replace deprected wchar string conversion

include/spdlog/details/os-inl.h

@@ -459,6 +459,41 @@ SPDLOG_INLINE void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target)
 
     throw_spdlog_ex(fmt::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
 }
+
+SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, memory_buf_t &target)
+{
+    if (str.size() > static_cast<size_t>((std::numeric_limits<int>::max)()))
+    {
+        throw_spdlog_ex("UTF-8 string is too big to be converted to UTF-16");
+    }
+
+    int str_size = static_cast<int>(str.size());
+    if (str_size == 0)
+    {
+        target.resize(0);
+        return;
+    }
+
+    int result_size = static_cast<int>(target.capacity());
+    if ((str_size + 1) * 2 < result_size)
+    {
+        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, NULL, 0);
+    }
+
+    if (result_size > 0)
+    {
+        target.resize(result_size);
+        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, (LPWSTR)target.data(), result_size);
+
+        if (result_size > 0)
+        {
+            target.resize(result_size);
+            return;
+        }
+    }
+
+    throw_spdlog_ex(fmt::format("WideCharToMultiByte failed. Last error: {}", ::GetLastError()));
+}
 #endif // (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 
 // return true on success

include/spdlog/details/os.h

@@ -85,6 +85,8 @@ SPDLOG_API bool in_terminal(FILE *file) SPDLOG_NOEXCEPT;
 
 #if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
 SPDLOG_API void wstr_to_utf8buf(wstring_view_t wstr, memory_buf_t &target);
+
+SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, memory_buf_t &target);
 #endif
 
 // Return directory name from given path or empty string

include/spdlog/sinks/win_eventlog_sink.h

@@ -39,8 +39,6 @@ Windows Registry Editor Version 5.00
 #include <mutex>
 #include <string>
 #include <vector>
-#include <locale>
-#include <codecvt>
 
 namespace spdlog {
 namespace sinks {
@@ -226,22 +224,35 @@ protected:
         formatted.push_back('\0');
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
-        auto buf = std::wstring_convert<std::codecvt_utf8<wchar_t>>().from_bytes(formatted.data());
-        LPCWSTR lp_wstr = reinterpret_cast<LPCWSTR>(buf.c_str());
+        try
+        {
+            memory_buf_t buf;
+            details::os::utf8_to_wstrbuf(string_view_t(formatted.data(), formatted.size()), buf);
 
-        succeeded = ::ReportEventW(event_log_handle(), eventlog::get_event_type(msg), eventlog::get_event_category(msg), event_id_,
+            LPCWSTR lp_wstr = reinterpret_cast<LPCWSTR>(buf.data());
+            succeeded = ::ReportEventW(event_log_handle(), eventlog::get_event_type(msg), eventlog::get_event_category(msg), event_id_,
                 current_user_sid_.as_sid(), 1, 0, &lp_wstr, nullptr);
+
+            if (!succeeded)
+            {
+                SPDLOG_THROW(win32_error("ReportEvent"));
+            }
+        }
+        catch (...)
+        {
+            // WCHAR string conversion can fail and if it does, we shouldn't call to report event function.
+        }
 #else
         LPCSTR lp_str = reinterpret_cast<LPCSTR>(formatted.data());
 
         succeeded = ::ReportEventA(event_log_handle(), eventlog::get_event_type(msg), eventlog::get_event_category(msg), event_id_,
                 current_user_sid_.as_sid(), 1, 0, &lp_str, nullptr);
-#endif
 
         if (!succeeded)
         {
             SPDLOG_THROW(win32_error("ReportEvent"));
         }
+#endif
     }
 
     void flush_() override {}