Merge #15639: bitcoin-wallet tool: Drop libbitcoin_server.a dependency

78a2fb55c bitcoin-wallet tool: Drop libbitcoin_server.a dependency (Russell Yanofsky)
b874747b5 Remove access to node globals from wallet-linked code (Russell Yanofsky)
fbc6bb8e8 bitcoin-wallet tool: Drop MakeChain calls (Russell Yanofsky)

Pull request description:

  Dropping the `bitcoin-wallet` dependency on `libbitcoin_server.a` ensures wallet code can't access node global state, avoiding bugs like https://github.com/bitcoin/bitcoin/pull/15557#discussion_r267735431

ACKs for commit 78a2fb:
  jnewbery:
    utACK 78a2fb55c97fbc26f7b74c5b1fb999a2aff8ce88. Nice work, Russ.
  MarcoFalke:
    utACK 78a2fb5
  MeshCollider:
    utACK https://github.com/bitcoin/bitcoin/pull/15639/commits/78a2fb55c97fbc26f7b74c5b1fb999a2aff8ce88

Tree-SHA512: ee6ea774f683b936bea66638211dd53c42b8316e1ef03dd58d12fb7ee3891432a43c5c149944173c1e2436aa756b672e1679c39fc10043792ac55cd4d8af2823

18 files changed, 89 insertions, 47 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index cb0604391e..6bc3655cad 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -593,7 +593,6 @@ endif
 bitcoin_wallet_LDADD = \
   $(LIBBITCOIN_WALLET_TOOL) \
   $(LIBBITCOIN_WALLET) \
-  $(LIBBITCOIN_SERVER) \
   $(LIBBITCOIN_COMMON) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_UTIL) \
diff --git a/src/bench/coin_selection.cpp b/src/bench/coin_selection.cpp
index 74641191a1..f2ab03e20e 100644
--- a/src/bench/coin_selection.cpp
+++ b/src/bench/coin_selection.cpp
@@ -29,7 +29,7 @@ static void addCoin(const CAmount& nValue, const CWallet& wallet, std::vector<st
 static void CoinSelection(benchmark::State& state)
 {
     auto chain = interfaces::MakeChain();
-    const CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+    const CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
     std::vector<std::unique_ptr<CWalletTx>> wtxs;
     LOCK(wallet.cs_wallet);
 
@@ -61,7 +61,7 @@ static void CoinSelection(benchmark::State& state)
 
 typedef std::set<CInputCoin> CoinSet;
 static auto testChain = interfaces::MakeChain();
-static const CWallet testWallet(*testChain, WalletLocation(), WalletDatabase::CreateDummy());
+static const CWallet testWallet(testChain.get(), WalletLocation(), WalletDatabase::CreateDummy());
 std::vector<std::unique_ptr<CWalletTx>> wtxn;
 
 // Copied from src/wallet/test/coinselector_tests.cpp
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 13e7848cc6..b61a51b235 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -363,6 +363,12 @@ public:
     {
         return MakeUnique<RpcHandlerImpl>(command);
     }
+    bool rpcEnableDeprecated(const std::string& method) override { return IsDeprecatedRPCEnabled(method); }
+    void rpcRunLater(const std::string& name, std::function<void()> fn, int64_t seconds) override
+    {
+        RPCRunLater(name, std::move(fn), seconds);
+    }
+    int rpcSerializationFlags() override { return RPCSerializationFlags(); }
     void requestMempoolTransactions(Notifications& notifications) override
     {
         LOCK2(::cs_main, ::mempool.cs);
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 3ace5a0ece..17d7b6d8f1 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -57,6 +57,10 @@ class Wallet;
 //!   notifications to the GUI should go away when GUI and wallet can directly
 //!   communicate with each other without going through the node
 //!   (https://github.com/bitcoin/bitcoin/pull/15288#discussion_r253321096).
+//!
+//! * The handleRpc, registerRpcs, rpcEnableDeprecated methods and other RPC
+//!   methods can go away if wallets listen for HTTP requests on their own
+//!   ports instead of registering to handle requests on the node HTTP port.
 class Chain
 {
 public:
@@ -274,6 +278,15 @@ public:
     //! needs to remain valid until Handler is disconnected.
     virtual std::unique_ptr<Handler> handleRpc(const CRPCCommand& command) = 0;
 
+    //! Check if deprecated RPC is enabled.
+    virtual bool rpcEnableDeprecated(const std::string& method) = 0;
+
+    //! Run function after given number of seconds. Cancel any previous calls with same name.
+    virtual void rpcRunLater(const std::string& name, std::function<void()> fn, int64_t seconds) = 0;
+
+    //! Current RPC serialization flags.
+    virtual int rpcSerializationFlags() = 0;
+
     //! Synchronously send TransactionAddedToMempool notifications about all
     //! current mempool transactions to the specified handler and return after
     //! the last one is sent. These notifications aren't coordinated with async
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index 44c23661fb..6f8542123d 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -77,7 +77,7 @@ bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType)
     return true;
 }
 
-bool IsStandardTx(const CTransaction& tx, std::string& reason)
+bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason)
 {
     if (tx.nVersion > CTransaction::MAX_STANDARD_VERSION || tx.nVersion < 1) {
         reason = "version";
@@ -123,10 +123,10 @@ bool IsStandardTx(const CTransaction& tx, std::string& reason)
 
         if (whichType == TX_NULL_DATA)
             nDataOut++;
-        else if ((whichType == TX_MULTISIG) && (!fIsBareMultisigStd)) {
+        else if ((whichType == TX_MULTISIG) && (!permit_bare_multisig)) {
             reason = "bare-multisig";
             return false;
-        } else if (IsDust(txout, ::dustRelayFee)) {
+        } else if (IsDust(txout, dust_relay_fee)) {
             reason = "dust";
             return false;
         }
@@ -239,17 +239,17 @@ bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
     return true;
 }
 
-int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost)
+int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop)
 {
-    return (std::max(nWeight, nSigOpCost * nBytesPerSigOp) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR;
+    return (std::max(nWeight, nSigOpCost * bytes_per_sigop) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR;
 }
 
-int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost)
+int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop)
 {
-    return GetVirtualTransactionSize(GetTransactionWeight(tx), nSigOpCost);
+    return GetVirtualTransactionSize(GetTransactionWeight(tx), nSigOpCost, bytes_per_sigop);
 }
 
-int64_t GetVirtualTransactionInputSize(const CTxIn& txin, int64_t nSigOpCost)
+int64_t GetVirtualTransactionInputSize(const CTxIn& txin, int64_t nSigOpCost, unsigned int bytes_per_sigop)
 {
-    return GetVirtualTransactionSize(GetTransactionInputWeight(txin), nSigOpCost);
+    return GetVirtualTransactionSize(GetTransactionInputWeight(txin), nSigOpCost, bytes_per_sigop);
 }
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 8660af26de..ebe040f0ea 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -86,7 +86,7 @@ bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
      * Check for standard transaction types
      * @return True if all outputs (scriptPubKeys) use only standard transaction forms
      */
-bool IsStandardTx(const CTransaction& tx, std::string& reason);
+bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason);
     /**
      * Check for standard transaction types
      * @param[in] mapInputs    Map of previous transactions that have outputs we're spending
@@ -101,8 +101,18 @@ bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
 
 /** Compute the virtual transaction size (weight reinterpreted as bytes). */
-int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost);
-int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost = 0);
-int64_t GetVirtualTransactionInputSize(const CTxIn& tx, int64_t nSigOpCost = 0);
+int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost, unsigned int bytes_per_sigop);
+int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
+int64_t GetVirtualTransactionInputSize(const CTxIn& tx, int64_t nSigOpCost, unsigned int bytes_per_sigop);
+
+static inline int64_t GetVirtualTransactionSize(const CTransaction& tx)
+{
+    return GetVirtualTransactionSize(tx, 0, 0);
+}
+
+static inline int64_t GetVirtualTransactionInputSize(const CTxIn& tx)
+{
+    return GetVirtualTransactionInputSize(tx, 0, 0);
+}
 
 #endif // BITCOIN_POLICY_POLICY_H
diff --git a/src/policy/settings.h b/src/policy/settings.h
index 1d2a1fb880..30a7189c93 100644
--- a/src/policy/settings.h
+++ b/src/policy/settings.h
@@ -6,7 +6,10 @@
 #ifndef BITCOIN_POLICY_SETTINGS_H
 #define BITCOIN_POLICY_SETTINGS_H
 
+#include <policy/policy.h>
+
 class CFeeRate;
+class CTransaction;
 
 // Policy settings which are configurable at runtime.
 extern CFeeRate incrementalRelayFee;
@@ -14,4 +17,19 @@ extern CFeeRate dustRelayFee;
 extern unsigned int nBytesPerSigOp;
 extern bool fIsBareMultisigStd;
 
+static inline bool IsStandardTx(const CTransaction& tx, std::string& reason)
+{
+    return IsStandardTx(tx, ::fIsBareMultisigStd, ::dustRelayFee, reason);
+}
+
+static inline int64_t GetVirtualTransactionSize(int64_t weight, int64_t sigop_cost)
+{
+    return GetVirtualTransactionSize(weight, sigop_cost, ::nBytesPerSigOp);
+}
+
+static inline int64_t GetVirtualTransactionSize(const CTransaction& tx, int64_t sigop_cost)
+{
+    return GetVirtualTransactionSize(tx, sigop_cost, ::nBytesPerSigOp);
+}
+
 #endif // BITCOIN_POLICY_SETTINGS_H
diff --git a/src/qt/test/addressbooktests.cpp b/src/qt/test/addressbooktests.cpp
index 7f5e92ea9f..e33a9a4e1e 100644
--- a/src/qt/test/addressbooktests.cpp
+++ b/src/qt/test/addressbooktests.cpp
@@ -58,7 +58,7 @@ void TestAddAddressesToSendBook()
 {
     TestChain100Setup test;
     auto chain = interfaces::MakeChain();
-    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateMock());
+    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateMock());
     bool firstRun;
     wallet->LoadWallet(firstRun);
 
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 2b50a2ba81..bd1c6cf0f4 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -135,7 +135,7 @@ void TestGUI()
         test.CreateAndProcessBlock({}, GetScriptForRawPubKey(test.coinbaseKey.GetPubKey()));
     }
     auto chain = interfaces::MakeChain();
-    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateMock());
+    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateMock());
     bool firstRun;
     wallet->LoadWallet(firstRun);
     {
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 8d15ecc28e..91331198e2 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -19,6 +19,7 @@
 #include <node/transaction.h>
 #include <policy/policy.h>
 #include <policy/rbf.h>
+#include <policy/settings.h>
 #include <primitives/transaction.h>
 #include <psbt.h>
 #include <rpc/rawtransaction_util.h>
diff --git a/src/wallet/feebumper.cpp b/src/wallet/feebumper.cpp
index e0f083b8ea..b547ea21d9 100644
--- a/src/wallet/feebumper.cpp
+++ b/src/wallet/feebumper.cpp
@@ -174,7 +174,7 @@ Result CreateTransaction(const CWallet* wallet, const uint256& txid, const CCoin
     // This may occur if the user set TotalFee or paytxfee too low, if fallbackfee is too low, or, perhaps,
     // in a rare situation where the mempool minimum fee increased significantly since the fee estimation just a
     // moment earlier. In this case, we report an error to the user, who may use total_fee to make an adjustment.
-    CFeeRate minMempoolFeeRate = mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000);
+    CFeeRate minMempoolFeeRate = wallet->chain().mempoolMinFee();
     if (nNewFeeRate.GetFeePerK() < minMempoolFeeRate.GetFeePerK()) {
         errors.push_back(strprintf(
             "New fee rate (%s) is lower than the minimum fee rate (%s) to get into the mempool -- "
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 37e2930ee6..cb6f7637ad 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1756,7 +1756,7 @@ static UniValue gettransaction(const JSONRPCRequest& request)
     ListTransactions(*locked_chain, pwallet, wtx, 0, false, details, filter, nullptr /* filter_label */);
     entry.pushKV("details", details);
 
-    std::string strHex = EncodeHexTx(*wtx.tx, RPCSerializationFlags());
+    std::string strHex = EncodeHexTx(*wtx.tx, pwallet->chain().rpcSerializationFlags());
     entry.pushKV("hex", strHex);
 
     return entry;
@@ -1974,7 +1974,7 @@ static UniValue walletpassphrase(const JSONRPCRequest& request)
     // wallet before the following callback is called. If a valid shared pointer
     // is acquired in the callback then the wallet is still loaded.
     std::weak_ptr<CWallet> weak_wallet = wallet;
-    RPCRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), [weak_wallet] {
+    pwallet->chain().rpcRunLater(strprintf("lockwallet(%s)", pwallet->GetName()), [weak_wallet] {
         if (auto shared_wallet = weak_wallet.lock()) {
             LOCK(shared_wallet->cs_wallet);
             shared_wallet->Lock();
@@ -3471,7 +3471,7 @@ public:
         UniValue obj(UniValue::VOBJ);
         CScript subscript;
         if (pwallet && pwallet->GetCScript(scriptID, subscript)) {
-            ProcessSubScript(subscript, obj, IsDeprecatedRPCEnabled("validateaddress"));
+            ProcessSubScript(subscript, obj, pwallet->chain().rpcEnableDeprecated("validateaddress"));
         }
         return obj;
     }
diff --git a/src/wallet/test/coinselector_tests.cpp b/src/wallet/test/coinselector_tests.cpp
index 5c65acf601..6c2003e274 100644
--- a/src/wallet/test/coinselector_tests.cpp
+++ b/src/wallet/test/coinselector_tests.cpp
@@ -29,7 +29,7 @@ typedef std::set<CInputCoin> CoinSet;
 
 static std::vector<COutput> vCoins;
 static auto testChain = interfaces::MakeChain();
-static CWallet testWallet(*testChain, WalletLocation(), WalletDatabase::CreateDummy());
+static CWallet testWallet(testChain.get(), WalletLocation(), WalletDatabase::CreateDummy());
 static CAmount balance = 0;
 
 CoinEligibilityFilter filter_standard(1, 6, 0);
diff --git a/src/wallet/test/wallet_test_fixture.cpp b/src/wallet/test/wallet_test_fixture.cpp
index 6a051214a9..7b82994539 100644
--- a/src/wallet/test/wallet_test_fixture.cpp
+++ b/src/wallet/test/wallet_test_fixture.cpp
@@ -9,7 +9,7 @@
 #include <wallet/rpcwallet.h>
 
 WalletTestingSetup::WalletTestingSetup(const std::string& chainName):
-    TestingSetup(chainName), m_wallet(*m_chain, WalletLocation(), WalletDatabase::CreateMock())
+    TestingSetup(chainName), m_wallet(m_chain.get(), WalletLocation(), WalletDatabase::CreateMock())
 {
     bool fFirstRun;
     m_wallet.LoadWallet(fFirstRun);
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 7c8085dc20..54e12f36ed 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -49,7 +49,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
 
     // Verify ScanForWalletTransactions accommodates a null start block.
     {
-        CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
@@ -64,7 +64,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
     // Verify ScanForWalletTransactions picks up transactions in both the old
     // and new block files.
     {
-        CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
@@ -83,7 +83,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
     // Verify ScanForWalletTransactions only picks transactions in the new block
     // file.
     {
-        CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
@@ -101,7 +101,7 @@ BOOST_FIXTURE_TEST_CASE(scan_for_wallet_transactions, TestChain100Setup)
 
     // Verify ScanForWalletTransactions scans no blocks.
     {
-        CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         AddKey(wallet, coinbaseKey);
         WalletRescanReserver reserver(&wallet);
         reserver.reserve();
@@ -135,7 +135,7 @@ BOOST_FIXTURE_TEST_CASE(importmulti_rescan, TestChain100Setup)
     // before the missing block, and success for a key whose creation time is
     // after.
     {
-        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         AddWallet(wallet);
         UniValue keys;
         keys.setArray();
@@ -198,7 +198,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
-        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
         LOCK(wallet->cs_wallet);
         wallet->mapKeyMetadata[coinbaseKey.GetPubKey().GetID()].nCreateTime = KEY_TIME;
         wallet->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
@@ -214,7 +214,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
     // Call importwallet RPC and verify all blocks with timestamps >= BLOCK_TIME
     // were scanned, and no prior blocks were scanned.
     {
-        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+        std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
 
         JSONRPCRequest request;
         request.params.setArray();
@@ -245,7 +245,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
 BOOST_FIXTURE_TEST_CASE(coin_mark_dirty_immature_credit, TestChain100Setup)
 {
     auto chain = interfaces::MakeChain();
-    CWallet wallet(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+    CWallet wallet(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
     CWalletTx wtx(&wallet, m_coinbase_txns.back());
     auto locked_chain = chain->lock();
     LOCK(wallet.cs_wallet);
@@ -340,7 +340,7 @@ public:
     ListCoinsTestingSetup()
     {
         CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
-        wallet = MakeUnique<CWallet>(*m_chain, WalletLocation(), WalletDatabase::CreateMock());
+        wallet = MakeUnique<CWallet>(m_chain.get(), WalletLocation(), WalletDatabase::CreateMock());
         bool firstRun;
         wallet->LoadWallet(firstRun);
         AddKey(*wallet, coinbaseKey);
@@ -451,7 +451,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup)
 BOOST_FIXTURE_TEST_CASE(wallet_disableprivkeys, TestChain100Setup)
 {
     auto chain = interfaces::MakeChain();
-    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(*chain, WalletLocation(), WalletDatabase::CreateDummy());
+    std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>(chain.get(), WalletLocation(), WalletDatabase::CreateDummy());
     wallet->SetMinVersion(FEATURE_LATEST);
     wallet->SetWalletFlag(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
     BOOST_CHECK(!wallet->TopUpKeyPool(1000));
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 743704d5f8..9ee6329f8c 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1287,7 +1287,6 @@ void CWallet::UpdatedBlockTip()
 
 
 void CWallet::BlockUntilSyncedToCurrentChain() {
-    AssertLockNotHeld(cs_main);
     AssertLockNotHeld(cs_wallet);
 
     {
@@ -3117,7 +3116,6 @@ bool CWallet::CommitTransaction(CTransactionRef tx, mapValue_t mapValue, std::ve
 
 DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
 {
-    auto locked_chain = chain().lock();
     LOCK(cs_wallet);
 
     fFirstRunRet = false;
@@ -3981,7 +3979,7 @@ bool CWallet::Verify(interfaces::Chain& chain, const WalletLocation& location, b
 
     if (salvage_wallet) {
         // Recover readable keypairs:
-        CWallet dummyWallet(chain, WalletLocation(), WalletDatabase::CreateDummy());
+        CWallet dummyWallet(&chain, WalletLocation(), WalletDatabase::CreateDummy());
         std::string backup_filename;
         if (!WalletBatch::Recover(wallet_path, (void *)&dummyWallet, WalletBatch::RecoverKeysOnlyFilter, backup_filename)) {
             return false;
@@ -4001,7 +3999,7 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
     if (gArgs.GetBoolArg("-zapwallettxes", false)) {
         chain.initMessage(_("Zapping all transactions from wallet..."));
 
-        std::unique_ptr<CWallet> tempWallet = MakeUnique<CWallet>(chain, location, WalletDatabase::Create(location.GetPath()));
+        std::unique_ptr<CWallet> tempWallet = MakeUnique<CWallet>(&chain, location, WalletDatabase::Create(location.GetPath()));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DBErrors::LOAD_OK) {
             chain.initError(strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
@@ -4015,7 +4013,7 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
     bool fFirstRun = true;
     // TODO: Can't use std::make_shared because we need a custom deleter but
     // should be possible to use std::allocate_shared.
-    std::shared_ptr<CWallet> walletInstance(new CWallet(chain, location, WalletDatabase::Create(location.GetPath())), ReleaseWallet);
+    std::shared_ptr<CWallet> walletInstance(new CWallet(&chain, location, WalletDatabase::Create(location.GetPath())), ReleaseWallet);
     DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
     if (nLoadWalletRet != DBErrors::LOAD_OK)
     {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 36c0e160dd..4cc6973802 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -704,7 +704,7 @@ private:
     bool AddWatchOnly(const CScript& dest) override EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
     /** Interface for accessing chain state. */
-    interfaces::Chain& m_chain;
+    interfaces::Chain* m_chain;
 
     /** Wallet location which includes wallet name (see WalletLocation). */
     WalletLocation m_location;
@@ -767,7 +767,7 @@ public:
     unsigned int nMasterKeyMaxID = 0;
 
     /** Construct wallet with specified name and database implementation. */
-    CWallet(interfaces::Chain& chain, const WalletLocation& location, std::unique_ptr<WalletDatabase> database) : m_chain(chain), m_location(location), database(std::move(database))
+    CWallet(interfaces::Chain* chain, const WalletLocation& location, std::unique_ptr<WalletDatabase> database) : m_chain(chain), m_location(location), database(std::move(database))
     {
     }
 
@@ -795,7 +795,7 @@ public:
     std::unique_ptr<interfaces::Handler> m_chain_notifications_handler;
 
     /** Interface for accessing chain state. */
-    interfaces::Chain& chain() const { return m_chain; }
+    interfaces::Chain& chain() const { assert(m_chain); return *m_chain; }
 
     const CWalletTx* GetWalletTx(const uint256& hash) const;
 
diff --git a/src/wallet/wallettool.cpp b/src/wallet/wallettool.cpp
index 797f051189..1ff1e8b840 100644
--- a/src/wallet/wallettool.cpp
+++ b/src/wallet/wallettool.cpp
@@ -4,7 +4,6 @@
 
 #include <base58.h>
 #include <fs.h>
-#include <interfaces/chain.h>
 #include <util/system.h>
 #include <wallet/wallet.h>
 #include <wallet/walletutil.h>
@@ -28,8 +27,7 @@ static std::shared_ptr<CWallet> CreateWallet(const std::string& name, const fs::
         return nullptr;
     }
     // dummy chain interface
-    auto chain = interfaces::MakeChain();
-    std::shared_ptr<CWallet> wallet_instance(new CWallet(*chain, WalletLocation(name), WalletDatabase::Create(path)), WalletToolReleaseWallet);
+    std::shared_ptr<CWallet> wallet_instance(new CWallet(nullptr /* chain */, WalletLocation(name), WalletDatabase::Create(path)), WalletToolReleaseWallet);
     bool first_run = true;
     DBErrors load_wallet_ret = wallet_instance->LoadWallet(first_run);
     if (load_wallet_ret != DBErrors::LOAD_OK) {
@@ -56,8 +54,7 @@ static std::shared_ptr<CWallet> LoadWallet(const std::string& name, const fs::pa
     }
 
     // dummy chain interface
-    auto chain = interfaces::MakeChain();
-    std::shared_ptr<CWallet> wallet_instance(new CWallet(*chain, WalletLocation(name), WalletDatabase::Create(path)), WalletToolReleaseWallet);
+    std::shared_ptr<CWallet> wallet_instance(new CWallet(nullptr /* chain */, WalletLocation(name), WalletDatabase::Create(path)), WalletToolReleaseWallet);
     DBErrors load_wallet_ret;
     try {
         bool first_run;