Bug in GSON: DeserializationHandler changes Serialization of Abstract classes

gistfile1.java

import static org.junit.Assert.*;

import java.lang.reflect.Type;

import org.junit.Test;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;


public class GsonSerializationTest {

	@Test
	public void test() {
		GsonBuilder builder = new GsonBuilder();
		//builder.setPrettyPrinting();
		builder.registerTypeAdapter(AbstractClazz.class, new MetaDeserializer());
		Gson gson = builder.create();


		Container c = new Container();
		c.obj = new ConcreteClazz();

		String json = gson.toJson(c);
		assertEquals("{\"obj\":{\"memberConcrete\":2,\"memberAbstract\":1}}", json);
	}

	private abstract static class AbstractClazz {
		@SuppressWarnings("unused")
		public int memberAbstract = 1;
	}

	private static final class ConcreteClazz extends AbstractClazz {
		@SuppressWarnings("unused")
		public int memberConcrete = 2;
	}

	private static final class Container {
		@SuppressWarnings("unused")
		public AbstractClazz obj;
	}

	private final class MetaDeserializer implements JsonDeserializer<Object> {

		@Override
		public Object deserialize(final JsonElement jsonElement, final Type type,
								  final JsonDeserializationContext jsonDeserializationContext)
						   throws JsonParseException
		{
			return null;
		}
	}

}