Values equal to 0 not serialized by ProtoBuf in .NET

[ghost]

I will show it basing on FeedHeader serialization:

new FeedHeader()
            {
                gtfs_realtime_version = "2.0",
                incrementality = FeedHeader.Incrementality.FULL_DATASET, // FeedHeader.Incrementality.FULL_DATASET == 0
                timestamp = Utils.ToUnixTime(DateTime.UtcNow)
            };

After serializing by ProtoBuf it seems that incrementality value (which is equal to 0) in FeedHeader class is not serialized, because when testing feed with https://github.com/CUTR-at-USF/gtfs-realtime-validator that validator shows me error "header incrementality not populated" and when I check (in that validator) protobuf file contents:

  "header": {
    "gtfs_realtime_version": "2.0",
    "timestamp": 1520343087
  }

Same problem is i.e. with:

• ScheduleRelationship enums
• delay in StopTimeEvent
• etc.

Check also attached file.

How to solve it? Can I control somehow which values should always be serialized even if they are null / zero / empty? I am using classess provided by Google:

[bugbiter]

I have the same issue with FeedHeader.Incrementality. Workaround?

[barbeau]

Looks like this is the underlying issue: https://stackoverflow.com/questions/12295976/force-protobuf-net-to-serialize-all-default-values

@bugbiter @piotrwojtowicz Are you able to try this workaround in your code to see if it works?

[adhunna]

Anyone found solution yet?