From: Tomasz Kamiński <tkaminsk@redhat.com>
Date: Tue, 24 Jun 2025 07:17:12 +0000 (+0200)
Subject: libstdc++: Report compilation error on formatting "%d" from month_last [PR120650]
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53d2ca1541b34bb2f840d5aede9b826025dd0bb7;p=thirdparty%2Fgcc.git

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.

	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)
---

diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
index 32ef3533c72..e9e6a440efb 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -1905,7 +1905,7 @@ namespace __format
     {
       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