Handle return values of win32 color functions in wincolor sink

include/spdlog/sinks/wincolor_sink-inl.h

@@ -133,12 +133,17 @@ template<typename ConsoleMutex>
 std::uint16_t SPDLOG_INLINE wincolor_sink<ConsoleMutex>::set_foreground_color_(std::uint16_t attribs)
 {        
     CONSOLE_SCREEN_BUFFER_INFO orig_buffer_info;
-    ::GetConsoleScreenBufferInfo(static_cast<HANDLE>(out_handle_), &orig_buffer_info);
+    if (!::GetConsoleScreenBufferInfo(static_cast<HANDLE>(out_handle_), &orig_buffer_info))
+    {        
+        return WHITE;
+    }
+   
     WORD back_color = orig_buffer_info.wAttributes;
     // retrieve the current background color
     back_color &= static_cast<WORD>(~(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY));
     // keep the background color unchanged
-    ::SetConsoleTextAttribute(static_cast<HANDLE>(out_handle_), static_cast<WORD>(attribs) | back_color);
+    auto ignored = ::SetConsoleTextAttribute(static_cast<HANDLE>(out_handle_), static_cast<WORD>(attribs) | back_color);
+    (void)(ignored);
     return static_cast<std::uint16_t>(orig_buffer_info.wAttributes); // return orig attribs
 }
 
@@ -147,7 +152,8 @@ template<typename ConsoleMutex>
 void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted, size_t start, size_t end)
 {
     auto size = static_cast<DWORD>(end - start);
-    ::WriteConsoleA(static_cast<HANDLE>(out_handle_), formatted.data() + start, size, nullptr, nullptr);
+    auto ignored = ::WriteConsoleA(static_cast<HANDLE>(out_handle_), formatted.data() + start, size, nullptr, nullptr);
+    (void)(ignored);
 }
 
 template<typename ConsoleMutex>
@@ -155,7 +161,8 @@ void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::write_to_file_(const memory_buf_
 {  
     auto size = static_cast<DWORD>(formatted.size());
     DWORD bytes_written = 0;
-    ::WriteFile(static_cast<HANDLE>(out_handle_), formatted.data(), size, &bytes_written, nullptr);
+    auto ignored = ::WriteFile(static_cast<HANDLE>(out_handle_), formatted.data(), size, &bytes_written, nullptr);
+    (void)(ignored);
 }
 
 // wincolor_stdout_sink