Merge 8da5ab60b5 into 66aa6a47bd

7c123c08dd  miner: add package feerate vector to CBlockTemplate (ismaelsadeeq)

Pull request description:

  This PR enables `BlockAssembler` to add all selected packages' fee and virtual size to a vector, and then return the vector as a member of `CBlockTemplate` struct.

  This PR is the first step in the https://github.com/bitcoin/bitcoin/issues/30392 project.

  The packages' vsize and fee are used in #30157 to select a percentile fee rate of the top block in the mempool.

ACKs for top commit:
  rkrux:
    tACK 7c123c08dd
  ryanofsky:
    Code review ACK 7c123c08dd. Changes since last review are rebasing due to a test conflict, giving the new field a better name and description, resolving the test conflict, and renaming a lot of test variables. The actual code change is still one-line change.
  glozow:
    reACK 7c123c08dd

Tree-SHA512: 767b0b3d4273cf1589fd2068d729a66c7414c0f9574b15989fbe293f8c85cd6c641dd783cde55bfabab32cd047d7d8a071d6897b06ed4295c0d071e588de0861

src/node/miner.cpp

@@ -421,6 +421,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
         }
 
         ++nPackagesSelected;
+        pblocktemplate->m_package_feerates.emplace_back(packageFees, static_cast<int32_t>(packageSize));
 
         // Update transactions that depend on each of these
         nDescendantsUpdated += UpdatePackagesForAdded(mempool, ancestors, mapModifiedTx);

src/node/miner.h

@@ -10,6 +10,7 @@
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <txmempool.h>
+#include <util/feefrac.h>
 
 #include <memory>
 #include <optional>
@@ -39,6 +40,9 @@ struct CBlockTemplate
     std::vector<CAmount> vTxFees;
     std::vector<int64_t> vTxSigOpsCost;
     std::vector<unsigned char> vchCoinbaseCommitment;
+    /* A vector of package fee rates, ordered by the sequence in which
+     * packages are selected for inclusion in the block template.*/
+    std::vector<FeeFrac> m_package_feerates;
 };
 
 // Container for tracking updates to ancestor feerate as we include (parent)

src/psbt.cpp

@@ -348,7 +348,7 @@ void UpdatePSBTOutput(const SigningProvider& provider, PartiallySignedTransactio
     // Construct a would-be spend of this output, to update sigdata with.
     // Note that ProduceSignature is used to fill in metadata (not actual signatures),
     // so provider does not need to provide any private keys (it can be a HidingSigningProvider).
-    MutableTransactionSignatureCreator creator(tx, /*input_idx=*/0, out.nValue, SIGHASH_ALL);
+    MutableTransactionSignatureCreator creator(tx, /*input_idx=*/0, out.nValue, SIGHASH_DEFAULT);
     ProduceSignature(provider, creator, out.scriptPubKey, sigdata);
 
     // Put redeem_script, witness_script, key paths, into PSBTOutput.
@@ -486,7 +486,8 @@ bool FinalizePSBT(PartiallySignedTransaction& psbtx)
     bool complete = true;
     const PrecomputedTransactionData txdata = PrecomputePSBTData(psbtx);
     for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
-        complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, &txdata, SIGHASH_ALL, nullptr, true);
+        int sighash_type = psbtx.inputs.at(i).sighash_type.value_or(SIGHASH_DEFAULT);
+        complete &= SignPSBTInput(DUMMY_SIGNING_PROVIDER, psbtx, i, &txdata, sighash_type, nullptr, true);
     }
 
     return complete;

src/psbt.h

@@ -50,6 +50,9 @@ static constexpr uint8_t PSBT_IN_TAP_LEAF_SCRIPT = 0x15;
 static constexpr uint8_t PSBT_IN_TAP_BIP32_DERIVATION = 0x16;
 static constexpr uint8_t PSBT_IN_TAP_INTERNAL_KEY = 0x17;
 static constexpr uint8_t PSBT_IN_TAP_MERKLE_ROOT = 0x18;
+static constexpr uint8_t PSBT_IN_MUSIG2_PARTICIPANT_PUBKEYS = 0x1a;
+static constexpr uint8_t PSBT_IN_MUSIG2_PUB_NONCE = 0x1b;
+static constexpr uint8_t PSBT_IN_MUSIG2_PARTIAL_SIG = 0x1c;
 static constexpr uint8_t PSBT_IN_PROPRIETARY = 0xFC;
 
 // Output types
@@ -59,6 +62,7 @@ static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02;
 static constexpr uint8_t PSBT_OUT_TAP_INTERNAL_KEY = 0x05;
 static constexpr uint8_t PSBT_OUT_TAP_TREE = 0x06;
 static constexpr uint8_t PSBT_OUT_TAP_BIP32_DERIVATION = 0x07;
+static constexpr uint8_t PSBT_OUT_MUSIG2_PARTICIPANT_PUBKEYS = 0x08;
 static constexpr uint8_t PSBT_OUT_PROPRIETARY = 0xFC;
 
 // The separator is 0x00. Reading this in means that the unserializer can interpret it
@@ -217,6 +221,11 @@ struct PSBTInput
     XOnlyPubKey m_tap_internal_key;
     uint256 m_tap_merkle_root;
 
+    // MuSig2 fields
+    std::map<CPubKey, std::vector<CPubKey>> m_musig2_participants;
+    std::map<std::pair<CPubKey, uint256>, std::map<CPubKey, std::vector<uint8_t>>> m_musig2_pubnonces;
+    std::map<std::pair<CPubKey, uint256>, std::map<CPubKey, uint256>> m_musig2_partial_sigs;
+
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
     std::set<PSBTProprietary> m_proprietary;
     std::optional<int> sighash_type;
@@ -337,6 +346,43 @@ struct PSBTInput
                 SerializeToVector(s, PSBT_IN_TAP_MERKLE_ROOT);
                 SerializeToVector(s, m_tap_merkle_root);
             }
+
+            // Write MuSig2 Participants
+            for (const auto& [agg_key, part_pubs] : m_musig2_participants) {
+                SerializeToVector(s, CompactSizeWriter(PSBT_IN_MUSIG2_PARTICIPANT_PUBKEYS), Span{agg_key});
+                std::vector<unsigned char> value;
+                VectorWriter s_value{value, 0};
+                for (auto& pk : part_pubs) {
+                    s_value << Span{pk};
+                }
+                s << value;
+            }
+
+            // Write MuSig2 pubnonces
+            for (const auto& [agg_key_leaf_hash, pubnonces] : m_musig2_pubnonces) {
+                const auto& [agg_key, leaf_hash] = agg_key_leaf_hash;
+                for (const auto& [pubkey, pubnonce] : pubnonces) {
+                    if (leaf_hash.IsNull()) {
+                        SerializeToVector(s, CompactSizeWriter(PSBT_IN_MUSIG2_PUB_NONCE), Span{pubkey}, Span{agg_key});
+                    } else {
+                        SerializeToVector(s, CompactSizeWriter(PSBT_IN_MUSIG2_PUB_NONCE), Span{pubkey}, Span{agg_key}, leaf_hash);
+                    }
+                    s << pubnonce;
+                }
+            }
+
+            // Write MuSig2 partial signatures
+            for (const auto& [agg_key_leaf_hash, psigs] : m_musig2_partial_sigs) {
+                const auto& [agg_key, leaf_hash] = agg_key_leaf_hash;
+                for (const auto& [pubkey, psig] : psigs) {
+                    if (leaf_hash.IsNull()) {
+                        SerializeToVector(s, CompactSizeWriter(PSBT_IN_MUSIG2_PARTIAL_SIG), Span{pubkey}, Span{agg_key});
+                    } else {
+                        SerializeToVector(s, CompactSizeWriter(PSBT_IN_MUSIG2_PARTIAL_SIG), Span{pubkey}, Span{agg_key}, leaf_hash);
+                    }
+                    SerializeToVector(s, psig);
+                }
+            }
         }
 
         // Write script sig
@@ -672,6 +718,80 @@ struct PSBTInput
                     UnserializeFromVector(s, m_tap_merkle_root);
                     break;
                 }
+                case PSBT_IN_MUSIG2_PARTICIPANT_PUBKEYS:
+                {
+                    if (!key_lookup.emplace(key).second) {
+                        throw std::ios_base::failure("Duplicate Key, input participant pubkeys for an aggregate key already provided");
+                    } else if (key.size() != 34) {
+                        throw std::ios_base::failure("Input musig2 participants pubkeys aggregate key is more than 33 bytes");
+                    }
+                    std::array<unsigned char, 33> agg_key_bytes;
+                    skey >> AsWritableBytes(Span{agg_key_bytes});
+                    CPubKey agg_key(agg_key_bytes);
+
+                    std::vector<CPubKey> participants;
+                    std::vector<unsigned char> val;
+                    s >> val;
+                    SpanReader s_val{val};
+                    while (!s_val.empty()) {
+                        std::array<unsigned char, 33> part_key_bytes;
+                        s_val >> AsWritableBytes(Span{part_key_bytes});
+                        participants.emplace_back(Span{part_key_bytes});
+                    }
+
+                    m_musig2_participants.emplace(agg_key, participants);
+                    break;
+                }
+                case PSBT_IN_MUSIG2_PUB_NONCE:
+                {
+                    if (!key_lookup.emplace(key).second) {
+                        throw std::ios_base::failure("Duplicate Key, input musig2 pubnonce already provided");
+                    } else if (key.size() != 67 && key.size() != 99) {
+                        throw std::ios_base::failure("Input musig2 pubnonce key is not expected size");
+                    }
+                    std::array<unsigned char, 33> part_pubkey_bytes;
+                    std::array<unsigned char, 33> agg_pubkey_bytes;
+                    uint256 leaf_hash;
+
+                    skey >> AsWritableBytes(Span{part_pubkey_bytes}) >> AsWritableBytes(Span{agg_pubkey_bytes});
+                    CPubKey agg_pub{Span{agg_pubkey_bytes}};
+                    CPubKey part_pub{Span{part_pubkey_bytes}};
+
+                    if (!skey.empty()) {
+                        skey >> leaf_hash;
+                    }
+
+                    std::vector<uint8_t> pubnonce;
+                    s >> pubnonce;
+
+                    m_musig2_pubnonces[std::make_pair(agg_pub, leaf_hash)].emplace(part_pub, pubnonce);
+                    break;
+                }
+                case PSBT_IN_MUSIG2_PARTIAL_SIG:
+                {
+                    if (!key_lookup.emplace(key).second) {
+                        throw std::ios_base::failure("Duplicate Key, input musig2 partial sig already provided");
+                    } else if (key.size() != 67 && key.size() != 99) {
+                        throw std::ios_base::failure("Input musig2 partial sig key is not expected size");
+                    }
+                    std::array<unsigned char, 33> part_pubkey_bytes;
+                    std::array<unsigned char, 33> agg_pubkey_bytes;
+                    uint256 leaf_hash;
+
+                    skey >> AsWritableBytes(Span{part_pubkey_bytes}) >> AsWritableBytes(Span{agg_pubkey_bytes});
+                    CPubKey agg_pub{Span{agg_pubkey_bytes}};
+                    CPubKey part_pub{Span{part_pubkey_bytes}};
+
+                    if (!skey.empty()) {
+                        skey >> leaf_hash;
+                    }
+
+                    uint256 partial_sig;
+                    UnserializeFromVector(s, partial_sig);
+
+                    m_musig2_partial_sigs[std::make_pair(agg_pub, leaf_hash)].emplace(part_pub, partial_sig);
+                    break;
+                }
                 case PSBT_IN_PROPRIETARY:
                 {
                     PSBTProprietary this_prop;
@@ -719,6 +839,7 @@ struct PSBTOutput
     XOnlyPubKey m_tap_internal_key;
     std::vector<std::tuple<uint8_t, uint8_t, std::vector<unsigned char>>> m_tap_tree;
     std::map<XOnlyPubKey, std::pair<std::set<uint256>, KeyOriginInfo>> m_tap_bip32_paths;
+    std::map<CPubKey, std::vector<CPubKey>> m_musig2_participants;
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
     std::set<PSBTProprietary> m_proprietary;
 
@@ -781,6 +902,17 @@ struct PSBTOutput
             s << value;
         }
 
+        // Write MuSig2 Participants
+        for (const auto& [agg_key, part_pubs] : m_musig2_participants) {
+            SerializeToVector(s, CompactSizeWriter(PSBT_OUT_MUSIG2_PARTICIPANT_PUBKEYS), Span{agg_key});
+            std::vector<unsigned char> value;
+            VectorWriter s_value{value, 0};
+            for (auto& pk : part_pubs) {
+                s_value << Span{pk};
+            }
+            s << value;
+        }
+
         // Write unknown things
         for (auto& entry : unknown) {
             s << entry.first;
@@ -907,6 +1039,30 @@ struct PSBTOutput
                     m_tap_bip32_paths.emplace(xonly, std::make_pair(leaf_hashes, DeserializeKeyOrigin(s, origin_len)));
                     break;
                 }
+                case PSBT_OUT_MUSIG2_PARTICIPANT_PUBKEYS:
+                {
+                    if (!key_lookup.emplace(key).second) {
+                        throw std::ios_base::failure("Duplicate Key, output participant pubkeys for an aggregate key already provided");
+                    } else if (key.size() != 34) {
+                        throw std::ios_base::failure("Output musig2 participants pubkeys aggregate key is more than 33 bytes");
+                    }
+                    std::array<unsigned char, 33> agg_key_bytes;
+                    skey.read(AsWritableBytes(Span{agg_key_bytes}));
+                    CPubKey agg_key(agg_key_bytes);
+
+                    std::vector<CPubKey> participants;
+                    std::vector<unsigned char> val;
+                    s >> val;
+                    SpanReader s_val{val};
+                    while (!s_val.empty()) {
+                        std::array<unsigned char, 33> part_key_bytes;
+                        s_val.read(AsWritableBytes(Span{part_key_bytes}));
+                        participants.emplace_back(Span{part_key_bytes});
+                    }
+
+                    m_musig2_participants.emplace(agg_key, participants);
+                    break;
+                }
                 case PSBT_OUT_PROPRIETARY:
                 {
                     PSBTProprietary this_prop;

src/rpc/rawtransaction.cpp

@@ -916,6 +916,37 @@ const RPCResult decodepsbt_inputs{
             }},
             {RPCResult::Type::STR_HEX, "taproot_internal_key", /*optional=*/ true, "The hex-encoded Taproot x-only internal key"},
             {RPCResult::Type::STR_HEX, "taproot_merkle_root", /*optional=*/ true, "The hex-encoded Taproot merkle root"},
+            {RPCResult::Type::ARR, "musig2_participant_pubkeys", /*optional*/true, "",
+            {
+                {RPCResult::Type::OBJ, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "aggregate_pubkey", "The plain aggregate public key for which the participants create."},
+                    {RPCResult::Type::ARR, "participant_pubkeys", "",
+                    {
+                        {RPCResult::Type::STR_HEX, "pubkey", "The plain public keys that are aggregated for aggregate_pubkey."},
+                    }},
+                }},
+            }},
+            {RPCResult::Type::ARR, "musig2_pubnonces", /*optional*/true, "",
+            {
+                {RPCResult::Type::OBJ, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "participant_pubkey", "The plain public key of the participant that created this pubnonce."},
+                    {RPCResult::Type::STR_HEX, "aggregate_pubkey", "The plain aggregate public key for which this pubnonce is for."},
+                    {RPCResult::Type::STR_HEX, "leaf_hash", /*optional=*/true, "The hash of the leaf script that contains the aggregate pubkey being signed for. Omitted when signing for the internal key."},
+                    {RPCResult::Type::STR_HEX, "pubnonce", "The public nonce itself."},
+                }},
+            }},
+            {RPCResult::Type::ARR, "musig2_partial_sigs", /*optional*/true, "",
+            {
+                {RPCResult::Type::OBJ, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "participant_pubkey", "The plain public key of the participant that created this partial signature."},
+                    {RPCResult::Type::STR_HEX, "aggregate_pubkey", "The plain aggregate public key for which this partial signature is for."},
+                    {RPCResult::Type::STR_HEX, "leaf_hash", /*optional=*/true, "The hash of the leaf script that contains the aggregate pubkey being signed for. Omitted when signing for the internal key."},
+                    {RPCResult::Type::STR_HEX, "partial_sig", "The partial signature itself."},
+                }},
+            }},
             {RPCResult::Type::OBJ_DYN, "unknown", /*optional=*/ true, "The unknown input fields",
             {
                 {RPCResult::Type::STR_HEX, "key", "(key-value pair) An unknown key-value pair"},
@@ -983,6 +1014,17 @@ const RPCResult decodepsbt_outputs{
                     }},
                 }},
             }},
+            {RPCResult::Type::ARR, "musig2_participant_pubkeys", /*optional*/true, "",
+            {
+                {RPCResult::Type::OBJ, "", "",
+                {
+                    {RPCResult::Type::STR_HEX, "aggregate_pubkey", "The plain aggregate public key for which the participants create."},
+                    {RPCResult::Type::ARR, "participant_pubkeys", "",
+                    {
+                        {RPCResult::Type::STR_HEX, "pubkey", "The plain public keys that are aggregated for aggregate_pubkey."},
+                    }},
+                }},
+            }},
             {RPCResult::Type::OBJ_DYN, "unknown", /*optional=*/true, "The unknown output fields",
             {
                 {RPCResult::Type::STR_HEX, "key", "(key-value pair) An unknown key-value pair"},
@@ -1304,6 +1346,52 @@ static RPCHelpMan decodepsbt()
             in.pushKV("taproot_merkle_root", HexStr(input.m_tap_merkle_root));
         }
 
+        // Write MuSig2 fields
+        if (!input.m_musig2_participants.empty()) {
+            UniValue musig_keys(UniValue::VARR);
+            for (const auto& [agg, parts] : input.m_musig2_participants) {
+                UniValue musig_part(UniValue::VOBJ);
+                musig_part.pushKV("aggregate_pubkey", HexStr(agg));
+                UniValue part_keys(UniValue::VARR);
+                for (const auto& pub : parts) {
+                    part_keys.push_back(HexStr(pub));
+                }
+                musig_part.pushKV("participant_pubkeys", part_keys);
+                musig_keys.push_back(musig_part);
+            }
+            in.pushKV("musig2_participant_pubkeys", musig_keys);
+        }
+        if (!input.m_musig2_pubnonces.empty()) {
+            UniValue musig_pubnonces(UniValue::UniValue::VARR);
+            for (const auto& [agg_lh, part_pubnonce] : input.m_musig2_pubnonces) {
+                const auto& [agg, lh] = agg_lh;
+                for (const auto& [part, pubnonce] : part_pubnonce) {
+                    UniValue info(UniValue::VOBJ);
+                    info.pushKV("participant_pubkey", HexStr(part));
+                    info.pushKV("aggregate_pubkey", HexStr(agg));
+                    if (!lh.IsNull()) info.pushKV("leaf_hash", HexStr(lh));
+                    info.pushKV("pubnonce", HexStr(pubnonce));
+                    musig_pubnonces.push_back(info);
+                }
+            }
+            in.pushKV("musig2_pubnonces", musig_pubnonces);
+        }
+        if (!input.m_musig2_partial_sigs.empty()) {
+            UniValue musig_partial_sigs(UniValue::UniValue::VARR);
+            for (const auto& [agg_lh, part_psig] : input.m_musig2_partial_sigs) {
+                const auto& [agg, lh] = agg_lh;
+                for (const auto& [part, psig] : part_psig) {
+                    UniValue info(UniValue::VOBJ);
+                    info.pushKV("participant_pubkey", HexStr(part));
+                    info.pushKV("aggregate_pubkey", HexStr(agg));
+                    if (!lh.IsNull()) info.pushKV("leaf_hash", HexStr(lh));
+                    info.pushKV("partial_sig", HexStr(psig));
+                    musig_partial_sigs.push_back(info);
+                }
+            }
+            in.pushKV("musig2_partial_sigs", musig_partial_sigs);
+        }
+
         // Proprietary
         if (!input.m_proprietary.empty()) {
             UniValue proprietary(UniValue::VARR);
@@ -1399,6 +1487,22 @@ static RPCHelpMan decodepsbt()
             out.pushKV("taproot_bip32_derivs", std::move(keypaths));
         }
 
+        // Write MuSig2 fields
+        if (!output.m_musig2_participants.empty()) {
+            UniValue musig_keys(UniValue::VARR);
+            for (const auto& [agg, parts] : output.m_musig2_participants) {
+                UniValue musig_part(UniValue::VOBJ);
+                musig_part.pushKV("aggregate_pubkey", HexStr(agg));
+                UniValue part_keys(UniValue::VARR);
+                for (const auto& pub : parts) {
+                    part_keys.push_back(HexStr(pub));
+                }
+                musig_part.pushKV("participant_pubkeys", part_keys);
+                musig_keys.push_back(musig_part);
+            }
+            out.pushKV("musig2_participant_pubkeys", musig_keys);
+        }
+
         // Proprietary
         if (!output.m_proprietary.empty()) {
             UniValue proprietary(UniValue::VARR);

src/test/miner_tests.cpp

@@ -16,6 +16,7 @@
 #include <txmempool.h>
 #include <uint256.h>
 #include <util/check.h>
+#include <util/feefrac.h>
 #include <util/strencodings.h>
 #include <util/time.h>
 #include <util/translation.h>
@@ -25,6 +26,7 @@
 #include <test/util/setup_common.h>
 
 #include <memory>
+#include <vector>
 
 #include <boost/test/unit_test.hpp>
 
@@ -123,19 +125,22 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     tx.vout[0].nValue = 5000000000LL - 1000;
     // This tx has a low fee: 1000 satoshis
     Txid hashParentTx = tx.GetHash(); // save this txid for later use
-    AddToMempool(tx_mempool, entry.Fee(1000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
+    const auto parent_tx{entry.Fee(1000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx)};
+    AddToMempool(tx_mempool, parent_tx);
 
     // This tx has a medium fee: 10000 satoshis
     tx.vin[0].prevout.hash = txFirst[1]->GetHash();
     tx.vout[0].nValue = 5000000000LL - 10000;
     Txid hashMediumFeeTx = tx.GetHash();
-    AddToMempool(tx_mempool, entry.Fee(10000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx));
+    const auto medium_fee_tx{entry.Fee(10000).Time(Now<NodeSeconds>()).SpendsCoinbase(true).FromTx(tx)};
+    AddToMempool(tx_mempool, medium_fee_tx);
 
     // This tx has a high fee, but depends on the first transaction
     tx.vin[0].prevout.hash = hashParentTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 50k satoshi fee
     Txid hashHighFeeTx = tx.GetHash();
-    AddToMempool(tx_mempool, entry.Fee(50000).Time(Now<NodeSeconds>()).SpendsCoinbase(false).FromTx(tx));
+    const auto high_fee_tx{entry.Fee(50000).Time(Now<NodeSeconds>()).SpendsCoinbase(false).FromTx(tx)};
+    AddToMempool(tx_mempool, high_fee_tx);
 
     std::unique_ptr<BlockTemplate> block_template = mining->createNewBlock(options);
     BOOST_REQUIRE(block_template);
@@ -145,6 +150,21 @@ void MinerTestingSetup::TestPackageSelection(const CScript& scriptPubKey, const
     BOOST_CHECK(block.vtx[2]->GetHash() == hashHighFeeTx);
     BOOST_CHECK(block.vtx[3]->GetHash() == hashMediumFeeTx);
 
+    // Test the inclusion of package feerates in the block template and ensure they are sequential.
+    const auto block_package_feerates = BlockAssembler{m_node.chainman->ActiveChainstate(), &tx_mempool, options}.CreateNewBlock()->m_package_feerates;
+    BOOST_CHECK(block_package_feerates.size() == 2);
+
+    // parent_tx and high_fee_tx are added to the block as a package.
+    const auto combined_txs_fee = parent_tx.GetFee() + high_fee_tx.GetFee();
+    const auto combined_txs_size = parent_tx.GetTxSize() + high_fee_tx.GetTxSize();
+    FeeFrac package_feefrac{combined_txs_fee, combined_txs_size};
+    // The package should be added first.
+    BOOST_CHECK(block_package_feerates[0] == package_feefrac);
+
+    // The medium_fee_tx should be added next.
+    FeeFrac medium_tx_feefrac{medium_fee_tx.GetFee(), medium_fee_tx.GetTxSize()};
+    BOOST_CHECK(block_package_feerates[1] == medium_tx_feefrac);
+
     // Test that a package below the block min tx fee doesn't get included
     tx.vin[0].prevout.hash = hashHighFeeTx;
     tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 0 fee