Function wally_txid

bitcoin/tx.c:474–489

}

void wally_txid(const struct wally_tx *wtx, struct bitcoin_txid *txid)
{
	u8 *arr;
	size_t len, written;
	int res;

	/* Never use BIP141 form for txid */
	res = wally_tx_get_length(wtx, 0, &len);
	assert(res == WALLY_OK);
	arr = tal_arr(NULL, u8, len);
	res = wally_tx_to_bytes(wtx, 0, arr, len, &written);
	assert(len == written);

	sha256_double(&txid->shad, arr, len);
	tal_free(arr);
}

/* We used to have beautiful, optimal code which fed the tx parts directly
 * into sha256_update().  But that was before libwally; but now we don't have