[Bug fortran/60500] New: Spurious warning on derived type initialization

["jonathan.hogg at stfc dot ac.uk" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60500

            Bug ID: 60500
           Summary: Spurious warning on derived type initialization
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jonathan.hogg at stfc dot ac.uk

The following code:

module spurious_warning
   implicit none

   type :: ntype
      integer :: level = 1
   end type ntype
contains
   subroutine sub1(n1, n2, st)
      integer, intent(in) :: n1, n2
      integer, intent(out) :: st

      type(ntype), dimension(:), allocatable :: work1
      integer, dimension(:), allocatable :: work2

      allocate(work1(n1), stat=st)
      if(st.ne.0) return

      allocate(work2(n2), stat=st)
      if(st.ne.0) return
   end subroutine sub1
end module spurious_warning

Produces the following spurious warning:
[user@host]$ gfortran-4.8 -O2 -Wall -c bug.f90
bug.f90: In function âsub1â:
bug.f90:12:0: warning: âwork1.dim[0].uboundâ may be used uninitialized in this
function [-Wmaybe-uninitialized]
       type(ntype), dimension(:), allocatable :: work1
 ^

With the following compiler version:
GNU Fortran (Ubuntu 4.8.1-2ubuntu1~12.04) 4.8.1

Notes:
Removal of -O2 removes the sprurious warning.
Removal of the second allocation removes spurious warning.
Removal of default value in type definition removes spurious warning.

Working theory: The automatic initialization accesses array size as part of
implementation?