Fix #2060 (... again... was missing another path)

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -4,6 +4,12 @@ Project: jackson-databind
 === Releases === 
 ------------------------------------------------------------------------
 
+2.9.7 (not yet released)
+
+#2060: `UnwrappingBeanPropertyWriter` incorrectly assumes the found serializer is
+  of type `UnwrappingBeanSerializer`
+ (reported by Petar T)
+
 2.9.6 (12-Jun-2018)
 
 #955: Add `MapperFeature.USE_BASE_TYPE_AS_DEFAULT_IMPL` to use declared base type
@@ -52,9 +58,6 @@ Project: jackson-databind
  (reported by Guixiong Wu)
 #2058: CVE-2018-12023: Block polymorphic deserialization of types from Oracle JDBC driver
  (reported by Guixiong Wu)
-#2060: `UnwrappingBeanPropertyWriter` incorrectly assumes the found serializer is
-  of type `UnwrappingBeanSerializer`
- (reported by Petar T)
 
 2.9.5 (26-Mar-2018)
 

src/main/java/com/fasterxml/jackson/databind/ser/impl/UnwrappingBeanPropertyWriter.java

@@ -213,8 +213,11 @@ protected JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map,
             serializer = provider.findValueSerializer(type, this);
         }
         NameTransformer t = _nameTransformer;
-        if (serializer.isUnwrappingSerializer()) {
-            t = NameTransformer.chainedTransformer(t, ((UnwrappingBeanSerializer) serializer)._nameTransformer);
+        if (serializer.isUnwrappingSerializer()
+            // as per [databind#2060], need to also check this, in case someone writes
+            // custom implementation that does not extend standard implementation:
+            && (serializer instanceof UnwrappingBeanSerializer)) {
+                t = NameTransformer.chainedTransformer(t, ((UnwrappingBeanSerializer) serializer)._nameTransformer);
         }
         serializer = serializer.unwrappingSerializer(t);