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.
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.
(cherry picked from commit
190aaaaf077fe5f318e168a7a1e1aa57058f377e)
{
constexpr typename basic_format_parse_context<_CharT>::iterator
parse(basic_format_parse_context<_CharT>& __pc)
- { return _M_f._M_parse(__pc, __format::_Month|__format::_Day); }
+ { return _M_f._M_parse(__pc, __format::_Month); }
template<typename _Out>
typename basic_format_context<_Out, _CharT>::iterator