ArgumentNullException ByteBuffer

[IlyaKvant]

Periodically, when one of the client disconnects from the clienthost in the build, this error occurs.

ArgumentNullException: Value cannot be null.
Parameter name: array
System.ArraySegment`1[T]..ctor (T[] array, System.Int32 offset, System.Int32 count) (at <00000000000000000000000000000000>:0)
FishNet.Managing.Transporting.TransportManager.<IterateOutgoing>g__ProcessPacketBundle|69_2 (FishNet.Connection.PacketBundle ppb, System.Boolean isLast, FishNet.Managing.Transporting.TransportManager+<>c__DisplayClass69_0& , FishNet.Managing.Transporting.TransportManager+<>c__DisplayClass69_1& , FishNet.Managing.Transporting.TransportManager+<>c__DisplayClass69_2& ) (at <00000000000000000000000000000000>:0)
FishNet.Managing.Transporting.TransportManager.<IterateOutgoing>g__SendAsServer|69_0 (FishNet.Managing.Transporting.TransportManager+<>c__DisplayClass69_0& ) (at <00000000000000000000000000000000>:0)
FishNet.Managing.Transporting.TransportManager.IterateOutgoing (System.Boolean asServer) (at <00000000000000000000000000000000>:0)
FishNet.Managing.Timing.TimeManager.IncreaseTick () (at <00000000000000000000000000000000>:0)
FishNet.Managing.Timing.TimeManager.TickUpdate () (at <00000000000000000000000000000000>:0)

FishNet/Assets/FishNet/Runtime/Managing/Transporting/TransportManager.cs

Lines 803 to 806 in 32528cb

	// Length should always be more than 0 but check to be safe.
	if (ppb.GetBuffer(i, out ByteBuffer bb))
	{
	ArraySegment<byte> segment = new(bb.Data, 0, bb.Length);

ArraySegment<byte> segment = new(bb.Data, 0, bb.Length); // - bb.Data is null

Apparently, when disconnecting, NetworkConnection.ResetState and ByteBuffer.Dispose are called, which sets the Data field to null. However, the HasData flag remains true.

FishNet/Assets/FishNet/Runtime/Connection/Buffer.cs

Lines 51 to 56 in 32528cb

	public void Dispose()
	{
	if (Data != null)
	ByteArrayPool.Store(Data);
	Data = null;
	}

Because of this, the PacketBundle.GetBuffer method returns a buffer that has already been reset to zero, but the further logic breaks down.

FishNet/Assets/FishNet/Runtime/Connection/Buffer.cs

Lines 270 to 272 in 32528cb

	bb = _buffers[index];
	return bb.HasData;
	}

I'm not 100% sure that this fix won't break some other logic, but it's definitely worth paying attention to the incorrect reset of the ByteBuffer state when calling ByteBuffer.Dispose.