[FR] - Additional check when sending funds to script without datum

[zandeck]

Internal/External
External otherwise.

Area
Plutus Related to Plutus Scripts (Alonzo).

Describe the feature you'd like

It is currently possible to submit a transaction to a script without a datum

cardano-cli transaction build-raw \
--alonzo-era \
--tx-in 7fec18529cec3654dd2fb62238fea5c8feb7b9a77f4f6ab8bcab06b3f7eca8e3#0 \
--tx-out $(cat ./contracts/script.addr)+8888880 \
--tx-out $(cat keys/payment2.addr)+23460388896 \
--fee 1000000 \
--protocol-params-file pparams.json \
--out-file tx.raw

Once this is done, there is no way afterwards to retrieve the UTxO on sitting on the contract.

And we endup having UTxO piling up on this address:

cardano-cli query utxo --testnet-magic 8 --address $(cat contracts/script.addr)
                           TxHash                                 TxIx        Amount
--------------------------------------------------------------------------------------
32eb8b686f7f62488c540e35ab94f7e11548f71c6e2af1291f623122131ceac4     1        989999000000 lovelace + TxOutDatumHashNone
4338cb66573353c368a716ed35c46d7f19d0474a156979d88b0678085e138282     0        99811570 lovelace + TxOutDatumHashNone
435eb9c07520bf0aa93d0ff69083b1d4e4ab72884c494f99eed0a3ae7bdc883c     0        49813066 lovelace + TxOutDatumHashNone
481a01c36c6f2dcb0f031e1e6d1a255a8773138f7fae11596a7ff53f1f5c5c54     0        8888880 lovelace + TxOutDatumHashNone
5925dc51db2fe7d168db02dc9e9fff61c4eb93e65dadaa22592aa0902ae1c998     0        999813154 lovelace + TxOutDatumHashNone
5c941072dac8c9a011b31aeebc00ed8416b3f782f0fb1978e347136b7511f065     1        40000000 lovelace + TxOutDatumHash ScriptDataInAlonzoEra "269499980312e03ec5c82239ca527534a15c0da27f026f15dc706e7d0cd6770a"
6bafbd83b11f0d70a980c8cbaa1422ffd943db9262841600e242a0ef4bfdf312     0        1645849 lovelace + TxOutDatumHashNone
98cf51f0e7cf191e9accc3825cfb92b355f7fa7662d4adfef71eb809e4a70161     1        998999000000 lovelace + TxOutDatumHashNone
a2a2b20eccac7fb5e4a0172564d0b2243ac56e1bc3652ed155610ee63802a045     1        3456789 lovelace + TxOutDatumHashNone

Describe alternatives you've considered

I was thinking of adding additional checks in the cli to prevent/ask confirmation if a transaction is being sent to a script without a datum. I don't really see though how the check can be done purely on the CLI side without communicating with the node first to check the address the funds are being sent is a script.

Additional context / screenshots

[Titan-C]

Or conversely. If datum is empty, or unit, because it might be a completely stateless script. Don't require on the redeeming transaction to supply an UTXO.

[waalge]

I've just run into this.
Does anyone know if/why its wrong/bad/suboptimal to have an empty datum for a UTXO at script address?
I just tried in vain to use the cli to retrieve one such utxo.

[Zagita21]

@waalge the way it currently works, whoever wants to spend a UTxO sitting at a script address must supply the datum (as well as the script). So if you send value without a datum, it is effectively burned because there is no datum anybody can supply that will validate. I think the OP is complaining that it is too easy to do this by accident on cli, with no obvious upside.

[waalge]

@Zagita21 so I've now gathered. I've yet to think of a reason why this would be desirable - to allow optional datums (fair) but that are then unspendable (huh?!).

[Jimbo4350]

Closing this. If this is still relevant please reopen.