Fix/create reference with descriptor using inheritance

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptor.java

@@ -1945,6 +1945,13 @@ public T createReference(Boolean readOnly, boolean disableLazyLoad, Object id, P
       }
     }
     try {
+     if (inheritInfo != null && !inheritInfo.isConcrete()) {
+        // we actually need to do a query because we don't know the type without the discriminator
+        // value, just select the id property and discriminator column (auto added)
+        DefaultOrmQuery<T> query = new DefaultOrmQuery<>(this, ebeanServer, ebeanServer.getExpressionFactory());
+        return query.select(getIdProperty().getName()).setId(id).findOne();
+      }
+
       EntityBean eb = createEntityBean();
       id = convertSetId(id, eb);
 

src/test/java/io/ebeaninternal/server/deploy/BeanDescriptorTest.java

@@ -1,10 +1,15 @@
 package io.ebeaninternal.server.deploy;
 
 import io.ebean.BaseTestCase;
+import io.ebean.Ebean;
 import io.ebean.bean.EntityBean;
 import io.ebean.plugin.Property;
 import org.junit.Test;
+import org.tests.model.basic.Animal;
+import org.tests.model.basic.AnimalShelter;
+import org.tests.model.basic.Cat;
 import org.tests.model.basic.Customer;
+import org.tests.model.basic.Dog;
 import org.tests.model.basic.Order;
 
 import java.util.Collection;
@@ -46,6 +51,29 @@ public void createReference_when_disabledLazyLoad() {
     Customer bean = customerDesc.createReference(Boolean.FALSE, true, 42, null);
     assertThat(server().getBeanState(bean).isDisableLazyLoad()).isTrue();
   }
+
+  @Test
+  public void createReference_with_inheritance() {
+    Cat cat = new Cat();
+    cat.setName("Puss");
+    Ebean.save(cat);
+
+    Dog dog = new Dog();
+    dog.setRegistrationNumber("DOGGIE");
+    Ebean.save(dog);
+
+    AnimalShelter shelter = new AnimalShelter();
+    shelter.setName("My Animal Shelter");
+    shelter.getAnimals().add(cat);
+    shelter.getAnimals().add(dog);
+
+    Ebean.save(shelter);
+
+    BeanDescriptor<Animal> animalDesc = spiEbeanServer().getBeanDescriptor(Animal.class);
+
+    Animal bean = animalDesc.createReference(Boolean.FALSE, false, dog.getId(), null);
+    assertThat(bean.getId()).isEqualTo(dog.getId());
+  }
 
   @Test
   public void allProperties() {