Limited_Controlled types as 'out' arguments

[Lutz Donnerhacke <lutz@iks-jena.de>]

I'm using an Limited_Controlled type as an 'out' parameter of a procedure.
While programming this procedure in question, I wonder how to Finalize the
object given as argument to the 'out' parameter.

------------------------------------------------------------------------
with Ada.Finalization;

package t1 is
   type Test is new Ada.Finalization.Limited_Controlled with record
      a : Character;
   end record;
   procedure Initialize(o : in out Test);
   procedure Finalize(o : in out Test);
   procedure Copy(to : out Test; from : Test);
end t1;
------------------------------------------------------------------------
with t1;
use t1;

procedure t is
   a, b, c : Test;
begin
   Copy(a, b);
   Copy(a, c);
end t;
------------------------------------------------------------------------
with Ada.Text_IO;
use Ada.Text_IO;

package body t1 is
   global : Character := '0';
   
   procedure Initialize(o : in out Test) is
   begin
      o.a := global;
      Put_Line("Initializing " & o.a);
      global := Character'Succ(global);
   end Initialize;
   
   procedure Finalize(o : in out Test) is
   begin
      Put_Line("Finalizing " & o.a);
   end Finalize;
   
   procedure Copy(to : out Test; from : Test) is
   begin
      to.a := global;
      Put_Line("Copying " & from.a & " to " & to.a);
      global := Character'Succ(global);
   end Copy;
end t1;
------------------------------------------------------------------------

This results in:
   Initializing 0
   Initializing 1
   Initializing 2
   Copying 1 to 3
   Copying 2 to 4
   Finalizing 2
   Finalizing 1
   Finalizing 4

Clearly, the variable 0 and 3 are never finalized. How implement I this
correctly (without refering to the rosen trick).