Hi-Lo doesn't work with TPC

[ajcvickers]

Latest daily build. Stack trace:

Unhandled exception. System.InvalidOperationException: Nullable object must have a value.
   at System.Nullable`1.get_Value()
   at Microsoft.EntityFrameworkCore.SqlServer.ValueGeneration.Internal.SqlServerValueGeneratorCache.GetOrAddSequenceState(IProperty property, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.SqlServer.ValueGeneration.Internal.SqlServerValueGeneratorSelector.Select(IProperty property, IEntityType entityType)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ValueGenerationManager.Generate(InternalEntityEntry entry, Boolean includePrimaryKey)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState entityState, Boolean acceptChanges, Boolean modifyProperties, Nullable`1 forceStateWhenUnknownKey)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.PaintAction(EntityEntryGraphNode`1 node)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.AttachGraph(InternalEntityEntry rootEntry, EntityState targetState, EntityState storeGeneratedWithKeySetTargetState, Boolean forceStateWhenUnknownKey)
   at Microsoft.EntityFrameworkCore.DbContext.SetEntityState(InternalEntityEntry entry, EntityState entityState)
   at Microsoft.EntityFrameworkCore.DbContext.SetEntityStates(IEnumerable`1 entities, EntityState entityState)
   at Microsoft.EntityFrameworkCore.DbContext.AddRange(IEnumerable`1 entities)
   at Microsoft.EntityFrameworkCore.DbContext.AddRange(Object[] entities)
   at Program.Main() in C:\local\code\AllTogetherNow\Daily\Daily.cs:line 186

Code:

public static class Your
{
    public static string ConnectionString = @"Data Source=(LocalDb)\MSSQLLocalDB;Database=SixOh";
}

public abstract class Animal
{
    public int Id { get; set; }
    public string Species { get; set; }
}

public class FarmAnimal : Animal
{
    public decimal Value { get; set; }
}

public class Pet : Animal
{
    public string Name { get; set; }
}

public class Cat : Pet
{
    public string EducationLevel { get; set; }
}

public class Dog : Pet
{
    public string FavoriteToy { get; set; }
}

public class SomeDbContext : DbContext
{
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseSqlServer(Your.ConnectionString)
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();

    
    public DbSet<Animal> Animals { get; set; }
    public DbSet<Pet> Pets { get; set; }
    public DbSet<Cat> Cats { get; set; }
    public DbSet<Dog> Dogs { get; set; }
    public DbSet<FarmAnimal> FarmAnimals { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Animal>().UseTpcMappingStrategy().Property(e => e.Id).UseHiLo();
        modelBuilder.Entity<Pet>().ToTable("Pets");;
        modelBuilder.Entity<Cat>().ToTable("Cats");
        modelBuilder.Entity<Dog>().ToTable("Dogs");
        modelBuilder.Entity<FarmAnimal>().ToTable("FarmAnimals");

    }
}

public class Program
{
    public static void Main()
    {
        using (var context = new SomeDbContext())
        {
            context.Database.EnsureDeleted();
            context.Database.EnsureCreated();

            context.AddRange(
                new Cat {Name = "Alice", Species = "Felis catus", EducationLevel = "MBA"},
                new Cat {Name = "Mac", Species = "Felis catus", EducationLevel = "BA"},
                new Dog {Name = "Toast", Species = "Canis familiaris", FavoriteToy = "Mr. Squirrel"},
                new FarmAnimal {Value = 100.0m, Species = "Ovis aries"});

            context.SaveChanges();
        }
    }
}