From 8dbae411f4d55950562e2bdd38ad1201af4a041c Mon Sep 17 00:00:00 2001
From: Roman Koshelev <roman.koshelev@bk.ru>
Date: Mon, 2 Oct 2023 19:21:14 +0300
Subject: [PATCH 1/2] refactoring

---
 include/fmt/format-inl.h | 15 ++++++---------
 include/fmt/ostream.h    | 11 ++++++-----
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 3680794c6211..7d09ca0cadfc 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -73,9 +73,8 @@ FMT_FUNC void report_error(format_func func, int error_code,
 }
 
 // A wrapper around fwrite that throws on error.
-inline void fwrite_fully(const void* ptr, size_t size, size_t count,
-                         FILE* stream) {
-  size_t written = std::fwrite(ptr, size, count, stream);
+inline void fwrite_fully(const void* ptr, size_t count, FILE* stream) {
+  size_t written = std::fwrite(ptr, 1, count, stream);
   if (written < count)
     FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
@@ -1433,13 +1432,11 @@ extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
     void*, const void*, dword, dword*, void*);
 
 FMT_FUNC bool write_console(std::FILE* f, string_view text) {
-  auto fd = _fileno(f);
+  int fd = _fileno(f);
   if (!_isatty(fd)) return false;
   auto u16 = utf8_to_utf16(text);
-  auto written = dword();
   return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
-                       static_cast<uint32_t>(u16.size()), &written,
-                       nullptr) != 0;
+                       static_cast<dword>(u16.size()), nullptr, nullptr) != 0;
 }
 #endif
 
@@ -1448,12 +1445,12 @@ FMT_FUNC bool write_console(std::FILE* f, string_view text) {
 FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args) {
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt, args);
-  fwrite_fully(buffer.data(), 1, buffer.size(), f);
+  fwrite_fully(buffer.data(), buffer.size(), f);
 }
 #endif
 
 FMT_FUNC void print(std::FILE* f, string_view text) {
-  if (!write_console(f, text)) fwrite_fully(text.data(), 1, text.size(), f);
+  if (!write_console(f, text)) fwrite_fully(text.data(), text.size(), f);
 }
 }  // namespace detail
 
diff --git a/include/fmt/ostream.h b/include/fmt/ostream.h
index a5eddcb0874f..021b5e58407c 100644
--- a/include/fmt/ostream.h
+++ b/include/fmt/ostream.h
@@ -38,24 +38,25 @@ auto get_file(std::filebuf&) -> FILE*;
 #endif
 
 inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
+  FILE* c_file = nullptr;
 #if FMT_MSC_VERSION
   if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
-    if (FILE* f = get_file(*buf)) return write_console(f, data);
+    c_file = get_file(*buf);
 #elif defined(_WIN32) && defined(__GLIBCXX__)
   auto* rdbuf = os.rdbuf();
-  FILE* c_file;
   if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
     c_file = sfbuf->file();
   else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
     c_file = fbuf->file();
   else
     return false;
-  if (c_file) return write_console(c_file, data);
 #else
-  ignore_unused(os, data);
+  ignore_unused(os);
 #endif
-  return false;
+  if (!c_file) return false;
+  return write_console(c_file, data);
 }
+
 inline bool write_ostream_unicode(std::wostream&,
                                   fmt::basic_string_view<wchar_t>) {
   return false;

From 4fe961f796b9f14011d6bdaa442df5c7e067c1c6 Mon Sep 17 00:00:00 2001
From: Roman Koshelev <roman.koshelev@bk.ru>
Date: Tue, 3 Oct 2023 10:03:22 +0300
Subject: [PATCH 2/2] add buffer flush before direct write

---
 include/fmt/format-inl.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 7d09ca0cadfc..4dc182f083c1 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -1434,6 +1434,7 @@ extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
 FMT_FUNC bool write_console(std::FILE* f, string_view text) {
   int fd = _fileno(f);
   if (!_isatty(fd)) return false;
+  std::fflush(f);
   auto u16 = utf8_to_utf16(text);
   return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
                        static_cast<dword>(u16.size()), nullptr, nullptr) != 0;