User defined IO: complex number problem

Hello community,

in the following program, user-defined IO formatted read behaves unusually on complex numbers in ifort 17.0.4.

module m
    implicit none

    type :: t_type
        complex :: x
        integer :: i
        character(len=10) :: s
    contains
        procedure :: t_read
        generic :: read(formatted) => t_read
    end type
contains
    subroutine t_read(t, unit, iotype, vlist, iostat, iomsg)
        implicit none
        class(t_type), intent(inout) :: t
        character(len=*), intent(in) :: iotype
        integer, intent(in), dimension(:) :: vlist
        integer, intent(in) :: unit
        integer, intent(out) :: iostat
        character(len=*), intent(inout) :: iomsg

        ! TEST 1 (OK):
        !read(unit,*,iostat=iostat,iomsg=iomsg) t%x, t%i    ! (1.0,2.0), 3
        !if (iostat /= 0) return

        ! TEST 2 (ERROR):
        !read(unit,*,iostat=iostat,iomsg=iomsg) t%x        ! (1.0,2.0)
        !if (iostat /= 0) return
        !read(unit,*,iostat=iostat,iomsg=iomsg) t%i        ! ERROR
        !if (iostat /= 0) return

        ! TEST 3 (DEBUG):
        read(unit,*,iostat=iostat,iomsg=iomsg) t%x        ! (1.0,2.0)
        if (iostat /= 0) return
        read(unit,*,iostat=iostat,iomsg=iomsg) t%s        ! ')'
        if (iostat /= 0) return
        read(unit,*,iostat=iostat,iomsg=iomsg) t%i        ! 3
        if (iostat /= 0) return
    end subroutine
end module

program p
    use m
    implicit none
    integer :: iostat
    character(len=255) :: str, iomsg
    type(t_type) :: t

    ! Defaults:
    t%x = (0.0,0.0)
    t%i = 0
    t%s = repeat('X',len(t%s))

    ! List-directed IO:
    str = '(1.0,2.0) 3'
    read(str,*,iostat=iostat,iomsg=iomsg) t

    ! Output:
    print *, t%x, t%i, "'", trim(t%s), "'"
    if (iostat /= 0) print *, trim(iomsg)

    ! OUTPUT for TEST 1:
    ! (1.000000,2.000000)           3 'XXXXXXXXXX'

    ! OUTPUT for TEST2:
    ! (1.000000,2.000000)           0 'XXXXXXXXXX'
    ! User Defined I/O procedure returned error 59, message: 'list-directed
    ! I/O syntax error, unit -5, file Internal List-Directed Read'

    ! OUTPUT for TEST 3:
    ! (1.000000,2.000000)           3 ')'
end program

The output from ifort 17.0.4 is reported for the three test-cases.

It looks as if the list-directed read does NOT advance beyond the closing parenthesis of the complex number literal in TEST 2, which is verified in TEST 3. Is this a bug or a feature?

Instead, with iifort 16.0.4, TEST 1 and TEST 2 yied similar output as expected.

Any ideas on workarounds that work both in ifort 16.0.4 AND 17.0.4 (and future versions) are appreciated.

Kind regards
Ferdinand