Dear all,

I've committed the attached patch to mainline as obvious after
regtesting on x86_64-pc-linux-gnu.

https://gcc.gnu.org/g:2cf5f485e0351bb1faf46196a99e524688f3966e

commit r13-6605-g2cf5f485e0351bb1faf46196a99e524688f3966e
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Sat Mar 11 15:37:37 2023 +0100

    Fortran: fix bounds check for copying of class expressions [PR106945]

    In the bounds check for copying of class expressions, the number of elements
    determined from a descriptor, returned as type gfc_array_index_type (i.e. a
    signed type), should be converted to the type of the passed element count,
    which is of type size_type_node (i.e. unsigned), for use in comparisons.

    gcc/fortran/ChangeLog:

            PR fortran/106945
            * trans-expr.cc (gfc_copy_class_to_class): Convert element counts in
            bounds check to common type for comparison.

    gcc/testsuite/ChangeLog:

            PR fortran/106945
            * gfortran.dg/pr106945.f90: New test.


The PR is marked as a 10/11/12/13 regression, and given its simplicity,
it should qualify for backports.

Thanks,
Harald