Streams and abnormality

[Simon Wright <simon@pushface.org>]

Using this code with GCC 4.6, 4.7 and GNAT GPL 2011,

      Str : aliased {a child of Root_Stream_Type};
      subtype Short_Int is Integer range 0 .. 42;
      S : Short_Int;
   begin
      Integer'Output (Str'Access, -1);
      S := Short_Int'Input (Str'Access);
      Put_Line (S'Img & " " & S'Valid'Img);

I get the output " 63 FALSE".

 My reading of AARM05 13.9.1(4..6) [1] is that - because S is a scalar
 object - S should not have been allowed to become abnormal; I think
 that, instead, some exception (Constraint_Error? Data_Error?) should
 have been raised.

[1] http://www.adaic.org/resources/add_content/standards/05aarm/html/AA-13-9-1.html