+ const char *cstr1 = s1.c_str();
+ const char *cstr2 = s2.c_str();
+ gchar *cstr1folded = NULL;
+ gchar *cstr2folded = NULL;
+ int retval;
+
+ if (!g_utf8_validate (cstr1, -1, NULL) ||
+ !g_utf8_validate (cstr2, -1, NULL)) {
+ // fall back to comparing ASCII
+ return g_ascii_strcasecmp (cstr1, cstr2);