EventSource passing wrong byte[] data to listener

[stephentoub]

Repro:

using System;
using System.Diagnostics.Tracing;

class Program
{
    static void Main()
    {
        var source = new MySource();
        var listener = new MyListener();
        source.Data(new byte[] { 1, 2, 3, 4, 5 });
    }
}

class MySource : EventSource
{
    [Event(1)]
    public void Data(byte[] data) => WriteEvent(1, data);
}

class MyListener : EventListener
{
    protected override void OnEventSourceCreated(EventSource eventSource) =>
        EnableEvents(eventSource, EventLevel.Verbose);

    protected override void OnEventWritten(EventWrittenEventArgs eventData)
    {
        foreach (var item in eventData.Payload)
        {
            byte[] data = item as byte[];
            if (data != null)
            {
                Console.WriteLine("Data: " + string.Join(",", data));
            }
        }
    }
}

This should print out Data: 1, 2, 3, 4, 5. Instead it prints out Data: 1, 1, 1, 1, 1.

This repros for me on both the .NET Framework and .NET Core.

cc: @davmason, @vancem

[davmason]

Thanks, Stephen. I fixed this for 4.6.2, and I could have sworn that I fixed it in coreclr but apparently not.