Merge bitcoin/bitcoin#28762: MiniMiner changes for package linearization

d9cc99d04e813caed51c5f7b6ebdc4c39c8823c9 [test] MiniMiner::Linearize and manual construction (glozow)
dfd6a3788c35be121eba1ad84f20effadcb7e7dc [refactor] unify fee amounts in miniminer_tests (glozow)
f4b1b24a3bcd0199a6d2e828ad46033e1368336e [MiniMiner] track inclusion order and add Linearize() function (glozow)
004075963f12f17c3c399d81e3b48d6a8151aebd [test] add case for MiniMiner working with negative fee txns (glozow)
fe6332c0badf07e99044b00084fc6b07f735a051 [MiniMiner] make target_feerate optional (glozow)
5a83f55c96661a886dd6f5231920b2f730cf6773 [MiniMiner] allow manual construction with non-mempool txns (glozow)
e3b2e630b219ca15fe0b2640ca422712c86ac33d [refactor] change MiniMinerMempoolEntry ctor to take values, update includes (glozow)
4aa98b79b266cd526efa577762b0bcfccbdeda11 [lint] update expected boost includes (glozow)

Pull request description:

  This is part of #27463. It splits off the `MiniMiner`-specific changes from #26711 for ease of review, as suggested in https://github.com/bitcoin/bitcoin/pull/26711#issuecomment-1786392253.

  - Allow using `MiniMiner` on transactions that aren't in the mempool.
  - Make `target_feerate` param of `BuildMockTemplate` optional, meaning "don't stop building the template until all the transactions have been selected."
    - Add clarification for how this is different from `target_feerate=0` (https://github.com/bitcoin/bitcoin/pull/26711#discussion_r1377019133)
  - Track the order in which transactions are included in the template to get the "linearization order" of the transactions.
  - Tests

  Reviewers can take a look at #26711 to see how these functions are used to linearize the `AncestorPackage` there.

ACKs for top commit:
  TheCharlatan:
    ACK d9cc99d04e813caed51c5f7b6ebdc4c39c8823c9
  kevkevinpal:
    reACK [d9cc99d](https://github.com/bitcoin/bitcoin/pull/28762/commits/d9cc99d04e813caed51c5f7b6ebdc4c39c8823c9)
  achow101:
    re-ACK d9cc99d04e813caed51c5f7b6ebdc4c39c8823c9

Tree-SHA512: 32b80064b6679536ac573d674825c5ca0cd6245e49c2fd5eaf260dc535335a57683c74ddd7ce1f249b5b12b2683de4362a7b0f1fc0814c3b3b9f14c682665583

4 files changed, 345 insertions, 29 deletions

diff --git a/src/node/mini_miner.cpp b/src/node/mini_miner.cpp
index 2827242f96..3d24a3f58e 100644
--- a/src/node/mini_miner.cpp
+++ b/src/node/mini_miner.cpp
@@ -4,9 +4,14 @@
 
 #include <node/mini_miner.h>
 
+#include <boost/multi_index/detail/hash_index_iterator.hpp>
+#include <boost/operators.hpp>
 #include <consensus/amount.h>
 #include <policy/feerate.h>
 #include <primitives/transaction.h>
+#include <sync.h>
+#include <txmempool.h>
+#include <uint256.h>
 #include <util/check.h>
 
 #include <algorithm>
@@ -72,7 +77,12 @@ MiniMiner::MiniMiner(const CTxMemPool& mempool, const std::vector<COutPoint>& ou
     // Add every entry to m_entries_by_txid and m_entries, except the ones that will be replaced.
     for (const auto& txiter : cluster) {
         if (!m_to_be_replaced.count(txiter->GetTx().GetHash())) {
-            auto [mapiter, success] = m_entries_by_txid.emplace(txiter->GetTx().GetHash(), MiniMinerMempoolEntry(txiter));
+            auto [mapiter, success] = m_entries_by_txid.emplace(txiter->GetTx().GetHash(),
+                MiniMinerMempoolEntry{/*fee_self=*/txiter->GetModifiedFee(),
+                                      /*fee_ancestor=*/txiter->GetModFeesWithAncestors(),
+                                      /*vsize_self=*/txiter->GetTxSize(),
+                                      /*vsize_ancestor=*/txiter->GetSizeWithAncestors(),
+                                      /*tx_in=*/txiter->GetSharedTx()});
             m_entries.push_back(mapiter);
         } else {
             auto outpoints_it = m_requested_outpoints_by_txid.find(txiter->GetTx().GetHash());
@@ -122,6 +132,48 @@ MiniMiner::MiniMiner(const CTxMemPool& mempool, const std::vector<COutPoint>& ou
     SanityCheck();
 }
 
+MiniMiner::MiniMiner(const std::vector<MiniMinerMempoolEntry>& manual_entries,
+                     const std::map<Txid, std::set<Txid>>& descendant_caches)
+{
+    for (const auto& entry : manual_entries) {
+        const auto& txid = entry.GetTx().GetHash();
+        // We need to know the descendant set of every transaction.
+        if (!Assume(descendant_caches.count(txid) > 0)) {
+            m_ready_to_calculate = false;
+            return;
+        }
+        // Just forward these args onto MiniMinerMempoolEntry
+        auto [mapiter, success] = m_entries_by_txid.emplace(txid, entry);
+        // Txids must be unique; this txid shouldn't already be an entry in m_entries_by_txid
+        if (Assume(success)) m_entries.push_back(mapiter);
+    }
+    // Descendant cache is already built, but we need to translate them to m_entries_by_txid iters.
+    for (const auto& [txid, desc_txids] : descendant_caches) {
+        // Descendant cache should include at least the tx itself.
+        if (!Assume(!desc_txids.empty())) {
+            m_ready_to_calculate = false;
+            return;
+        }
+        std::vector<MockEntryMap::iterator> cached_descendants;
+        for (const auto& desc_txid : desc_txids) {
+            auto desc_it{m_entries_by_txid.find(desc_txid)};
+            // Descendants should only include transactions with corresponding entries.
+            if (!Assume(desc_it != m_entries_by_txid.end())) {
+                m_ready_to_calculate = false;
+                return;
+            } else {
+                cached_descendants.emplace_back(desc_it);
+            }
+        }
+        m_descendant_set_by_txid.emplace(txid, cached_descendants);
+    }
+    Assume(m_to_be_replaced.empty());
+    Assume(m_requested_outpoints_by_txid.empty());
+    Assume(m_bump_fees.empty());
+    Assume(m_inclusion_order.empty());
+    SanityCheck();
+}
+
 // Compare by min(ancestor feerate, individual feerate), then iterator
 //
 // Under the ancestor-based mining approach, high-feerate children can pay for parents, but high-feerate
@@ -201,8 +253,10 @@ void MiniMiner::SanityCheck() const
         [&](const auto& txid){return m_entries_by_txid.find(txid) == m_entries_by_txid.end();}));
 }
 
-void MiniMiner::BuildMockTemplate(const CFeeRate& target_feerate)
+void MiniMiner::BuildMockTemplate(std::optional<CFeeRate> target_feerate)
 {
+    const auto num_txns{m_entries_by_txid.size()};
+    uint32_t sequence_num{0};
     while (!m_entries_by_txid.empty()) {
         // Sort again, since transaction removal may change some m_entries' ancestor feerates.
         std::sort(m_entries.begin(), m_entries.end(), AncestorFeerateComparator());
@@ -213,7 +267,8 @@ void MiniMiner::BuildMockTemplate(const CFeeRate& target_feerate)
         const auto ancestor_package_size = (*best_iter)->second.GetSizeWithAncestors();
         const auto ancestor_package_fee = (*best_iter)->second.GetModFeesWithAncestors();
         // Stop here. Everything that didn't "make it into the block" has bumpfee.
-        if (ancestor_package_fee < target_feerate.GetFee(ancestor_package_size)) {
+        if (target_feerate.has_value() &&
+            ancestor_package_fee < target_feerate->GetFee(ancestor_package_size)) {
             break;
         }
 
@@ -237,14 +292,32 @@ void MiniMiner::BuildMockTemplate(const CFeeRate& target_feerate)
                 to_process.erase(iter);
             }
         }
+        // Track the order in which transactions were selected.
+        for (const auto& ancestor : ancestors) {
+            m_inclusion_order.emplace(Txid::FromUint256(ancestor->first), sequence_num);
+        }
         DeleteAncestorPackage(ancestors);
         SanityCheck();
+        ++sequence_num;
+    }
+    if (!target_feerate.has_value()) {
+        Assume(m_in_block.size() == num_txns);
+    } else {
+        Assume(m_in_block.empty() || m_total_fees >= target_feerate->GetFee(m_total_vsize));
     }
-    Assume(m_in_block.empty() || m_total_fees >= target_feerate.GetFee(m_total_vsize));
+    Assume(m_in_block.empty() || sequence_num > 0);
+    Assume(m_in_block.size() == m_inclusion_order.size());
     // Do not try to continue building the block template with a different feerate.
     m_ready_to_calculate = false;
 }
 
+
+std::map<Txid, uint32_t> MiniMiner::Linearize()
+{
+    BuildMockTemplate(std::nullopt);
+    return m_inclusion_order;
+}
+
 std::map<COutPoint, CAmount> MiniMiner::CalculateBumpFees(const CFeeRate& target_feerate)
 {
     if (!m_ready_to_calculate) return {};
diff --git a/src/node/mini_miner.h b/src/node/mini_miner.h
index 9d9d66bf0b..8f86709ae4 100644
--- a/src/node/mini_miner.h
+++ b/src/node/mini_miner.h
@@ -5,33 +5,45 @@
 #ifndef BITCOIN_NODE_MINI_MINER_H
 #define BITCOIN_NODE_MINI_MINER_H
 
-#include <txmempool.h>
+#include <consensus/amount.h>
+#include <primitives/transaction.h>
+#include <uint256.h>
 
+#include <map>
 #include <memory>
 #include <optional>
+#include <set>
 #include <stdint.h>
+#include <vector>
+
+class CFeeRate;
+class CTxMemPool;
 
 namespace node {
 
 // Container for tracking updates to ancestor feerate as we include ancestors in the "block"
 class MiniMinerMempoolEntry
 {
-    const CAmount fee_individual;
     const CTransactionRef tx;
     const int64_t vsize_individual;
-    CAmount fee_with_ancestors;
     int64_t vsize_with_ancestors;
+    const CAmount fee_individual;
+    CAmount fee_with_ancestors;
 
 // This class must be constructed while holding mempool.cs. After construction, the object's
 // methods can be called without holding that lock.
 
 public:
-    explicit MiniMinerMempoolEntry(CTxMemPool::txiter entry) :
-        fee_individual{entry->GetModifiedFee()},
-        tx{entry->GetSharedTx()},
-        vsize_individual(entry->GetTxSize()),
-        fee_with_ancestors{entry->GetModFeesWithAncestors()},
-        vsize_with_ancestors(entry->GetSizeWithAncestors())
+    explicit MiniMinerMempoolEntry(CAmount fee_self,
+                                   CAmount fee_ancestor,
+                                   int64_t vsize_self,
+                                   int64_t vsize_ancestor,
+                                   const CTransactionRef& tx_in):
+        tx{tx_in},
+        vsize_individual{vsize_self},
+        vsize_with_ancestors{vsize_ancestor},
+        fee_individual{fee_self},
+        fee_with_ancestors{fee_ancestor}
     { }
 
     CAmount GetModifiedFee() const { return fee_individual; }
@@ -55,8 +67,14 @@ struct IteratorComparator
     }
 };
 
-/** A minimal version of BlockAssembler. Allows us to run the mining algorithm on a subset of
- * mempool transactions, ignoring consensus rules, to calculate mining scores. */
+/** A minimal version of BlockAssembler, using the same ancestor set scoring algorithm. Allows us to
+ * run this algorithm on a limited set of transactions (e.g. subset of mempool or transactions that
+ * are not yet in mempool) instead of the entire mempool, ignoring consensus rules.
+ * Callers may use this to:
+ * - Calculate the "bump fee" needed to spend an unconfirmed UTXO at a given feerate
+ * - "Linearize" a list of transactions to see the order in which they would be selected for
+ *   inclusion in a block
+ */
 class MiniMiner
 {
     // When true, a caller may use CalculateBumpFees(). Becomes false if we failed to retrieve
@@ -72,7 +90,11 @@ class MiniMiner
     // the same tx will have the same bumpfee. Excludes non-mempool transactions.
     std::map<uint256, std::vector<COutPoint>> m_requested_outpoints_by_txid;
 
-    // What we're trying to calculate.
+    // Txid to a number representing the order in which this transaction was included (smaller
+    // number = included earlier).  Transactions included in an ancestor set together have the same
+    // sequence number.
+    std::map<Txid, uint32_t> m_inclusion_order;
+    // What we're trying to calculate. Outpoint to the fee needed to bring the transaction to the target feerate.
     std::map<COutPoint, CAmount> m_bump_fees;
 
     // The constructed block template
@@ -102,14 +124,32 @@ public:
     /** Returns true if CalculateBumpFees may be called, false if not. */
     bool IsReadyToCalculate() const { return m_ready_to_calculate; }
 
-    /** Build a block template until the target feerate is hit. */
-    void BuildMockTemplate(const CFeeRate& target_feerate);
+    /** Build a block template until the target feerate is hit. If target_feerate is not given,
+     * builds a block template until all transactions have been selected. */
+    void BuildMockTemplate(std::optional<CFeeRate> target_feerate);
 
     /** Returns set of txids in the block template if one has been constructed. */
     std::set<uint256> GetMockTemplateTxids() const { return m_in_block; }
 
+    /** Constructor that takes a list of outpoints that may or may not belong to transactions in the
+     * mempool. Copies out information about the relevant transactions in the mempool into
+     * MiniMinerMempoolEntrys.
+    */
     MiniMiner(const CTxMemPool& mempool, const std::vector<COutPoint>& outpoints);
 
+    /** Constructor in which the MiniMinerMempoolEntry entries have been constructed manually,
+     * presumably because these transactions are not in the mempool (yet). It is assumed that all
+     * entries are unique and their values are correct, otherwise results computed by MiniMiner may
+     * be incorrect. Callers should check IsReadyToCalculate() after construction.
+     * @param[in] descendant_caches A map from each transaction to the set of txids of this
+     *                              transaction's descendant set, including itself. Each tx in
+     *                              manual_entries must have a corresponding entry in this map, and
+     *                              all of the txids in a descendant set must correspond to a tx in
+     *                              manual_entries.
+     */
+    MiniMiner(const std::vector<MiniMinerMempoolEntry>& manual_entries,
+              const std::map<Txid, std::set<Txid>>& descendant_caches);
+
     /** Construct a new block template and, for each outpoint corresponding to a transaction that
      * did not make it into the block, calculate the cost of bumping those transactions (and their
      * ancestors) to the minimum feerate. Returns a map from outpoint to bump fee, or an empty map
@@ -120,6 +160,12 @@ public:
      * not make it into the block to the target feerate. Returns the total bump fee, or std::nullopt
      * if it cannot be calculated. */
     std::optional<CAmount> CalculateTotalBumpFees(const CFeeRate& target_feerate);
+
+    /** Construct a new block template with all of the transactions and calculate the order in which
+     * they are selected. Returns the sequence number (lower = selected earlier) with which each
+     * transaction was selected, indexed by txid, or an empty map if it cannot be calculated.
+     */
+    std::map<Txid, uint32_t> Linearize();
 };
 } // namespace node
 
diff --git a/src/test/miniminer_tests.cpp b/src/test/miniminer_tests.cpp
index f65356936b..76c079a6e7 100644
--- a/src/test/miniminer_tests.cpp
+++ b/src/test/miniminer_tests.cpp
@@ -15,6 +15,11 @@
 
 BOOST_FIXTURE_TEST_SUITE(miniminer_tests, TestingSetup)
 
+const CAmount low_fee{CENT/2000}; // 500 ṩ
+const CAmount med_fee{CENT/200}; // 5000 ṩ
+const CAmount high_fee{CENT/10}; // 100_000 ṩ
+
+
 static inline CTransactionRef make_tx(const std::vector<COutPoint>& inputs, size_t num_outputs)
 {
     CMutableTransaction tx = CMutableTransaction();
@@ -67,21 +72,51 @@ Value Find(const std::map<Key, Value>& map, const Key& key)
     return it->second;
 }
 
-BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
+BOOST_FIXTURE_TEST_CASE(miniminer_negative, TestChain100Setup)
 {
     CTxMemPool& pool = *Assert(m_node.mempool);
     LOCK2(::cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
-    const CAmount low_fee{CENT/2000};
-    const CAmount normal_fee{CENT/200};
-    const CAmount high_fee{CENT/10};
+    // Create a transaction that will be prioritised to have a negative modified fee.
+    const CAmount positive_base_fee{1000};
+    const CAmount negative_fee_delta{-50000};
+    const CAmount negative_modified_fees{positive_base_fee + negative_fee_delta};
+    BOOST_CHECK(negative_modified_fees < 0);
+    const auto tx_mod_negative = make_tx({COutPoint{m_coinbase_txns[4]->GetHash(), 0}}, /*num_outputs=*/1);
+    pool.addUnchecked(entry.Fee(positive_base_fee).FromTx(tx_mod_negative));
+    pool.PrioritiseTransaction(tx_mod_negative->GetHash(), negative_fee_delta);
+    const COutPoint only_outpoint{tx_mod_negative->GetHash(), 0};
+
+    // When target feerate is 0, transactions with negative fees are not selected.
+    node::MiniMiner mini_miner_target0(pool, {only_outpoint});
+    BOOST_CHECK(mini_miner_target0.IsReadyToCalculate());
+    const CFeeRate feerate_zero(0);
+    mini_miner_target0.BuildMockTemplate(feerate_zero);
+    // Check the quit condition:
+    BOOST_CHECK(negative_modified_fees < feerate_zero.GetFee(pool.GetIter(tx_mod_negative->GetHash()).value()->GetTxSize()));
+    BOOST_CHECK(mini_miner_target0.GetMockTemplateTxids().empty());
+
+    // With no target feerate, the template includes all transactions, even negative feerate ones.
+    node::MiniMiner mini_miner_no_target(pool, {only_outpoint});
+    BOOST_CHECK(mini_miner_no_target.IsReadyToCalculate());
+    mini_miner_no_target.BuildMockTemplate(std::nullopt);
+    const auto template_txids{mini_miner_no_target.GetMockTemplateTxids()};
+    BOOST_CHECK_EQUAL(template_txids.size(), 1);
+    BOOST_CHECK(template_txids.count(tx_mod_negative->GetHash().ToUint256()) > 0);
+}
+
+BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
+{
+    CTxMemPool& pool = *Assert(m_node.mempool);
+    LOCK2(::cs_main, pool.cs);
+    TestMemPoolEntryHelper entry;
 
     // Create a parent tx0 and child tx1 with normal fees:
     const auto tx0 = make_tx({COutPoint{m_coinbase_txns[0]->GetHash(), 0}}, /*num_outputs=*/2);
-    pool.addUnchecked(entry.Fee(normal_fee).FromTx(tx0));
+    pool.addUnchecked(entry.Fee(med_fee).FromTx(tx0));
     const auto tx1 = make_tx({COutPoint{tx0->GetHash(), 0}}, /*num_outputs=*/1);
-    pool.addUnchecked(entry.Fee(normal_fee).FromTx(tx1));
+    pool.addUnchecked(entry.Fee(med_fee).FromTx(tx1));
 
     // Create a low-feerate parent tx2 and high-feerate child tx3 (cpfp)
     const auto tx2 = make_tx({COutPoint{m_coinbase_txns[1]->GetHash(), 0}}, /*num_outputs=*/2);
@@ -94,9 +129,11 @@ BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
     pool.addUnchecked(entry.Fee(low_fee).FromTx(tx4));
     const auto tx5 = make_tx({COutPoint{tx4->GetHash(), 0}}, /*num_outputs=*/1);
     pool.addUnchecked(entry.Fee(low_fee).FromTx(tx5));
+    const CAmount tx5_delta{CENT/100};
     // Make tx5's modified fee much higher than its base fee. This should cause it to pass
     // the fee-related checks despite being low-feerate.
-    pool.PrioritiseTransaction(tx5->GetHash(), CENT/100);
+    pool.PrioritiseTransaction(tx5->GetHash(), tx5_delta);
+    const CAmount tx5_mod_fee{low_fee + tx5_delta};
 
     // Create a high-feerate parent tx6, low-feerate child tx7
     const auto tx6 = make_tx({COutPoint{m_coinbase_txns[3]->GetHash(), 0}}, /*num_outputs=*/2);
@@ -273,6 +310,64 @@ BOOST_FIXTURE_TEST_CASE(miniminer_1p1c, TestChain100Setup)
             }
         }
     }
+
+    // Check m_inclusion_order for equivalent mempool- and manually-constructed MiniMiners.
+    // (We cannot check bump fees in manually-constructed MiniMiners because it doesn't know what
+    // outpoints are requested).
+    std::vector<node::MiniMinerMempoolEntry> miniminer_info;
+    {
+        const int32_t tx0_vsize{tx_dims.at(tx0->GetHash()).vsize};
+        const int32_t tx1_vsize{tx_dims.at(tx1->GetHash()).vsize};
+        const int32_t tx2_vsize{tx_dims.at(tx2->GetHash()).vsize};
+        const int32_t tx3_vsize{tx_dims.at(tx3->GetHash()).vsize};
+        const int32_t tx4_vsize{tx_dims.at(tx4->GetHash()).vsize};
+        const int32_t tx5_vsize{tx_dims.at(tx5->GetHash()).vsize};
+        const int32_t tx6_vsize{tx_dims.at(tx6->GetHash()).vsize};
+        const int32_t tx7_vsize{tx_dims.at(tx7->GetHash()).vsize};
+
+        miniminer_info.emplace_back(/*fee_self=*/med_fee,/*fee_ancestor=*/med_fee,/*vsize_self=*/tx0_vsize,/*vsize_ancestor=*/tx0_vsize, tx0);
+        miniminer_info.emplace_back(             med_fee,               2*med_fee,               tx1_vsize,       tx0_vsize + tx1_vsize, tx1);
+        miniminer_info.emplace_back(             low_fee,                 low_fee,               tx2_vsize,                   tx2_vsize, tx2);
+        miniminer_info.emplace_back(            high_fee,      low_fee + high_fee,               tx3_vsize,       tx2_vsize + tx3_vsize, tx3);
+        miniminer_info.emplace_back(             low_fee,                 low_fee,               tx4_vsize,                   tx4_vsize, tx4);
+        miniminer_info.emplace_back(         tx5_mod_fee,   low_fee + tx5_mod_fee,               tx5_vsize,       tx4_vsize + tx5_vsize, tx5);
+        miniminer_info.emplace_back(            high_fee,                high_fee,               tx6_vsize,                   tx6_vsize, tx6);
+        miniminer_info.emplace_back(             low_fee,      high_fee + low_fee,               tx7_vsize,       tx6_vsize + tx7_vsize, tx7);
+    }
+    std::map<Txid, std::set<Txid>> descendant_caches;
+    descendant_caches.emplace(tx0->GetHash(), std::set<Txid>{tx0->GetHash(), tx1->GetHash()});
+    descendant_caches.emplace(tx1->GetHash(), std::set<Txid>{tx1->GetHash()});
+    descendant_caches.emplace(tx2->GetHash(), std::set<Txid>{tx2->GetHash(), tx3->GetHash()});
+    descendant_caches.emplace(tx3->GetHash(), std::set<Txid>{tx3->GetHash()});
+    descendant_caches.emplace(tx4->GetHash(), std::set<Txid>{tx4->GetHash(), tx5->GetHash()});
+    descendant_caches.emplace(tx5->GetHash(), std::set<Txid>{tx5->GetHash()});
+    descendant_caches.emplace(tx6->GetHash(), std::set<Txid>{tx6->GetHash(), tx7->GetHash()});
+    descendant_caches.emplace(tx7->GetHash(), std::set<Txid>{tx7->GetHash()});
+
+    node::MiniMiner miniminer_manual(miniminer_info, descendant_caches);
+    // Use unspent outpoints to avoid entries being omitted.
+    node::MiniMiner miniminer_pool(pool, all_unspent_outpoints);
+    BOOST_CHECK(miniminer_manual.IsReadyToCalculate());
+    BOOST_CHECK(miniminer_pool.IsReadyToCalculate());
+    for (const auto& sequences : {miniminer_manual.Linearize(), miniminer_pool.Linearize()}) {
+        // tx6 is selected first: high feerate with no parents to bump
+        BOOST_CHECK_EQUAL(Find(sequences, tx6->GetHash()), 0);
+
+        // tx2 + tx3 CPFP are selected next
+        BOOST_CHECK_EQUAL(Find(sequences, tx2->GetHash()), 1);
+        BOOST_CHECK_EQUAL(Find(sequences, tx3->GetHash()), 1);
+
+        // tx4 + prioritised tx5 CPFP
+        BOOST_CHECK_EQUAL(Find(sequences, tx4->GetHash()), 2);
+        BOOST_CHECK_EQUAL(Find(sequences, tx5->GetHash()), 2);
+
+        BOOST_CHECK_EQUAL(Find(sequences, tx0->GetHash()), 3);
+        BOOST_CHECK_EQUAL(Find(sequences, tx1->GetHash()), 3);
+
+
+        // tx7 is selected last: low feerate with no children
+        BOOST_CHECK_EQUAL(Find(sequences, tx7->GetHash()), 4);
+    }
 }
 
 BOOST_FIXTURE_TEST_CASE(miniminer_overlap, TestChain100Setup)
@@ -308,10 +403,6 @@ BOOST_FIXTURE_TEST_CASE(miniminer_overlap, TestChain100Setup)
     LOCK2(::cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
-    const CAmount low_fee{CENT/2000}; // 500 ṩ
-    const CAmount med_fee{CENT/200}; // 5000 ṩ
-    const CAmount high_fee{CENT/10}; // 100_000 ṩ
-
     // Create 3 parents of different feerates, and 1 child spending outputs from all 3 parents.
     const auto tx0 = make_tx({COutPoint{m_coinbase_txns[0]->GetHash(), 0}}, /*num_outputs=*/2);
     pool.addUnchecked(entry.Fee(low_fee).FromTx(tx0));
@@ -450,6 +541,50 @@ BOOST_FIXTURE_TEST_CASE(miniminer_overlap, TestChain100Setup)
         BOOST_CHECK(tx7_bumpfee != bump_fees.end());
         BOOST_CHECK_EQUAL(tx7_bumpfee->second, 0);
     }
+    // Check linearization order
+    std::vector<node::MiniMinerMempoolEntry> miniminer_info;
+    miniminer_info.emplace_back(/*fee_self=*/low_fee,   /*fee_ancestor=*/low_fee,/*vsize_self=*/tx_vsizes[0],                     /*vsize_ancestor=*/tx_vsizes[0], tx0);
+    miniminer_info.emplace_back(             med_fee,                    med_fee,               tx_vsizes[1],                                        tx_vsizes[1], tx1);
+    miniminer_info.emplace_back(            high_fee,                   high_fee,               tx_vsizes[2],                                        tx_vsizes[2], tx2);
+    miniminer_info.emplace_back(            high_fee, low_fee+med_fee+2*high_fee,               tx_vsizes[3], tx_vsizes[0]+tx_vsizes[1]+tx_vsizes[2]+tx_vsizes[3], tx3);
+
+    miniminer_info.emplace_back(            high_fee,                   high_fee,               tx_vsizes[4],                                        tx_vsizes[4], tx4);
+    miniminer_info.emplace_back(             low_fee,         low_fee + high_fee,               tx_vsizes[5],                           tx_vsizes[4]+tx_vsizes[5], tx5);
+    miniminer_info.emplace_back(             med_fee,   high_fee+low_fee+med_fee,               tx_vsizes[6],              tx_vsizes[4]+tx_vsizes[5]+tx_vsizes[6], tx6);
+    miniminer_info.emplace_back(            high_fee,  high_fee+low_fee+high_fee,               tx_vsizes[7],              tx_vsizes[4]+tx_vsizes[5]+tx_vsizes[7], tx7);
+
+    std::map<Txid, std::set<Txid>> descendant_caches;
+    descendant_caches.emplace(tx0->GetHash(), std::set<Txid>{tx0->GetHash(), tx3->GetHash()});
+    descendant_caches.emplace(tx1->GetHash(), std::set<Txid>{tx1->GetHash(), tx3->GetHash()});
+    descendant_caches.emplace(tx2->GetHash(), std::set<Txid>{tx2->GetHash(), tx3->GetHash()});
+    descendant_caches.emplace(tx3->GetHash(), std::set<Txid>{tx3->GetHash()});
+    descendant_caches.emplace(tx4->GetHash(), std::set<Txid>{tx4->GetHash(), tx5->GetHash(), tx6->GetHash(), tx7->GetHash()});
+    descendant_caches.emplace(tx5->GetHash(), std::set<Txid>{tx5->GetHash(), tx6->GetHash(), tx7->GetHash()});
+    descendant_caches.emplace(tx6->GetHash(), std::set<Txid>{tx6->GetHash()});
+    descendant_caches.emplace(tx7->GetHash(), std::set<Txid>{tx7->GetHash()});
+
+    node::MiniMiner miniminer_manual(miniminer_info, descendant_caches);
+    // Use unspent outpoints to avoid entries being omitted.
+    node::MiniMiner miniminer_pool(pool, all_unspent_outpoints);
+    BOOST_CHECK(miniminer_manual.IsReadyToCalculate());
+    BOOST_CHECK(miniminer_pool.IsReadyToCalculate());
+    for (const auto& sequences : {miniminer_manual.Linearize(), miniminer_pool.Linearize()}) {
+        // tx2 and tx4 selected first: high feerate with nothing to bump
+        BOOST_CHECK_EQUAL(Find(sequences, tx4->GetHash()), 0);
+        BOOST_CHECK_EQUAL(Find(sequences, tx2->GetHash()), 1);
+
+        // tx5 + tx7 CPFP
+        BOOST_CHECK_EQUAL(Find(sequences, tx5->GetHash()), 2);
+        BOOST_CHECK_EQUAL(Find(sequences, tx7->GetHash()), 2);
+
+        // tx0 and tx1 CPFP'd by tx3
+        BOOST_CHECK_EQUAL(Find(sequences, tx0->GetHash()), 3);
+        BOOST_CHECK_EQUAL(Find(sequences, tx1->GetHash()), 3);
+        BOOST_CHECK_EQUAL(Find(sequences, tx3->GetHash()), 3);
+
+        // tx6 at medium feerate
+        BOOST_CHECK_EQUAL(Find(sequences, tx6->GetHash()), 4);
+    }
 }
 BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
 {
@@ -507,4 +642,64 @@ BOOST_FIXTURE_TEST_CASE(calculate_cluster, TestChain100Setup)
     }
 }
 
+BOOST_FIXTURE_TEST_CASE(manual_ctor, TestChain100Setup)
+{
+    CTxMemPool& pool = *Assert(m_node.mempool);
+    LOCK2(cs_main, pool.cs);
+    {
+        // 3 pairs of fee-bumping grandparent + parent, plus 1 low-feerate child.
+        // 0 fee + high fee
+        auto grandparent_zero_fee = make_tx({{m_coinbase_txns.at(0)->GetHash(), 0}}, 1);
+        auto parent_high_feerate = make_tx({{grandparent_zero_fee->GetHash(), 0}}, 1);
+        // double low fee + med fee
+        auto grandparent_double_low_feerate = make_tx({{m_coinbase_txns.at(2)->GetHash(), 0}}, 1);
+        auto parent_med_feerate = make_tx({{grandparent_double_low_feerate->GetHash(), 0}}, 1);
+        // low fee + double low fee
+        auto grandparent_low_feerate = make_tx({{m_coinbase_txns.at(1)->GetHash(), 0}}, 1);
+        auto parent_double_low_feerate = make_tx({{grandparent_low_feerate->GetHash(), 0}}, 1);
+        // child is below the cpfp package feerates because it is larger than everything else
+        auto child = make_tx({{parent_high_feerate->GetHash(), 0}, {parent_double_low_feerate->GetHash(), 0}, {parent_med_feerate->GetHash(), 0}}, 1);
+
+        // We artificially record each transaction (except the child) with a uniform vsize of 100vB.
+        const int64_t tx_vsize{100};
+        const int64_t child_vsize{1000};
+
+        std::vector<node::MiniMinerMempoolEntry> miniminer_info;
+        miniminer_info.emplace_back(/*fee_self=*/0,         /*fee_ancestor=*/0,/*vsize_self=*/tx_vsize,/*vsize_ancestor=*/tx_vsize, grandparent_zero_fee);
+        miniminer_info.emplace_back(      high_fee,                   high_fee,               tx_vsize,                 2*tx_vsize, parent_high_feerate);
+        miniminer_info.emplace_back(     2*low_fee,                  2*low_fee,               tx_vsize,                   tx_vsize, grandparent_double_low_feerate);
+        miniminer_info.emplace_back(       med_fee,          2*low_fee+med_fee,               tx_vsize,                 2*tx_vsize, parent_med_feerate);
+        miniminer_info.emplace_back(       low_fee,                    low_fee,               tx_vsize,                   tx_vsize, grandparent_low_feerate);
+        miniminer_info.emplace_back(     2*low_fee,                  3*low_fee,               tx_vsize,                 2*tx_vsize, parent_double_low_feerate);
+        miniminer_info.emplace_back(       low_fee, high_fee+med_fee+6*low_fee,            child_vsize,     6*tx_vsize+child_vsize, child);
+        std::map<Txid, std::set<Txid>> descendant_caches;
+        descendant_caches.emplace(grandparent_zero_fee->GetHash(), std::set<Txid>{grandparent_zero_fee->GetHash(), parent_high_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(grandparent_low_feerate->GetHash(), std::set<Txid>{grandparent_low_feerate->GetHash(), parent_double_low_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(grandparent_double_low_feerate->GetHash(), std::set<Txid>{grandparent_double_low_feerate->GetHash(), parent_med_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(parent_high_feerate->GetHash(), std::set<Txid>{parent_high_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(parent_med_feerate->GetHash(), std::set<Txid>{parent_med_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(parent_double_low_feerate->GetHash(), std::set<Txid>{parent_double_low_feerate->GetHash(), child->GetHash()});
+        descendant_caches.emplace(child->GetHash(), std::set<Txid>{child->GetHash()});
+
+        node::MiniMiner miniminer_manual(miniminer_info, descendant_caches);
+        BOOST_CHECK(miniminer_manual.IsReadyToCalculate());
+        const auto sequences{miniminer_manual.Linearize()};
+
+        // CPFP zero + high
+        BOOST_CHECK_EQUAL(sequences.at(grandparent_zero_fee->GetHash()), 0);
+        BOOST_CHECK_EQUAL(sequences.at(parent_high_feerate->GetHash()), 0);
+
+        // CPFP double low + med
+        BOOST_CHECK_EQUAL(sequences.at(grandparent_double_low_feerate->GetHash()), 1);
+        BOOST_CHECK_EQUAL(sequences.at(parent_med_feerate->GetHash()), 1);
+
+        // CPFP low + med
+        BOOST_CHECK_EQUAL(sequences.at(grandparent_low_feerate->GetHash()), 2);
+        BOOST_CHECK_EQUAL(sequences.at(parent_double_low_feerate->GetHash()), 2);
+
+        // Child at the end
+        BOOST_CHECK_EQUAL(sequences.at(child->GetHash()), 3);
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/test/lint/lint-includes.py b/test/lint/lint-includes.py
index 8e79ba5121..6386a92c0f 100755
--- a/test/lint/lint-includes.py
+++ b/test/lint/lint-includes.py
@@ -23,6 +23,7 @@ EXCLUDED_DIRS = ["contrib/devtools/bitcoin-tidy/",
                 ]
 
 EXPECTED_BOOST_INCLUDES = ["boost/date_time/posix_time/posix_time.hpp",
+                           "boost/multi_index/detail/hash_index_iterator.hpp",
                            "boost/multi_index/hashed_index.hpp",
                            "boost/multi_index/identity.hpp",
                            "boost/multi_index/indexed_by.hpp",
@@ -30,6 +31,7 @@ EXPECTED_BOOST_INCLUDES = ["boost/date_time/posix_time/posix_time.hpp",
                            "boost/multi_index/sequenced_index.hpp",
                            "boost/multi_index/tag.hpp",
                            "boost/multi_index_container.hpp",
+                           "boost/operators.hpp",
                            "boost/process.hpp",
                            "boost/signals2/connection.hpp",
                            "boost/signals2/optional_last_value.hpp",