title = _("Save collection");
- gdlg = file_util_gen_dlg(title, "dlg_collection_save", NULL, FALSE, collection_save_or_load_dialog_close_cb, cd);
+ gdlg = file_util_gen_dlg(title, "dlg_collection_save", nullptr, FALSE, collection_save_or_load_dialog_close_cb, cd);
generic_dialog_add_message(GENERIC_DIALOG(gdlg), nullptr, title, _("Existing collections:"), FALSE);
generic_dialog_add_button(gdlg, GQ_ICON_SAVE, _("Save"), collection_save_cb, TRUE);