[Bug fortran/99602] [11 regression] runtime error: pointer actual argument not associated

["juergen.reuter at desy dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99602

--- Comment #6 from Jürgen Reuter <juergen.reuter at desy dot de> ---
Actually, the last example missed a line that I overeagerly deleted too much.
This one is the correct reproducer:
module m
  implicit none
  private
  public :: m_t
  type :: m_t
     private
  end type m_t
end module m

module m2_testbed
  use m
  implicit none
  private
  public :: prepare_m2
  procedure (prepare_m2_proc), pointer :: prepare_m2 => null ()

  abstract interface
     subroutine prepare_m2_proc (m2)
       import
       class(m_t), intent(inout), pointer :: m2
     end subroutine prepare_m2_proc
  end interface

end module m2_testbed

module a
  use m
  use m2_testbed, only: prepare_m2
  implicit none
  private
  public :: a_1

contains

  subroutine a_1 ()
    class(m_t), pointer :: mm
    mm => null ()
    call prepare_m2 (mm)
  end subroutine a_1

end module a


module m2
  use m
  implicit none
  private
  public :: m2_t

  type, extends (m_t) :: m2_t
     private
   contains
     procedure :: read => m2_read
  end type m2_t
contains

  subroutine m2_read (mm)
    class(m2_t), intent(out), target :: mm
  end subroutine m2_read
end module m2

program main
  use m2_testbed
  use a, only: a_1
  implicit none
  prepare_m2 => prepare_whizard_m2
  call a_1 ()

contains

  subroutine prepare_whizard_m2 (mm)
    use m
    use m2
    class(m_t), intent(inout), pointer :: mm
    if (.not. associated (mm))  allocate (m2_t :: mm)    
    select type (mm)
    type is (m2_t)
       call mm%read ()
    end select
  end subroutine prepare_whizard_m2
end program main