Erroneous circular dependency detection when updating entities with composite primary key and one-to-one relationships

[stanislav-a-frolov]

Hello, everyone.

Having following model with composite primary key and optional one-to-one relationship with shared key part (Id2)

public class Model1
{
    public int Id1 { get; set; }
    public int Id2 { get; set; }
    public int? Model2Id1 { get; set; }
    public Model2? Model2 { get; set; }
}
public class Model2
{
    public int Id1 { get; set; }
    public int Id2 { get; set; }
    public Model1? Model1 { get; set; }
}

public class AppDbContext : DbContext
{
    public AppDbContext(DbContextOptions options) : base(options) {}

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Model1>(entity => entity.HasKey(entity => new { entity.Id1, entity.Id2 }));
        modelBuilder.Entity<Model2>(entity =>
        {
            entity.HasKey(entity => new { entity.Id1, entity.Id2 });
            entity.HasOne(e => e.Model1).WithOne(e => e.Model2).HasForeignKey<Model1>(e=> new { e.Model2Id1, e.Id2 }).IsRequired(false);
        });
    }
}

I perform following operations on empty db (note that Model2 is not referenced):

context.AddRange(
    new Model1 { Id2 = 1, Id1 = 1, Model2Id1 = null },
    new Model1 { Id2 = 1, Id1 = 2, Model2Id1 = null }
);
var models = new[] {
    new Model1 { Id2 = 2, Id1 = 1, Model2Id1 = null },
    new Model1 { Id2 = 2, Id1 = 2, Model2Id1 = null }
};
context.AddRange(models);
context.SaveChanges();
context.UpdateRange(models);
context.SaveChanges();

and get System.InvalidOperationException: Unable to save changes because a circular dependency was detected in the data to be saved
That's for ef core7, version 6 is fine.
Minimalistic project for repro is attached:
TestEf7.zip

[ajcvickers]

/cc @AndriySvyryd

[AndriySvyryd]

Duplicate of #29647