[google#1487] ensure that when printing color text the background col…

…or of the terminal on windows is preserved

src/colorprint.cc

@@ -135,19 +135,25 @@ void ColorPrintf(std::ostream& out, LogColor color, const char* fmt,
   // Gets the current text color.
   CONSOLE_SCREEN_BUFFER_INFO buffer_info;
   GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
-  const WORD old_color_attrs = buffer_info.wAttributes;
+  const WORD original_color_attrs = buffer_info.wAttributes;
 
   // We need to flush the stream buffers into the console before each
   // SetConsoleTextAttribute call lest it affect the text that is already
   // printed but has not yet reached the console.
   out.flush();
-  SetConsoleTextAttribute(stdout_handle,
-                          GetPlatformColorCode(color) | FOREGROUND_INTENSITY);
+
+  const WORD original_background_attrs =
+      original_color_attrs & (BACKGROUND_RED | BACKGROUND_GREEN |
+                              BACKGROUND_BLUE | BACKGROUND_INTENSITY);
+
+  SetConsoleTextAttribute(stdout_handle, GetPlatformColorCode(color) |
+                                            FOREGROUND_INTENSITY | 
+                                            original_background_attrs);
   out << FormatString(fmt, args);
 
   out.flush();
-  // Restores the text color.
-  SetConsoleTextAttribute(stdout_handle, old_color_attrs);
+  // Restores the text and background color.
+  SetConsoleTextAttribute(stdout_handle, original_color_attrs);
 #else
   const char* color_code = GetPlatformColorCode(color);
   if (color_code) out << FormatString("\033[0;3%sm", color_code);