Exception when Serializing Null Strings

[Moe-Baker]

Hello, NGO causes an exception when serializing a null string. The code throws an exception on this method as it doesn't do null checks. Are null strings supported or is this expected behavior.

[NoelStephensUnity]

@Moe-Baker

There are two places that that could be invoked:

• When sending the disconnect reason via DisconnectReasonMessage.
  • This always assigns a valid string value prior to sending the message.
• When using FastBufferWriter.WriteValueSafe(string s, bool oneByteChars = false).
  • This requires the invoking code to not check if the string being sent is null prior to attempting to write it.

Could you provide me with the code/script that is invoking this for context purposes? I might be able to provide you with an alternative that will avoid that exception.

[Moe-Baker]

Could you provide me with the code/script that is invoking this for context purposes?

This code causes the exception, basically a usage of INetworkSerializable. I already have a workaround, so I wanted to report this if this is a bug.

[Serializable]
public struct MiniGamesUserProfileDefinition : INetworkSerializable
{
    public string Username;

    public string FirebaseID;

    public int Level;
    public string Country;
    public string ClanName;

    public string Character;
    public string Background;
    public string Badge;

    public MiniGamesUserProfile ToProfile() => MiniGamesUserProfile.DefinitionToProfile(this);

    public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
    {
        if (serializer.IsWriter)
        {
            //NGO doesn't serialize null strings for some reason, so we replace all possibly null string with empty strings
            ClanName ??= string.Empty;
            Badge ??= string.Empty;
        }

        serializer.SerializeValue(ref Username);
        serializer.SerializeValue(ref FirebaseID);
        serializer.SerializeValue(ref Country);
        serializer.SerializeValue(ref Character);
        serializer.SerializeValue(ref Level);
        serializer.SerializeValue(ref ClanName);
        serializer.SerializeValue(ref Badge);
        serializer.SerializeValue(ref Background);
    }

    public MiniGamesUserProfileDefinition(string Username, string FirebaseID, string Country, string Character, int Level, string ClanName, string Badge, string Background)
    {
        this.Username = Username;
        this.FirebaseID = FirebaseID;
        this.Country = Country;
        this.Character = Character;
        this.Level = Level;
        this.ClanName = ClanName;
        this.Badge = Badge;
        this.Background = Background;
    }
}

[NoelStephensUnity]

@Moe-Baker Ahhh, yeah super appreciate the script reference... helps me a bunch.

So, your approach is one way to handle this for sure and most of NGO's serialization of things like strings/arrays doesn't support handling null entries.

The exception is the same kind of exception you would get if you had a string property that was null and tried to access it directly without checking if it was null or empty.

It is recommended to make sure strings are at least assigned "empty" if you are trying to serialize them.

[Moe-Baker]

Understandable, thank you for the help.