[Bug c++/109556] [13/14 Regression] internal compiler error: in iterative_hash_template_arg, at cp/pt.cc:1927

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109556

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Patrick Palka
<ppa...@gcc.gnu.org>:

https://gcc.gnu.org/g:90361bc6f4ffffedb444e86380b6d1e08475fa74

commit r13-7227-g90361bc6f4ffffedb444e86380b6d1e08475fa74
Author: Patrick Palka <ppa...@redhat.com>
Date:   Wed Apr 19 13:07:46 2023 -0400

    c++: bad ggc_free in try_class_unification [PR109556]

    Aside from correcting how try_class_unification copies multi-dimensional
    'targs', r13-377-g3e948d645bc908 also made it ggc_free this copy as an
    optimization.  But this is wrong since the call to unify within might've
    captured the args in persistent memory such as the satisfaction cache
    (as part of constrained auto deduction).

            PR c++/109556

    gcc/cp/ChangeLog:

            * pt.cc (try_class_unification): Don't ggc_free the copy of
            'targs'.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-placeholder13.C: New test.

    (cherry picked from commit 5e284ebbc3082c5a8974d24e3a0977aa48f3cc60)