28 files changed, 228 insertions, 203 deletions
diff --git a/src/bench/base58.cpp b/src/bench/base58.cpp
index 3319c179bf..65e27a615d 100644
--- a/src/bench/base58.cpp
+++ b/src/bench/base58.cpp
@@ -7,34 +7,37 @@
 #include "validation.h"
 #include "base58.h"
 
+#include <array>
 #include <vector>
 #include <string>
 
 
 static void Base58Encode(benchmark::State& state)
 {
-    unsigned char buff[32] = {
-        17, 79, 8, 99, 150, 189, 208, 162, 22, 23, 203, 163, 36, 58, 147,
-        227, 139, 2, 215, 100, 91, 38, 11, 141, 253, 40, 117, 21, 16, 90,
-        200, 24
+    static const std::array<unsigned char, 32> buff = {
+        {
+            17, 79, 8, 99, 150, 189, 208, 162, 22, 23, 203, 163, 36, 58, 147,
+            227, 139, 2, 215, 100, 91, 38, 11, 141, 253, 40, 117, 21, 16, 90,
+            200, 24
+        }
     };
-    unsigned char* b = buff;
     while (state.KeepRunning()) {
-        EncodeBase58(b, b + 32);
+        EncodeBase58(buff.begin(), buff.end());
     }
 }
 
 
 static void Base58CheckEncode(benchmark::State& state)
 {
-    unsigned char buff[32] = {
-        17, 79, 8, 99, 150, 189, 208, 162, 22, 23, 203, 163, 36, 58, 147,
-        227, 139, 2, 215, 100, 91, 38, 11, 141, 253, 40, 117, 21, 16, 90,
-        200, 24
+    static const std::array<unsigned char, 32> buff = {
+        {
+            17, 79, 8, 99, 150, 189, 208, 162, 22, 23, 203, 163, 36, 58, 147,
+            227, 139, 2, 215, 100, 91, 38, 11, 141, 253, 40, 117, 21, 16, 90,
+            200, 24
+        }
     };
-    unsigned char* b = buff;
     std::vector<unsigned char> vch;
-    vch.assign(b, b + 32);
+    vch.assign(buff.begin(), buff.end());
     while (state.KeepRunning()) {
         EncodeBase58Check(vch);
     }
diff --git a/src/bench/verify_script.cpp b/src/bench/verify_script.cpp
index 23bbadc88d..ef7381c120 100644
--- a/src/bench/verify_script.cpp
+++ b/src/bench/verify_script.cpp
@@ -11,6 +11,8 @@
 #include "script/sign.h"
 #include "streams.h"
 
+#include <array>
+
 // FIXME: Dedup with BuildCreditingTransaction in test/script_tests.cpp.
 static CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey)
 {
@@ -55,8 +57,12 @@ static void VerifyScriptBench(benchmark::State& state)
 
     // Keypair.
     CKey key;
-    const unsigned char vchKey[32] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
-    key.Set(vchKey, vchKey + 32, false);
+    static const std::array<unsigned char, 32> vchKey = {
+        {
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
+        }
+    };
+    key.Set(vchKey.begin(), vchKey.end(), false);
     CPubKey pubkey = key.GetPubKey();
     uint160 pubkeyHash;
     CHash160().Write(pubkey.begin(), pubkey.size()).Finalize(pubkeyHash.begin());
diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index 885b787b4d..8b48c7f8e4 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -191,8 +191,14 @@ static void http_error_cb(enum evhttp_request_error err, void *ctx)
 
 UniValue CallRPC(const std::string& strMethod, const UniValue& params)
 {
-    std::string host = GetArg("-rpcconnect", DEFAULT_RPCCONNECT);
-    int port = GetArg("-rpcport", BaseParams().RPCPort());
+    std::string host;
+    // In preference order, we choose the following for the port:
+    //     1. -rpcport
+    //     2. port in -rpcconnect (ie following : in ipv4 or ]: in ipv6)
+    //     3. default port for chain
+    int port = BaseParams().RPCPort();
+    SplitHostPort(GetArg("-rpcconnect", DEFAULT_RPCCONNECT), port, host);
+    port = GetArg("-rpcport", port);
 
     // Obtain event base
     raii_event_base base = obtain_event_base();
diff --git a/src/blockencodings.cpp b/src/blockencodings.cpp
index 7adab586e8..6f27b7b9dc 100644
--- a/src/blockencodings.cpp
+++ b/src/blockencodings.cpp
@@ -48,7 +48,7 @@ uint64_t CBlockHeaderAndShortTxIDs::GetShortID(const uint256& txhash) const {
 ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& cmpctblock, const std::vector<std::pair<uint256, CTransactionRef>>& extra_txn) {
     if (cmpctblock.header.IsNull() || (cmpctblock.shorttxids.empty() && cmpctblock.prefilledtxn.empty()))
         return READ_STATUS_INVALID;
-    if (cmpctblock.shorttxids.size() + cmpctblock.prefilledtxn.size() > MAX_BLOCK_WEIGHT / MIN_SERIALIZEABLE_TRANSACTION_WEIGHT)
+    if (cmpctblock.shorttxids.size() + cmpctblock.prefilledtxn.size() > MAX_BLOCK_WEIGHT / MIN_SERIALIZABLE_TRANSACTION_WEIGHT)
         return READ_STATUS_INVALID;
 
     assert(header.IsNull() && txn_available.empty());
diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h
index a1bb99a802..ddd4ee9fab 100644
--- a/src/consensus/consensus.h
+++ b/src/consensus/consensus.h
@@ -21,7 +21,7 @@ static const int COINBASE_MATURITY = 100;
 static const int WITNESS_SCALE_FACTOR = 4;
 
 static const size_t MIN_TRANSACTION_WEIGHT = WITNESS_SCALE_FACTOR * 60; // 60 is the lower bound for the size of a valid serialized CTransaction
-static const size_t MIN_SERIALIZEABLE_TRANSACTION_WEIGHT = WITNESS_SCALE_FACTOR * 10; // 10 is the lower bound for the size of a serialized CTransaction
+static const size_t MIN_SERIALIZABLE_TRANSACTION_WEIGHT = WITNESS_SCALE_FACTOR * 10; // 10 is the lower bound for the size of a serialized CTransaction
 
 /** Flags for nSequence and nLockTime locks */
 enum {
diff --git a/src/core_memusage.h b/src/core_memusage.h
index e4ccd54c42..f038e7b154 100644
--- a/src/core_memusage.h
+++ b/src/core_memusage.h
@@ -10,7 +10,7 @@
 #include "memusage.h"
 
 static inline size_t RecursiveDynamicUsage(const CScript& script) {
-    return memusage::DynamicUsage(*static_cast<const CScriptBase*>(&script));
+    return memusage::DynamicUsage(script);
 }
 
 static inline size_t RecursiveDynamicUsage(const COutPoint& out) {
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 1c53d8d49d..290a2efca2 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -7,6 +7,7 @@
 #include "chainparamsbase.h"
 #include "compat.h"
 #include "util.h"
+#include "utilstrencodings.h"
 #include "netbase.h"
 #include "rpc/protocol.h" // For HTTP status codes
 #include "sync.h"
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 3fb1c18f03..1f668a5d4c 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -58,25 +58,6 @@ std::string GetNetworkName(enum Network net) {
     }
 }
 
-void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
-    size_t colon = in.find_last_of(':');
-    // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
-    bool fHaveColon = colon != in.npos;
-    bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
-    bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
-    if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
-        int32_t n;
-        if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
-            in = in.substr(0, colon);
-            portOut = n;
-        }
-    }
-    if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
-        hostOut = in.substr(1, in.size()-2);
-    else
-        hostOut = in;
-}
-
 bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
 {
     vIP.clear();
diff --git a/src/netbase.h b/src/netbase.h
index c9d108aadd..fd4b34c8f1 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -39,7 +39,6 @@ public:
 
 enum Network ParseNetwork(std::string net);
 std::string GetNetworkName(enum Network net);
-void SplitHostPort(std::string in, int &portOut, std::string &hostOut);
 bool SetProxy(enum Network net, const proxyType &addrProxy);
 bool GetProxy(enum Network net, proxyType &proxyInfoOut);
 bool IsProxy(const CNetAddr &addr);
diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index 45f9765231..0f186fa845 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -117,7 +117,7 @@ public:
      * Create new TxConfirmStats. This is called by BlockPolicyEstimator's
      * constructor with default values.
      * @param defaultBuckets contains the upper limits for the bucket boundaries
-     * @param maxConfirms max number of confirms to track
+     * @param maxPeriods max number of periods to track
      * @param decay how much to decay the historical moving average per block
      */
     TxConfirmStats(const std::vector<double>& defaultBuckets, const std::map<double, unsigned int>& defaultBucketMap,
@@ -698,7 +698,7 @@ CFeeRate CBlockPolicyEstimator::estimateRawFee(int confTarget, double successThr
         break;
     }
     default: {
-        throw std::out_of_range("CBlockPoicyEstimator::estimateRawFee unknown FeeEstimateHorizon");
+        throw std::out_of_range("CBlockPolicyEstimator::estimateRawFee unknown FeeEstimateHorizon");
     }
     }
 
@@ -730,7 +730,7 @@ unsigned int CBlockPolicyEstimator::HighestTargetTracked(FeeEstimateHorizon hori
         return longStats->GetMaxConfirms();
     }
     default: {
-        throw std::out_of_range("CBlockPoicyEstimator::HighestTargetTracked unknown FeeEstimateHorizon");
+        throw std::out_of_range("CBlockPolicyEstimator::HighestTargetTracked unknown FeeEstimateHorizon");
     }
     }
 }
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index f1dd51b9fd..041034bb8b 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -106,7 +106,7 @@ public:
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(prevout);
-        READWRITE(*(CScriptBase*)(&scriptSig));
+        READWRITE(scriptSig);
         READWRITE(nSequence);
     }
 
@@ -146,7 +146,7 @@ public:
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(nValue);
-        READWRITE(*(CScriptBase*)(&scriptPubKey));
+        READWRITE(scriptPubKey);
     }
 
     void SetNull()
diff --git a/src/protocol.h b/src/protocol.h
index eba39ab1e5..7890bb627d 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -163,7 +163,7 @@ extern const char *PONG;
 /**
  * The notfound message is a reply to a getdata message which requested an
  * object the receiving node does not have available for relay.
- * @ince protocol version 70001.
+ * @since protocol version 70001.
  * @see https://bitcoin.org/en/developer-reference#notfound
  */
 extern const char *NOTFOUND;
diff --git a/src/random.cpp b/src/random.cpp
index 67efc7d945..1ee6158e4b 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -36,6 +36,10 @@
 
 #include <mutex>
 
+#if defined(__x86_64__) || defined(__amd64__) || defined(__i386__)
+#include <cpuid.h>
+#endif
+
 #include <openssl/err.h>
 #include <openssl/rand.h>
 
@@ -72,18 +76,9 @@ static bool rdrand_supported = false;
 static constexpr uint32_t CPUID_F1_ECX_RDRAND = 0x40000000;
 static void RDRandInit()
 {
-    uint32_t eax, ecx, edx;
-#if defined(__i386__) && ( defined(__PIC__) || defined(__PIE__))
-    // Avoid clobbering ebx, as that is used for PIC on x86.
-    uint32_t tmp;
-    __asm__ ("mov %%ebx, %1; cpuid; mov %1, %%ebx": "=a"(eax), "=g"(tmp), "=c"(ecx), "=d"(edx) : "a"(1));
-#else
-    uint32_t ebx;
-    __asm__ ("cpuid": "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(1));
-#endif
-    //! When calling cpuid function #1, ecx register will have this set if RDRAND is available.
-    if (ecx & CPUID_F1_ECX_RDRAND) {
-        LogPrintf("Using RdRand as entropy source\n");
+    uint32_t eax, ebx, ecx, edx;
+    if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) && (ecx & CPUID_F1_ECX_RDRAND)) {
+        LogPrintf("Using RdRand as an additional entropy source\n");
         rdrand_supported = true;
     }
     hwrand_initialized.store(true);
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index c17ca2fa3a..6178a1c7ab 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -798,7 +798,7 @@ static void ApplyStats(CCoinsStats &stats, CHashWriter& ss, const uint256& hash,
     stats.nTransactions++;
     for (const auto output : outputs) {
         ss << VARINT(output.first + 1);
-        ss << *(const CScriptBase*)(&output.second.out.scriptPubKey);
+        ss << output.second.out.scriptPubKey;
         ss << VARINT(output.second.out.nValue);
         stats.nTransactionOutputs++;
         stats.nTotalAmount += output.second.out.nValue;
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 7149c938fc..8a121774a0 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -1099,7 +1099,7 @@ public:
         // Serialize the script
         if (nInput != nIn)
             // Blank out other inputs' signatures
-            ::Serialize(s, CScriptBase());
+            ::Serialize(s, CScript());
         else
             SerializeScriptCode(s);
         // Serialize the nSequence
@@ -1207,7 +1207,7 @@ uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsig
         // The prevout may already be contained in hashPrevout, and the nSequence
         // may already be contain in hashSequence.
         ss << txTo.vin[nIn].prevout;
-        ss << static_cast<const CScriptBase&>(scriptCode);
+        ss << scriptCode;
         ss << amount;
         ss << txTo.vin[nIn].nSequence;
         // Outputs (none/one/all, depending on flags)
diff --git a/src/script/script.h b/src/script/script.h
index bbb37f049e..d16bfd0e00 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -8,6 +8,7 @@
 
 #include "crypto/common.h"
 #include "prevector.h"
+#include "serialize.h"
 
 #include <assert.h>
 #include <climits>
@@ -404,6 +405,13 @@ public:
     CScript(std::vector<unsigned char>::const_iterator pbegin, std::vector<unsigned char>::const_iterator pend) : CScriptBase(pbegin, pend) { }
     CScript(const unsigned char* pbegin, const unsigned char* pend) : CScriptBase(pbegin, pend) { }
 
+    ADD_SERIALIZE_METHODS;
+
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        READWRITE(static_cast<CScriptBase&>(*this));
+    }
+
     CScript& operator+=(const CScript& b)
     {
         insert(end(), b.begin(), b.end());
diff --git a/src/test/dbwrapper_tests.cpp b/src/test/dbwrapper_tests.cpp
index be631ce7a6..6ed6e7744e 100644
--- a/src/test/dbwrapper_tests.cpp
+++ b/src/test/dbwrapper_tests.cpp
@@ -24,8 +24,7 @@ BOOST_FIXTURE_TEST_SUITE(dbwrapper_tests, BasicTestingSetup)
 BOOST_AUTO_TEST_CASE(dbwrapper)
 {
     // Perform tests both obfuscated and non-obfuscated.
-    for (int i = 0; i < 2; i++) {
-        bool obfuscate = (bool)i;
+    for (bool obfuscate : {false, true}) {
         fs::path ph = fs::temp_directory_path() / fs::unique_path();
         CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);
         char key = 'k';
@@ -45,8 +44,7 @@ BOOST_AUTO_TEST_CASE(dbwrapper)
 BOOST_AUTO_TEST_CASE(dbwrapper_batch)
 {
     // Perform tests both obfuscated and non-obfuscated.
-    for (int i = 0; i < 2; i++) {
-        bool obfuscate = (bool)i;
+    for (bool obfuscate : {false, true}) {
         fs::path ph = fs::temp_directory_path() / fs::unique_path();
         CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);
 
@@ -82,8 +80,7 @@ BOOST_AUTO_TEST_CASE(dbwrapper_batch)
 BOOST_AUTO_TEST_CASE(dbwrapper_iterator)
 {
     // Perform tests both obfuscated and non-obfuscated.
-    for (int i = 0; i < 2; i++) {
-        bool obfuscate = (bool)i;
+    for (bool obfuscate : {false, true}) {
         fs::path ph = fs::temp_directory_path() / fs::unique_path();
         CDBWrapper dbw(ph, (1 << 20), true, false, obfuscate);
 
@@ -95,7 +92,7 @@ BOOST_AUTO_TEST_CASE(dbwrapper_iterator)
         uint256 in2 = InsecureRand256();
         BOOST_CHECK(dbw.Write(key2, in2));
 
-        std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper*>(&dbw)->NewIterator());
+        std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper&>(dbw).NewIterator());
 
         // Be sure to seek past the obfuscation key (if it exists)
         it->Seek(key);
@@ -210,13 +207,8 @@ BOOST_AUTO_TEST_CASE(iterator_ordering)
         BOOST_CHECK(dbw.Write(key, value));
     }
 
-    std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper*>(&dbw)->NewIterator());
-    for (int c=0; c<2; ++c) {
-        int seek_start;
-        if (c == 0)
-            seek_start = 0x00;
-        else
-            seek_start = 0x80;
+    std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper&>(dbw).NewIterator());
+    for (int seek_start : {0x00, 0x80}) {
         it->Seek((uint8_t)seek_start);
         for (int x=seek_start; x<256; ++x) {
             uint8_t key;
@@ -286,13 +278,8 @@ BOOST_AUTO_TEST_CASE(iterator_string_ordering)
         }
     }
 
-    std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper*>(&dbw)->NewIterator());
-    for (int c=0; c<2; ++c) {
-        int seek_start;
-        if (c == 0)
-            seek_start = 0;
-        else
-            seek_start = 5;
+    std::unique_ptr<CDBIterator> it(const_cast<CDBWrapper&>(dbw).NewIterator());
+    for (int seek_start : {0, 5}) {
         snprintf(buf, sizeof(buf), "%d", seek_start);
         StringContentsSerializer seek_key(buf);
         it->Seek(seek_key);
diff --git a/src/test/netbase_tests.cpp b/src/test/netbase_tests.cpp
index b45a7fcc57..1baf7643e5 100644
--- a/src/test/netbase_tests.cpp
+++ b/src/test/netbase_tests.cpp
@@ -4,6 +4,7 @@
 
 #include "netbase.h"
 #include "test/test_bitcoin.h"
+#include "utilstrencodings.h"
 
 #include <string>
 
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index a74f40251a..f609cb1af4 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -196,8 +196,8 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
     // Test that invalidity under a set of flags doesn't preclude validity
     // under other (eg consensus) flags.
     // spend_tx is invalid according to DERSIG
-    CValidationState state;
     {
+        CValidationState state;
         PrecomputedTransactionData ptd_spend_tx(spend_tx);
 
         BOOST_CHECK(!CheckInputs(spend_tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
diff --git a/src/txdb.cpp b/src/txdb.cpp
index 002f6550bc..aa0b73a417 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -172,7 +172,7 @@ bool CBlockTreeDB::ReadLastBlockFile(int &nFile) {
 
 CCoinsViewCursor *CCoinsViewDB::Cursor() const
 {
-    CCoinsViewDBCursor *i = new CCoinsViewDBCursor(const_cast<CDBWrapper*>(&db)->NewIterator(), GetBestBlock());
+    CCoinsViewDBCursor *i = new CCoinsViewDBCursor(const_cast<CDBWrapper&>(db).NewIterator(), GetBestBlock());
     /* It seems that there are no "const iterators" for LevelDB.  Since we
        only need read operations on it, use a const-cast to get around
        that restriction.  */
diff --git a/src/util.h b/src/util.h
index 824ad51ac4..e1bdfb1988 100644
--- a/src/util.h
+++ b/src/util.h
@@ -215,7 +215,7 @@ public:
      * Return string argument or default value
      *
      * @param strArg Argument to get (e.g. "-foo")
-     * @param default (e.g. "1")
+     * @param strDefault (e.g. "1")
      * @return command-line argument or default value
      */
     std::string GetArg(const std::string& strArg, const std::string& strDefault);
@@ -224,7 +224,7 @@ public:
      * Return integer argument or default value
      *
      * @param strArg Argument to get (e.g. "-foo")
-     * @param default (e.g. 1)
+     * @param nDefault (e.g. 1)
      * @return command-line argument (0 if invalid number) or default value
      */
     int64_t GetArg(const std::string& strArg, int64_t nDefault);
@@ -233,7 +233,7 @@ public:
      * Return boolean argument or default value
      *
      * @param strArg Argument to get (e.g. "-foo")
-     * @param default (true or false)
+     * @param fDefault (true or false)
      * @return command-line argument or default value
      */
     bool GetBoolArg(const std::string& strArg, bool fDefault);
diff --git a/src/utilstrencodings.cpp b/src/utilstrencodings.cpp
index 2fabb8cf7a..9ee14070a2 100644
--- a/src/utilstrencodings.cpp
+++ b/src/utilstrencodings.cpp
@@ -91,6 +91,25 @@ std::vector<unsigned char> ParseHex(const std::string& str)
     return ParseHex(str.c_str());
 }
 
+void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
+    size_t colon = in.find_last_of(':');
+    // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
+    bool fHaveColon = colon != in.npos;
+    bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
+    bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
+    if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
+        int32_t n;
+        if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
+            in = in.substr(0, colon);
+            portOut = n;
+        }
+    }
+    if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
+        hostOut = in.substr(1, in.size()-2);
+    else
+        hostOut = in;
+}
+
 std::string EncodeBase64(const unsigned char* pch, size_t len)
 {
     static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
diff --git a/src/utilstrencodings.h b/src/utilstrencodings.h
index 8b37fe12e0..707fdaad16 100644
--- a/src/utilstrencodings.h
+++ b/src/utilstrencodings.h
@@ -48,6 +48,7 @@ std::string DecodeBase32(const std::string& str);
 std::string EncodeBase32(const unsigned char* pch, size_t len);
 std::string EncodeBase32(const std::string& str);
 
+void SplitHostPort(std::string in, int &portOut, std::string &hostOut);
 std::string i64tostr(int64_t n);
 std::string itostr(int n);
 int64_t atoi64(const char* psz);
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index f983a61a9f..ee8c7548fc 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -740,9 +740,9 @@ UniValue getbalance(const JSONRPCRequest& request)
             "\nResult:\n"
             "amount              (numeric) The total amount in " + CURRENCY_UNIT + " received for this account.\n"
             "\nExamples:\n"
-            "\nThe total amount in the wallet\n"
+            "\nThe total amount in the wallet with 1 or more confirmations\n"
             + HelpExampleCli("getbalance", "") +
-            "\nThe total amount in the wallet at least 5 blocks confirmed\n"
+            "\nThe total amount in the wallet at least 6 blocks confirmed\n"
             + HelpExampleCli("getbalance", "\"*\" 6") +
             "\nAs a json rpc call\n"
             + HelpExampleRpc("getbalance", "\"*\", 6")
diff --git a/src/wallet/rpcwallet.h b/src/wallet/rpcwallet.h
index bd5dad18ca..31e2f6a699 100644
--- a/src/wallet/rpcwallet.h
+++ b/src/wallet/rpcwallet.h
@@ -16,7 +16,7 @@ void RegisterWalletRPCCommands(CRPCTable &t);
  * @param[in] request JSONRPCRequest that wishes to access a wallet
  * @return NULL if no wallet should be used, or a pointer to the CWallet
  */
-CWallet *GetWalletForJSONRPCRequest(const JSONRPCRequest&);
+CWallet *GetWalletForJSONRPCRequest(const JSONRPCRequest& request);
 
 std::string HelpRequiringPassphrase(CWallet *);
 void EnsureWalletIsUnlocked(CWallet *);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 8c4f637306..13da7bb2c2 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2991,7 +2991,8 @@ DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
         if (dbw->Rewrite("\x04pool"))
         {
             LOCK(cs_wallet);
-            setKeyPool.clear();
+            setInternalKeyPool.clear();
+            setExternalKeyPool.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
@@ -3019,7 +3020,8 @@ DBErrors CWallet::ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256
     {
         if (dbw->Rewrite("\x04pool"))
         {
-            setKeyPool.clear();
+            setInternalKeyPool.clear();
+            setExternalKeyPool.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
@@ -3044,7 +3046,8 @@ DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx>& vWtx)
         if (dbw->Rewrite("\x04pool"))
         {
             LOCK(cs_wallet);
-            setKeyPool.clear();
+            setInternalKeyPool.clear();
+            setExternalKeyPool.clear();
             // Note: can't top-up keypool here, because wallet is locked.
             // User will be prompted to unlock wallet the next operation
             // that requires a new key.
@@ -3128,9 +3131,16 @@ bool CWallet::NewKeyPool()
     {
         LOCK(cs_wallet);
         CWalletDB walletdb(*dbw);
-        for (int64_t nIndex : setKeyPool)
+
+        for (int64_t nIndex : setInternalKeyPool) {
+            walletdb.ErasePool(nIndex);
+        }
+        setInternalKeyPool.clear();
+
+        for (int64_t nIndex : setExternalKeyPool) {
             walletdb.ErasePool(nIndex);
-        setKeyPool.clear();
+        }
+        setExternalKeyPool.clear();
 
         if (!TopUpKeyPool()) {
             return false;
@@ -3142,25 +3152,8 @@ bool CWallet::NewKeyPool()
 
 size_t CWallet::KeypoolCountExternalKeys()
 {
-    AssertLockHeld(cs_wallet); // setKeyPool
-
-    // immediately return setKeyPool's size if HD or HD_SPLIT is disabled or not supported
-    if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT))
-        return setKeyPool.size();
-
-    CWalletDB walletdb(*dbw);
-
-    // count amount of external keys
-    size_t amountE = 0;
-    for(const int64_t& id : setKeyPool)
-    {
-        CKeyPool tmpKeypool;
-        if (!walletdb.ReadPool(id, tmpKeypool))
-            throw std::runtime_error(std::string(__func__) + ": read failed");
-        amountE += !tmpKeypool.fInternal;
-    }
-
-    return amountE;
+    AssertLockHeld(cs_wallet); // setExternalKeyPool
+    return setExternalKeyPool.size();
 }
 
 bool CWallet::TopUpKeyPool(unsigned int kpSize)
@@ -3180,10 +3173,8 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
 
         // count amount of available keys (internal, external)
         // make sure the keypool of external and internal keys fits the user selected target (-keypool)
-        int64_t amountExternal = KeypoolCountExternalKeys();
-        int64_t amountInternal = setKeyPool.size() - amountExternal;
-        int64_t missingExternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - amountExternal, (int64_t) 0);
-        int64_t missingInternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - amountInternal, (int64_t) 0);
+        int64_t missingExternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setExternalKeyPool.size(), (int64_t) 0);
+        int64_t missingInternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setInternalKeyPool.size(), (int64_t) 0);
 
         if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT))
         {
@@ -3195,20 +3186,32 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
         for (int64_t i = missingInternal + missingExternal; i--;)
         {
             int64_t nEnd = 1;
-            if (i < missingInternal)
+            if (i < missingInternal) {
                 internal = true;
-            if (!setKeyPool.empty())
-                nEnd = *(--setKeyPool.end()) + 1;
+            }
+
+            if (!setInternalKeyPool.empty()) {
+                nEnd = *(setInternalKeyPool.rbegin()) + 1;
+            }
+            if (!setExternalKeyPool.empty()) {
+                nEnd = std::max(nEnd, *(setExternalKeyPool.rbegin()) + 1);
+            }
+
             if (!walletdb.WritePool(nEnd, CKeyPool(GenerateNewKey(internal), internal)))
                 throw std::runtime_error(std::string(__func__) + ": writing generated key failed");
-            setKeyPool.insert(nEnd);
-            LogPrintf("keypool added key %d, size=%u, internal=%d\n", nEnd, setKeyPool.size(), internal);
+
+            if (internal) {
+                setInternalKeyPool.insert(nEnd);
+            } else {
+                setExternalKeyPool.insert(nEnd);
+            }
+            LogPrintf("keypool added key %d, size=%u (%u internal), new key is %s\n", nEnd, setInternalKeyPool.size() + setExternalKeyPool.size(), setInternalKeyPool.size(), internal ? "internal" : "external");
         }
     }
     return true;
 }
 
-void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool internal)
+void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal)
 {
     nIndex = -1;
     keypool.vchPubKey = CPubKey();
@@ -3218,30 +3221,30 @@ void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool int
         if (!IsLocked())
             TopUpKeyPool();
 
+        bool fReturningInternal = IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT) && fRequestedInternal;
+        std::set<int64_t>& setKeyPool = fReturningInternal ? setInternalKeyPool : setExternalKeyPool;
+
         // Get the oldest key
         if(setKeyPool.empty())
             return;
 
         CWalletDB walletdb(*dbw);
 
-        // try to find a key that matches the internal/external filter
-        for(const int64_t& id : setKeyPool)
-        {
-            CKeyPool tmpKeypool;
-            if (!walletdb.ReadPool(id, tmpKeypool))
-                throw std::runtime_error(std::string(__func__) + ": read failed");
-            if (!HaveKey(tmpKeypool.vchPubKey.GetID()))
-                throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
-            if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT) || tmpKeypool.fInternal == internal)
-            {
-                nIndex = id;
-                keypool = tmpKeypool;
-                setKeyPool.erase(id);
-                assert(keypool.vchPubKey.IsValid());
-                LogPrintf("keypool reserve %d\n", nIndex);
-                return;
-            }
+        auto it = setKeyPool.begin();
+        nIndex = *it;
+        setKeyPool.erase(it);
+        if (!walletdb.ReadPool(nIndex, keypool)) {
+            throw std::runtime_error(std::string(__func__) + ": read failed");
+        }
+        if (!HaveKey(keypool.vchPubKey.GetID())) {
+            throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
         }
+        if (keypool.fInternal != fReturningInternal) {
+            throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
+        }
+
+        assert(keypool.vchPubKey.IsValid());
+        LogPrintf("keypool reserve %d\n", nIndex);
     }
 }
 
@@ -3253,12 +3256,16 @@ void CWallet::KeepKey(int64_t nIndex)
     LogPrintf("keypool keep %d\n", nIndex);
 }
 
-void CWallet::ReturnKey(int64_t nIndex)
+void CWallet::ReturnKey(int64_t nIndex, bool fInternal)
 {
     // Return to key pool
     {
         LOCK(cs_wallet);
-        setKeyPool.insert(nIndex);
+        if (fInternal) {
+            setInternalKeyPool.insert(nIndex);
+        } else {
+            setExternalKeyPool.insert(nIndex);
+        }
     }
     LogPrintf("keypool return %d\n", nIndex);
 }
@@ -3282,48 +3289,35 @@ bool CWallet::GetKeyFromPool(CPubKey& result, bool internal)
     return true;
 }
 
-int64_t CWallet::GetOldestKeyPoolTime()
-{
-    LOCK(cs_wallet);
-
-    // if the keypool is empty, return <NOW>
-    if (setKeyPool.empty())
+static int64_t GetOldestKeyTimeInPool(const std::set<int64_t>& setKeyPool, CWalletDB& walletdb) {
+    if (setKeyPool.empty()) {
         return GetTime();
+    }
 
     CKeyPool keypool;
-    CWalletDB walletdb(*dbw);
-
-    if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT))
-    {
-        // if HD & HD Chain Split is enabled, response max(oldest-internal-key, oldest-external-key)
-        int64_t now = GetTime();
-        int64_t oldest_external = now, oldest_internal = now;
-
-        for(const int64_t& id : setKeyPool)
-        {
-            if (!walletdb.ReadPool(id, keypool)) {
-                throw std::runtime_error(std::string(__func__) + ": read failed");
-            }
-            if (keypool.fInternal && keypool.nTime < oldest_internal) {
-                oldest_internal = keypool.nTime;
-            }
-            else if (!keypool.fInternal && keypool.nTime < oldest_external) {
-                oldest_external = keypool.nTime;
-            }
-            if (oldest_internal != now && oldest_external != now) {
-                break;
-            }
-        }
-        return std::max(oldest_internal, oldest_external);
-    }
-    // load oldest key from keypool, get time and return
     int64_t nIndex = *(setKeyPool.begin());
-    if (!walletdb.ReadPool(nIndex, keypool))
+    if (!walletdb.ReadPool(nIndex, keypool)) {
         throw std::runtime_error(std::string(__func__) + ": read oldest key in keypool failed");
+    }
     assert(keypool.vchPubKey.IsValid());
     return keypool.nTime;
 }
 
+int64_t CWallet::GetOldestKeyPoolTime()
+{
+    LOCK(cs_wallet);
+
+    CWalletDB walletdb(*dbw);
+
+    // load oldest key from keypool, get time and return
+    int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, walletdb);
+    if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
+        oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, walletdb), oldestKey);
+    }
+
+    return oldestKey;
+}
+
 std::map<CTxDestination, CAmount> CWallet::GetAddressBalances()
 {
     std::map<CTxDestination, CAmount> balances;
@@ -3482,6 +3476,7 @@ bool CReserveKey::GetReservedKey(CPubKey& pubkey, bool internal)
         else {
             return false;
         }
+        fInternal = keypool.fInternal;
     }
     assert(vchPubKey.IsValid());
     pubkey = vchPubKey;
@@ -3498,19 +3493,14 @@ void CReserveKey::KeepKey()
 
 void CReserveKey::ReturnKey()
 {
-    if (nIndex != -1)
-        pwallet->ReturnKey(nIndex);
+    if (nIndex != -1) {
+        pwallet->ReturnKey(nIndex, fInternal);
+    }
     nIndex = -1;
     vchPubKey = CPubKey();
 }
 
-void CWallet::GetAllReserveKeys(std::set<CKeyID>& setAddress) const
-{
-    setAddress.clear();
-
-    CWalletDB walletdb(*dbw);
-
-    LOCK2(cs_main, cs_wallet);
+static void LoadReserveKeysToSet(std::set<CKeyID>& setAddress, const std::set<int64_t>& setKeyPool, CWalletDB& walletdb) {
     for (const int64_t& id : setKeyPool)
     {
         CKeyPool keypool;
@@ -3518,12 +3508,27 @@ void CWallet::GetAllReserveKeys(std::set<CKeyID>& setAddress) const
             throw std::runtime_error(std::string(__func__) + ": read failed");
         assert(keypool.vchPubKey.IsValid());
         CKeyID keyID = keypool.vchPubKey.GetID();
-        if (!HaveKey(keyID))
-            throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
         setAddress.insert(keyID);
     }
 }
 
+void CWallet::GetAllReserveKeys(std::set<CKeyID>& setAddress) const
+{
+    setAddress.clear();
+
+    CWalletDB walletdb(*dbw);
+
+    LOCK2(cs_main, cs_wallet);
+    LoadReserveKeysToSet(setAddress, setInternalKeyPool, walletdb);
+    LoadReserveKeysToSet(setAddress, setExternalKeyPool, walletdb);
+
+    for (const CKeyID& keyID : setAddress) {
+        if (!HaveKey(keyID)) {
+            throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
+        }
+    }
+}
+
 void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script)
 {
     std::shared_ptr<CReserveKey> rKey = std::make_shared<CReserveKey>(this);
@@ -4057,13 +4062,19 @@ bool CWallet::ParameterInteraction()
         }
     }
 
-    // -zapwallettx implies a rescan
-    if (GetBoolArg("-zapwallettxes", false)) {
+    int zapwallettxes = GetArg("-zapwallettxes", 0);
+    // -zapwallettxes implies dropping the mempool on startup
+    if (zapwallettxes != 0 && SoftSetBoolArg("-persistmempool", false)) {
+        LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -persistmempool=0\n", __func__, zapwallettxes);
+    }
+
+    // -zapwallettxes implies a rescan
+    if (zapwallettxes != 0) {
         if (is_multiwallet) {
             return InitError(strprintf("%s is only allowed with a single wallet file", "-zapwallettxes"));
         }
         if (SoftSetBoolArg("-rescan", true)) {
-            LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> setting -rescan=1\n", __func__);
+            LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -rescan=1\n", __func__, zapwallettxes);
         }
     }
 
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index bb9d146a20..b716e46a7d 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -699,7 +699,8 @@ private:
     /* HD derive new child key (on internal or external chain) */
     void DeriveNewChildKey(CKeyMetadata& metadata, CKey& secret, bool internal = false);
 
-    std::set<int64_t> setKeyPool;
+    std::set<int64_t> setInternalKeyPool;
+    std::set<int64_t> setExternalKeyPool;
 
     int64_t nTimeFirstKey;
 
@@ -744,7 +745,11 @@ public:
 
     void LoadKeyPool(int nIndex, const CKeyPool &keypool)
     {
-        setKeyPool.insert(nIndex);
+        if (keypool.fInternal) {
+            setInternalKeyPool.insert(nIndex);
+        } else {
+            setExternalKeyPool.insert(nIndex);
+        }
 
         // If no metadata exists yet, create a default with the pool key's
         // creation time. Note that this may be overwritten by actually
@@ -974,9 +979,9 @@ public:
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys();
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool internal);
+    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal);
     void KeepKey(int64_t nIndex);
-    void ReturnKey(int64_t nIndex);
+    void ReturnKey(int64_t nIndex, bool fInternal);
     bool GetKeyFromPool(CPubKey &key, bool internal = false);
     int64_t GetOldestKeyPoolTime();
     void GetAllReserveKeys(std::set<CKeyID>& setAddress) const;
@@ -1030,8 +1035,8 @@ public:
     
     unsigned int GetKeyPoolSize()
     {
-        AssertLockHeld(cs_wallet); // setKeyPool
-        return setKeyPool.size();
+        AssertLockHeld(cs_wallet); // set{Ex,In}ternalKeyPool
+        return setInternalKeyPool.size() + setExternalKeyPool.size();
     }
 
     bool SetDefaultKey(const CPubKey &vchPubKey);
@@ -1135,11 +1140,13 @@ protected:
     CWallet* pwallet;
     int64_t nIndex;
     CPubKey vchPubKey;
+    bool fInternal;
 public:
     CReserveKey(CWallet* pwalletIn)
     {
         nIndex = -1;
         pwallet = pwalletIn;
+        fInternal = false;
     }
 
     CReserveKey() = default;
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 2a33dca240..65a28af46d 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -94,23 +94,23 @@ bool CWalletDB::WriteMasterKey(unsigned int nID, const CMasterKey& kMasterKey)
 
 bool CWalletDB::WriteCScript(const uint160& hash, const CScript& redeemScript)
 {
-    return WriteIC(std::make_pair(std::string("cscript"), hash), *(const CScriptBase*)(&redeemScript), false);
+    return WriteIC(std::make_pair(std::string("cscript"), hash), redeemScript, false);
 }
 
 bool CWalletDB::WriteWatchOnly(const CScript &dest, const CKeyMetadata& keyMeta)
 {
-    if (!WriteIC(std::make_pair(std::string("watchmeta"), *(const CScriptBase*)(&dest)), keyMeta)) {
+    if (!WriteIC(std::make_pair(std::string("watchmeta"), dest), keyMeta)) {
         return false;
     }
-    return WriteIC(std::make_pair(std::string("watchs"), *(const CScriptBase*)(&dest)), '1');
+    return WriteIC(std::make_pair(std::string("watchs"), dest), '1');
 }
 
 bool CWalletDB::EraseWatchOnly(const CScript &dest)
 {
-    if (!EraseIC(std::make_pair(std::string("watchmeta"), *(const CScriptBase*)(&dest)))) {
+    if (!EraseIC(std::make_pair(std::string("watchmeta"), dest))) {
         return false;
     }
-    return EraseIC(std::make_pair(std::string("watchs"), *(const CScriptBase*)(&dest)));
+    return EraseIC(std::make_pair(std::string("watchs"), dest));
 }
 
 bool CWalletDB::WriteBestBlock(const CBlockLocator& locator)
@@ -323,7 +323,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
         {
             wss.nWatchKeys++;
             CScript script;
-            ssKey >> *(CScriptBase*)(&script);
+            ssKey >> script;
             char fYes;
             ssValue >> fYes;
             if (fYes == '1')
@@ -440,7 +440,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             else if (strType == "watchmeta")
             {
               CScript script;
-              ssKey >> *(CScriptBase*)(&script);
+              ssKey >> script;
               keyID = CScriptID(script);
             }
 
@@ -474,7 +474,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             uint160 hash;
             ssKey >> hash;
             CScript script;
-            ssValue >> *(CScriptBase*)(&script);
+            ssValue >> script;
             if (!pwallet->LoadCScript(script))
             {
                 strErr = "Error reading wallet database: LoadCScript failed";