Did I find a bug here?

[reinert <reinkor@gmail.com>]

Assume this simple program:

procedure test0 is
  type A_Type is (A,B,C);
  subtype A_sub_Type is A_Type with Static_Predicate => A_sub_Type in A | B;
  X : A_type      := A;
  Y : A_sub_Type  := A;
begin
  case A_sub_Type(X) is
    when A => null;
    when B => null;
    when others => null;  -- ???? Should the compiler complain here?
  end case;
end test0;

Should the compiler complain about "when others => null" ? My compiler does not (running debian 10 updated, gnat-8).

reinert