Dear All,

Thanks to Dimitry Liakh for both reporting the problem and doing a lot
of the diagnostic work. Once the offending line in a very complicated
code was located, the fix was trivial. Generating a reduced testcase
took rather longer :-)

The comment in the testcase tells the story. The fix is a one-liner
that follows immediately from the explanation.

Bootstrapped and regtested on FC23/x86_64 - OK for trunk and 7-branch.

Cheers

Paul

2017-10-26  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/81758
    * trans-expr.c (trans_class_vptr_len_assignment): 'vptr_expr'
    must only be set if the right hand side expression is of class
    type.

2017-10-26  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/81758
    * gfortran.dg/class_63.f90: New test.