#840 Ensure primitive types are assignable to Comparable/Serializable fields

src/com/esotericsoftware/kryo/util/Util.java

@@ -233,15 +233,19 @@ public static Class getElementClass (Class arrayClass) {
 	public static boolean isAssignableTo (Class<?> from, Class<?> to) {
 		if (to == Object.class) return true;
 		if (to.isAssignableFrom(from)) return true;
-		if (from.isPrimitive()) return isPrimitiveWrapperOf(to, from);
+		if (from.isPrimitive()) return isPrimitiveWrapperOf(to, from) || to.isAssignableFrom(getPrimitiveWrapper(from));
 		if (to.isPrimitive()) return isPrimitiveWrapperOf(from, to);
 		if (from == ClosureSerializer.Closure.class) return to.isInterface();
 		return false;
 	}
 
 	private static boolean isPrimitiveWrapperOf (Class<?> targetClass, Class<?> primitive) {
-		if (!primitive.isPrimitive()) throw new IllegalArgumentException("First argument has to be primitive type");
-		return primitiveWrappers.get(primitive) == targetClass;
+		return getPrimitiveWrapper(primitive) == targetClass;
+	}
+
+	private static Class<?> getPrimitiveWrapper (Class<?> primitive) {
+		if (!primitive.isPrimitive()) throw new IllegalArgumentException("Argument has to be primitive type");
+		return primitiveWrappers.get(primitive);
 	}
 
 	public static boolean isAscii (String value) {

test/com/esotericsoftware/kryo/serializers/CompatibleFieldSerializerTest.java

@@ -493,19 +493,28 @@ void testClassWithObjectField() {
 		assertEquals(o2, kryo.readClassAndObject(new Input(output2.getBuffer())));
 	}
 
+	// https://github.com/EsotericSoftware/kryo/issues/821
 	@Test
 	void testClassWithLambdaField () {
 		CompatibleFieldSerializer.CompatibleFieldSerializerConfig config = new CompatibleFieldSerializer.CompatibleFieldSerializerConfig();
-		config.setChunkedEncoding(true);
-		config.setReadUnknownFieldData(true);
-		kryo.setDefaultSerializer(new CompatibleFieldSerializerFactory());
+		kryo.setDefaultSerializer(new CompatibleFieldSerializerFactory(config));
 		kryo.register(ClassWithLambdaField.class);
 		kryo.register(SerializedLambda.class);
 		kryo.register(ClosureSerializer.Closure.class, new ClosureSerializer());
 
 		roundTrip(236, new ClassWithLambdaField());
 	}
 
+	// https://github.com/EsotericSoftware/kryo/issues/840
+	@Test
+	void testClassWithGenericField () {
+		CompatibleFieldSerializer.CompatibleFieldSerializerConfig config = new CompatibleFieldSerializer.CompatibleFieldSerializerConfig();
+		kryo.setDefaultSerializer(new CompatibleFieldSerializerFactory(config));
+		kryo.register(ClassWithGenericField.class);
+
+		roundTrip(9, new ClassWithGenericField<>(1));
+	}
+
 	public static class TestClass {
 		public String text = "something";
 		public int moo = 120;
@@ -783,4 +792,23 @@ public boolean equals (Object o) {
 			return Objects.equals(callback.call(), that.callback.call());
 		}
 	}
+
+	public static class ClassWithGenericField<T extends Comparable<T>> {
+
+		private T value;
+
+		public ClassWithGenericField() {
+		}
+
+		public ClassWithGenericField(T value) {
+			this.value = value;
+		}
+
+		public boolean equals (Object o) {
+			if (this == o) return true;
+			if (o == null || getClass() != o.getClass()) return false;
+			ClassWithGenericField<?> that = (ClassWithGenericField<?>)o;
+			return Objects.equals(value, that.value);
+		}
+	}
 }

test/com/esotericsoftware/kryo/util/UtilTest.java

@@ -23,6 +23,8 @@
 
 import org.junit.jupiter.api.Test;
 
+import java.io.Serializable;
+
 class UtilTest {
 
     @Test
@@ -33,6 +35,10 @@ void testIsAssignableTo() {
         assertTrue(Util.isAssignableTo(long.class, long.class));
         assertTrue(Util.isAssignableTo(Long.class, Object.class));
         assertTrue(Util.isAssignableTo(long.class, Object.class));
+        assertTrue(Util.isAssignableTo(Integer.class, Comparable.class));
+        assertTrue(Util.isAssignableTo(Integer.class, Serializable.class));
+        assertTrue(Util.isAssignableTo(int.class, Comparable.class));
+        assertTrue(Util.isAssignableTo(int.class, Serializable.class));
 
         assertFalse(Util.isAssignableTo(String.class, Long.class));
         assertFalse(Util.isAssignableTo(String.class, long.class));