[Bug fortran/48059] New: [OOP] ICE in in gfc_conv_component_ref: character function of extended type

["boschmann at tp1 dot physik.uni-siegen.de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48059

           Summary: [OOP] ICE in in gfc_conv_component_ref: character
                    function of extended type
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: boschmann@tp1.physik.uni-siegen.de


The code:
module a_module
  type :: a_type
     integer::length=0
  end type a_type
  type,extends(a_type) :: b_type
  end type b_type
contains
  function a_string(this) result(form)
    class(a_type),intent(in)::this
    character(max(1,this%length))::form
  end function a_string
  subroutine b_sub(this)
    class(b_type),intent(inout),target::this
    print *,a_string(this)
  end subroutine b_sub
end module a_module

The ICE message:
a.f90: In Funktion Âb_subÂ:
a.f90:14:0: interner Compiler-Fehler: in gfc_conv_component_ref, bei
fortran/trans-expr.c:523

Fortran version:
GNU Fortran (GCC) 4.6.0 20110310 (experimental)

I know that the length specification in a_string is a little bit creepy, but it
is valid. I had a discussion with the NAG about this before and they decided to
give a "questionable" warning message but no error message.

It anyway went right until today. I have updated gfortran and got this ICE for
the first time although the code is a few months old now. Unfortunately, I'm
not totally sure when I have done the last update before.