
The patch to disallow a NULL specification in combination with GENERATED ... AS IDENTITY applied to both ALWAYS and BY DEFAULT variants of that clause, not only the former. Noted by Shay Rojansky. Discussion: https://postgr.es/m/CADT4RqAwD3A=RvGiQU9AiTK-6VeuXcycwPHmJPv_OBCJFYOEww@mail.gmail.com