omp task bug with private and firstprivate

Hi,

I think there is a bug with the following simplified code, ifort is giving forrtl: severe (151): allocatable array is already allocated, when compiled with ifort -fopenmp -O2. when compiled with -C it seems to give the good results.

module toto
implicit none
type t
double precision,dimension(:),allocatable :: a
      contains
      procedure,pass :: copy_t
      generic,public :: assignment(=) => copy_t
end type t
contains
subroutine copy_t(t1,t2)
      class(t),intent(in) :: t2
      class(t),intent(out) :: t1
      allocate(t1%a(size(t2%a)),source=t2%a)
end subroutine
end module toto

program foo

use toto
use omp_lib
implicit none
type(t) :: g1,g2,g3
      integer :: i,j

!$omp parallel
!$omp master
allocate(g2%a(10),g3%a(10))
g2%a=-1
do i=1,10
      !$omp task shared(g2,g3) private(g1)
      !$ print *,omp_get_thread_num(),allocated(g1%a)
        g1=g2
        do j=1,20
                g3%a=g1%a+j
        end do
        !$omp end task
        g2%a=i
        !$omp taskwait
        g1=g2
        !$omp task shared(g3) firstprivate(g1)
      !$ print *,omp_get_thread_num(),allocated(g1%a)
        do j=1,20
                g3%a=g1%a+j
        end do
        !$omp end task
        g2%a=i+1
        !$omp taskwait

end do
print *,'g3a',g3%a
!$omp end master
!$omp end parallel

end program foo