From: Tomasz Kamiński <tkaminsk@redhat.com>
Date: Wed, 4 Jun 2025 09:05:11 +0000 (+0200)
Subject: libstdc++: Fix format call in formatting with empty specs for durations.
X-Git-Tag: releases/gcc-15.2.0~413
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b2338ebf3e698589c69a521b4b4a7908dd959751;p=thirdparty%2Fgcc.git

libstdc++: Fix format call in formatting with empty specs for durations.

This patches fixes an obvious error, where the output iterator argument was
missing for call to format_to, when duration with custom representation types
are used.

libstdc++-v3/ChangeLog:

	* include/bits/chrono_io.h (__formatter_chrono:_M_s): Add missing
	__out argument to format_to call.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Tomasz Kamiński <tkaminsk@redhat.com>
(cherry picked from commit ac0a04b7a254fb8e1d8d7088336bcb4375807b1e)
---

diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
index 7ab989f59a1..32ef3533c72 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -1318,7 +1318,8 @@ namespace __format
 		  else
 		    {
 		      auto __str = std::format(_S_empty_spec, __ss.count());
-		      __out = std::format_to(_GLIBCXX_WIDEN("{:0>{}s}"),
+		      __out = std::format_to(std::move(__out),
+					     _GLIBCXX_WIDEN("{:0>{}s}"),
 					     __str,
 					     __hms.fractional_width);
 		    }