[MD] Skip returning IR when meet nullptr in ConcatDataset

mindspore/ccsrc/minddata/dataset/api/datasets.cc

@@ -478,9 +478,10 @@ BucketBatchByLengthDataset::BucketBatchByLengthDataset(
 
 ConcatDataset::ConcatDataset(const std::vector<std::shared_ptr<Dataset>> &datasets) {
   std::vector<std::shared_ptr<DatasetNode>> all_datasets;
-  (void)std::transform(
-    datasets.begin(), datasets.end(), std::back_inserter(all_datasets),
-    [](std::shared_ptr<Dataset> dataset) -> std::shared_ptr<DatasetNode> { return dataset->IRNode(); });
+  (void)std::transform(datasets.begin(), datasets.end(), std::back_inserter(all_datasets),
+                       [](std::shared_ptr<Dataset> dataset) -> std::shared_ptr<DatasetNode> {
+                         return (dataset != nullptr) ? dataset->IRNode() : nullptr;
+                       });
 
   auto ds = std::make_shared<ConcatNode>(all_datasets);
 

tests/ut/cpp/dataset/c_api_dataset_ops_test.cc

@@ -340,6 +340,46 @@ TEST_F(MindDataTestPipeline, TestConcatFail2) {
   EXPECT_EQ(iter, nullptr);
 }
 
+TEST_F(MindDataTestPipeline, TestConcatFail3) {
+  MS_LOG(INFO) << "Doing MindDataTestPipeline-TestConcatFail3.";
+  // This case is expected to fail because the input dataset is nullptr.
+
+  // Create an ImageFolder Dataset
+  std::string folder_path = datasets_root_path_ + "/testPK/data/";
+  std::shared_ptr<Dataset> ds = ImageFolder(folder_path, true, RandomSampler(false, 10));
+  EXPECT_NE(ds, nullptr);
+
+  // Create a Concat operation on the ds
+  // Input dataset to concat is null
+  ds = ds->Concat({nullptr});
+  EXPECT_NE(ds, nullptr);
+
+  // Create an iterator over the result of the above dataset
+  std::shared_ptr<Iterator> iter = ds->CreateIterator();
+  // Expect failure: invalid Op input
+  EXPECT_EQ(iter, nullptr);
+}
+
+TEST_F(MindDataTestPipeline, TestConcatFail4) {
+  MS_LOG(INFO) << "Doing MindDataTestPipeline-TestConcatFail4.";
+  // This case is expected to fail because the input dataset is nullptr.
+
+  // Create an ImageFolder Dataset
+  std::string folder_path = datasets_root_path_ + "/testPK/data/";
+  std::shared_ptr<Dataset> ds = ImageFolder(folder_path, true, RandomSampler(false, 10));
+  EXPECT_NE(ds, nullptr);
+
+  // Create a Concat operation on the ds
+  // Input dataset to concat is null
+  ds = ds + nullptr;
+  EXPECT_NE(ds, nullptr);
+
+  // Create an iterator over the result of the above dataset
+  std::shared_ptr<Iterator> iter = ds->CreateIterator();
+  // Expect failure: invalid Op input
+  EXPECT_EQ(iter, nullptr);
+}
+
 TEST_F(MindDataTestPipeline, TestConcatSuccess) {
   MS_LOG(INFO) << "Doing MindDataTestPipeline-TestConcatSuccess.";