Remove access to node globals from wallet-linked code

Remove last few instances of accesses to node global variables from wallet
code. Also remove accesses to node globals from code in policy/policy.cpp that
isn't actually called by wallet code, but does get linked into wallet code.

This is the last change needed to allow bitcoin-wallet tool to be linked
without depending on libbitcoin_server.a, to ensure wallet code doesn't access
node global state and avoid bugs like
https://github.com/bitcoin/bitcoin/pull/15557#discussion_r267735431

9 files changed, 65 insertions, 18 deletions

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/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/wallet.cpp b/src/wallet/wallet.cpp
index 68e2bb0252..212bce49fe 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);
 
     {