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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/110968] format out of bounds read on
 format("{:05L}",-1.f)
Date: Thu, 10 Aug 2023 13:19:49 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110968

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
--- a/libstdc++-v3/include/std/format
+++ b/libstdc++-v3/include/std/format
@@ -1634,7 +1634,8 @@ namespace __format
                __wstr =3D _M_localize(__str, __expc, __fc.locale());
              else
                __wstr =3D _M_localize(__str, __expc, __loc.value());
-             __str =3D __wstr;
+             if (!__wstr.empty())
+               __str =3D __wstr;
            }

          size_t __width =3D _M_spec._M_get_width(__fc);=