251    std::vector<CRecipient> recipients;
252    CAmount new_outputs_value = 0;
253    const auto& txouts = outputs.empty() ? tx->vout : outputs;
254    for (size_t i = 0; i < txouts.size(); ++i) {
255        const CTxOut& output = txouts.at(i);
256        CTxDestination dest;
257        ExtractDestination(output.scriptPubKey, dest);
258        if (original_change_index.has_value() ?  original_change_index.value() == i : OutputIsChange(wallet, output)) {
259            new_coin_control.destChange = dest;
260        } else {
261            CRecipient recipient = {dest, output.nValue, false};
262            recipients.push_back(recipient);
263        }
264        new_outputs_value += output.nValue;
265    }
266
267    // If no recipients, means that we are sending coins to a change address
268    if (recipients.empty()) {
269        // Just as a sanity check, ensure that the change address exist
270        if (std::get_if<CNoDestination>(&new_coin_control.destChange)) {
271            errors.emplace_back(Untranslated("Unable to create transaction. Transaction must have at least one recipient"));
272            return Result::INVALID_PARAMETER;
273        }
274
275        // Add change as recipient with SFFO flag enabled, so fees are deduced from it.
276        // If the output differs from the original tx output (because the user customized it) a new change output will be created.
277        recipients.emplace_back(CRecipient{new_coin_control.destChange, new_outputs_value, /*fSubtractFeeFromAmount=*/true});
278        new_coin_control.destChange = CNoDestination();
279    }
280
281    if (coin_control.m_feerate) {
282        // The user provided a feeRate argument.
283        // We calculate this here to avoid compiler warning on the cs_wallet lock
284        // We need to make a temporary transaction with no input witnesses as the dummy signer expects them to be empty for external inputs
285        CMutableTransaction temp_mtx{*tx};
286        for (auto& txin : temp_mtx.vin) {
287            txin.scriptSig.clear();
288            txin.scriptWitness.SetNull();
289        }
290        temp_mtx.vout = txouts;
291        const int64_t maxTxSize{CalculateMaximumSignedTxSize(CTransaction(temp_mtx), &wallet, &new_coin_control).vsize};
292        Result res = CheckFeeRate(wallet, temp_mtx, *new_coin_control.m_feerate, maxTxSize, old_fee, errors);
293        if (res != Result::OK) {
294            return res;
295        }
296    } else {
297        // The user did not provide a feeRate argument
298        new_coin_control.m_feerate = EstimateFeeRate(wallet, wtx, old_fee, new_coin_control);
299    }
300
301    // Fill in required inputs we are double-spending(all of them)
302    // N.B.: bip125 doesn't require all the inputs in the replaced transaction to be
303    // used in the replacement transaction, but it's very important for wallets to make
304    // sure that happens. If not, it would be possible to bump a transaction A twice to
305    // A2 and A3 where A2 and A3 don't conflict (or alternatively bump A to A2 and A2
306    // to A3 where A and A3 don't conflict). If both later get confirmed then the sender
307    // has accidentally double paid.
308    for (const auto& inputs : tx->vin) {
309        new_coin_control.Select(COutPoint(inputs.prevout));
310    }
311    new_coin_control.m_allow_other_inputs = true;
312
313    // We cannot source new unconfirmed inputs(bip125 rule 2)
314    new_coin_control.m_min_depth = 1;
315
316    auto res = CreateTransaction(wallet, recipients, /*change_pos=*/std::nullopt, new_coin_control, false);
317    if (!res) {
318        errors.emplace_back(Untranslated("Unable to create transaction.") + Untranslated(" ") + util::ErrorString(res));
319        return Result::WALLET_ERROR;
320    }
321
322    const auto& txr = *res;
323    // Write back new fee if successful
324    new_fee = txr.fee;
325
326    // Write back transaction
327    mtx = CMutableTransaction(*txr.tx);
328
329    return Result::OK;
330}
331
332bool SignTransaction(CWallet& wallet, CMutableTransaction& mtx) {
333    LOCK(wallet.cs_wallet);
334
335    if (wallet.IsWalletFlagSet(WALLET_FLAG_EXTERNAL_SIGNER)) {
336        // Make a blank psbt
337        PartiallySignedTransaction psbtx(mtx);
338
339        // First fill transaction with our data without signing,
340        // so external signers are not asked to sign more than once.
341        bool complete;
342        wallet.FillPSBT(psbtx, {.sign = false, .bip32_derivs = true}, complete);
343        auto err{wallet.FillPSBT(psbtx, {.sign = true, .bip32_derivs = false}, complete)};
344        if (err) return false;
345        complete = FinalizeAndExtractPSBT(psbtx, mtx);
346        return complete;
347    } else {
348        return wallet.SignTransaction(mtx);
349    }
350}
351
352Result CommitTransaction(CWallet& wallet, const Txid& txid, CMutableTransaction&& mtx, std::vector<bilingual_str>& errors, Txid& bumped_txid)
353{
354    LOCK(wallet.cs_wallet);
355    if (!errors.empty()) {
356        return Result::MISC_ERROR;
357    }
358    auto it = txid.IsNull() ? wallet.mapWallet.end() : wallet.mapWallet.find(txid);
359    if (it == wallet.mapWallet.end()) {
360        errors.emplace_back(Untranslated("Invalid or non-wallet transaction id"));
361        return Result::MISC_ERROR;
362    }
363    const CWalletTx& oldWtx = it->second;
364
365    // make sure the transaction still has no descendants and hasn't been mined in the meantime
366    Result result = PreconditionChecks(wallet, oldWtx, /* require_mine=*/ false, errors);
367    if (result != Result::OK) {
368        return result;
369    }
370
371    // commit/broadcast the tx
372    CTransactionRef tx = MakeTransactionRef(std::move(mtx));
373    wallet.CommitTransaction(tx, oldWtx.GetHash(), oldWtx.m_comment, oldWtx.m_comment_to, oldWtx.m_messages, oldWtx.m_payment_requests);
374
375    // mark the original tx as bumped
376    bumped_txid = tx->GetHash();
377    if (!wallet.MarkReplaced(oldWtx.GetHash(), bumped_txid)) {
378        errors.emplace_back(Untranslated("Created new bumpfee transaction but could not mark the original transaction as replaced"));
379    }
380    return Result::OK;
381}
382
383} // namespace feebumper
384} // namespace wallet
385