Fix #2565

release-notes/CREDITS-2.x

@@ -1013,6 +1013,10 @@ Stefan Wendt (stewe@github)
   * Reported #2560: Check `WRAP_EXCEPTIONS` in `CollectionDeserializer.handleNonArray()`
   (2.10.2)
 
+Máté Rédecsi (rmatesz@github)
+  * Reported #953: i-I case convertion problem in Turkish locale with case-insensitive deserialization
+ (2.11.0)
+
 Ville Koskela (vjkoskela@github)
   * Contributed #2487: BeanDeserializerBuilder Protected Factory Method for Extension
   (2.11.0)
@@ -1034,6 +1038,6 @@ Joseph Koshakow (jkosh44@github)
     the same POJO for two different type ids
  (2.11.0)
 
-Máté Rédecsi (rmatesz@github)
-  * Reported #953: i-I case convertion problem in Turkish locale with case-insensitive deserialization
+Haowei Wen (yushijinhun@github)
+  * Reported #2565: Java 8 `Optional` not working with `@JsonUnwrapped` on unwrappable type
  (2.11.0)

release-notes/VERSION-2.x

@@ -25,6 +25,8 @@ Project: jackson-databind
   for non-static inner classes
 #2525: Incorrect `JsonStreamContext` for `TokenBuffer` and `TreeTraversingParser`
 #2555: Use `@JsonProperty(index)` for sorting properties on serialization
+#2565: Java 8 `Optional` not working with `@JsonUnwrapped` on unwrappable type
+ (reported by Haowei W)
 - Add `SerializerProvider.findContentValueSerializer()` methods
 
 2.10.2 (not yet released)

src/main/java/com/fasterxml/jackson/databind/ser/std/ReferenceTypeSerializer.java

@@ -130,7 +130,12 @@ protected ReferenceTypeSerializer(ReferenceTypeSerializer<?> base, BeanProperty
     public JsonSerializer<T> unwrappingSerializer(NameTransformer transformer) {
         JsonSerializer<Object> valueSer = _valueSerializer;
         if (valueSer != null) {
+            // 09-Dec-2019, tatu: [databind#2565] Can not assume that serializer in
+            //    question actually can unwrap
             valueSer = valueSer.unwrappingSerializer(transformer);
+            if (valueSer == _valueSerializer) {
+                return this;
+            }
         }
         NameTransformer unwrapper = (_unwrapper == null) ? transformer
                 : NameTransformer.chainedTransformer(transformer, _unwrapper);

src/test/java/com/fasterxml/jackson/databind/deser/jdk/JDKAtomicTypesDeserTest.java

@@ -97,7 +97,7 @@ static class Issue1256Bean {
     // [databind#2303]
     static class MyBean2303 {
         public AtomicReference<AtomicReference<Integer>> refRef;
-    }    
+    }
 
     /*
     /**********************************************************

src/test/java/com/fasterxml/jackson/databind/ser/jdk/AtomicTypeSerializationTest.java

@@ -5,6 +5,7 @@
 import java.util.concurrent.atomic.*;
 
 import com.fasterxml.jackson.annotation.*;
+
 import com.fasterxml.jackson.databind.BaseMapTest;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
@@ -64,13 +65,19 @@ static class Foo implements Strategy {
         }
     }
 
+    // [databind#2565]: problems with JsonUnwrapped, non-unwrappable type
+    static class MyBean2565 {
+        @JsonUnwrapped
+        public AtomicReference<String> maybeText = new AtomicReference<>("value");
+    }
+
     /*
     /**********************************************************
     /* Test methods
     /**********************************************************
      */
 
-    private final ObjectMapper MAPPER = objectMapper();
+    private final ObjectMapper MAPPER = newJsonMapper();
 
     public void testAtomicBoolean() throws Exception
     {
@@ -135,4 +142,11 @@ public void testPolymorphicReferenceListOf() throws Exception
         String json = MAPPER.writeValueAsString(new ContainerB());
         assertEquals("{\"strategy\":[" + EXPECTED + "]}", json);
     }
+
+    // [databind#2565]: problems with JsonUnwrapped, non-unwrappable type
+    public void testWithUnwrappableUnwrapped() throws Exception
+    {
+        assertEquals(aposToQuotes("{'maybeText':'value'}"),
+                MAPPER.writeValueAsString(new MyBean2565()));
+    }
 }