Validate ClassName and SuperClassName only when required in deserializer

Common/Core/vtkDeserializer.cxx

@@ -81,32 +81,33 @@ bool vtkDeserializer::DeserializeJSON(
   }
   std::string className;
   std::vector<std::string> superClassNames;
+  if (objectBase == nullptr)
   {
-    const auto iter = state.find("ClassName");
-    if (iter == state.end())
-    {
-      vtkErrorMacro(<< "Failed to find 'ClassName' in state at id=" << identifier);
-      return false;
-    }
-    else
-    {
-      className = iter->get<std::string>();
-    }
-  }
-  {
-    const auto iter = state.find("SuperClassNames");
-    if (iter == state.end())
+    // Only look for ClassName and SuperClassNames if we are going to construct the object.
     {
-      vtkErrorMacro(<< "Failed to find 'SuperClassNames' in state at id=" << identifier);
-      return false;
+      const auto iter = state.find("ClassName");
+      if (iter == state.end())
+      {
+        vtkErrorMacro(<< "Failed to find 'ClassName' in state at id=" << identifier);
+        return false;
+      }
+      else
+      {
+        className = iter->get<std::string>();
+      }
     }
-    else
     {
-      superClassNames = iter->get<std::vector<std::string>>();
+      const auto iter = state.find("SuperClassNames");
+      if (iter == state.end())
+      {
+        vtkErrorMacro(<< "Failed to find 'SuperClassNames' in state at id=" << identifier);
+        return false;
+      }
+      else
+      {
+        superClassNames = iter->get<std::vector<std::string>>();
+      }
     }
-  }
-  if (objectBase == nullptr)
-  {
     if (auto ptr = this->ConstructObject(className, superClassNames))
     {
       objectBase = vtk::TakeSmartPointer(ptr);

Serialization/Manager/Testing/Python/TestUpdateObjectFromState.py

@@ -56,5 +56,30 @@ class TestUpdateObjectFromState(vtkTesting.vtkTest):
         self.assertTupleEqual(camera.GetPosition(), (0, 0.2, 1.3))
         self.assertEqual(camera.GetViewAngle(), 60)
 
+    def test3(self):
+        from vtkmodules.vtkSerializationManager import vtkObjectManager
+        from vtkmodules.vtkRenderingCore import vtkCamera
+        import json
+
+        # Scenario 3:
+        # An object is registered and serialized. Later, a new state is created with modified properties.
+        # Unlike Scenario 2, this new state does not have keys that were originally part of the state like
+        # "ClassName", "SuperClassNames" and "vtk-object-manager-kept-alive"
+        # Call UpdateObjectFromState() with modified state. Verify the real object's properties match
+        # with the state's properties.
+
+        manager = vtkObjectManager()
+        manager.Initialize()
+
+        camera = vtkCamera()
+        cid = manager.RegisterObject(camera)
+        manager.UpdateStatesFromObjects()
+
+        manager.UpdateObjectFromState(json.dumps({"Id": cid, "Position": (0, 0.2, 1.3)}))
+        self.assertTupleEqual(camera.GetPosition(), (0, 0.2, 1.3))
+
+        manager.UpdateObjectFromState(json.dumps({"Id": cid, "ViewAngle": 60}))
+        self.assertEqual(camera.GetViewAngle(), 60)
+
 if __name__ == "__main__":
     vtkTesting.main([(TestUpdateObjectFromState, 'test')])