Ensuring that AadMetadata and EncryptionAlgorithm are initialized deterministically

Author: argmarco-tkd

cpp/src/parquet/encryption/properties_test.cc

@@ -250,6 +250,27 @@ TEST(TestEncryptionProperties, UseAES_GCM_CTR_V1Algorithm) {
   ASSERT_EQ(ParquetCipher::AES_GCM_CTR_V1, props->algorithm().algorithm);
 }
 
+// Verify AadMetadata is safe to value-initialize (all fields deterministic).
+// Regression guard: an uninitialized bool in supply_aad_prefix caused thrift
+// serialization failures on Windows (MSVC debug fills with 0xCC).
+TEST(TestEncryptionProperties, AadMetadataDefaultInitialization) {
+  AadMetadata aad{};
+  ASSERT_EQ("", aad.aad_prefix);
+  ASSERT_EQ("", aad.aad_file_unique);
+  ASSERT_EQ(false, aad.supply_aad_prefix);
+}
+
+// Verify EncryptionAlgorithm is safe to value-initialize — particularly the
+// nested AadMetadata::supply_aad_prefix bool that previously lacked a default
+// member initializer.
+TEST(TestEncryptionProperties, EncryptionAlgorithmDefaultInitialization) {
+  EncryptionAlgorithm algo{};
+  ASSERT_EQ(ParquetCipher::AES_GCM_V1, algo.algorithm);
+  ASSERT_EQ("", algo.aad.aad_prefix);
+  ASSERT_EQ("", algo.aad.aad_file_unique);
+  ASSERT_EQ(false, algo.aad.supply_aad_prefix);
+}
+
 TEST(TestExternalFileEncryptionProperties, SuperClassFieldsSetCorrectly) {
   std::string column_name_1 = "column_1";
   ColumnEncryptionProperties::Builder column_builder_1(column_name_1);

cpp/src/parquet/metadata.cc

@@ -1753,7 +1753,7 @@ class ColumnChunkMetaDataBuilder::ColumnChunkMetaDataBuilderImpl {
         eck.__set_path_in_schema(column_->path()->ToDotVector());
         // check if column has its own encryption algorithm
         if (encrypt_md->parquet_cipher().has_value()) {
-          EncryptionAlgorithm column_encryption_algorithm;
+          EncryptionAlgorithm column_encryption_algorithm{};
           column_encryption_algorithm.algorithm = encrypt_md->parquet_cipher().value();
           eck.__set_encryption_algorithm(ToThrift(column_encryption_algorithm));
         }

cpp/src/parquet/types.h

@@ -580,7 +580,7 @@ bool IsParquetCipherSupported(ParquetCipher::type cipher);
 struct AadMetadata {
   std::string aad_prefix;
   std::string aad_file_unique;
-  bool supply_aad_prefix;
+  bool supply_aad_prefix = false;
 };
 
 struct EncryptionAlgorithm {