BUG: emit FATAL error when input model file cannot be loaded

Applications/Classification/otbImageClassifier.cxx

@@ -119,6 +119,12 @@ private:
     otbAppLogINFO("Loading model");
     m_Model = MachineLearningModelFactoryType::CreateMachineLearningModel(GetParameterString("model"),
                                                                           MachineLearningModelFactoryType::ReadMode);
+
+    if (m_Model.IsNull())
+      {
+      otbAppLogFATAL(<< "Error when loading model " << GetParameterString("model") << " : unsupported model type");
+      }
+
     m_Model->Load(GetParameterString("model"));
     otbAppLogINFO("Model loaded");
 

Applications/Classification/otbTrainImagesClassifier.cxx

@@ -214,6 +214,12 @@ void TrainImagesClassifier::Classify(ListSampleType::Pointer validationListSampl
   //Classification
   ModelPointerType model = MachineLearningModelFactoryType::CreateMachineLearningModel(GetParameterString("io.out"),
                                                                                        MachineLearningModelFactoryType::ReadMode);
+
+  if (model.IsNull())
+    {
+    otbAppLogFATAL(<< "Error when loading model " << GetParameterString("io.out"));
+    }
+
   model->Load(GetParameterString("io.out"));
   model->SetInputListSample(validationListSample);
   model->SetTargetListSample(predictedList);