{"checksum", 'c', POPT_ARG_VAL, &always_checksum, 1, 0, 0 },
{"no-checksum", 0, POPT_ARG_VAL, &always_checksum, 0, 0, 0 },
{"no-c", 0, POPT_ARG_VAL, &always_checksum, 0, 0, 0 },
{"checksum", 'c', POPT_ARG_VAL, &always_checksum, 1, 0, 0 },
{"no-checksum", 0, POPT_ARG_VAL, &always_checksum, 0, 0, 0 },
{"no-c", 0, POPT_ARG_VAL, &always_checksum, 0, 0, 0 },