ID3D12GraphicsCommandList.SetDescriptorHeaps with null

[MarcioAB]

DebugLayer is showing the following error in ID3D12GraphicsCommandList.SetDescriptorHeaps:

Error
pDescriptorHeaps[0] is NULL but NumDescriptorHeaps is > 0.
To unset all descriptor heaps, pass 0 for NumDescriptorHeaps.

Below a simple code to reproduce the issue:

ID3D12DescriptorHeap d1 = default;  // <---- d1 = null
CL12.SetDescriptorHeaps(d1);  // <--- error

or

ID3D12DescriptorHeap d1 = new ID3D12DescriptorHeap(IntPtr.Zero);  // <--- d1 = null
CL12.SetDescriptorHeaps(d1);  // <--- error

I understand the related SetDescriptorHeaps code is this one, so it should work:

public unsafe void SetDescriptorHeaps(ID3D12DescriptorHeap? heap) {
    nint num = ((heap == null) ? IntPtr.Zero : heap.NativePointer);
    SetDescriptorHeaps(1u, &num);
}