Minor refactoring wrt #2632

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/DatabindContext.java

@@ -153,15 +153,11 @@ public JavaType constructType(Type type) {
 
     /**
      * Convenience method for constructing subtypes, retaining generic
-     * type parameter (if any)
+     * type parameter (if any).
+     *<p>
+     * Note: since 2.11 handling has varied a bit across serialization, deserialization.
      */
-    public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass) {
-        // simple optimization to avoid costly introspection if type-erased type does NOT differ
-        if (baseType.getRawClass() == subclass) {
-            return baseType;
-        }
-        return getConfig().constructSpecializedType(baseType, subclass);
-    }
+    public abstract JavaType constructSpecializedType(JavaType baseType, Class<?> subclass);
 
     /**
      * Lookup method called when code needs to resolve class name from input;

src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java

@@ -252,6 +252,13 @@ public final TypeFactory getTypeFactory() {
         return _config.getTypeFactory();
     }
 
+    @Override // since 2.11
+    public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass) {
+        // No specialized handling for deserialization, but needs to be implemented
+        return baseType.hasRawClass(subclass) ? baseType
+                : getConfig().constructSpecializedType(baseType, subclass);
+    }
+
     /**
      * Method for accessing default Locale to use: convenience method for
      *<pre>

src/main/java/com/fasterxml/jackson/databind/SerializerProvider.java

@@ -313,8 +313,7 @@ public void setNullKeySerializer(JsonSerializer<Object> nks)
 
     /*
     /**********************************************************
-    /* DatabindContext implementation (and closely related
-    /* but ser-specific)
+    /* DatabindContext implementation (and closely related but ser-specific)
     /**********************************************************
      */
 
@@ -334,6 +333,13 @@ public final TypeFactory getTypeFactory() {
         return _config.getTypeFactory();
     }
 
+    @Override // since 2.11
+    public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass) {
+        // Need little bit different handling due to [databind#2632]
+        return baseType.hasRawClass(subclass) ? baseType
+                : getConfig().constructSpecializedType(baseType, subclass);
+    }
+
     @Override
     public final Class<?> getActiveView() { return _serializationView; }
 

src/test/java/com/fasterxml/jackson/databind/jsontype/SubTypeResolutionTest.java

@@ -139,7 +139,7 @@ public void testSpecializeIncompatibleRawType() throws Exception
             assertNotNull(json);
             fail("Should not (yet?) pass");
         } catch (JsonMappingException e) {
-            verifyException(e, "Failed to specialize base type ");
+                verifyException(e, "Failed to specialize base type ");
         }
     }
 }