[Bug libstdc++/120650] Error of requesting %d from month_day_last is not detected at compile time

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120650

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tomasz Kaminski <tkami...@gcc.gnu.org>:

https://gcc.gnu.org/g:190aaaaf077fe5f318e168a7a1e1aa57058f377e

commit r16-1668-g190aaaaf077fe5f318e168a7a1e1aa57058f377e
Author: Tomasz KamiÅski <tkami...@redhat.com>
Date:   Tue Jun 24 09:17:12 2025 +0200

    libstdc++: Report compilation error on formatting "%d" from month_last
[PR120650]

    For month_day we incorrectly reported day information to be available,
which lead
    to format_error being thrown from the call to formatter::format at runtime,
instead
    of making call to format ill-formed.

    The included test cover most of the combinations of _ChronoParts and format
    specifiers.

            PR libstdc++/120650

    libstdc++-v3/ChangeLog:

            * include/bits/chrono_io.h
            (formatter<chrono::month_day_last,_CharT>::parse): Call _M_parse
with
            only Month being available.
            * testsuite/std/time/format/data_not_present_neg.cc: New test.