Fix #1125

Author: cowtowncoder

release-notes/VERSION

@@ -6,6 +6,7 @@ Project: jackson-databind
 
 2.7.3 (not yet released)
 
+#1125: Problem with polymorphic types, losing properties from base type(s)
 #1150: Problem with Object id handling, explicit `null` token
  (reported by Xavi T)
 

src/main/java/com/fasterxml/jackson/databind/type/SimpleType.java

@@ -127,16 +127,43 @@ protected JavaType _narrow(Class<?> subclass)
         }
         // Should we check that there is a sub-class relationship?
         // 15-Jan-2016, tatu: Almost yes, but there are some complications with
-        //    placeholder values, so no.
-        /*
+        //    placeholder values (`Void`, `NoClass`), so can not quite do yet.
+        // TODO: fix in 2.8
         if (!_class.isAssignableFrom(subclass)) {
+            /*
             throw new IllegalArgumentException("Class "+subclass.getName()+" not sub-type of "
                     +_class.getName());
+                    */
+            return new SimpleType(subclass, _bindings, this, _superInterfaces,
+                    _valueHandler, _typeHandler, _asStatic);
         }
-        */
-        // 15-Jan-2015, tatu: Not correct; should really re-resolve...
-        return new SimpleType(subclass, _bindings, this, _superInterfaces,
-                _valueHandler, _typeHandler, _asStatic);
+        // Otherwise, stitch together the hierarchy. First, super-class
+        Class<?> next = subclass.getSuperclass();
+        if (next == _class) { // straight up parent class? Great.
+            return new SimpleType(subclass, _bindings, this,
+                    _superInterfaces, _valueHandler, _typeHandler, _asStatic);
+        }
+        if ((next != null) && _class.isAssignableFrom(next)) {
+            JavaType superb = _narrow(next);
+            return new SimpleType(subclass, _bindings, superb,
+                    null, _valueHandler, _typeHandler, _asStatic);
+        }
+        // if not found, try a super-interface
+        Class<?>[] nextI = subclass.getInterfaces();
+        for (Class<?> iface : nextI) {
+            if (iface == _class) { // directly implemented
+                return new SimpleType(subclass, _bindings, null,
+                        new JavaType[] { this }, _valueHandler, _typeHandler, _asStatic);
+            }
+            if (_class.isAssignableFrom(iface)) { // indirect, so recurse
+                JavaType superb = _narrow(iface);
+                return new SimpleType(subclass, _bindings, null,
+                        new JavaType[] { superb }, _valueHandler, _typeHandler, _asStatic);
+            }
+        }
+        // should not get here but...
+        throw new IllegalArgumentException("Internal error: Can not resolve sub-type for Class "+subclass.getName()+" to "
+                +_class.getName());
     }
 
     @Override

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

@@ -160,7 +160,7 @@ public void testDeserializationWithArrayOfSize2() throws Exception
         assertEquals(Arrays.asList("a", "b"), ((MyInter) inter).blah);
     }
 
-    // [Databind#148]
+    // [databind#148]
     public void testDefaultAsNoClass() throws Exception
     {
         Object ob = MAPPER.readerFor(DefaultWithNoClass.class).readValue("{ }");
@@ -178,7 +178,7 @@ public void testDefaultAsVoid() throws Exception
         assertNull(ob);
     }
 
-    // [Databind#148]
+    // [databind#148]
     public void testBadTypeAsNull() throws Exception
     {
         ObjectMapper mapper = new ObjectMapper();
@@ -189,7 +189,7 @@ public void testBadTypeAsNull() throws Exception
         assertNull(ob);
     }
 
-    // [Databind#511]
+    // [databind#511]
     public void testInvalidTypeId511() throws Exception {
         ObjectReader reader = MAPPER.reader().without(
                 DeserializationFeature.FAIL_ON_INVALID_SUBTYPE,
@@ -203,7 +203,7 @@ public void testInvalidTypeId511() throws Exception {
         assertNotNull(badResult);
     }
 
-    // [Databind#656]
+    // [databind#656]
     public void testDefaultImplWithObjectWrapper() throws Exception
     {
         BaseFor656 value = MAPPER.readValue(aposToQuotes("{'foobar':{'a':3}}"), BaseFor656.class);