[Bug fortran/95446] New: False positive for optional arguments of elemental procedure

["m.diehl at mpie dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95446

            Bug ID: 95446
           Summary: False positive for optional arguments of elemental
                    procedure
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: m.diehl at mpie dot de
  Target Milestone: ---

to my understanding, the following code is valid

program elemental_optional
  implicit none
  integer :: m(5), r(5)

  m = 1

  r = outer()
  r = outer(m)

  contains

  function outer(o) result(l)
    integer, intent(in), optional :: o(:)
    integer :: u(5), l(5)

    l = inner(o,u)

  end function outer

  elemental function inner(a,b) result(x)
    integer, intent(in), optional :: a
    integer, intent(in) :: b
    integer :: x

    if(present(a)) then
      x = a*b
    else
      x = b
    endif
  end function inner

end program elemental_optional

however, when compiling with "-pedantic-errors", the following error message
shows up:

Error: ‘o’ at (1) is an array and OPTIONAL; IF IT IS MISSING, it cannot be the
actual argument of an ELEMENTAL procedure unless there is a non-optional
argument with the same rank (12.4.1.5) [-Werror=pedantic]