https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110708
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:74f1c016f44daf18e4bed76b283cd5bfd0b5c8c7 commit r13-7629-g74f1c016f44daf18e4bed76b283cd5bfd0b5c8c7 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Jul 18 10:36:37 2023 +0100 libstdc++: Check for multiple modifiers in chrono format string [PR110708] The logic for handling modified chrono specs like %Ey was just restarting the loop after each modifier, and not checking whether we'd already seen a modifier. libstdc++-v3/ChangeLog: PR libstdc++/110708 * include/bits/chrono_io.h (__formatter_chrono::_M_parse): Only allow a single modifier. * testsuite/std/time/format.cc: Check multiple modifiers. (cherry picked from commit 52bfec7ea0eb0f1a4c5bfa55b0d6b9b6c8808e26)