From 2e58c3a82f4cbbd3b19bfd3db55feeeb8885ada6 Mon Sep 17 00:00:00 2001
From: user202729 <25191436+user202729@users.noreply.github.com>
Date: Mon, 6 Apr 2026 09:49:45 +0700
Subject: [PATCH] Avoid dropping null byte in format string

---
 include/fmt/base.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/fmt/base.h b/include/fmt/base.h
index 49868b6d751a..be7a40d52e70 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -2690,16 +2690,16 @@ template <typename... T> struct fstring {
     static_assert(count<(is_view<remove_cvref_t<T>>::value &&
                          std::is_reference<T>::value)...>() == 0,
                   "passing views as lvalues is disallowed");
-    if (FMT_USE_CONSTEVAL) parse_format_string<char>(s, checker(s, arg_pack()));
+    if (FMT_USE_CONSTEVAL)
+      parse_format_string<char>(str, checker(str, arg_pack()));
     constexpr bool unused = detail::enforce_compile_checks<sizeof(s) != 0>();
     (void)unused;
   }
   template <typename S,
             FMT_ENABLE_IF(std::is_convertible<const S&, string_view>::value)>
   FMT_CONSTEVAL FMT_ALWAYS_INLINE fstring(const S& s) : str(s) {
-    auto sv = string_view(str);
     if (FMT_USE_CONSTEVAL)
-      detail::parse_format_string<char>(sv, checker(sv, arg_pack()));
+      detail::parse_format_string<char>(str, checker(str, arg_pack()));
     constexpr bool unused = detail::enforce_compile_checks<sizeof(s) != 0>();
     (void)unused;
   }