ProtoSchemaConverter renders invalid schema for oneof in unwrap mode

[aka-peter]

Describe the bug, including details regarding any error messages, version, and platform.

When unwrap is enabled all fields of the TestProto3.OneOfTestMessage will be required.

message TestProto3.OneOfTestMessage {
  required int32 first = 1;
  required int32 second = 2;
}

parquet-java/parquet-protobuf/src/test/resources/TestProto3.proto

Line 116 in 73a4430

message OneOfTestMessage {

This will never work but tests are missing for unwrap of TestProto3.OneOfTestMessage

The required repetition is added here:

parquet-java/parquet-protobuf/src/main/java/org/apache/parquet/proto/ProtoSchemaConverter.java

Line 278 in 73a4430

Repetition repetition = unwrapProtoWrappers ? Repetition.REQUIRED : getRepetition(descriptor);

This could be caught early by adding withValidation(true) here:

parquet-java/parquet-protobuf/src/test/java/org/apache/parquet/proto/TestUtils.java

Line 221 in 73a4430

.withMessage(cls)

If validation is disabled it will fail when trying to read one of the non-existing fields in the oneof.

Is there really a need for setting all primitive fields in unwrap to required?

Component(s)

No response