Accessing DbSet.Local with context pooling causes a memory leak

[Lawlzee]

LocalViewListener._viewActions are not reset when a context is returned to the context pool. This means, every time DbSet<T>.Local is called, a "viewAction" is inserted LocalViewListener._viewActions, which causes a memory leak.

.NET Interactive dib script to reproduce the leak

#!csharp

#r "nuget: Microsoft.EntityFrameworkCore.SqlServer, 6.0.9"

#!csharp

using Microsoft.EntityFrameworkCore;

public class Blog
{
    public int Id { get; set; }
}

public class BlogDbContext : DbContext
{
    public BlogDbContext(DbContextOptions<BlogDbContext> options) : base(options)
    {
    }

    public DbSet<Blog> Blogs { get; private set; }
}

#!csharp

using Microsoft.Extensions.DependencyInjection;

IServiceCollection serviceCollection = new ServiceCollection();
serviceCollection.AddDbContextPool<BlogDbContext>(opt => opt.UseSqlServer("connectionString"));

var serviceProvider = serviceCollection.BuildServiceProvider();
var scopeFactory = serviceProvider.GetRequiredService<IServiceScopeFactory>();

#!csharp

using System.Reflection;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.ChangeTracking.Internal;

var _viewActionsField = typeof(LocalViewListener).GetField("_viewActions", BindingFlags.NonPublic | BindingFlags.Instance);

for (int i = 0; i < 1000; i++)
{
    using var scope = scopeFactory.CreateScope();
    var context = scope.ServiceProvider.GetRequiredService<BlogDbContext>();

    //Force the creation a value in LocalViewListener._viewActions
    var _ = context.Blogs.Local;

    ILocalViewListener localViewListener = context.Blogs.GetService<ILocalViewListener>();
    var _viewActions = (List<Action<InternalEntityEntry, EntityState>>)_viewActionsField.GetValue(localViewListener);

    if (_viewActions.Count > 1)
    {
        return "Memory leak!";
    }
}