The comment in the patch says it all.

Bootstrapped and regtested on FC28/x86_64 - OK for trunk?

Paul

2018-07-05  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/66679
    * trans-intrinsic.c (gfc_conv_intrinsic_transfer): Class array
    elements are returned as references to the data element. Get
    the class expression by stripping back the references. Use this
    for the element size.

2018-07-05  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/66679
    * gfortran.dg/transfer_class_3.f90: New test.