display error.

gui.cc

@@ -67,7 +67,7 @@ void displayerror (std::string error) {
 			 GTK_DIALOG_DESTROY_WITH_PARENT,
 			 GTK_MESSAGE_ERROR,
 			 GTK_BUTTONS_OK,
-			 error.c_str());
+			 "%s", error.c_str());
 	gtk_window_set_title(GTK_WINDOW(dialog), "Error");
 	gtk_dialog_run(GTK_DIALOG(dialog));
 	gtk_widget_destroy(dialog);