Fix: If the arguments 'naok' or 'verbose' are not given, the C code will likely crash.

src/dotCall64.c

@@ -119,13 +119,13 @@ SEXP dC64(SEXP args_in) {
 	// We don't need to PROTECT args and args_names, because they are protected by being a subobject of args_in.
 
 	// Check the NAOK argument
-	if(LENGTH(naok) != 1)
+	if(!naok || LENGTH(naok) != 1)
 		error(_("argument 'NAOK' has to be of length 1 (dotCall64)"));
 	flag_naok = asInteger(naok);
  
 
 	// Check the VERBOSE argument
-	if(LENGTH(verbose) != 1)
+	if(!verbose || LENGTH(verbose) != 1)
 		error(_("argument 'VERBOSE' has to be of length 1 (dotCall64)"));
 	flag_verbose = asInteger(verbose);
         if(!(flag_verbose == 0 || flag_verbose == 1 || flag_verbose == 2))
@@ -556,6 +556,8 @@ static void argsfind(SEXP args_in, SEXP *args, SEXP *names,int *len, char *packa
 	strcpy(packageName, "");
 	*signature = NULL;
 	*intent = NULL;
+	*naok = NULL;
+	*verbose = NULL;
 
 	for(s = args_in; s != R_NilValue;) {