Deserialization fail after switching PrefixStyle to Fixed32

Question

I have a test suite for a communication library I'm developing using protobuf-net that is running okay. All tests pass. But if I change the PrefixStyle from Base128 to Fixed32, the deserialization fail.

The exception I receive from the TryDeserializeWithLengthPrefix function is:

System.ArgumentNullException was caught
  Message="Value cannot be null.\r\nParameter name: type"
  Source="protobuf-net"
  ParamName="type"

Everything just works if I simple keep the PrefixStyle.Base128 when serializing and deserializing the message.

Does anyone know what may be happening?

Answer 1

Hohum, yup looks like a bug (now logged); repeatable example below. I'll see if I can fix it on the train (shortly). Sorry 'bout that:

using System;
using System.IO;
using ProtoBuf;
[ProtoContract]
public class Strange // test entity
{
    [ProtoMember(1)]
    public string Foo { get; set; } // test prop
    [ProtoMember(2)]
    public int Bar { get; set; } // test prop

    static void Main() {
        var original = new Strange { Foo = "abc", Bar = 123 };
        // serialize and deserialize with base-128
        using (MemoryStream ms = new MemoryStream()) {
            Serializer.SerializeWithLengthPrefix(ms, original, PrefixStyle.Base128,1);
            ms.Position = 0;
            object obj;
            Serializer.NonGeneric.TryDeserializeWithLengthPrefix(ms,
                PrefixStyle.Base128, i => typeof(Strange),out obj);
            var clone = (Strange)obj;
            Console.WriteLine("Foo via Base128: " + clone.Foo); // works fine
            Console.WriteLine("Bar via Base128: " + clone.Bar);
        }
        // serialize and deserialize with fixed-32
        using (MemoryStream ms = new MemoryStream())
        {
            Serializer.SerializeWithLengthPrefix(ms, original, PrefixStyle.Fixed32,1);
            ms.Position = 0;
            object obj;
            // BOOM here; oh how embarrassing
            Serializer.NonGeneric.TryDeserializeWithLengthPrefix(ms,
                PrefixStyle.Fixed32, i => typeof(Strange), out obj);
            var clone = (Strange)obj;
            Console.WriteLine("Foo via Fixed32: " + clone.Foo);
            Console.WriteLine("Bar via Fixed32: " + clone.Bar);
        }
    }
}