GNAT bug with overriding and Limited_Controlled?

[Maciej Sobczak <see.my.homepage@gmail.com>]

While chasing some strange bug[*] I have stomped onto something
interesting:

with Ada.Finalization;

procedure Test is

   package P is

      type T is new Ada.Finalization.Limited_Controlled
        with null record;

      overriding
      procedure Initialize (X : in out T);

      overriding
      procedure Adjust (X : in out T);

      overriding
      procedure Finalize (X : in out T);

   end P;

   package body P is
      procedure Initialize (X : in out T) is
      begin
         null;
      end Initialize;

      procedure Adjust (X : in out T) is
      begin
         null;
      end Adjust;

      procedure Finalize (X : in out T) is
      begin
         null;
      end Finalize;
   end P;

begin
   null;
end Test;

As far as I understand, the Ada.Finalization.Limited_Controlled type
has no Adjust operation. Therefore, the T type cannot override it. Yet
the above is happily accepted by GNAT GPL 2009 (20090519).

As an exercise try to misspell the operation name as a sanity check
that the overriding keyword is recognized at all.

Is it a compiler bug? I think so, but if not, where is the original
magic Adjust that the above code is apparently overriding?

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com

Database Access Library for Ada: www.inspirel.com/soci-ada