diff --git a/configure.ac b/configure.ac
index 2f7f8b6fb17d..c68d83079a78 100644
--- a/configure.ac
+++ b/configure.ac
@@ -19,6 +19,12 @@ BITCOIN_GUI_NAME=dash-qt
 BITCOIN_CLI_NAME=dash-cli
 BITCOIN_TX_NAME=dash-tx
 
+dnl Unless the user specified ARFLAGS, force it to be cr
+AC_ARG_VAR(ARFLAGS, [Flags for the archiver, defaults to <cr> if not set])
+if test "x${ARFLAGS+set}" != "xset"; then
+  ARFLAGS="cr"
+fi
+
 AC_CANONICAL_HOST
 
 AH_TOP([#ifndef DASH_CONFIG_H])
@@ -290,9 +296,32 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   # Check for optional instruction set support. Enabling these does _not_ imply that all code will
   # be compiled with them, rather that specific objects/libs may use them after checking for runtime
   # compatibility.
-  AX_CHECK_COMPILE_FLAG([-msse4.2],[[enable_sse42=yes; SSE42_CXXFLAGS="-msse4.2"]],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-msse4.2],[[SSE42_CXXFLAGS="-msse4.2"]],,[[$CXXFLAG_WERROR]])
 
 fi
+
+TEMP_CXXFLAGS="$CXXFLAGS"
+CXXFLAGS="$CXXFLAGS $SSE42_CXXFLAGS"
+AC_MSG_CHECKING(for assembler crc32 support)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+    #include <stdint.h>
+    #if defined(_MSC_VER)
+    #include <intrin.h>
+    #elif defined(__GNUC__) && defined(__SSE4_2__)
+    #include <nmmintrin.h>
+    #endif
+  ]],[[
+    uint64_t l = 0;
+    l = _mm_crc32_u8(l, 0);
+    l = _mm_crc32_u32(l, 0);
+    l = _mm_crc32_u64(l, 0);
+    return l;
+  ]])],
+ [ AC_MSG_RESULT(yes); enable_hwcrc32=yes],
+ [ AC_MSG_RESULT(no)]
+)
+CXXFLAGS="$TEMP_CXXFLAGS"
+
 CPPFLAGS="$CPPFLAGS -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS"
 
 AC_ARG_WITH([utils],
@@ -1188,7 +1217,7 @@ AM_CONDITIONAL([USE_QRCODE], [test x$use_qr = xyes])
 AM_CONDITIONAL([USE_LCOV],[test x$use_lcov = xyes])
 AM_CONDITIONAL([GLIBC_BACK_COMPAT],[test x$use_glibc_compat = xyes])
 AM_CONDITIONAL([HARDEN],[test x$use_hardening = xyes])
-AM_CONDITIONAL([ENABLE_SSE42],[test x$enable_sse42 = xyes])
+AM_CONDITIONAL([ENABLE_HWCRC32],[test x$enable_hwcrc32 = xyes])
 
 AC_DEFINE(CLIENT_VERSION_MAJOR, _CLIENT_VERSION_MAJOR, [Major version])
 AC_DEFINE(CLIENT_VERSION_MINOR, _CLIENT_VERSION_MINOR, [Minor version])
@@ -1321,4 +1350,5 @@ echo "  CPPFLAGS            = $CPPFLAGS"
 echo "  CXX                 = $CXX"
 echo "  CXXFLAGS            = $CXXFLAGS"
 echo "  LDFLAGS             = $LDFLAGS"
+echo "  ARFLAGS             = $ARFLAGS"
 echo 
diff --git a/contrib/devtools/github-merge.py b/contrib/devtools/github-merge.py
index e9816f7d1916..c664cf81fa9f 100755
--- a/contrib/devtools/github-merge.py
+++ b/contrib/devtools/github-merge.py
@@ -175,6 +175,7 @@ def main():
     if info is None:
         exit(1)
     title = info['title'].strip()
+    body = info['body'].strip()
     # precedence order for destination branch argument:
     #   - command line argument
     #   - githubmerge.branch setting
@@ -229,6 +230,7 @@ def main():
             firstline = 'Merge #%s' % (pull,)
         message = firstline + '\n\n'
         message += subprocess.check_output([GIT,'log','--no-merges','--topo-order','--pretty=format:%h %s (%an)',base_branch+'..'+head_branch]).decode('utf-8')
+        message += '\n\nPull request description:\n\n  ' + body.replace('\n', '\n  ') + '\n'
         try:
             subprocess.check_call([GIT,'merge','-q','--commit','--no-edit','--no-ff','-m',message.encode('utf-8'),head_branch])
         except subprocess.CalledProcessError as e:
diff --git a/contrib/verifybinaries/verify.sh b/contrib/verifybinaries/verify.sh
index c2cc2b7013ad..409f517c9fb2 100755
--- a/contrib/verifybinaries/verify.sh
+++ b/contrib/verifybinaries/verify.sh
@@ -3,7 +3,8 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-###   This script attempts to download the signature file SHA256SUMS.asc from bitcoin.org
+###   This script attempts to download the signature file SHA256SUMS.asc from
+###   bitcoincore.org and bitcoin.org and compares them.
 ###   It first checks if the signature passes, and then downloads the files specified in
 ###   the file, and checks if the hashes of these files match those that are specified
 ###   in the signature file.
@@ -22,7 +23,9 @@ TMPFILE="hashes.tmp"
 
 SIGNATUREFILENAME="SHA256SUMS.asc"
 RCSUBDIR="test"
-BASEDIR="https://bitcoin.org/bin/"
+HOST1="https://bitcoincore.org"
+HOST2="https://bitcoin.org"
+BASEDIR="/bin/"
 VERSIONPREFIX="bitcoin-core-"
 RCVERSIONSTRING="rc"
 
@@ -81,7 +84,7 @@ else
 fi
 
 #first we fetch the file containing the signature
-WGETOUT=$(wget -N "$BASEDIR$SIGNATUREFILENAME" 2>&1)
+WGETOUT=$(wget -N "$HOST1$BASEDIR$SIGNATUREFILENAME" 2>&1)
 
 #and then see if wget completed successfully
 if [ $? -ne 0 ]; then
@@ -92,6 +95,22 @@ if [ $? -ne 0 ]; then
    exit 2
 fi
 
+WGETOUT=$(wget -N -O "$SIGNATUREFILENAME.2" "$HOST2$BASEDIR$SIGNATUREFILENAME" 2>&1)
+if [ $? -ne 0 ]; then
+   echo "bitcoin.org failed to provide signature file, but bitcoincore.org did?"
+   echo "wget output:"
+   echo "$WGETOUT"|sed 's/^/\t/g'
+   clean_up $SIGNATUREFILENAME
+   exit 3
+fi
+
+SIGFILEDIFFS="$(diff $SIGNATUREFILENAME $SIGNATUREFILENAME.2)"
+if [ "$SIGFILEDIFFS" != "" ]; then
+   echo "bitcoin.org and bitcoincore.org signature files were not equal?"
+   clean_up $SIGNATUREFILENAME $SIGNATUREFILENAME.2
+   exit 4
+fi
+
 #then we check it
 GPGOUT=$(gpg --yes --decrypt --output "$TMPFILE" "$SIGNATUREFILENAME" 2>&1)
 
@@ -111,7 +130,7 @@ if [ $RET -ne 0 ]; then
 
    echo "gpg output:"
    echo "$GPGOUT"|sed 's/^/\t/g'
-   clean_up $SIGNATUREFILENAME $TMPFILE
+   clean_up $SIGNATUREFILENAME $SIGNATUREFILENAME.2 $TMPFILE
    exit "$RET"
 fi
 
@@ -131,7 +150,7 @@ FILES=$(awk '{print $2}' "$TMPFILE")
 for file in $FILES
 do
    echo "Downloading $file"
-   wget --quiet -N "$BASEDIR$file"
+   wget --quiet -N "$HOST1$BASEDIR$file"
 done
 
 #check hashes
@@ -149,7 +168,7 @@ fi
 
 if [ -n "$2" ]; then
    echo "Clean up the binaries"
-   clean_up $FILES $SIGNATUREFILENAME $TMPFILE
+   clean_up $FILES $SIGNATUREFILENAME $SIGNATUREFILENAME.2 $TMPFILE
 else
    echo "Keep the binaries in $WORKINGDIR"
    clean_up $TMPFILE
diff --git a/doc/REST-interface.md b/doc/REST-interface.md
index d7d5c8d4c60c..d360d8981a42 100644
--- a/doc/REST-interface.md
+++ b/doc/REST-interface.md
@@ -40,11 +40,13 @@ Only supports JSON as output format.
 * headers : (numeric) the current number of headers we have validated
 * bestblockhash : (string) the hash of the currently best block
 * difficulty : (numeric) the current difficulty
+* mediantime : (numeric) the median time of the 11 blocks before the most recent block on the blockchain
 * verificationprogress : (numeric) estimate of verification progress [0..1]
 * chainwork : (string) total amount of work in active chain, in hexadecimal
 * pruned : (boolean) if the blocks are subject to pruning
 * pruneheight : (numeric) heighest block available
 * softforks : (array) status of softforks in progress
+* bip9_softforks : (object) status of BIP9 softforks in progress
 
 #### Query UTXO set
 `GET /rest/getutxos/<checkmempool>/<txid>-<n>/<txid>-<n>/.../<txid>-<n>.<bin|hex|json>`
@@ -57,25 +59,25 @@ Example:
 ```
 $ curl localhost:18332/rest/getutxos/checkmempool/b2cdfd7b89def827ff8af7cd9bff7627ff72e5e8b0f71210f92ea7a4000c5d75-0.json 2>/dev/null | json_pp
 {
-   "chaintipHash" : "00000000fb01a7f3745a717f8caebee056c484e6e0bfe4a9591c235bb70506fb",
    "chainHeight" : 325347,
+   "chaintipHash" : "00000000fb01a7f3745a717f8caebee056c484e6e0bfe4a9591c235bb70506fb",
+   "bitmap": "1",
    "utxos" : [
       {
+         "txvers" : 1
+         "height" : 2147483647,
+         "value" : 8.8687,		 
          "scriptPubKey" : {
-            "addresses" : [
-               "mi7as51dvLJsizWnTMurtRmrP8hG2m1XvD"
-            ],
-            "type" : "pubkeyhash",
+            "asm" : "OP_DUP OP_HASH160 1c7cebb529b86a04c683dfa87be49de35bcf589e OP_EQUALVERIFY OP_CHECKSIG",
             "hex" : "76a9141c7cebb529b86a04c683dfa87be49de35bcf589e88ac",
             "reqSigs" : 1,
-            "asm" : "OP_DUP OP_HASH160 1c7cebb529b86a04c683dfa87be49de35bcf589e OP_EQUALVERIFY OP_CHECKSIG"
-         },
-         "value" : 8.8687,
-         "height" : 2147483647,
-         "txvers" : 1
+            "type" : "pubkeyhash",
+            "addresses" : [
+               "mi7as51dvLJsizWnTMurtRmrP8hG2m1XvD"
+            ]
+         }
       }
-   ],
-   "bitmap" : "1"
+   ]
 }
 ```
 
@@ -87,6 +89,8 @@ Only supports JSON as output format.
 * size : (numeric) the number of transactions in the TX mempool
 * bytes : (numeric) size of the TX mempool in bytes
 * usage : (numeric) total TX mempool memory usage
+* maxmempool : (numeric) maximum memory usage for the mempool in bytes
+* mempoolminfee : (numeric) minimum feerate (DASH per KB) for tx to be accepted
 
 `GET /rest/mempool/contents.json`
 
diff --git a/src/Makefile.leveldb.include b/src/Makefile.leveldb.include
index ac38141f43d7..833f3d2a10ca 100644
--- a/src/Makefile.leveldb.include
+++ b/src/Makefile.leveldb.include
@@ -142,7 +142,7 @@ leveldb_libmemenv_a_SOURCES += leveldb/helpers/memenv/memenv.h
 
 leveldb_libleveldb_sse42_a_CPPFLAGS = $(leveldb_libleveldb_a_CPPFLAGS)
 leveldb_libleveldb_sse42_a_CXXFLAGS = $(leveldb_libleveldb_a_CXXFLAGS)
-if ENABLE_SSE42
+if ENABLE_HWCRC32
 leveldb_libleveldb_sse42_a_CPPFLAGS += -DLEVELDB_PLATFORM_POSIX_SSE
 leveldb_libleveldb_sse42_a_CXXFLAGS += $(SSE42_CXXFLAGS)
 endif
diff --git a/src/base58.cpp b/src/base58.cpp
index 0ae0ff2a4a33..47de1f98335c 100644
--- a/src/base58.cpp
+++ b/src/base58.cpp
@@ -110,7 +110,7 @@ std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend)
 
 std::string EncodeBase58(const std::vector<unsigned char>& vch)
 {
-    return EncodeBase58(&vch[0], &vch[0] + vch.size());
+    return EncodeBase58(vch.data(), vch.data() + vch.size());
 }
 
 bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet)
@@ -160,7 +160,7 @@ void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const
     vchVersion = vchVersionIn;
     vchData.resize(nSize);
     if (!vchData.empty())
-        memcpy(&vchData[0], pdata, nSize);
+        memcpy(vchData.data(), pdata, nSize);
 }
 
 void CBase58Data::SetData(const std::vector<unsigned char>& vchVersionIn, const unsigned char* pbegin, const unsigned char* pend)
@@ -180,8 +180,8 @@ bool CBase58Data::SetString(const char* psz, unsigned int nVersionBytes)
     vchVersion.assign(vchTemp.begin(), vchTemp.begin() + nVersionBytes);
     vchData.resize(vchTemp.size() - nVersionBytes);
     if (!vchData.empty())
-        memcpy(&vchData[0], &vchTemp[nVersionBytes], vchData.size());
-    memory_cleanse(&vchTemp[0], vchTemp.size());
+        memcpy(vchData.data(), vchTemp.data() + nVersionBytes, vchData.size());
+    memory_cleanse(vchTemp.data(), vchTemp.size());
     return true;
 }
 
@@ -262,7 +262,7 @@ CTxDestination CBitcoinAddress::Get() const
     if (!IsValid())
         return CNoDestination();
     uint160 id;
-    memcpy(&id, &vchData[0], 20);
+    memcpy(&id, vchData.data(), 20);
     if (vchVersion == Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
         return CKeyID(id);
     else if (vchVersion == Params().Base58Prefix(CChainParams::SCRIPT_ADDRESS))
@@ -293,7 +293,7 @@ bool CBitcoinAddress::GetKeyID(CKeyID& keyID) const
     if (!IsValid() || vchVersion != Params().Base58Prefix(CChainParams::PUBKEY_ADDRESS))
         return false;
     uint160 id;
-    memcpy(&id, &vchData[0], 20);
+    memcpy(&id, vchData.data(), 20);
     keyID = CKeyID(id);
     return true;
 }
diff --git a/src/base58.h b/src/base58.h
index afb986be2621..840ae7bad566 100644
--- a/src/base58.h
+++ b/src/base58.h
@@ -149,7 +149,7 @@ template<typename K, int Size, CChainParams::Base58Type Type> class CBitcoinExtK
         K ret;
         if (vchData.size() == Size) {
             // If base58 encoded data does not hold an ext key, return a !IsValid() key
-            ret.Decode(&vchData[0]);
+            ret.Decode(vchData.data());
         }
         return ret;
     }
diff --git a/src/bench/base58.cpp b/src/bench/base58.cpp
index 3319c179bf54..65e27a615d93 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/compressor.cpp b/src/compressor.cpp
index 20c154fc1e58..f4c12f38d2d1 100644
--- a/src/compressor.cpp
+++ b/src/compressor.cpp
@@ -93,7 +93,7 @@ bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector<unsigne
         script[0] = OP_DUP;
         script[1] = OP_HASH160;
         script[2] = 20;
-        memcpy(&script[3], &in[0], 20);
+        memcpy(&script[3], in.data(), 20);
         script[23] = OP_EQUALVERIFY;
         script[24] = OP_CHECKSIG;
         return true;
@@ -101,7 +101,7 @@ bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector<unsigne
         script.resize(23);
         script[0] = OP_HASH160;
         script[1] = 20;
-        memcpy(&script[2], &in[0], 20);
+        memcpy(&script[2], in.data(), 20);
         script[22] = OP_EQUAL;
         return true;
     case 0x02:
@@ -109,14 +109,14 @@ bool CScriptCompressor::Decompress(unsigned int nSize, const std::vector<unsigne
         script.resize(35);
         script[0] = 33;
         script[1] = nSize;
-        memcpy(&script[2], &in[0], 32);
+        memcpy(&script[2], in.data(), 32);
         script[34] = OP_CHECKSIG;
         return true;
     case 0x04:
     case 0x05:
         unsigned char vch[33] = {};
         vch[0] = nSize - 2;
-        memcpy(&vch[1], &in[0], 32);
+        memcpy(&vch[1], in.data(), 32);
         CPubKey pubkey(&vch[0], &vch[33]);
         if (!pubkey.Decompress())
             return false;
diff --git a/src/core_read.cpp b/src/core_read.cpp
index f6bac8cde0cb..18ddd9433391 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -27,7 +27,7 @@ CScript ParseScript(const std::string& s)
 
     if (mapOpNames.empty())
     {
-        for (int op = 0; op <= OP_NOP10; op++)
+        for (unsigned int op = 0; op <= OP_NOP10; op++)
         {
             // Allow OP_RESERVED to get into mapOpNames
             if (op < OP_NOP && op != OP_RESERVED)
diff --git a/src/dash-cli.cpp b/src/dash-cli.cpp
index bd4cca441981..9d873b167b29 100644
--- a/src/dash-cli.cpp
+++ b/src/dash-cli.cpp
@@ -204,8 +204,14 @@ static void http_error_cb(enum evhttp_request_error err, void *ctx)
 
 UniValue CallRPC(const std::string& strMethod, const UniValue& params)
 {
-    std::string host = gArgs.GetArg("-rpcconnect", DEFAULT_RPCCONNECT);
-    int port = gArgs.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(gArgs.GetArg("-rpcconnect", DEFAULT_RPCCONNECT), port, host);
+    port = gArgs.GetArg("-rpcport", port);
 
     // Obtain event base
     raii_event_base base = obtain_event_base();
diff --git a/src/hash.cpp b/src/hash.cpp
index 066d45972e8e..d76dfefa8f8c 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -17,36 +17,34 @@ unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char
 {
     // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
     uint32_t h1 = nHashSeed;
-    if (vDataToHash.size() > 0)
-    {
-        const uint32_t c1 = 0xcc9e2d51;
-        const uint32_t c2 = 0x1b873593;
+    const uint32_t c1 = 0xcc9e2d51;
+    const uint32_t c2 = 0x1b873593;
 
-        const int nblocks = vDataToHash.size() / 4;
+    const int nblocks = vDataToHash.size() / 4;
 
-        //----------
-        // body
-        const uint8_t* blocks = &vDataToHash[0] + nblocks * 4;
+    //----------
+    // body
+    const uint8_t* blocks = vDataToHash.data();
 
-        for (int i = -nblocks; i; i++) {
-            uint32_t k1 = ReadLE32(blocks + i*4);
+    for (int i = 0; i < nblocks; ++i) {
+        uint32_t k1 = ReadLE32(blocks + i*4);
 
-            k1 *= c1;
-            k1 = ROTL32(k1, 15);
-            k1 *= c2;
+        k1 *= c1;
+        k1 = ROTL32(k1, 15);
+        k1 *= c2;
 
-            h1 ^= k1;
-            h1 = ROTL32(h1, 13);
-            h1 = h1 * 5 + 0xe6546b64;
-        }
+        h1 ^= k1;
+        h1 = ROTL32(h1, 13);
+        h1 = h1 * 5 + 0xe6546b64;
+    }
 
-        //----------
-        // tail
-        const uint8_t* tail = (const uint8_t*)(&vDataToHash[0] + nblocks * 4);
+    //----------
+    // tail
+    const uint8_t* tail = vDataToHash.data() + nblocks * 4;
 
-        uint32_t k1 = 0;
+    uint32_t k1 = 0;
 
-        switch (vDataToHash.size() & 3) {
+    switch (vDataToHash.size() & 3) {
         case 3:
             k1 ^= tail[2] << 16;
         case 2:
@@ -57,7 +55,6 @@ unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char
             k1 = ROTL32(k1, 15);
             k1 *= c2;
             h1 ^= k1;
-        }
     }
 
     //----------
diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 4f369b241644..ca6d6b94102c 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/init.cpp b/src/init.cpp
index 0012281d921e..35dd2cc58fbf 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1850,7 +1850,9 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
         LogPrintf("Shutdown requested. Exiting.\n");
         return false;
     }
-    LogPrintf(" block index %15dms\n", GetTimeMillis() - nStart);
+    if (fLoaded) {
+        LogPrintf(" block index %15dms\n", GetTimeMillis() - nStart);
+    }
 
     fs::path est_path = GetDataDir() / FEE_ESTIMATES_FILENAME;
     CAutoFile est_filein(fsbridge::fopen(est_path, "rb"), SER_DISK, CLIENT_VERSION);
diff --git a/src/key.cpp b/src/key.cpp
index 5f4cda26da13..6327cc91256d 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -138,7 +138,7 @@ CPrivKey CKey::GetPrivKey() const {
     size_t privkeylen;
     privkey.resize(279);
     privkeylen = 279;
-    ret = ec_privkey_export_der(secp256k1_context_sign, (unsigned char*)&privkey[0], &privkeylen, begin(), fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
+    ret = ec_privkey_export_der(secp256k1_context_sign, (unsigned char*) privkey.data(), &privkeylen, begin(), fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
     assert(ret);
     privkey.resize(privkeylen);
     return privkey;
@@ -167,7 +167,7 @@ bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, uint32_
     secp256k1_ecdsa_signature sig;
     int ret = secp256k1_ecdsa_sign(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, test_case ? extra_entropy : NULL);
     assert(ret);
-    secp256k1_ecdsa_signature_serialize_der(secp256k1_context_sign, (unsigned char*)&vchSig[0], &nSigLen, &sig);
+    secp256k1_ecdsa_signature_serialize_der(secp256k1_context_sign, (unsigned char*)vchSig.data(), &nSigLen, &sig);
     vchSig.resize(nSigLen);
     return true;
 }
@@ -202,7 +202,7 @@ bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig)
 }
 
 bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) {
-    if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size()))
+    if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), privkey.data(), privkey.size()))
         return false;
     fCompressed = vchPubKey.IsCompressed();
     fValid = true;
@@ -245,8 +245,8 @@ void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
     static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};
     std::vector<unsigned char, secure_allocator<unsigned char>> vout(64);
     CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(vout.data());
-    key.Set(&vout[0], &vout[32], true);
-    memcpy(chaincode.begin(), &vout[32], 32);
+    key.Set(vout.data(), vout.data() + 32, true);
+    memcpy(chaincode.begin(), vout.data() + 32, 32);
     nDepth = 0;
     nChild = 0;
     memset(vchFingerprint, 0, sizeof(vchFingerprint));
diff --git a/src/net.cpp b/src/net.cpp
index 3b7cbed43063..27bbf58a9865 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -3365,5 +3365,5 @@ uint64_t CConnman::CalculateKeyedNetGroup(const CAddress& ad) const
 {
     std::vector<unsigned char> vchNetGroup(ad.GetGroup());
 
-    return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP).Write(&vchNetGroup[0], vchNetGroup.size()).Finalize();
+    return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP).Write(vchNetGroup.data(), vchNetGroup.size()).Finalize();
 }
diff --git a/src/netaddress.cpp b/src/netaddress.cpp
index 8252232f7b70..77ef7f381402 100644
--- a/src/netaddress.cpp
+++ b/src/netaddress.cpp
@@ -583,7 +583,7 @@ std::vector<unsigned char> CService::GetKey() const
 {
      std::vector<unsigned char> vKey;
      vKey.resize(18);
-     memcpy(&vKey[0], ip, 16);
+     memcpy(vKey.data(), ip, 16);
      vKey[16] = port / 0x100;
      vKey[17] = port & 0x0FF;
      return vKey;
diff --git a/src/netbase.cpp b/src/netbase.cpp
index a6d2bdc6bf9e..baf42f4e9e95 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();
@@ -563,7 +544,7 @@ static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDe
     // do socks negotiation
     if (proxy.randomize_credentials) {
         ProxyCredentials random_auth;
-        static std::atomic_int counter;
+        static std::atomic_int counter(0);
         random_auth.username = random_auth.password = strprintf("%i", counter++);
         if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
             return false;
diff --git a/src/netbase.h b/src/netbase.h
index 221986cba39e..dfb0c1d41c27 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -40,7 +40,6 @@ class proxyType
 
 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/prevector.h b/src/prevector.h
index 597838a175c1..c5f84f1b7a74 100644
--- a/src/prevector.h
+++ b/src/prevector.h
@@ -220,7 +220,7 @@ class prevector {
         }
     }
 
-    prevector() : _size(0) {}
+    prevector() : _size(0), _union{{}} {}
 
     explicit prevector(size_type n) : _size(0) {
         resize(n);
diff --git a/src/pubkey.cpp b/src/pubkey.cpp
index f8f68af6f831..11b8afc192d7 100644
--- a/src/pubkey.cpp
+++ b/src/pubkey.cpp
@@ -172,10 +172,7 @@ bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchS
     if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, &(*this)[0], size())) {
         return false;
     }
-    if (vchSig.size() == 0) {
-        return false;
-    }
-    if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, &vchSig[0], vchSig.size())) {
+    if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, vchSig.data(), vchSig.size())) {
         return false;
     }
     /* libsecp256k1's ECDSA verification requires lower-S signatures, which have
@@ -274,7 +271,7 @@ bool CExtPubKey::Derive(CExtPubKey &out, unsigned int _nChild) const {
 
 /* static */ bool CPubKey::CheckLowS(const std::vector<unsigned char>& vchSig) {
     secp256k1_ecdsa_signature sig;
-    if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, &vchSig[0], vchSig.size())) {
+    if (!ecdsa_signature_parse_der_lax(secp256k1_context_verify, &sig, vchSig.data(), vchSig.size())) {
         return false;
     }
     return (!secp256k1_ecdsa_signature_normalize(secp256k1_context_verify, NULL, &sig));
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
index 84e796b97dc4..cb37ca83439b 100644
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -389,6 +389,10 @@ void TransactionView::changedAmount(const QString &amount)
 
 void TransactionView::exportClicked()
 {
+    if (!model || !model->getOptionsModel()) {
+        return;
+    }
+
     // CSV is currently the only supported format
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Export Transaction History"), QString(),
diff --git a/src/random.cpp b/src/random.cpp
index b171b3dabfed..41146451c48e 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 73ce295ea418..71f5d00af0d2 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1229,7 +1229,7 @@ UniValue gettxout(const JSONRPCRequest& request)
     if (fMempool) {
         LOCK(mempool.cs);
         CCoinsViewMemPool view(pcoinsTip, mempool);
-        if (!view.GetCoin(out, coin) || mempool.isSpent(out)) { // TODO: filtering spent coins should be done by the CCoinsViewMemPool
+        if (!view.GetCoin(out, coin) || mempool.isSpent(out)) {
             return NullUniValue;
         }
     } else {
diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 0baf44eaab08..10ca11922859 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -101,6 +101,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "listunspent", 3, "include_unsafe" },
     { "listunspent", 4, "query_options" },
     { "getblock", 1, "verbosity" },
+    { "getblock", 1, "verbose" },
     { "getblockheader", 1, "verbose" },
     { "getblockheaders", 1, "count" },
     { "getblockheaders", 2, "verbose" },
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index ef886dbc1b7c..4e98a61ee197 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -335,6 +335,14 @@ UniValue validateaddress(const JSONRPCRequest& request)
             "  \"ismine\" : true|false,        (boolean) If the address is yours or not\n"
             "  \"iswatchonly\" : true|false,   (boolean) If the address is watchonly\n"
             "  \"isscript\" : true|false,      (boolean) If the key is a script\n"
+            "  \"script\" : \"type\"             (string, optional) The output script type. Possible types: nonstandard, pubkey, pubkeyhash, scripthash, multisig, nulldata\n"
+            "  \"hex\" : \"hex\",                (string, optional) The redeemscript for the p2sh address\n"
+            "  \"addresses\"                   (string, optional) Array of addresses associated with the known redeemscript\n"
+            "    [\n"
+            "      \"address\"\n"
+            "      ,...\n"
+            "    ]\n"
+            "  \"sigsrequired\" : xxxxx        (numeric, optional) Number of signatures required to spend multisig output\n"
             "  \"pubkey\" : \"publickeyhex\",    (string) The hex value of the raw public key\n"
             "  \"iscompressed\" : true|false,  (boolean) If the address is compressed\n"
             "  \"account\" : \"account\"         (string) DEPRECATED. The account associated with the address, \"\" is the default account\n"
diff --git a/src/serialize.h b/src/serialize.h
index 6afb0677d445..e02903c7a0de 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -630,7 +630,7 @@ class LimitedString
         }
         string.resize(size);
         if (size != 0)
-            s.read((char*)&string[0], size);
+            s.read((char*)string.data(), size);
     }
 
     template<typename Stream>
@@ -638,7 +638,7 @@ class LimitedString
     {
         WriteCompactSize(s, string.size());
         if (!string.empty())
-            s.write((char*)&string[0], string.size());
+            s.write((char*)string.data(), string.size());
     }
 };
 
@@ -778,7 +778,7 @@ void Serialize(Stream& os, const std::basic_string<C>& str)
 {
     WriteCompactSize(os, str.size());
     if (!str.empty())
-        os.write((char*)&str[0], str.size() * sizeof(str[0]));
+        os.write((char*)str.data(), str.size() * sizeof(C));
 }
 
 template<typename Stream, typename C>
@@ -787,7 +787,7 @@ void Unserialize(Stream& is, std::basic_string<C>& str)
     unsigned int nSize = ReadCompactSize(is);
     str.resize(nSize);
     if (nSize != 0)
-        is.read((char*)&str[0], nSize * sizeof(str[0]));
+        is.read((char*)str.data(), nSize * sizeof(C));
 }
 
 
@@ -800,7 +800,7 @@ void Serialize_impl(Stream& os, const prevector<N, T>& v, const unsigned char&)
 {
     WriteCompactSize(os, v.size());
     if (!v.empty())
-        os.write((char*)&v[0], v.size() * sizeof(T));
+        os.write((char*)v.data(), v.size() * sizeof(T));
 }
 
 template<typename Stream, unsigned int N, typename T, typename V>
@@ -868,7 +868,7 @@ void Serialize_impl(Stream& os, const std::vector<T, A>& v, const unsigned char&
 {
     WriteCompactSize(os, v.size());
     if (!v.empty())
-        os.write((char*)&v[0], v.size() * sizeof(T));
+        os.write((char*)v.data(), v.size() * sizeof(T));
 }
 
 template<typename Stream, typename T, typename A, typename V>
diff --git a/src/streams.h b/src/streams.h
index 57fa9a879b3f..5611af103a7d 100644
--- a/src/streams.h
+++ b/src/streams.h
@@ -346,7 +346,7 @@ class CDataStream
     {
         // Special case: stream << stream concatenates like stream += stream
         if (!vch.empty())
-            s.write((char*)&vch[0], vch.size() * sizeof(vch[0]));
+            s.write((char*)vch.data(), vch.size() * sizeof(value_type));
     }
 
     template<typename T>
diff --git a/src/support/lockedpool.cpp b/src/support/lockedpool.cpp
index c5a49b68f194..ef477cf4e43e 100644
--- a/src/support/lockedpool.cpp
+++ b/src/support/lockedpool.cpp
@@ -148,9 +148,9 @@ class Win32LockedPageAllocator: public LockedPageAllocator
 {
 public:
     Win32LockedPageAllocator();
-    void* AllocateLocked(size_t len, bool *lockingSuccess);
-    void FreeLocked(void* addr, size_t len);
-    size_t GetLimit();
+    void* AllocateLocked(size_t len, bool *lockingSuccess) override;
+    void FreeLocked(void* addr, size_t len) override;
+    size_t GetLimit() override;
 private:
     size_t page_size;
 };
@@ -200,9 +200,9 @@ class PosixLockedPageAllocator: public LockedPageAllocator
 {
 public:
     PosixLockedPageAllocator();
-    void* AllocateLocked(size_t len, bool *lockingSuccess);
-    void FreeLocked(void* addr, size_t len);
-    size_t GetLimit();
+    void* AllocateLocked(size_t len, bool *lockingSuccess) override;
+    void FreeLocked(void* addr, size_t len) override;
+    size_t GetLimit() override;
 private:
     size_t page_size;
 };
diff --git a/src/test/allocator_tests.cpp b/src/test/allocator_tests.cpp
index 1c668590f003..72db4b8d2b68 100644
--- a/src/test/allocator_tests.cpp
+++ b/src/test/allocator_tests.cpp
@@ -131,7 +131,7 @@ class TestLockedPageAllocator: public LockedPageAllocator
 {
 public:
     TestLockedPageAllocator(int count_in, int lockedcount_in): count(count_in), lockedcount(lockedcount_in) {}
-    void* AllocateLocked(size_t len, bool *lockingSuccess)
+    void* AllocateLocked(size_t len, bool *lockingSuccess) override
     {
         *lockingSuccess = false;
         if (count > 0) {
@@ -146,10 +146,10 @@ class TestLockedPageAllocator: public LockedPageAllocator
         }
         return 0;
     }
-    void FreeLocked(void* addr, size_t len)
+    void FreeLocked(void* addr, size_t len) override
     {
     }
-    size_t GetLimit()
+    size_t GetLimit() override
     {
         return std::numeric_limits<size_t>::max();
     }
diff --git a/src/test/netbase_tests.cpp b/src/test/netbase_tests.cpp
index d0af22d1ff67..ef7c49aabfe4 100644
--- a/src/test/netbase_tests.cpp
+++ b/src/test/netbase_tests.cpp
@@ -5,6 +5,7 @@
 
 #include "netbase.h"
 #include "test/test_dash.h"
+#include "utilstrencodings.h"
 
 #include <string>
 
diff --git a/src/torcontrol.cpp b/src/torcontrol.cpp
index 0f6e11a2eab3..b7c07f17f492 100644
--- a/src/torcontrol.cpp
+++ b/src/torcontrol.cpp
@@ -663,7 +663,7 @@ void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorContro
                 // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), boost::bind(&TorController::auth_cb, this, _1, _2));
                 cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
                 clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
-                GetRandBytes(&clientNonce[0], TOR_NONCE_SIZE);
+                GetRandBytes(clientNonce.data(), TOR_NONCE_SIZE);
                 _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), boost::bind(&TorController::authchallenge_cb, this, _1, _2));
             } else {
                 if (status_cookie.first) {
diff --git a/src/txmempool.h b/src/txmempool.h
index 64f032534eaa..6b1e1f117dcf 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -657,13 +657,6 @@ class CTxMemPool
         return (mapTx.count(hash) != 0);
     }
 
-    bool exists(const COutPoint& outpoint) const
-    {
-        LOCK(cs);
-        auto it = mapTx.find(outpoint.hash);
-        return (it != mapTx.end() && outpoint.n < it->GetTx().vout.size());
-    }
-
     CTransactionRef get(const uint256& hash) const;
     TxMempoolInfo info(const uint256& hash) const;
     std::vector<TxMempoolInfo> infoAll() const;
@@ -717,6 +710,13 @@ class CTxMemPool
 /** 
  * CCoinsView that brings transactions from a memorypool into view.
  * It does not check for spendings by memory pool transactions.
+ * Instead, it provides access to all Coins which are either unspent in the
+ * base CCoinsView, or are outputs from any mempool transaction!
+ * This allows transaction replacement to work as expected, as you want to
+ * have all inputs "available" to check signatures, and any cycles in the
+ * dependency graph are checked directly in AcceptToMemoryPool.
+ * It also allows you to sign a double-spend directly in signrawtransaction,
+ * as long as the conflicting transaction is not yet confirmed.
  */
 class CCoinsViewMemPool : public CCoinsViewBacked
 {
diff --git a/src/utilstrencodings.cpp b/src/utilstrencodings.cpp
index 339f805b794f..9e67aba6e7db 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+/";
@@ -228,7 +247,7 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
 std::string DecodeBase64(const std::string& str)
 {
     std::vector<unsigned char> vchRet = DecodeBase64(str.c_str());
-    return (vchRet.size() == 0) ? std::string() : std::string((const char*)&vchRet[0], vchRet.size());
+    return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
 std::string EncodeBase32(const unsigned char* pch, size_t len)
@@ -415,7 +434,7 @@ std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
 std::string DecodeBase32(const std::string& str)
 {
     std::vector<unsigned char> vchRet = DecodeBase32(str.c_str());
-    return (vchRet.size() == 0) ? std::string() : std::string((const char*)&vchRet[0], vchRet.size());
+    return std::string((const char*)vchRet.data(), vchRet.size());
 }
 
 static bool ParsePrechecks(const std::string& str)
diff --git a/src/utilstrencodings.h b/src/utilstrencodings.h
index a35cea289caf..94981127d562 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/validation.cpp b/src/validation.cpp
index b3ccadc4b1a5..d90c622feb5b 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -734,24 +734,20 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         CCoinsViewMemPool viewMemPool(pcoinsTip, pool);
         view.SetBackend(viewMemPool);
 
-        // do we already have it?
-        for (size_t out = 0; out < tx.vout.size(); out++) {
-            COutPoint outpoint(hash, out);
-            bool had_coin_in_cache = pcoinsTip->HaveCoinInCache(outpoint);
-            if (view.HaveCoin(outpoint)) {
-                if (!had_coin_in_cache) {
-                    coins_to_uncache.push_back(outpoint);
-                }
-                return state.Invalid(false, REJECT_DUPLICATE, "txn-already-known");
-            }
-        }
-
         // do all inputs exist?
         for (const CTxIn txin : tx.vin) {
             if (!pcoinsTip->HaveCoinInCache(txin.prevout)) {
                 coins_to_uncache.push_back(txin.prevout);
             }
             if (!view.HaveCoin(txin.prevout)) {
+                // Are inputs missing because we already have the tx?
+                for (size_t out = 0; out < tx.vout.size(); out++) {
+                    // Optimistically just do efficient check of cache for outputs
+                    if (pcoinsTip->HaveCoinInCache(COutPoint(hash, out))) {
+                        return state.Invalid(false, REJECT_DUPLICATE, "txn-already-known");
+                    }
+                }
+                // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet
                 if (pfMissingInputs) {
                     *pfMissingInputs = true;
                 }
@@ -1314,7 +1310,7 @@ static void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
     // hash rate operating on the fork.
     // We define it this way because it allows us to only store the highest fork tip (+ base) which meets
     // the 7-block condition and from this always have the most-likely-to-cause-warning fork
-    if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
+    if (pfork && (!pindexBestForkTip || pindexNewForkTip->nHeight > pindexBestForkTip->nHeight) &&
             pindexNewForkTip->nChainWork - pfork->nChainWork > (GetBlockProof(*pfork) * 7) &&
             chainActive.Height() - pindexNewForkTip->nHeight < 72)
     {
diff --git a/src/wallet/db.h b/src/wallet/db.h
index a5ac3bf93720..d1f4c633553c 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -95,13 +95,13 @@ class CWalletDBWrapper
     friend class CDB;
 public:
     /** Create dummy DB handle */
-    CWalletDBWrapper() : nLastSeen(0), nLastFlushed(0), nLastWalletUpdate(0), env(nullptr)
+    CWalletDBWrapper() : nUpdateCounter(0), nLastSeen(0), nLastFlushed(0), nLastWalletUpdate(0), env(nullptr)
     {
     }
 
     /** Create DB handle to real database */
     CWalletDBWrapper(CDBEnv *env_in, const std::string &strFile_in) :
-        nLastSeen(0), nLastFlushed(0), nLastWalletUpdate(0), env(env_in), strFile(strFile_in)
+        nUpdateCounter(0), nLastSeen(0), nLastFlushed(0), nLastWalletUpdate(0), env(env_in), strFile(strFile_in)
     {
     }
 
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index fe72bfe93de9..6d0362c7ba74 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -363,7 +363,7 @@ UniValue removeprunedfunds(const JSONRPCRequest& request)
             "\nExamples:\n"
             + HelpExampleCli("removeprunedfunds", "\"a8d0c0184dde994a09ec054286f1ce581bebf46446a512166eae7628734ea0a5\"") +
             "\nAs a JSON-RPC call\n"
-            + HelpExampleRpc("removprunedfunds", "\"a8d0c0184dde994a09ec054286f1ce581bebf46446a512166eae7628734ea0a5\"")
+            + HelpExampleRpc("removeprunedfunds", "\"a8d0c0184dde994a09ec054286f1ce581bebf46446a512166eae7628734ea0a5\"")
         );
 
     LOCK2(cs_main, pwallet->cs_wallet);
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 2cbb0ce52ee9..00b78daf518b 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -767,9 +767,9 @@ 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/wallet.cpp b/src/wallet/wallet.cpp
index 7b659b92a0b5..58b8b69d0e5b 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -5131,20 +5131,24 @@ bool CWallet::ParameterInteraction()
         LogPrintf("%s: parameter interaction: -blocksonly=1 -> setting -walletbroadcast=0\n", __func__);
     }
 
-    if (gArgs.GetBoolArg("-salvagewallet", false) && gArgs.SoftSetBoolArg("-rescan", true)) {
+    if (gArgs.GetBoolArg("-salvagewallet", false)) {
         if (is_multiwallet) {
             return InitError(strprintf("%s is only allowed with a single wallet file", "-salvagewallet"));
         }
         // Rewrite just private keys: rescan to find transactions
-        LogPrintf("%s: parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
+        if (gArgs.SoftSetBoolArg("-rescan", true)) {
+            LogPrintf("%s: parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
+        }
     }
 
     // -zapwallettx implies a rescan
-    if (gArgs.GetBoolArg("-zapwallettxes", false) && gArgs.SoftSetBoolArg("-rescan", true)) {
+    if (gArgs.GetBoolArg("-zapwallettxes", false)) {
         if (is_multiwallet) {
             return InitError(strprintf("%s is only allowed with a single wallet file", "-zapwallettxes"));
         }
-        LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> setting -rescan=1\n", __func__);
+        if (gArgs.SoftSetBoolArg("-rescan", true)) {
+            LogPrintf("%s: parameter interaction: -zapwallettxes=<mode> -> setting -rescan=1\n", __func__);
+        }
     }
 
     if (is_multiwallet) {
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 49edb91d2fa9..face9a01491f 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -782,7 +782,7 @@ DBErrors CWalletDB::ZapWalletTx(std::vector<CWalletTx>& vWtx)
 
 void MaybeCompactWalletDB()
 {
-    static std::atomic<bool> fOneThread;
+    static std::atomic<bool> fOneThread(false);
     if (fOneThread.exchange(true)) {
         return;
     }
diff --git a/test/functional/getblocktemplate_proposals.py b/test/functional/getblocktemplate_proposals.py
deleted file mode 100755
index fca99c7df571..000000000000
--- a/test/functional/getblocktemplate_proposals.py
+++ /dev/null
@@ -1,157 +0,0 @@
-#!/usr/bin/env python3
-# Copyright (c) 2014-2016 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
-"""Test block proposals with getblocktemplate."""
-
-from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-
-from binascii import a2b_hex, b2a_hex
-from hashlib import sha256
-from struct import pack
-
-def b2x(b):
-    return b2a_hex(b).decode('ascii')
-
-# NOTE: This does not work for signed numbers (set the high bit) or zero (use b'\0')
-def encodeUNum(n):
-    s = bytearray(b'\1')
-    while n > 127:
-        s[0] += 1
-        s.append(n % 256)
-        n //= 256
-    s.append(n)
-    return bytes(s)
-
-def varlenEncode(n):
-    if n < 0xfd:
-        return pack('<B', n)
-    if n <= 0xffff:
-        return b'\xfd' + pack('<H', n)
-    if n <= 0xffffffff:
-        return b'\xfe' + pack('<L', n)
-    return b'\xff' + pack('<Q', n)
-
-def dblsha(b):
-    return sha256(sha256(b).digest()).digest()
-
-def genmrklroot(leaflist):
-    cur = leaflist
-    while len(cur) > 1:
-        n = []
-        if len(cur) & 1:
-            cur.append(cur[-1])
-        for i in range(0, len(cur), 2):
-            n.append(dblsha(cur[i] + cur[i+1]))
-        cur = n
-    return cur[0]
-
-def template_to_bytearray(tmpl, txlist):
-    blkver = pack('<L', tmpl['version'])
-    mrklroot = genmrklroot(list(dblsha(a) for a in txlist))
-    timestamp = pack('<L', tmpl['curtime'])
-    nonce = b'\0\0\0\0'
-    blk = blkver + a2b_hex(tmpl['previousblockhash'])[::-1] + mrklroot + timestamp + a2b_hex(tmpl['bits'])[::-1] + nonce
-    blk += varlenEncode(len(txlist))
-    for tx in txlist:
-        blk += tx
-    return bytearray(blk)
-
-def template_to_hex(tmpl, txlist):
-    return b2x(template_to_bytearray(tmpl, txlist))
-
-def assert_template(node, tmpl, txlist, expect):
-    rsp = node.getblocktemplate({'data':template_to_hex(tmpl, txlist),'mode':'proposal'})
-    if rsp != expect:
-        raise AssertionError('unexpected: %s' % (rsp,))
-
-class GetBlockTemplateProposalTest(BitcoinTestFramework):
-
-    def __init__(self):
-        super().__init__()
-        self.num_nodes = 2
-        self.setup_clean_chain = False
-
-    def run_test(self):
-        node = self.nodes[0]
-        node.generate(1) # Mine a block to leave initial block download
-        tmpl = node.getblocktemplate()
-        if 'coinbasetxn' not in tmpl:
-            rawcoinbase = encodeUNum(tmpl['height'])
-            rawcoinbase += b'\x01-'
-            hexcoinbase = b2x(rawcoinbase)
-            hexoutval = b2x(pack('<Q', tmpl['coinbasevalue']))
-            tmpl['coinbasetxn'] = {'data': '01000000' + '01' + '0000000000000000000000000000000000000000000000000000000000000000ffffffff' + ('%02x' % (len(rawcoinbase),)) + hexcoinbase + 'fffffffe' + '01' + hexoutval + '00' + '00000000'}
-        txlist = list(bytearray(a2b_hex(a['data'])) for a in (tmpl['coinbasetxn'],) + tuple(tmpl['transactions']))
-
-        # Test 0: Capability advertised
-        assert('proposal' in tmpl['capabilities'])
-
-        # NOTE: This test currently FAILS (regtest mode doesn't enforce block height in coinbase)
-        ## Test 1: Bad height in coinbase
-        #txlist[0][4+1+36+1+1] += 1
-        #assert_template(node, tmpl, txlist, 'FIXME')
-        #txlist[0][4+1+36+1+1] -= 1
-
-        # Test 2: Bad input hash for gen tx
-        txlist[0][4+1] += 1
-        assert_template(node, tmpl, txlist, 'bad-cb-missing')
-        txlist[0][4+1] -= 1
-
-        # Test 3: Truncated final tx
-        lastbyte = txlist[-1].pop()
-        assert_raises_jsonrpc(-22, "Block decode failed", assert_template, node, tmpl, txlist, 'n/a')
-        txlist[-1].append(lastbyte)
-
-        # Test 4: Add an invalid tx to the end (duplicate of gen tx)
-        txlist.append(txlist[0])
-        assert_template(node, tmpl, txlist, 'bad-txns-duplicate')
-        txlist.pop()
-
-        # Test 5: Add an invalid tx to the end (non-duplicate)
-        txlist.append(bytearray(txlist[0]))
-        txlist[-1][4+1] = 0xff
-        assert_template(node, tmpl, txlist, 'bad-txns-inputs-missingorspent')
-        txlist.pop()
-
-        # Test 6: Future tx lock time
-        txlist[0][-4:] = b'\xff\xff\xff\xff'
-        assert_template(node, tmpl, txlist, 'bad-txns-nonfinal')
-        txlist[0][-4:] = b'\0\0\0\0'
-
-        # Test 7: Bad tx count
-        txlist.append(b'')
-        assert_raises_jsonrpc(-22, 'Block decode failed', assert_template, node, tmpl, txlist, 'n/a')
-        txlist.pop()
-
-        # Test 8: Bad bits
-        realbits = tmpl['bits']
-        tmpl['bits'] = '1c0000ff'  # impossible in the real world
-        assert_template(node, tmpl, txlist, 'bad-diffbits')
-        tmpl['bits'] = realbits
-
-        # Test 9: Bad merkle root
-        rawtmpl = template_to_bytearray(tmpl, txlist)
-        rawtmpl[4+32] = (rawtmpl[4+32] + 1) % 0x100
-        rsp = node.getblocktemplate({'data':b2x(rawtmpl),'mode':'proposal'})
-        if rsp != 'bad-txnmrklroot':
-            raise AssertionError('unexpected: %s' % (rsp,))
-
-        # Test 10: Bad timestamps
-        realtime = tmpl['curtime']
-        tmpl['curtime'] = 0x7fffffff
-        assert_template(node, tmpl, txlist, 'time-too-new')
-        tmpl['curtime'] = 0
-        assert_template(node, tmpl, txlist, 'time-too-old')
-        tmpl['curtime'] = realtime
-
-        # Test 11: Valid block
-        assert_template(node, tmpl, txlist, None)
-
-        # Test 12: Orphan block
-        tmpl['previousblockhash'] = 'ff00' * 16
-        assert_template(node, tmpl, txlist, 'inconclusive-not-best-prevblk')
-
-if __name__ == '__main__':
-    GetBlockTemplateProposalTest().main()
diff --git a/test/functional/mining.py b/test/functional/mining.py
new file mode 100755
index 000000000000..dbd4e29ecae8
--- /dev/null
+++ b/test/functional/mining.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+# Copyright (c) 2014-2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test mining RPCs
+
+- getblocktemplate proposal mode
+- submitblock"""
+
+from binascii import b2a_hex
+import copy
+
+from test_framework.blocktools import create_coinbase
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.mininode import CBlock
+from test_framework.util import *
+
+def b2x(b):
+    return b2a_hex(b).decode('ascii')
+
+def assert_template(node, block, expect, rehash=True):
+    if rehash:
+        block.hashMerkleRoot = block.calc_merkle_root()
+    rsp = node.getblocktemplate({'data': b2x(block.serialize()), 'mode': 'proposal'})
+    assert_equal(rsp, expect)
+
+class MiningTest(BitcoinTestFramework):
+
+    def __init__(self):
+        super().__init__()
+        self.num_nodes = 2
+        self.setup_clean_chain = False
+
+    def run_test(self):
+        node = self.nodes[0]
+        # Mine a block to leave initial block download
+        node.generate(1)
+        tmpl = node.getblocktemplate()
+        self.log.info("getblocktemplate: Test capability advertised")
+        assert 'proposal' in tmpl['capabilities']
+        assert 'coinbasetxn' not in tmpl
+
+        coinbase_tx = create_coinbase(height=int(tmpl["height"]) + 1)
+        # sequence numbers must not be max for nLockTime to have effect
+        coinbase_tx.vin[0].nSequence = 2 ** 32 - 2
+        coinbase_tx.rehash()
+
+        block = CBlock()
+        block.nVersion = tmpl["version"]
+        block.hashPrevBlock = int(tmpl["previousblockhash"], 16)
+        block.nTime = tmpl["curtime"]
+        block.nBits = int(tmpl["bits"], 16)
+        block.nNonce = 0
+        block.vtx = [coinbase_tx]
+
+        self.log.info("getblocktemplate: Test valid block")
+        assert_template(node, block, None)
+
+        self.log.info("submitblock: Test block decode failure")
+        assert_raises_jsonrpc(-22, "Block decode failed", node.submitblock, b2x(block.serialize()[:-15]))
+
+        self.log.info("getblocktemplate: Test bad input hash for coinbase transaction")
+        bad_block = copy.deepcopy(block)
+        bad_block.vtx[0].vin[0].prevout.hash += 1
+        bad_block.vtx[0].rehash()
+        assert_template(node, bad_block, 'bad-cb-missing')
+
+        self.log.info("submitblock: Test invalid coinbase transaction")
+        assert_raises_jsonrpc(-22, "Block does not start with a coinbase", node.submitblock, b2x(bad_block.serialize()))
+
+        self.log.info("getblocktemplate: Test truncated final transaction")
+        assert_raises_jsonrpc(-22, "Block decode failed", node.getblocktemplate, {'data': b2x(block.serialize()[:-1]), 'mode': 'proposal'})
+
+        self.log.info("getblocktemplate: Test duplicate transaction")
+        bad_block = copy.deepcopy(block)
+        bad_block.vtx.append(bad_block.vtx[0])
+        assert_template(node, bad_block, 'bad-txns-duplicate')
+
+        self.log.info("getblocktemplate: Test invalid transaction")
+        bad_block = copy.deepcopy(block)
+        bad_tx = copy.deepcopy(bad_block.vtx[0])
+        bad_tx.vin[0].prevout.hash = 255
+        bad_tx.rehash()
+        bad_block.vtx.append(bad_tx)
+        assert_template(node, bad_block, 'bad-txns-inputs-missingorspent')
+
+        self.log.info("getblocktemplate: Test nonfinal transaction")
+        bad_block = copy.deepcopy(block)
+        bad_block.vtx[0].nLockTime = 2 ** 32 - 1
+        bad_block.vtx[0].rehash()
+        assert_template(node, bad_block, 'bad-txns-nonfinal')
+
+        self.log.info("getblocktemplate: Test bad tx count")
+        # The tx count is immediately after the block header
+        TX_COUNT_OFFSET = 80
+        bad_block_sn = bytearray(block.serialize())
+        assert_equal(bad_block_sn[TX_COUNT_OFFSET], 1)
+        bad_block_sn[TX_COUNT_OFFSET] += 1
+        assert_raises_jsonrpc(-22, "Block decode failed", node.getblocktemplate, {'data': b2x(bad_block_sn), 'mode': 'proposal'})
+
+        self.log.info("getblocktemplate: Test bad bits")
+        bad_block = copy.deepcopy(block)
+        bad_block.nBits = 469762303  # impossible in the real world
+        assert_template(node, bad_block, 'bad-diffbits')
+
+        self.log.info("getblocktemplate: Test bad merkle root")
+        bad_block = copy.deepcopy(block)
+        bad_block.hashMerkleRoot += 1
+        assert_template(node, bad_block, 'bad-txnmrklroot', False)
+
+        self.log.info("getblocktemplate: Test bad timestamps")
+        bad_block = copy.deepcopy(block)
+        bad_block.nTime = 2 ** 31 - 1
+        assert_template(node, bad_block, 'time-too-new')
+        bad_block.nTime = 0
+        assert_template(node, bad_block, 'time-too-old')
+
+        self.log.info("getblocktemplate: Test not best block")
+        bad_block = copy.deepcopy(block)
+        bad_block.hashPrevBlock = 123
+        assert_template(node, bad_block, 'inconclusive-not-best-prevblk')
+
+if __name__ == '__main__':
+    MiningTest().main()
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 88281d04aa85..1983d9bb268a 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -119,6 +119,7 @@
     'signmessages.py',
     'nulldummy.py',
     'import-rescan.py',
+    'mining.py',
     'rpcnamedargs.py',
     'listsinceblock.py',
     'p2p-leaktests.py',
@@ -152,7 +153,6 @@
     'bipdersig-p2p.py', # NOTE: needs dash_hash to pass
     'bipdersig.py',
     'example_test.py',
-    'getblocktemplate_proposals.py',
     'txn_doublespend.py',
     'txn_clone.py --mineblock',
     'txindex.py',