diff --git a/src/wallet/mod.rs b/src/wallet/mod.rs index 5caf1624..5100dbd3 100644 --- a/src/wallet/mod.rs +++ b/src/wallet/mod.rs @@ -809,7 +809,14 @@ where let drain_val = (coin_selection.selected_amount() - outgoing).saturating_sub(fee_amount); if tx.output.is_empty() { - if params.drain_to.is_some() { + // Uh oh, our transaction has no outputs. + // We allow this when: + // - We have a drain_to address and the utxos we must spend (this happens, + // for example, when we RBF) + // - We have a drain_to address and drain_wallet set + // Otherwise, we don't know who we should send the funds to, and how much + // we should send! + if params.drain_to.is_some() && (params.drain_wallet || !params.utxos.is_empty()) { if drain_val.is_dust(&drain_output.script_pubkey) { return Err(Error::InsufficientFunds { needed: drain_output.script_pubkey.dust_value().as_sat(), @@ -2248,6 +2255,40 @@ pub(crate) mod test { assert_eq!(drain_output.value, 30_000 - details.fee.unwrap_or(0)); } + #[test] + fn test_create_tx_drain_to_and_utxos() { + let (wallet, _, _) = get_funded_wallet(get_test_wpkh()); + let addr = wallet.get_address(New).unwrap(); + let utxos: Vec<_> = wallet + .get_available_utxos() + .unwrap() + .into_iter() + .map(|(u, _)| u.outpoint) + .collect(); + let mut builder = wallet.build_tx(); + builder + .drain_to(addr.script_pubkey()) + .add_utxos(&utxos) + .unwrap(); + let (psbt, details) = builder.finish().unwrap(); + + assert_eq!(psbt.unsigned_tx.output.len(), 1); + assert_eq!( + psbt.unsigned_tx.output[0].value, + 50_000 - details.fee.unwrap_or(0) + ); + } + + #[test] + #[should_panic(expected = "NoRecipients")] + fn test_create_tx_drain_to_no_drain_wallet_no_utxos() { + let (wallet, _, _) = get_funded_wallet(get_test_wpkh()); + let drain_addr = wallet.get_address(New).unwrap(); + let mut builder = wallet.build_tx(); + builder.drain_to(drain_addr.script_pubkey()); + builder.finish().unwrap(); + } + #[test] fn test_create_tx_default_fee_rate() { let (wallet, _, _) = get_funded_wallet(get_test_wpkh()); diff --git a/src/wallet/tx_builder.rs b/src/wallet/tx_builder.rs index 5f16b853..1546b967 100644 --- a/src/wallet/tx_builder.rs +++ b/src/wallet/tx_builder.rs @@ -586,6 +586,9 @@ impl<'a, D: BatchDatabase, Cs: CoinSelectionAlgorithm> TxBuilder<'a, D, Cs, C /// difference is that it is valid to use `drain_to` without setting any ordinary recipients /// with [`add_recipient`] (but it is perfectly fine to add recipients as well). /// + /// If you choose not to set any recipients, you should either provide the utxos that the + /// transaction should spend via [`add_utxos`], or set [`drain_wallet`] to spend all of them. + /// /// When bumping the fees of a transaction made with this option, you probably want to /// use [`allow_shrinking`] to allow this output to be reduced to pay for the extra fees. /// @@ -616,6 +619,7 @@ impl<'a, D: BatchDatabase, Cs: CoinSelectionAlgorithm> TxBuilder<'a, D, Cs, C /// /// [`allow_shrinking`]: Self::allow_shrinking /// [`add_recipient`]: Self::add_recipient + /// [`add_utxos`]: Self::add_utxos /// [`drain_wallet`]: Self::drain_wallet pub fn drain_to(&mut self, script_pubkey: Script) -> &mut Self { self.params.drain_to = Some(script_pubkey);