty_Problem_XML_deserialization() throws IOException {
        byte[] problemXmlBytes = "<problem/>".getBytes(StandardCharsets.UTF_8);
        Problem problem = XML_MAPPER.readValue(problemXmlBytes, Problem.class);
        assertEquals(Problem.DEFAULT_TYPE, problem.getType());
        assertEquals(Problem.DEFAULT_STATUS, problem.getStatus());
    }

}

Both tests pass on 2.11.4, whereas, on 2.12.{0…4}, test_empty_Problem_JSON_deserialization() passes and test_empty_Problem_XML_deserialization() fails with the following message:

com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.vlkan.jackson.MixinTest$DefaultProblem` (although at least one Creator exists): no default no-arguments constructor found
 at [Source: (byte[])"<problem/>"; line: 1, column: 1]

	at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
	at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1588)
	at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1213)
	at com.fasterxml.jackson.databind.deser.ValueInstantiator.createUsingDefault(ValueInstantiator.java:248)
	at com.fasterxml.jackson.databind.deser.std.StdValueInstantiator.createUsingDefault(StdValueInstantiator.java:275)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.getEmptyValue(BeanDeserializerBase.java:1042)
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer._deserializeFromEmptyString(StdDeserializer.java:322)
	at com.fasterxml.jackson.databind.deser.std.StdDeserializer._deserializeFromString(StdDeserializer.java:270)
	at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromString(BeanDeserializerBase.java:1495)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:207)
	at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:197)
	at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedUsingDefaultImpl(AsPropertyTypeDeserializer.java:194)
	at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:96)
	at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserializeWithType(AbstractDeserializer.java:263)
	at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:74)
	at com.fasterxml.jackson.dataformat.xml.deser.XmlDeserializationContext.readRootValue(XmlDeserializationContext.java:91)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4593)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3609)
	at com.vlkan.jackson.MixinTest.test_empty_Problem_XML_deserialization(MixinTest.java:129)
        ...

In order to make test_empty_Problem_XML_deserialization() pass on 2.12.{0…4}, one needs to add a no-arg ctor to DefaultProblem.