diff --git a/contrib/init/dashd.service b/contrib/init/dashd.service
index a256c6a03a02..ea4548dfb2fd 100644
--- a/contrib/init/dashd.service
+++ b/contrib/init/dashd.service
@@ -1,22 +1,25 @@
+# It is not recommended to modify this file in-place, because it will
+# be overwritten during package upgrades. If you want to add further
+# options or overwrite existing ones then use
+# $ systemctl edit dashd.service
+# See "man systemd.service" for details.
+
+# Note that almost all daemon options could be specified in
+# /etc/dash/dash.conf
+
 [Unit]
-Description=Dash's distributed currency daemon
+Description=Dash daemon
 After=network.target
 
 [Service]
+ExecStart=/usr/bin/dashd -daemon -conf=/etc/dash/dash.conf -pid=/run/dashd/dashd.pid
+# Creates /run/dash owned by dashcore
+RuntimeDirectory=dashd
 User=dashcore
-Group=dashcore
-
 Type=forking
-PIDFile=/var/lib/dashd/dashd.pid
-ExecStart=/usr/bin/dashd -daemon -pid=/var/lib/dashd/dashd.pid \
--conf=/etc/dashcore/dash.conf -datadir=/var/lib/dashd -disablewallet
-
-Restart=always
+PIDFile=/run/dashd/dashd.pid
+Restart=on-failure
 PrivateTmp=true
-TimeoutStopSec=60s
-TimeoutStartSec=2s
-StartLimitInterval=120s
-StartLimitBurst=5
 
 [Install]
 WantedBy=multi-user.target
diff --git a/src/Makefile.am b/src/Makefile.am
index c3243fcb9c3e..1b9664675932 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -669,11 +669,10 @@ CLEANFILES += univalue/*.gcda univalue/*.gcno
 CLEANFILES += wallet/*.gcda wallet/*.gcno
 CLEANFILES += wallet/test/*.gcda wallet/test/*.gcno
 CLEANFILES += zmq/*.gcda zmq/*.gcno
+CLEANFILES += obj/build.h
 
 IMMER_DIST = immer
 
-DISTCLEANFILES = obj/build.h
-
 EXTRA_DIST = $(CTAES_DIST)
 EXTRA_DIST += $(IMMER_DIST)
 
diff --git a/src/Makefile.bench.include b/src/Makefile.bench.include
index 8f08f5e2b577..20192f9fed9f 100644
--- a/src/Makefile.bench.include
+++ b/src/Makefile.bench.include
@@ -7,11 +7,12 @@ bin_PROGRAMS += bench/bench_dash
 BENCH_SRCDIR = bench
 BENCH_BINARY = bench/bench_dash$(EXEEXT)
 
-RAW_TEST_FILES = \
+RAW_BENCH_FILES = \
   bench/data/block813851.raw
-GENERATED_TEST_FILES = $(RAW_TEST_FILES:.raw=.raw.h)
+GENERATED_BENCH_FILES = $(RAW_BENCH_FILES:.raw=.raw.h)
 
 bench_bench_dash_SOURCES = \
+  $(RAW_BENCH_FILES) \
   bench/bench_dash.cpp \
   bench/bench.cpp \
   bench/bench.h \
@@ -36,7 +37,7 @@ bench_bench_dash_SOURCES = \
   bench/prevector.cpp \
   bench/string_cast.cpp
 
-nodist_bench_bench_dash_SOURCES = $(GENERATED_TEST_FILES)
+nodist_bench_bench_dash_SOURCES = $(GENERATED_BENCH_FILES)
 
 bench_bench_dash_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(EVENT_CLFAGS) $(EVENT_PTHREADS_CFLAGS) -I$(builddir)/bench/
 bench_bench_dash_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
@@ -64,7 +65,7 @@ endif
 bench_bench_dash_LDADD += $(BACKTRACE_LIB) $(BOOST_LIBS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(BLS_LIBS)
 bench_bench_dash_LDFLAGS = $(LDFLAGS_WRAP_EXCEPTIONS) $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
-CLEAN_BITCOIN_BENCH = bench/*.gcda bench/*.gcno $(GENERATED_TEST_FILES)
+CLEAN_BITCOIN_BENCH = bench/*.gcda bench/*.gcno $(GENERATED_BENCH_FILES)
 
 CLEANFILES += $(CLEAN_BITCOIN_BENCH)
 
diff --git a/src/arith_uint256.h b/src/arith_uint256.h
index 0ee4cf9622d8..89a5272f1f9f 100644
--- a/src/arith_uint256.h
+++ b/src/arith_uint256.h
@@ -25,7 +25,7 @@ template<unsigned int BITS>
 class base_uint
 {
 protected:
-    enum { WIDTH=BITS/32 };
+    static constexpr int WIDTH = BITS / 32;
     uint32_t pn[WIDTH];
 public:
 
diff --git a/src/chain.h b/src/chain.h
index f29580e7fbdc..4e3bbbad2d7b 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -304,7 +304,7 @@ class CBlockIndex
         return (int64_t)nTimeMax;
     }
 
-    enum { nMedianTimeSpan=11 };
+    static constexpr int nMedianTimeSpan = 11;
 
     int64_t GetMedianTimePast() const
     {
diff --git a/src/coins.cpp b/src/coins.cpp
index 4023cdeb95e3..c7365b2774b8 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -146,56 +146,58 @@ void CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) {
 }
 
 bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn) {
-    for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
-        if (it->second.flags & CCoinsCacheEntry::DIRTY) { // Ignore non-dirty entries (optimization).
-            CCoinsMap::iterator itUs = cacheCoins.find(it->first);
-            if (itUs == cacheCoins.end()) {
-                // The parent cache does not have an entry, while the child does
-                // We can ignore it if it's both FRESH and pruned in the child
-                if (!(it->second.flags & CCoinsCacheEntry::FRESH && it->second.coin.IsSpent())) {
-                    // Otherwise we will need to create it in the parent
-                    // and move the data up and mark it as dirty
-                    CCoinsCacheEntry& entry = cacheCoins[it->first];
-                    entry.coin = std::move(it->second.coin);
-                    cachedCoinsUsage += entry.coin.DynamicMemoryUsage();
-                    entry.flags = CCoinsCacheEntry::DIRTY;
-                    // We can mark it FRESH in the parent if it was FRESH in the child
-                    // Otherwise it might have just been flushed from the parent's cache
-                    // and already exist in the grandparent
-                    if (it->second.flags & CCoinsCacheEntry::FRESH)
-                        entry.flags |= CCoinsCacheEntry::FRESH;
+    for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end(); it = mapCoins.erase(it)) {
+        // Ignore non-dirty entries (optimization).
+        if (!(it->second.flags & CCoinsCacheEntry::DIRTY)) {
+            continue;
+        }
+        CCoinsMap::iterator itUs = cacheCoins.find(it->first);
+        if (itUs == cacheCoins.end()) {
+            // The parent cache does not have an entry, while the child does
+            // We can ignore it if it's both FRESH and pruned in the child
+            if (!(it->second.flags & CCoinsCacheEntry::FRESH && it->second.coin.IsSpent())) {
+                // Otherwise we will need to create it in the parent
+                // and move the data up and mark it as dirty
+                CCoinsCacheEntry& entry = cacheCoins[it->first];
+                entry.coin = std::move(it->second.coin);
+                cachedCoinsUsage += entry.coin.DynamicMemoryUsage();
+                entry.flags = CCoinsCacheEntry::DIRTY;
+                // We can mark it FRESH in the parent if it was FRESH in the child
+                // Otherwise it might have just been flushed from the parent's cache
+                // and already exist in the grandparent
+                if (it->second.flags & CCoinsCacheEntry::FRESH) {
+                    entry.flags |= CCoinsCacheEntry::FRESH;
                 }
-            } else {
-                // Assert that the child cache entry was not marked FRESH if the
-                // parent cache entry has unspent outputs. If this ever happens,
-                // it means the FRESH flag was misapplied and there is a logic
-                // error in the calling code.
-                if ((it->second.flags & CCoinsCacheEntry::FRESH) && !itUs->second.coin.IsSpent())
-                    throw std::logic_error("FRESH flag misapplied to cache entry for base transaction with spendable outputs");
+            }
+        } else {
+            // Assert that the child cache entry was not marked FRESH if the
+            // parent cache entry has unspent outputs. If this ever happens,
+            // it means the FRESH flag was misapplied and there is a logic
+            // error in the calling code.
+            if ((it->second.flags & CCoinsCacheEntry::FRESH) && !itUs->second.coin.IsSpent()) {
+                throw std::logic_error("FRESH flag misapplied to cache entry for base transaction with spendable outputs");
+            }
 
-                // Found the entry in the parent cache
-                if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coin.IsSpent()) {
-                    // The grandparent does not have an entry, and the child is
-                    // modified and being pruned. This means we can just delete
-                    // it from the parent.
-                    cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
-                    cacheCoins.erase(itUs);
-                } else {
-                    // A normal modification.
-                    cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
-                    itUs->second.coin = std::move(it->second.coin);
-                    cachedCoinsUsage += itUs->second.coin.DynamicMemoryUsage();
-                    itUs->second.flags |= CCoinsCacheEntry::DIRTY;
-                    // NOTE: It is possible the child has a FRESH flag here in
-                    // the event the entry we found in the parent is pruned. But
-                    // we must not copy that FRESH flag to the parent as that
-                    // pruned state likely still needs to be communicated to the
-                    // grandparent.
-                }
+            // Found the entry in the parent cache
+            if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coin.IsSpent()) {
+                // The grandparent does not have an entry, and the child is
+                // modified and being pruned. This means we can just delete
+                // it from the parent.
+                cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
+                cacheCoins.erase(itUs);
+            } else {
+                // A normal modification.
+                cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
+                itUs->second.coin = std::move(it->second.coin);
+                cachedCoinsUsage += itUs->second.coin.DynamicMemoryUsage();
+                itUs->second.flags |= CCoinsCacheEntry::DIRTY;
+                // NOTE: It is possible the child has a FRESH flag here in
+                // the event the entry we found in the parent is pruned. But
+                // we must not copy that FRESH flag to the parent as that
+                // pruned state likely still needs to be communicated to the
+                // grandparent.
             }
         }
-        CCoinsMap::iterator itOld = it++;
-        mapCoins.erase(itOld);
     }
     hashBlock = hashBlockIn;
     return true;
diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h
index 0efe580c1e08..cd631168f3cb 100644
--- a/src/consensus/consensus.h
+++ b/src/consensus/consensus.h
@@ -24,12 +24,9 @@ static const unsigned int MAX_TX_EXTRA_PAYLOAD = 10000;
 static const int COINBASE_MATURITY = 100;
 
 /** Flags for nSequence and nLockTime locks */
-enum {
-    /* Interpret sequence numbers as relative lock-time constraints. */
-    LOCKTIME_VERIFY_SEQUENCE = (1 << 0),
-
-    /* Use GetMedianTimePast() instead of nTime for end point timestamp. */
-    LOCKTIME_MEDIAN_TIME_PAST = (1 << 1),
-};
+/** Interpret sequence numbers as relative lock-time constraints. */
+static constexpr unsigned int LOCKTIME_VERIFY_SEQUENCE = (1 << 0);
+/** Use GetMedianTimePast() instead of nTime for end point timestamp. */
+static constexpr unsigned int LOCKTIME_MEDIAN_TIME_PAST = (1 << 1);
 
 #endif // BITCOIN_CONSENSUS_CONSENSUS_H
diff --git a/src/init.cpp b/src/init.cpp
index 542c64580899..d5efb219e17c 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -2189,9 +2189,15 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
     // ********************************************************* Step 12: start node
 
+    int chain_active_height;
+
     //// debug print
-    LogPrintf("mapBlockIndex.size() = %u\n",   mapBlockIndex.size());
-    LogPrintf("chainActive.Height() = %d\n",   chainActive.Height());
+    {
+        LOCK(cs_main);
+        LogPrintf("mapBlockIndex.size() = %u\n", mapBlockIndex.size());
+        chain_active_height = chainActive.Height();
+    }
+    LogPrintf("chainActive.Height() = %d\n",   chain_active_height);
     if (gArgs.GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION))
         StartTorControl(threadGroup, scheduler);
 
@@ -2206,7 +2212,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
     connOptions.nMaxOutbound = std::min(MAX_OUTBOUND_CONNECTIONS, connOptions.nMaxConnections);
     connOptions.nMaxAddnode = MAX_ADDNODE_CONNECTIONS;
     connOptions.nMaxFeeler = 1;
-    connOptions.nBestHeight = chainActive.Height();
+    connOptions.nBestHeight = chain_active_height;
     connOptions.uiInterface = &uiInterface;
     connOptions.m_msgproc = peerLogic.get();
     connOptions.nSendBufferMaxSize = 1000*gArgs.GetArg("-maxsendbuffer", DEFAULT_MAXSENDBUFFER);
diff --git a/src/net.cpp b/src/net.cpp
index c111a411ae13..4cf72c3ce8d7 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1007,6 +1007,16 @@ static bool CompareNodeTXTime(const NodeEvictionCandidate &a, const NodeEviction
     return a.nTimeConnected > b.nTimeConnected;
 }
 
+
+//! Sort an array by the specified comparator, then erase the last K elements.
+template<typename T, typename Comparator>
+static void EraseLastKElements(std::vector<T> &elements, Comparator comparator, size_t k)
+{
+    std::sort(elements.begin(), elements.end(), comparator);
+    size_t eraseSize = std::min(k, elements.size());
+    elements.erase(elements.end() - eraseSize, elements.end());
+}
+
 /** Try to find a connection to evict when the node is full.
  *  Extreme care must be taken to avoid opening the node to attacker
  *   triggered network partitioning.
@@ -1056,42 +1066,23 @@ bool CConnman::AttemptToEvictConnection()
         }
     }
 
-    if (vEvictionCandidates.empty()) return false;
-
     // Protect connections with certain characteristics
 
     // Deterministically select 4 peers to protect by netgroup.
     // An attacker cannot predict which netgroups will be protected
-    std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), CompareNetGroupKeyed);
-    vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
-
-    if (vEvictionCandidates.empty()) return false;
-
+    EraseLastKElements(vEvictionCandidates, CompareNetGroupKeyed, 4);
     // Protect the 8 nodes with the lowest minimum ping time.
     // An attacker cannot manipulate this metric without physically moving nodes closer to the target.
-    std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeMinPingTime);
-    vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(8, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
-
-    if (vEvictionCandidates.empty()) return false;
-
+    EraseLastKElements(vEvictionCandidates, ReverseCompareNodeMinPingTime, 8);
     // Protect 4 nodes that most recently sent us transactions.
     // An attacker cannot manipulate this metric without performing useful work.
-    std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), CompareNodeTXTime);
-    vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
-
-    if (vEvictionCandidates.empty()) return false;
-
+    EraseLastKElements(vEvictionCandidates, CompareNodeTXTime, 4);
     // Protect 4 nodes that most recently sent us blocks.
     // An attacker cannot manipulate this metric without performing useful work.
-    std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), CompareNodeBlockTime);
-    vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
-
-    if (vEvictionCandidates.empty()) return false;
-
+    EraseLastKElements(vEvictionCandidates, CompareNodeBlockTime, 4);
     // Protect the half of the remaining nodes which have been connected the longest.
     // This replicates the non-eviction implicit behavior, and precludes attacks that start later.
-    std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeTimeConnected);
-    vEvictionCandidates.erase(vEvictionCandidates.end() - static_cast<int>(vEvictionCandidates.size() / 2), vEvictionCandidates.end());
+    EraseLastKElements(vEvictionCandidates, ReverseCompareNodeTimeConnected, vEvictionCandidates.size() / 2);
 
     if (vEvictionCandidates.empty()) return false;
 
@@ -1102,12 +1093,12 @@ bool CConnman::AttemptToEvictConnection()
     int64_t nMostConnectionsTime = 0;
     std::map<uint64_t, std::vector<NodeEvictionCandidate> > mapNetGroupNodes;
     for (const NodeEvictionCandidate &node : vEvictionCandidates) {
-        mapNetGroupNodes[node.nKeyedNetGroup].push_back(node);
-        int64_t grouptime = mapNetGroupNodes[node.nKeyedNetGroup][0].nTimeConnected;
-        size_t groupsize = mapNetGroupNodes[node.nKeyedNetGroup].size();
+        std::vector<NodeEvictionCandidate> &group = mapNetGroupNodes[node.nKeyedNetGroup];
+        group.push_back(node);
+        int64_t grouptime = group[0].nTimeConnected;
 
-        if (groupsize > nMostConnections || (groupsize == nMostConnections && grouptime > nMostConnectionsTime)) {
-            nMostConnections = groupsize;
+        if (group.size() > nMostConnections || (group.size() == nMostConnections && grouptime > nMostConnectionsTime)) {
+            nMostConnections = group.size();
             nMostConnectionsTime = grouptime;
             naMostConnections = node.nKeyedNetGroup;
         }
@@ -3248,8 +3239,7 @@ CNode::~CNode()
 {
     CloseSocket(hSocket);
 
-    if (pfilter)
-        delete pfilter;
+    delete pfilter;
 }
 
 void CNode::AskFor(const CInv& inv, int64_t doubleRequestDelay)
diff --git a/src/protocol.h b/src/protocol.h
index 4bf0cdf00a69..25a3cc708fda 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -27,16 +27,13 @@
 class CMessageHeader
 {
 public:
-    enum {
-        MESSAGE_START_SIZE = 4,
-        COMMAND_SIZE = 12,
-        MESSAGE_SIZE_SIZE = 4,
-        CHECKSUM_SIZE = 4,
-
-        MESSAGE_SIZE_OFFSET = MESSAGE_START_SIZE + COMMAND_SIZE,
-        CHECKSUM_OFFSET = MESSAGE_SIZE_OFFSET + MESSAGE_SIZE_SIZE,
-        HEADER_SIZE = MESSAGE_START_SIZE + COMMAND_SIZE + MESSAGE_SIZE_SIZE + CHECKSUM_SIZE
-    };
+    static constexpr size_t MESSAGE_START_SIZE = 4;
+    static constexpr size_t COMMAND_SIZE = 12;
+    static constexpr size_t MESSAGE_SIZE_SIZE = 4;
+    static constexpr size_t CHECKSUM_SIZE = 4;
+    static constexpr size_t MESSAGE_SIZE_OFFSET = MESSAGE_START_SIZE + COMMAND_SIZE;
+    static constexpr size_t CHECKSUM_OFFSET = MESSAGE_SIZE_OFFSET + MESSAGE_SIZE_SIZE;
+    static constexpr size_t HEADER_SIZE = MESSAGE_START_SIZE + COMMAND_SIZE + MESSAGE_SIZE_SIZE + CHECKSUM_SIZE;
     typedef unsigned char MessageStartChars[MESSAGE_START_SIZE];
 
     explicit CMessageHeader(const MessageStartChars& pchMessageStartIn);
diff --git a/src/qt/forms/receivecoinsdialog.ui b/src/qt/forms/receivecoinsdialog.ui
index cc19bb21259c..ea953290411f 100644
--- a/src/qt/forms/receivecoinsdialog.ui
+++ b/src/qt/forms/receivecoinsdialog.ui
@@ -28,23 +28,6 @@
      <layout class="QVBoxLayout" name="verticalLayout_3">
       <item>
        <layout class="QGridLayout" name="gridLayout">
-        <item row="7" column="2">
-         <widget class="QCheckBox" name="reuseAddress">
-          <property name="toolTip">
-           <string>Reuse one of the previously used receiving addresses.&lt;br&gt;Reusing addresses has security and privacy issues.&lt;br&gt;Do not use this unless re-generating a payment request made before.</string>
-          </property>
-          <property name="text">
-           <string>R&amp;euse an existing receiving address (not recommended)</string>
-          </property>
-         </widget>
-        </item>
-        <item row="7" column="0">
-         <widget class="QLabel" name="label_4">
-          <property name="text">
-           <string/>
-          </property>
-         </widget>
-        </item>
         <item row="6" column="0">
          <widget class="QLabel" name="label_3">
           <property name="toolTip">
@@ -127,7 +110,7 @@
           </property>
          </widget>
         </item>
-        <item row="8" column="2">
+        <item row="7" column="2">
          <layout class="QHBoxLayout" name="horizontalLayout">
           <item>
            <widget class="QPushButton" name="receiveButton">
@@ -176,7 +159,7 @@
           </item>
          </layout>
         </item>
-        <item row="8" column="0">
+        <item row="7" column="0">
          <widget class="QLabel" name="label_7">
           <property name="text">
            <string/>
@@ -308,7 +291,6 @@
   <tabstop>reqLabel</tabstop>
   <tabstop>reqAmount</tabstop>
   <tabstop>reqMessage</tabstop>
-  <tabstop>reuseAddress</tabstop>
   <tabstop>receiveButton</tabstop>
   <tabstop>clearButton</tabstop>
   <tabstop>recentRequestsView</tabstop>
diff --git a/src/qt/forms/sendcoinsentry.ui b/src/qt/forms/sendcoinsentry.ui
index 20433f7a7675..c2330854ce84 100644
--- a/src/qt/forms/sendcoinsentry.ui
+++ b/src/qt/forms/sendcoinsentry.ui
@@ -151,7 +151,7 @@
      </widget>
     </item>
     <item row="2" column="1">
-     <layout class="QHBoxLayout" name="horizontalLayoutAmount" stretch="0,1">
+     <layout class="QHBoxLayout" name="horizontalLayoutAmount" stretch="0,1,0">
       <item>
        <widget class="BitcoinAmountField" name="payAmount"/>
       </item>
@@ -165,6 +165,13 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QPushButton" name="useAvailableBalanceButton">
+        <property name="text">
+         <string>Use available balance</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </item>
     <item row="3" column="0">
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index eb8214ea837e..3e92c398f752 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -1083,6 +1083,18 @@ QString formatNiceTimeOffset(qint64 secs)
     return timeBehindText;
 }
 
+QString formatBytes(uint64_t bytes)
+{
+    if(bytes < 1024)
+        return QString(QObject::tr("%1 B")).arg(bytes);
+    if(bytes < 1024 * 1024)
+        return QString(QObject::tr("%1 KB")).arg(bytes / 1024);
+    if(bytes < 1024 * 1024 * 1024)
+        return QString(QObject::tr("%1 MB")).arg(bytes / 1024 / 1024);
+
+    return QString(QObject::tr("%1 GB")).arg(bytes / 1024 / 1024 / 1024);
+}
+
 void ClickableLabel::mouseReleaseEvent(QMouseEvent *event)
 {
     Q_EMIT clicked(event->pos());
diff --git a/src/qt/guiutil.h b/src/qt/guiutil.h
index b17214fece11..155eebe7580b 100644
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -249,6 +249,8 @@ namespace GUIUtil
 
     QString formatNiceTimeOffset(qint64 secs);
 
+    QString formatBytes(uint64_t bytes);
+
     class ClickableLabel : public QLabel
     {
         Q_OBJECT
diff --git a/src/qt/paymentrequestplus.cpp b/src/qt/paymentrequestplus.cpp
index 165e49915045..b52dc3455f35 100644
--- a/src/qt/paymentrequestplus.cpp
+++ b/src/qt/paymentrequestplus.cpp
@@ -197,8 +197,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
         qWarning() << "PaymentRequestPlus::getMerchant: SSL error: " << err.what();
     }
 
-    if (website)
-        delete[] website;
+    delete[] website;
     X509_STORE_CTX_free(store_ctx);
     for (unsigned int i = 0; i < certs.size(); i++)
         X509_free(certs[i]);
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index 497fd3b79d78..42bcf3b79700 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -363,8 +363,7 @@ void PaymentServer::initNetManager()
 {
     if (!optionsModel)
         return;
-    if (netManager != nullptr)
-        delete netManager;
+    delete netManager;
 
     // netManager is used to fetch paymentrequests given in dash: URIs
     netManager = new QNetworkAccessManager(this);
diff --git a/src/qt/peertablemodel.cpp b/src/qt/peertablemodel.cpp
index b81b644da98d..dd69e17bd929 100644
--- a/src/qt/peertablemodel.cpp
+++ b/src/qt/peertablemodel.cpp
@@ -33,6 +33,10 @@ bool NodeLessThan::operator()(const CNodeCombinedStats &left, const CNodeCombine
         return pLeft->cleanSubVer.compare(pRight->cleanSubVer) < 0;
     case PeerTableModel::Ping:
         return pLeft->dMinPing < pRight->dMinPing;
+    case PeerTableModel::Sent:
+        return pLeft->nSendBytes < pRight->nSendBytes;
+    case PeerTableModel::Received:
+        return pLeft->nRecvBytes < pRight->nRecvBytes;
     }
 
     return false;
@@ -114,7 +118,7 @@ PeerTableModel::PeerTableModel(ClientModel *parent) :
     clientModel(parent),
     timer(0)
 {
-    columns << tr("NodeId") << tr("Node/Service") << tr("User Agent") << tr("Ping");
+    columns << tr("NodeId") << tr("Node/Service") << tr("Ping") << tr("Sent") << tr("Received") << tr("User Agent");
     priv.reset(new PeerTablePriv());
     // default to unsorted
     priv->sortColumn = -1;
@@ -173,10 +177,20 @@ QVariant PeerTableModel::data(const QModelIndex &index, int role) const
             return QString::fromStdString(rec->nodeStats.cleanSubVer);
         case Ping:
             return GUIUtil::formatPingTime(rec->nodeStats.dMinPing);
+        case Sent:
+            return GUIUtil::formatBytes(rec->nodeStats.nSendBytes);
+        case Received:
+            return GUIUtil::formatBytes(rec->nodeStats.nRecvBytes);
         }
     } else if (role == Qt::TextAlignmentRole) {
-        if (index.column() == Ping)
-            return (QVariant)(Qt::AlignRight | Qt::AlignVCenter);
+        switch (index.column()) {
+            case Ping:
+            case Sent:
+            case Received:
+                return QVariant(Qt::AlignRight | Qt::AlignVCenter);
+            default:
+                return QVariant();
+        }
     }
 
     return QVariant();
diff --git a/src/qt/peertablemodel.h b/src/qt/peertablemodel.h
index 3e4f0a68c460..af98417f3467 100644
--- a/src/qt/peertablemodel.h
+++ b/src/qt/peertablemodel.h
@@ -55,8 +55,10 @@ class PeerTableModel : public QAbstractTableModel
     enum ColumnIndex {
         NetNodeId = 0,
         Address = 1,
-        Subversion = 2,
-        Ping = 3
+        Ping = 2,
+        Sent = 3,
+        Received = 4,
+        Subversion = 5
     };
 
     /** @name Methods overridden from QAbstractTableModel
diff --git a/src/qt/receivecoinsdialog.cpp b/src/qt/receivecoinsdialog.cpp
index a98ef412e883..0fb4e905962c 100644
--- a/src/qt/receivecoinsdialog.cpp
+++ b/src/qt/receivecoinsdialog.cpp
@@ -106,7 +106,6 @@ void ReceiveCoinsDialog::clear()
     ui->reqAmount->clear();
     ui->reqLabel->setText("");
     ui->reqMessage->setText("");
-    ui->reuseAddress->setChecked(false);
     updateDisplayUnit();
 }
 
@@ -135,25 +134,8 @@ void ReceiveCoinsDialog::on_receiveButton_clicked()
 
     QString address;
     QString label = ui->reqLabel->text();
-    if(ui->reuseAddress->isChecked())
-    {
-        /* Choose existing receiving address */
-        AddressBookPage dlg(platformStyle, AddressBookPage::ForSelection, AddressBookPage::ReceivingTab, this);
-        dlg.setModel(model->getAddressTableModel());
-        if(dlg.exec())
-        {
-            address = dlg.getReturnValue();
-            if(label.isEmpty()) /* If no label provided, use the previously used label */
-            {
-                label = model->getAddressTableModel()->labelForAddress(address);
-            }
-        } else {
-            return;
-        }
-    } else {
-        /* Generate new receiving address */
-        address = model->getAddressTableModel()->addRow(AddressTableModel::Receive, label, "");
-    }
+    /* Generate new receiving address */
+    address = model->getAddressTableModel()->addRow(AddressTableModel::Receive, label, "");
     SendCoinsRecipient info(address, label,
         ui->reqAmount->value(), ui->reqMessage->text());
     ReceiveRequestDialog *dialog = new ReceiveRequestDialog(this);
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index cd6a4f9c983a..0f568f639c15 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -1043,18 +1043,6 @@ void RPCConsole::on_sldGraphRange_valueChanged(int value)
     setTrafficGraphRange(static_cast<TrafficGraphData::GraphRange>(value));
 }
 
-QString RPCConsole::FormatBytes(quint64 bytes)
-{
-    if(bytes < 1024)
-        return QString(tr("%1 B")).arg(bytes);
-    if(bytes < 1024 * 1024)
-        return QString(tr("%1 KB")).arg(bytes / 1024);
-    if(bytes < 1024 * 1024 * 1024)
-        return QString(tr("%1 MB")).arg(bytes / 1024 / 1024);
-
-    return QString(tr("%1 GB")).arg(bytes / 1024 / 1024 / 1024);
-}
-
 void RPCConsole::setTrafficGraphRange(TrafficGraphData::GraphRange range)
 {
     ui->trafficGraph->setGraphRangeMins(range);
@@ -1063,8 +1051,8 @@ void RPCConsole::setTrafficGraphRange(TrafficGraphData::GraphRange range)
 
 void RPCConsole::updateTrafficStats(quint64 totalBytesIn, quint64 totalBytesOut)
 {
-    ui->lblBytesIn->setText(FormatBytes(totalBytesIn));
-    ui->lblBytesOut->setText(FormatBytes(totalBytesOut));
+    ui->lblBytesIn->setText(GUIUtil::formatBytes(totalBytesIn));
+    ui->lblBytesOut->setText(GUIUtil::formatBytes(totalBytesOut));
 }
 
 void RPCConsole::peerSelected(const QItemSelection &selected, const QItemSelection &deselected)
@@ -1158,8 +1146,8 @@ void RPCConsole::updateNodeDetail(const CNodeCombinedStats *stats)
     ui->peerServices->setText(GUIUtil::formatServicesStr(stats->nodeStats.nServices));
     ui->peerLastSend->setText(stats->nodeStats.nLastSend ? GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nLastSend) : tr("never"));
     ui->peerLastRecv->setText(stats->nodeStats.nLastRecv ? GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nLastRecv) : tr("never"));
-    ui->peerBytesSent->setText(FormatBytes(stats->nodeStats.nSendBytes));
-    ui->peerBytesRecv->setText(FormatBytes(stats->nodeStats.nRecvBytes));
+    ui->peerBytesSent->setText(GUIUtil::formatBytes(stats->nodeStats.nSendBytes));
+    ui->peerBytesRecv->setText(GUIUtil::formatBytes(stats->nodeStats.nRecvBytes));
     ui->peerConnTime->setText(GUIUtil::formatDurationStr(GetSystemTimeInSeconds() - stats->nodeStats.nTimeConnected));
     ui->peerPingTime->setText(GUIUtil::formatPingTime(stats->nodeStats.dPingTime));
     ui->peerPingWait->setText(GUIUtil::formatPingTime(stats->nodeStats.dPingWait));
diff --git a/src/qt/rpcconsole.h b/src/qt/rpcconsole.h
index 748a00476129..9bec0d365509 100644
--- a/src/qt/rpcconsole.h
+++ b/src/qt/rpcconsole.h
@@ -140,7 +140,6 @@ public Q_SLOTS:
     void handleRestart(QStringList args);
 
 private:
-    static QString FormatBytes(quint64 bytes);
     void startExecutor();
     void setTrafficGraphRange(TrafficGraphData::GraphRange range);
     /** Build parameter list for restart */
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index b3d15b8e68b8..1d7aa9a46bae 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -497,6 +497,7 @@ SendCoinsEntry *SendCoinsDialog::addEntry()
     entry->setModel(model);
     ui->entries->addWidget(entry);
     connect(entry, SIGNAL(removeEntry(SendCoinsEntry*)), this, SLOT(removeEntry(SendCoinsEntry*)));
+    connect(entry, SIGNAL(useAvailableBalance(SendCoinsEntry*)), this, SLOT(useAvailableBalance(SendCoinsEntry*)));
     connect(entry, SIGNAL(payAmountChanged()), this, SLOT(coinControlUpdateLabels()));
     connect(entry, SIGNAL(subtractFeeFromAmountChanged()), this, SLOT(coinControlUpdateLabels()));
 
@@ -707,6 +708,31 @@ void SendCoinsDialog::on_buttonMinimizeFee_clicked()
     minimizeFeeSection(true);
 }
 
+void SendCoinsDialog::useAvailableBalance(SendCoinsEntry* entry)
+{
+    // Get CCoinControl instance if CoinControl is enabled or create a new one.
+    CCoinControl coin_control;
+    if (model->getOptionsModel()->getCoinControlFeatures()) {
+        coin_control = *CoinControlDialog::coinControl;
+    }
+
+    // Calculate available amount to send.
+    CAmount amount = model->getBalance(&coin_control);
+    for (int i = 0; i < ui->entries->count(); ++i) {
+        SendCoinsEntry* e = qobject_cast<SendCoinsEntry*>(ui->entries->itemAt(i)->widget());
+        if (e && !e->isHidden() && e != entry) {
+            amount -= e->getValue().amount;
+        }
+    }
+
+    if (amount > 0) {
+      entry->checkSubtractFeeFromAmount();
+      entry->setAmount(amount);
+    } else {
+      entry->setAmount(0);
+    }
+}
+
 void SendCoinsDialog::setMinimumFee()
 {
     ui->customFee->setValue(GetRequiredFee(1000));
diff --git a/src/qt/sendcoinsdialog.h b/src/qt/sendcoinsdialog.h
index 0d95bc091e8e..60e9259f4365 100644
--- a/src/qt/sendcoinsdialog.h
+++ b/src/qt/sendcoinsdialog.h
@@ -79,6 +79,7 @@ private Q_SLOTS:
     void on_buttonChooseFee_clicked();
     void on_buttonMinimizeFee_clicked();
     void removeEntry(SendCoinsEntry* entry);
+    void useAvailableBalance(SendCoinsEntry* entry);
     void updateDisplayUnit();
     void coinControlFeatureChanged(bool);
     void coinControlButtonClicked();
diff --git a/src/qt/sendcoinsentry.cpp b/src/qt/sendcoinsentry.cpp
index 92292a8423ad..c07764a2737c 100644
--- a/src/qt/sendcoinsentry.cpp
+++ b/src/qt/sendcoinsentry.cpp
@@ -50,6 +50,7 @@ SendCoinsEntry::SendCoinsEntry(const PlatformStyle *_platformStyle, QWidget *par
     connect(ui->deleteButton, SIGNAL(clicked()), this, SLOT(deleteClicked()));
     connect(ui->deleteButton_is, SIGNAL(clicked()), this, SLOT(deleteClicked()));
     connect(ui->deleteButton_s, SIGNAL(clicked()), this, SLOT(deleteClicked()));
+    connect(ui->useAvailableBalanceButton, SIGNAL(clicked()), this, SLOT(useAvailableBalanceClicked()));
 }
 
 SendCoinsEntry::~SendCoinsEntry()
@@ -114,11 +115,21 @@ void SendCoinsEntry::clear()
     updateDisplayUnit();
 }
 
+void SendCoinsEntry::checkSubtractFeeFromAmount()
+{
+    ui->checkboxSubtractFeeFromAmount->setChecked(true);
+}
+
 void SendCoinsEntry::deleteClicked()
 {
     Q_EMIT removeEntry(this);
 }
 
+void SendCoinsEntry::useAvailableBalanceClicked()
+{
+    Q_EMIT useAvailableBalance(this);
+}
+
 bool SendCoinsEntry::validate()
 {
     if (!model)
@@ -230,6 +241,11 @@ void SendCoinsEntry::setAddress(const QString &address)
     ui->payAmount->setFocus();
 }
 
+void SendCoinsEntry::setAmount(const CAmount &amount)
+{
+    ui->payAmount->setValue(amount);
+}
+
 bool SendCoinsEntry::isClear()
 {
     return ui->payTo->text().isEmpty() && ui->payTo_is->text().isEmpty() && ui->payTo_s->text().isEmpty();
diff --git a/src/qt/sendcoinsentry.h b/src/qt/sendcoinsentry.h
index a8be670c2aa0..557fea4e5476 100644
--- a/src/qt/sendcoinsentry.h
+++ b/src/qt/sendcoinsentry.h
@@ -38,6 +38,7 @@ class SendCoinsEntry : public QStackedWidget
 
     void setValue(const SendCoinsRecipient &value);
     void setAddress(const QString &address);
+    void setAmount(const CAmount &amount);
 
     /** Set up the tab chain manually, as Qt messes up the tab chain by default in some cases
      *  (issue https://bugreports.qt-project.org/browse/QTBUG-10907).
@@ -48,14 +49,17 @@ class SendCoinsEntry : public QStackedWidget
 
 public Q_SLOTS:
     void clear();
+    void checkSubtractFeeFromAmount();
 
 Q_SIGNALS:
     void removeEntry(SendCoinsEntry *entry);
+    void useAvailableBalance(SendCoinsEntry* entry);
     void payAmountChanged();
     void subtractFeeFromAmountChanged();
 
 private Q_SLOTS:
     void deleteClicked();
+    void useAvailableBalanceClicked();
     void on_payTo_textChanged(const QString &address);
     void on_addressBookButton_clicked();
     void on_pasteButton_clicked();
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 6454a04c7cb7..278e80f32fd2 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -94,7 +94,10 @@ void TestSendCoins()
         wallet.SetAddressBook(test.coinbaseKey.GetPubKey().GetID(), "", "receive");
         wallet.AddKeyPubKey(test.coinbaseKey, test.coinbaseKey.GetPubKey());
     }
-    wallet.ScanForWalletTransactions(chainActive.Genesis(), nullptr, true);
+    {
+        LOCK(cs_main);
+        wallet.ScanForWalletTransactions(chainActive.Genesis(), nullptr, true);
+    }
     wallet.SetBroadcastTransactions(true);
 
     // Create widgets for sending coins and listing transactions.
diff --git a/src/qt/transactiondesc.cpp b/src/qt/transactiondesc.cpp
index fdb3ef7736c6..032063021fdd 100644
--- a/src/qt/transactiondesc.cpp
+++ b/src/qt/transactiondesc.cpp
@@ -25,7 +25,7 @@
 QString TransactionDesc::FormatTxStatus(const CWalletTx& wtx)
 {
     AssertLockHeld(cs_main);
-    if (!CheckFinalTx(wtx))
+    if (!CheckFinalTx(*wtx.tx))
     {
         if (wtx.tx->nLockTime < LOCKTIME_THRESHOLD)
             return tr("Open for %n more block(s)", "", wtx.tx->nLockTime - chainActive.Height());
diff --git a/src/qt/transactionrecord.cpp b/src/qt/transactionrecord.cpp
index bf54f0744839..a1bca6bce39e 100644
--- a/src/qt/transactionrecord.cpp
+++ b/src/qt/transactionrecord.cpp
@@ -285,7 +285,7 @@ void TransactionRecord::updateStatus(const CWalletTx &wtx, int chainLockHeight)
         status.label = QString::fromStdString(addrBookIt->second.name);
     }
 
-    if (!CheckFinalTx(wtx))
+    if (!CheckFinalTx(*wtx.tx))
     {
         if (wtx.tx->nLockTime < LOCKTIME_THRESHOLD)
         {
diff --git a/src/qt/transactiontablemodel.cpp b/src/qt/transactiontablemodel.cpp
index 9cdabba8bd86..af51573c3441 100644
--- a/src/qt/transactiontablemodel.cpp
+++ b/src/qt/transactiontablemodel.cpp
@@ -244,7 +244,7 @@ class TransactionTablePriv
         std::map<uint256, CWalletTx>::iterator mi = wallet->mapWallet.find(rec->hash);
         if(mi != wallet->mapWallet.end())
         {
-            std::string strHex = EncodeHexTx(static_cast<CTransaction>(mi->second));
+            std::string strHex = EncodeHexTx(*mi->second.tx);
             return QString::fromStdString(strHex);
         }
         return QString();
diff --git a/src/qt/walletmodeltransaction.cpp b/src/qt/walletmodeltransaction.cpp
index 8d7c8ff87d86..0703b029470a 100644
--- a/src/qt/walletmodeltransaction.cpp
+++ b/src/qt/walletmodeltransaction.cpp
@@ -33,7 +33,7 @@ CWalletTx *WalletModelTransaction::getTransaction() const
 
 unsigned int WalletModelTransaction::getTransactionSize()
 {
-    return (!walletTransaction ? 0 : (::GetSerializeSize(walletTransaction->tx, SER_NETWORK, PROTOCOL_VERSION)));
+    return (!walletTransaction ? 0 : (::GetSerializeSize(*walletTransaction->tx, SER_NETWORK, PROTOCOL_VERSION)));
 }
 
 CAmount WalletModelTransaction::getTransactionFee() const
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 81ec5c1b5178..bb6b7aa74083 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1396,45 +1396,46 @@ UniValue getblockchaininfo(const JSONRPCRequest& request)
             "Returns an object containing various state info regarding blockchain processing.\n"
             "\nResult:\n"
             "{\n"
-            "  \"chain\": \"xxxx\",        (string) current network name as defined in BIP70 (main, test, regtest)\n"
-            "  \"blocks\": xxxxxx,         (numeric) the current number of blocks processed in the server\n"
-            "  \"headers\": xxxxxx,        (numeric) the current number of headers we have validated\n"
-            "  \"bestblockhash\": \"...\", (string) the hash of the currently best block\n"
-            "  \"difficulty\": xxxxxx,     (numeric) the current difficulty\n"
-            "  \"mediantime\": xxxxxx,     (numeric) median time for the current best block\n"
+            "  \"chain\": \"xxxx\",              (string) current network name as defined in BIP70 (main, test, regtest)\n"
+            "  \"blocks\": xxxxxx,             (numeric) the current number of blocks processed in the server\n"
+            "  \"headers\": xxxxxx,            (numeric) the current number of headers we have validated\n"
+            "  \"bestblockhash\": \"...\",       (string) the hash of the currently best block\n"
+            "  \"difficulty\": xxxxxx,         (numeric) the current difficulty\n"
+            "  \"mediantime\": xxxxxx,         (numeric) median time for the current best block\n"
             "  \"verificationprogress\": xxxx, (numeric) estimate of verification progress [0..1]\n"
-            "  \"chainwork\": \"xxxx\"     (string) total amount of work in active chain, in hexadecimal\n"
-            "  \"size_on_disk\": xxxxxx,   (numeric) the estimated size of the block and undo files on disk\n"
-            "  \"pruned\": xx,             (boolean) if the blocks are subject to pruning\n"
-            "  \"pruneheight\": xxxxxx,    (numeric) lowest-height complete block stored (only present if pruning is enabled)\n"
-            "  \"automatic_pruning\": xx,  (boolean) whether automatic pruning is enabled (only present if pruning is enabled)\n"
+            "  \"initialblockdownload\": xxxx, (bool) (debug information) estimate of whether this node is in Initial Block Download mode.\n"
+            "  \"chainwork\": \"xxxx\"           (string) total amount of work in active chain, in hexadecimal\n"
+            "  \"size_on_disk\": xxxxxx,       (numeric) the estimated size of the block and undo files on disk\n"
+            "  \"pruned\": xx,                 (boolean) if the blocks are subject to pruning\n"
+            "  \"pruneheight\": xxxxxx,        (numeric) lowest-height complete block stored (only present if pruning is enabled)\n"
+            "  \"automatic_pruning\": xx,      (boolean) whether automatic pruning is enabled (only present if pruning is enabled)\n"
             "  \"prune_target_size\": xxxxxx,  (numeric) the target size used by pruning (only present if automatic pruning is enabled)\n"
-            "  \"softforks\": [            (array) status of softforks in progress\n"
+            "  \"softforks\": [                (array) status of softforks in progress\n"
             "     {\n"
-            "        \"id\": \"xxxx\",        (string) name of softfork\n"
-            "        \"version\": xx,         (numeric) block version\n"
-            "        \"reject\": {            (object) progress toward rejecting pre-softfork blocks\n"
-            "           \"status\": xx,       (boolean) true if threshold reached\n"
+            "        \"id\": \"xxxx\",           (string) name of softfork\n"
+            "        \"version\": xx,          (numeric) block version\n"
+            "        \"reject\": {             (object) progress toward rejecting pre-softfork blocks\n"
+            "           \"status\": xx,        (boolean) true if threshold reached\n"
             "        },\n"
             "     }, ...\n"
             "  ],\n"
-            "  \"bip9_softforks\": {          (object) status of BIP9 softforks in progress\n"
-            "     \"xxxx\" : {                (string) name of the softfork\n"
-            "        \"status\": \"xxxx\",    (string) one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\"\n"
-            "        \"bit\": xx,             (numeric) the bit (0-28) in the block version field used to signal this softfork (only for \"started\" status)\n"
-            "        \"startTime\": xx,       (numeric) the minimum median time past of a block at which the bit gains its meaning\n"
-            "        \"timeout\": xx,         (numeric) the median time past of a block at which the deployment is considered failed if not yet locked in\n"
-            "        \"since\": xx,           (numeric) height of the first block to which the status applies\n"
-            "        \"statistics\": {        (object) numeric statistics about BIP9 signalling for a softfork (only for \"started\" status)\n"
-            "           \"period\": xx,       (numeric) the length in blocks of the BIP9 signalling period \n"
-            "           \"threshold\": xx,    (numeric) the number of blocks with the version bit set required to activate the feature \n"
-            "           \"elapsed\": xx,      (numeric) the number of blocks elapsed since the beginning of the current period \n"
-            "           \"count\": xx,        (numeric) the number of blocks with the version bit set in the current period \n"
-            "           \"possible\": xx      (boolean) returns false if there are not enough blocks left in this period to pass activation threshold \n"
+            "  \"bip9_softforks\": {           (object) status of BIP9 softforks in progress\n"
+            "     \"xxxx\" : {                 (string) name of the softfork\n"
+            "        \"status\": \"xxxx\",       (string) one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\"\n"
+            "        \"bit\": xx,              (numeric) the bit (0-28) in the block version field used to signal this softfork (only for \"started\" status)\n"
+            "        \"startTime\": xx,        (numeric) the minimum median time past of a block at which the bit gains its meaning\n"
+            "        \"timeout\": xx,          (numeric) the median time past of a block at which the deployment is considered failed if not yet locked in\n"
+            "        \"since\": xx,            (numeric) height of the first block to which the status applies\n"
+            "        \"statistics\": {         (object) numeric statistics about BIP9 signalling for a softfork (only for \"started\" status)\n"
+            "           \"period\": xx,        (numeric) the length in blocks of the BIP9 signalling period \n"
+            "           \"threshold\": xx,     (numeric) the number of blocks with the version bit set required to activate the feature \n"
+            "           \"elapsed\": xx,       (numeric) the number of blocks elapsed since the beginning of the current period \n"
+            "           \"count\": xx,         (numeric) the number of blocks with the version bit set in the current period \n"
+            "           \"possible\": xx       (boolean) returns false if there are not enough blocks left in this period to pass activation threshold \n"
             "        }\n"
             "     }\n"
             "  }\n"
-            "  \"warnings\" : \"...\",         (string) any network and blockchain warnings.\n"
+            "  \"warnings\" : \"...\",           (string) any network and blockchain warnings.\n"
             "}\n"
             "\nExamples:\n"
             + HelpExampleCli("getblockchaininfo", "")
@@ -1451,6 +1452,7 @@ UniValue getblockchaininfo(const JSONRPCRequest& request)
     obj.push_back(Pair("difficulty",            (double)GetDifficulty()));
     obj.push_back(Pair("mediantime",            (int64_t)chainActive.Tip()->GetMedianTimePast()));
     obj.push_back(Pair("verificationprogress",  GuessVerificationProgress(Params().TxData(), chainActive.Tip())));
+    obj.push_back(Pair("initialblockdownload",  IsInitialBlockDownload()));
     obj.push_back(Pair("chainwork",             chainActive.Tip()->nChainWork.GetHex()));
     obj.push_back(Pair("size_on_disk",          CalculateCurrentUsage()));
     obj.push_back(Pair("pruned",                fPruneMode));
diff --git a/src/test/DoS_tests.cpp b/src/test/DoS_tests.cpp
index df9370b06dc5..122974a33a64 100644
--- a/src/test/DoS_tests.cpp
+++ b/src/test/DoS_tests.cpp
@@ -66,11 +66,14 @@ BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
     dummyNode1.fSuccessfullyConnected = true;
 
     // This test requires that we have a chain with non-zero work.
+    LOCK(cs_main);
     BOOST_CHECK(chainActive.Tip() != nullptr);
     BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
 
     // Test starts here
+    LOCK(dummyNode1.cs_sendProcessing);
     peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
+    LOCK(dummyNode1.cs_vSend);
     BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
     dummyNode1.vSendMsg.clear();
 
@@ -183,7 +186,11 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
     peerLogic->InitializeNode(&dummyNode1);
     dummyNode1.nVersion = 1;
     dummyNode1.fSuccessfullyConnected = true;
-    Misbehaving(dummyNode1.GetId(), 100); // Should get banned
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode1.GetId(), 100); // Should get banned
+    }
+    LOCK(dummyNode1.cs_sendProcessing);
     peerLogic->SendMessages(&dummyNode1, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr1));
     BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001|0x0000ff00))); // Different IP, not banned
@@ -194,11 +201,18 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
     peerLogic->InitializeNode(&dummyNode2);
     dummyNode2.nVersion = 1;
     dummyNode2.fSuccessfullyConnected = true;
-    Misbehaving(dummyNode2.GetId(), 50);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode2.GetId(), 50);
+    }
+    LOCK(dummyNode2.cs_sendProcessing);
     peerLogic->SendMessages(&dummyNode2, interruptDummy);
     BOOST_CHECK(!connman->IsBanned(addr2)); // 2 not banned yet...
     BOOST_CHECK(connman->IsBanned(addr1));  // ... but 1 still should be
-    Misbehaving(dummyNode2.GetId(), 50);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode2.GetId(), 50);
+    }
     peerLogic->SendMessages(&dummyNode2, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr2));
 
@@ -219,13 +233,23 @@ BOOST_AUTO_TEST_CASE(DoS_banscore)
     peerLogic->InitializeNode(&dummyNode1);
     dummyNode1.nVersion = 1;
     dummyNode1.fSuccessfullyConnected = true;
-    Misbehaving(dummyNode1.GetId(), 100);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode1.GetId(), 100);
+    }
+    LOCK(dummyNode1.cs_sendProcessing);
     peerLogic->SendMessages(&dummyNode1, interruptDummy);
     BOOST_CHECK(!connman->IsBanned(addr1));
-    Misbehaving(dummyNode1.GetId(), 10);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode1.GetId(), 10);
+    }
     peerLogic->SendMessages(&dummyNode1, interruptDummy);
     BOOST_CHECK(!connman->IsBanned(addr1));
-    Misbehaving(dummyNode1.GetId(), 1);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode1.GetId(), 1);
+    }
     peerLogic->SendMessages(&dummyNode1, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr1));
     gArgs.ForceSetArg("-banscore", std::to_string(DEFAULT_BANSCORE_THRESHOLD));
@@ -249,7 +273,11 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
     dummyNode.nVersion = 1;
     dummyNode.fSuccessfullyConnected = true;
 
-    Misbehaving(dummyNode.GetId(), 100);
+    {
+        LOCK(cs_main);
+        Misbehaving(dummyNode.GetId(), 100);
+    }
+    LOCK(dummyNode.cs_sendProcessing);
     peerLogic->SendMessages(&dummyNode, interruptDummy);
     BOOST_CHECK(connman->IsBanned(addr));
 
@@ -266,6 +294,7 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
 CTransactionRef RandomOrphan()
 {
     std::map<uint256, COrphanTx>::iterator it;
+    LOCK(cs_main);
     it = mapOrphanTransactions.lower_bound(InsecureRand256());
     if (it == mapOrphanTransactions.end())
         it = mapOrphanTransactions.begin();
@@ -335,6 +364,7 @@ BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
         BOOST_CHECK(!AddOrphanTx(MakeTransactionRef(tx), i));
     }
 
+    LOCK(cs_main);
     // Test EraseOrphansFor:
     for (NodeId i = 0; i < 3; i++)
     {
diff --git a/src/test/blockencodings_tests.cpp b/src/test/blockencodings_tests.cpp
index c8e1c7783e70..852beafa3e8e 100644
--- a/src/test/blockencodings_tests.cpp
+++ b/src/test/blockencodings_tests.cpp
@@ -62,6 +62,7 @@ BOOST_AUTO_TEST_CASE(SimpleRoundTripTest)
     CBlock block(BuildBlockTestCase());
 
     pool.addUnchecked(block.vtx[2]->GetHash(), entry.FromTx(*block.vtx[2]));
+    LOCK(pool.cs);
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[2]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
     // Do a simple ShortTxIDs RT
@@ -161,6 +162,7 @@ BOOST_AUTO_TEST_CASE(NonCoinbasePreforwardRTTest)
     CBlock block(BuildBlockTestCase());
 
     pool.addUnchecked(block.vtx[2]->GetHash(), entry.FromTx(*block.vtx[2]));
+    LOCK(pool.cs);
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[2]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
     uint256 txhash;
@@ -227,6 +229,7 @@ BOOST_AUTO_TEST_CASE(SufficientPreforwardRTTest)
     CBlock block(BuildBlockTestCase());
 
     pool.addUnchecked(block.vtx[1]->GetHash(), entry.FromTx(*block.vtx[1]));
+    LOCK(pool.cs);
     BOOST_CHECK_EQUAL(pool.mapTx.find(block.vtx[1]->GetHash())->GetSharedTx().use_count(), SHARED_TX_OFFSET + 0);
 
     uint256 txhash;
diff --git a/src/test/mempool_tests.cpp b/src/test/mempool_tests.cpp
index 4618f222bfd9..dcc154d67dac 100644
--- a/src/test/mempool_tests.cpp
+++ b/src/test/mempool_tests.cpp
@@ -164,6 +164,7 @@ BOOST_AUTO_TEST_CASE(MempoolIndexingTest)
     sortedOrder[2] = tx1.GetHash().ToString(); // 10000
     sortedOrder[3] = tx4.GetHash().ToString(); // 15000
     sortedOrder[4] = tx2.GetHash().ToString(); // 20000
+    LOCK(pool.cs);
     CheckSort<descendant_score>(pool, sortedOrder);
 
     /* low fee but with high fee child */
@@ -374,6 +375,7 @@ BOOST_AUTO_TEST_CASE(MempoolAncestorIndexingTest)
     }
     sortedOrder[4] = tx3.GetHash().ToString(); // 0
 
+    LOCK(pool.cs);
     CheckSort<ancestor_score>(pool, sortedOrder);
 
     /* low fee parent with high fee child */
diff --git a/src/test/test_dash.cpp b/src/test/test_dash.cpp
index c494bcb3e3c6..f5b6ea2924ac 100644
--- a/src/test/test_dash.cpp
+++ b/src/test/test_dash.cpp
@@ -204,7 +204,10 @@ CBlock TestChainSetup::CreateBlock(const std::vector<CMutableTransaction>& txns,
 
     // IncrementExtraNonce creates a valid coinbase and merkleRoot
     unsigned int extraNonce = 0;
-    IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    {
+        LOCK(cs_main);
+        IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    }
 
     while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;
 
diff --git a/src/test/test_dash_fuzzy.cpp b/src/test/test_dash_fuzzy.cpp
index dc38d1abf1dd..ed99ae27bf0b 100644
--- a/src/test/test_dash_fuzzy.cpp
+++ b/src/test/test_dash_fuzzy.cpp
@@ -19,6 +19,7 @@
 #include "undo.h"
 #include "version.h"
 #include "pubkey.h"
+#include "blockencodings.h"
 
 #include <stdint.h>
 #include <unistd.h>
@@ -45,6 +46,8 @@ enum TEST_ID {
     CBLOOMFILTER_DESERIALIZE,
     CDISKBLOCKINDEX_DESERIALIZE,
     CTXOUTCOMPRESSOR_DESERIALIZE,
+    BLOCKTRANSACTIONS_DESERIALIZE,
+    BLOCKTRANSACTIONSREQUEST_DESERIALIZE,
     TEST_ID_END
 };
 
@@ -249,6 +252,26 @@ int do_fuzz()
 
             break;
         }
+        case BLOCKTRANSACTIONS_DESERIALIZE:
+        {
+            try
+            {
+                BlockTransactions bt;
+                ds >> bt;
+            } catch (const std::ios_base::failure& e) {return 0;}
+
+            break;
+        }
+        case BLOCKTRANSACTIONSREQUEST_DESERIALIZE:
+        {
+            try
+            {
+                BlockTransactionsRequest btr;
+                ds >> btr;
+            } catch (const std::ios_base::failure& e) {return 0;}
+
+            break;
+        }
         default:
             return 0;
     }
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index ff8406b60ed8..a8ff74219e83 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -65,18 +65,27 @@ BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
 
     // Test 1: block with both of those transactions should be rejected.
     block = CreateAndProcessBlock(spends, scriptPubKey);
-    BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    {
+        LOCK(cs_main);
+        BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    }
 
     // Test 2: ... and should be rejected if spend1 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[0]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
-    BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    {
+        LOCK(cs_main);
+        BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    }
     mempool.clear();
 
     // Test 3: ... and should be rejected if spend2 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
-    BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    {
+        LOCK(cs_main);
+        BOOST_CHECK(chainActive.Tip()->GetBlockHash() != block.GetHash());
+    }
     mempool.clear();
 
     // Final sanity test: first spend in mempool, second in block, that's OK:
@@ -84,7 +93,10 @@ BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
     oneSpend.push_back(spends[0]);
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(oneSpend, scriptPubKey);
-    BOOST_CHECK(chainActive.Tip()->GetBlockHash() == block.GetHash());
+    {
+        LOCK(cs_main);
+        BOOST_CHECK(chainActive.Tip()->GetBlockHash() == block.GetHash());
+    }
     // spends[1] should have been removed from the mempool when the
     // block with spends[0] is accepted:
     BOOST_CHECK_EQUAL(mempool.size(), 0);
@@ -146,7 +158,10 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
 {
     // Test that passing CheckInputs with one set of script flags doesn't imply
     // that we would pass again with a different set of flags.
-    InitScriptExecutionCache();
+    {
+        LOCK(cs_main);
+        InitScriptExecutionCache();
+    }
 
     CScript p2pk_scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     CScript p2sh_scriptPubKey = GetScriptForDestination(CScriptID(p2pk_scriptPubKey));
diff --git a/src/txdb.h b/src/txdb.h
index 092204668fbb..4f8019d3ed6b 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -117,13 +117,13 @@ class CBlockTreeDB : public CDBWrapper
     CBlockTreeDB& operator=(const CBlockTreeDB&) = delete;
 
     bool WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo);
-    bool ReadBlockFileInfo(int nFile, CBlockFileInfo &fileinfo);
+    bool ReadBlockFileInfo(int nFile, CBlockFileInfo &info);
     bool ReadLastBlockFile(int &nFile);
-    bool WriteReindexing(bool fReindex);
-    bool ReadReindexing(bool &fReindex);
+    bool WriteReindexing(bool fReindexing);
+    bool ReadReindexing(bool &fReindexing);
     bool HasTxIndex(const uint256 &txid);
     bool ReadTxIndex(const uint256 &txid, CDiskTxPos &pos);
-    bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> > &list);
+    bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> > &vect);
     bool ReadSpentIndex(CSpentIndexKey &key, CSpentIndexValue &value);
     bool UpdateSpentIndex(const std::vector<std::pair<CSpentIndexKey, CSpentIndexValue> >&vect);
     bool UpdateAddressUnspentIndex(const std::vector<std::pair<CAddressUnspentKey, CAddressUnspentValue > >&vect);
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 1a012fab7b12..bae5292b8ed7 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -319,7 +319,7 @@ void CTxMemPoolEntry::UpdateDescendantState(int64_t modifySize, CAmount modifyFe
     assert(int64_t(nCountWithDescendants) > 0);
 }
 
-void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int modifySigOps)
+void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps)
 {
     nSizeWithAncestors += modifySize;
     assert(int64_t(nSizeWithAncestors) > 0);
diff --git a/src/txmempool.h b/src/txmempool.h
index d81b3210e9d7..46bbe5a5c915 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -113,7 +113,7 @@ class CTxMemPoolEntry
     // Adjusts the descendant state.
     void UpdateDescendantState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount);
     // Adjusts the ancestor state
-    void UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int modifySigOps);
+    void UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps);
     // Updates the fee delta used for mining priority score, and the
     // modified fees with descendants.
     void UpdateFeeDelta(int64_t feeDelta);
diff --git a/src/uint256.h b/src/uint256.h
index a1ad3db12900..9d74c292a31c 100644
--- a/src/uint256.h
+++ b/src/uint256.h
@@ -20,7 +20,7 @@ template<unsigned int BITS>
 class base_blob
 {
 protected:
-    enum { WIDTH=BITS/8 };
+    static constexpr int WIDTH = BITS / 8;
     uint8_t data[WIDTH];
 public:
     base_blob()
diff --git a/src/validation.cpp b/src/validation.cpp
index 3b77081a3d15..7b69a61b2b64 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -81,7 +81,7 @@ CWaitableCriticalSection csBestBlock;
 CConditionVariable cvBlockChange;
 int nScriptCheckThreads = 0;
 std::atomic_bool fImporting(false);
-bool fReindex = false;
+std::atomic_bool fReindex(false);
 bool fTxIndex = true;
 bool fAddressIndex = false;
 bool fTimestampIndex = false;
@@ -188,7 +188,7 @@ namespace {
       * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as
       * well.
       *
-      * Because we alreardy walk mapBlockIndex in height-order at startup, we go
+      * Because we already walk mapBlockIndex in height-order at startup, we go
       * ahead and mark descendants of invalid blocks as FAILED_CHILD at that time,
       * instead of putting things in this set.
       */
@@ -3968,7 +3968,7 @@ bool static LoadBlockIndexDB(const CChainParams& chainparams)
     // Check whether we need to continue reindexing
     bool fReindexing = false;
     pblocktree->ReadReindexing(fReindexing);
-    fReindex |= fReindexing;
+    if(fReindexing) fReindex = true;
 
     // Check whether we have a transaction index
     pblocktree->ReadFlag("txindex", fTxIndex);
diff --git a/src/validation.h b/src/validation.h
index 841d856844fb..4ee306055634 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -170,7 +170,7 @@ extern const std::string strMessageMagic;
 extern CWaitableCriticalSection csBestBlock;
 extern CConditionVariable cvBlockChange;
 extern std::atomic_bool fImporting;
-extern bool fReindex;
+extern std::atomic_bool fReindex;
 extern int nScriptCheckThreads;
 extern bool fTxIndex;
 extern bool fAddressIndex;
diff --git a/src/wallet/crypter.h b/src/wallet/crypter.h
index 18ecdd71dfbd..71ddfa73d649 100644
--- a/src/wallet/crypter.h
+++ b/src/wallet/crypter.h
@@ -9,6 +9,8 @@
 #include "serialize.h"
 #include "support/allocators/secure.h"
 
+#include <atomic>
+
 const unsigned int WALLET_CRYPTO_KEY_SIZE = 32;
 const unsigned int WALLET_CRYPTO_SALT_SIZE = 8;
 const unsigned int WALLET_CRYPTO_IV_SIZE = 16;
@@ -124,7 +126,7 @@ class CCryptoKeyStore : public CBasicKeyStore
 
     //! if fUseCrypto is true, mapKeys must be empty
     //! if fUseCrypto is false, vMasterKey must be empty
-    bool fUseCrypto;
+    std::atomic<bool> fUseCrypto;
 
     //! keeps track of whether Unlock has run a thorough check before
     bool fDecryptionThoroughlyChecked;
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
index 2e05ccd01f97..c57e91dc5181 100644
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -64,11 +64,16 @@ std::string GetWalletHelpString(bool showDebug)
 
 bool WalletParameterInteraction()
 {
-    gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
-    const bool is_multiwallet = gArgs.GetArgs("-wallet").size() > 1;
+    if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
+        for (const std::string& wallet : gArgs.GetArgs("-wallet")) {
+            LogPrintf("%s: parameter interaction: -disablewallet -> ignoring -wallet=%s\n", __func__, wallet);
+        }
 
-    if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET))
         return true;
+    }
+
+    gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
+    const bool is_multiwallet = gArgs.GetArgs("-wallet").size() > 1;
 
     if (gArgs.GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY) && gArgs.SoftSetBoolArg("-walletbroadcast", false)) {
         LogPrintf("%s: parameter interaction: -blocksonly=1 -> setting -walletbroadcast=0\n", __func__);
@@ -192,15 +197,18 @@ bool WalletParameterInteraction()
 
 void RegisterWalletRPC(CRPCTable &t)
 {
-    if (gArgs.GetBoolArg("-disablewallet", false)) return;
+    if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
+        return;
+    }
 
     RegisterWalletRPCCommands(t);
 }
 
 bool VerifyWallets()
 {
-    if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET))
+    if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
         return true;
+    }
 
     uiInterface.InitMessage(_("Verifying wallet(s)..."));
 
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 28c948892110..d9017dcfd395 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -341,7 +341,7 @@ UniValue importprunedfunds(const JSONRPCRequest& request)
 
     LOCK2(cs_main, pwallet->cs_wallet);
 
-    if (pwallet->IsMine(wtx)) {
+    if (pwallet->IsMine(*wtx.tx)) {
         pwallet->AddToWallet(wtx, false);
         return NullUniValue;
     }
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 757f07424a16..96ebf0bf677f 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -708,7 +708,7 @@ UniValue getreceivedbyaddress(const JSONRPCRequest& request)
     }
     CScript scriptPubKey = GetScriptForDestination(dest);
     if (!IsMine(*pwallet, scriptPubKey)) {
-        return ValueFromAmount(0);
+        throw JSONRPCError(RPC_WALLET_ERROR, "Address not found in wallet");
     }
 
     // Minimum confirmations
@@ -1997,7 +1997,7 @@ UniValue gettransaction(const JSONRPCRequest& request)
     ListTransactions(pwallet, wtx, "*", 0, false, details, filter);
     entry.push_back(Pair("details", details));
 
-    std::string strHex = EncodeHexTx(static_cast<CTransaction>(wtx));
+    std::string strHex = EncodeHexTx(*wtx.tx);
     entry.push_back(Pair("hex", strHex));
 
     return entry;
diff --git a/src/wallet/test/accounting_tests.cpp b/src/wallet/test/accounting_tests.cpp
index d597bd911dcc..cb4b889633e3 100644
--- a/src/wallet/test/accounting_tests.cpp
+++ b/src/wallet/test/accounting_tests.cpp
@@ -83,7 +83,7 @@ BOOST_AUTO_TEST_CASE(acc_orderupgrade)
 
     wtx.mapValue["comment"] = "y";
     {
-        CMutableTransaction tx(wtx);
+        CMutableTransaction tx(*wtx.tx);
         --tx.nLockTime;  // Just to change the hash :)
         wtx.SetTx(MakeTransactionRef(std::move(tx)));
     }
@@ -93,7 +93,7 @@ BOOST_AUTO_TEST_CASE(acc_orderupgrade)
 
     wtx.mapValue["comment"] = "x";
     {
-        CMutableTransaction tx(wtx);
+        CMutableTransaction tx(*wtx.tx);
         --tx.nLockTime;  // Just to change the hash :)
         wtx.SetTx(MakeTransactionRef(std::move(tx)));
     }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 62349e6131ce..b8d4f0c7d606 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -489,6 +489,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
         vpwallets[0] = &wallet;
         ::importwallet(request);
 
+        LOCK(wallet.cs_wallet);
         BOOST_CHECK_EQUAL(wallet.mapWallet.size(), 3);
         BOOST_CHECK_EQUAL(coinbaseTxns.size(), 103);
         for (size_t i = 0; i < coinbaseTxns.size(); ++i) {
@@ -534,6 +535,7 @@ static int64_t AddTx(CWallet& wallet, uint32_t lockTime, int64_t mockTime, int64
     SetMockTime(mockTime);
     CBlockIndex* block = nullptr;
     if (blockTime > 0) {
+        LOCK(cs_main);
         auto inserted = mapBlockIndex.emplace(GetRandHash(), new CBlockIndex);
         assert(inserted.second);
         const uint256& hash = inserted.first->first;
@@ -547,6 +549,7 @@ static int64_t AddTx(CWallet& wallet, uint32_t lockTime, int64_t mockTime, int64
         wtx.SetMerkleBranch(block, 0);
     }
     wallet.AddToWallet(wtx);
+    LOCK(wallet.cs_wallet);
     return wallet.mapWallet.at(wtx.GetHash()).nTimeSmart;
 }
 
@@ -583,6 +586,7 @@ BOOST_AUTO_TEST_CASE(ComputeTimeSmart)
 BOOST_AUTO_TEST_CASE(LoadReceiveRequests)
 {
     CTxDestination dest = CKeyID();
+    LOCK(pwalletMain->cs_wallet);
     pwalletMain->AddDestData(dest, "misc", "val_misc");
     pwalletMain->AddDestData(dest, "rr0", "val_rr0");
     pwalletMain->AddDestData(dest, "rr1", "val_rr1");
@@ -625,9 +629,16 @@ class ListCoinsTestingSetup : public TestChain100Setup
         BOOST_CHECK(wallet->CreateTransaction({recipient}, wtx, reservekey, fee, changePos, error, dummy));
         CValidationState state;
         BOOST_CHECK(wallet->CommitTransaction(wtx, reservekey, nullptr, state));
+        CMutableTransaction blocktx;
+        {
+            LOCK(wallet->cs_wallet);
+            blocktx = CMutableTransaction(*wallet->mapWallet.at(wtx.tx->GetHash()).tx);
+        }
+        CreateAndProcessBlock({CMutableTransaction(blocktx)}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
+        LOCK(cs_main);
+        LOCK(wallet->cs_wallet);
         auto it = wallet->mapWallet.find(wtx.GetHash());
         BOOST_CHECK(it != wallet->mapWallet.end());
-        CreateAndProcessBlock({CMutableTransaction(*it->second.tx)}, GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
         it->second.SetMerkleBranch(chainActive.Tip(), 1);
         return it->second;
     }
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 08a81a4ba7fc..576f5a7c8969 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -679,6 +679,9 @@ void CWallet::SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator> ran
             copyFrom = &mapWallet[hash];
         }
     }
+
+    assert(copyFrom);
+
     // Now copy data from copyFrom to rest:
     for (TxSpends::iterator it = range.first; it != range.second; ++it)
     {
@@ -1493,6 +1496,7 @@ int CWallet::GetRealOutpointPrivateSendRounds(const COutPoint& outpoint, int nRo
     uint256 hash = outpoint.hash;
     unsigned int nout = outpoint.n;
 
+    // TODO wtx should refer to a CWalletTx object, not a pointer, based on surrounding code
     const CWalletTx* wtx = GetWalletTx(hash);
     if(wtx != nullptr)
     {
@@ -1500,7 +1504,7 @@ int CWallet::GetRealOutpointPrivateSendRounds(const COutPoint& outpoint, int nRo
         if (mdwi == mDenomWtxes.end()) {
             // not known yet, let's add it
             LogPrint(BCLog::PRIVATESEND, "GetRealOutpointPrivateSendRounds INSERTING %s\n", hash.ToString());
-            mDenomWtxes[hash] = CMutableTransaction(*wtx);
+            mDenomWtxes[hash] = CMutableTransaction(*wtx->tx);
         } else if(mDenomWtxes[hash].vout[nout].nRounds != -10) {
             // found and it's not an initial value, just return it
             return mDenomWtxes[hash].vout[nout].nRounds;
@@ -2043,7 +2047,7 @@ bool CWalletTx::RelayWalletTransaction(CConnman* connman)
             LogPrintf("Relaying wtx %s\n", hash.ToString());
 
             if (connman) {
-                connman->RelayTransaction((CTransaction)*this);
+                connman->RelayTransaction(*tx);
                 return true;
             }
         }
@@ -2075,7 +2079,7 @@ CAmount CWalletTx::GetDebit(const isminefilter& filter) const
             debit += nDebitCached;
         else
         {
-            nDebitCached = pwallet->GetDebit(*this, ISMINE_SPENDABLE);
+            nDebitCached = pwallet->GetDebit(*tx, ISMINE_SPENDABLE);
             fDebitCached = true;
             debit += nDebitCached;
         }
@@ -2086,7 +2090,7 @@ CAmount CWalletTx::GetDebit(const isminefilter& filter) const
             debit += nWatchDebitCached;
         else
         {
-            nWatchDebitCached = pwallet->GetDebit(*this, ISMINE_WATCH_ONLY);
+            nWatchDebitCached = pwallet->GetDebit(*tx, ISMINE_WATCH_ONLY);
             fWatchDebitCached = true;
             debit += nWatchDebitCached;
         }
@@ -2108,7 +2112,7 @@ CAmount CWalletTx::GetCredit(const isminefilter& filter) const
             credit += nCreditCached;
         else
         {
-            nCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
+            nCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
             fCreditCached = true;
             credit += nCreditCached;
         }
@@ -2119,7 +2123,7 @@ CAmount CWalletTx::GetCredit(const isminefilter& filter) const
             credit += nWatchCreditCached;
         else
         {
-            nWatchCreditCached = pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
+            nWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
             fWatchCreditCached = true;
             credit += nWatchCreditCached;
         }
@@ -2133,7 +2137,7 @@ CAmount CWalletTx::GetImmatureCredit(bool fUseCache) const
     {
         if (fUseCache && fImmatureCreditCached)
             return nImmatureCreditCached;
-        nImmatureCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
+        nImmatureCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
         fImmatureCreditCached = true;
         return nImmatureCreditCached;
     }
@@ -2177,7 +2181,7 @@ CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool& fUseCache) const
     {
         if (fUseCache && fImmatureWatchCreditCached)
             return nImmatureWatchCreditCached;
-        nImmatureWatchCreditCached = pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
+        nImmatureWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
         fImmatureWatchCreditCached = true;
         return nImmatureWatchCreditCached;
     }
@@ -2297,7 +2301,7 @@ CAmount CWalletTx::GetChange() const
 {
     if (fChangeCached)
         return nChangeCached;
-    nChangeCached = pwallet->GetChange(*this);
+    nChangeCached = pwallet->GetChange(*tx);
     fChangeCached = true;
     return nChangeCached;
 }
@@ -2311,7 +2315,7 @@ bool CWalletTx::InMempool() const
 bool CWalletTx::IsTrusted() const
 {
     // Quick answer in most cases
-    if (!CheckFinalTx(*this))
+    if (!CheckFinalTx(*tx))
         return false;
     int nDepth = GetDepthInMainChain();
     if (nDepth >= 1)
@@ -2677,7 +2681,7 @@ void CWallet::AvailableCoins(std::vector<COutput> &vCoins, bool fOnlySafe, const
         for (auto pcoin : GetSpendableTXs()) {
             const uint256& wtxid = pcoin->GetHash();
 
-            if (!CheckFinalTx(*pcoin))
+            if (!CheckFinalTx(*pcoin->tx))
                 continue;
 
             if (pcoin->IsCoinBase() && pcoin->GetBlocksToMaturity() > 0)
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 2ca5aee8f844..728799d5863f 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -229,10 +229,6 @@ class CMerkleTx
         Init();
     }
 
-    /** Helper conversion operator to allow passing CMerkleTx where CTransaction is expected.
-     *  TODO: adapt callers and remove this operator. */
-    operator const CTransaction&() const { return *tx; }
-
     void Init()
     {
         hashBlock = uint256();
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index d98b51343df1..3c9b96a617f8 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -275,7 +275,7 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
             CWalletTx wtx;
             ssValue >> wtx;
             CValidationState state;
-            if (!(CheckTransaction(wtx, state) && (wtx.GetHash() == hash) && state.IsValid()))
+            if (!(CheckTransaction(*wtx.tx, state) && (wtx.GetHash() == hash) && state.IsValid()))
                 return false;
 
             // Undo serialize changes in 31600
diff --git a/test/functional/blockchain.py b/test/functional/blockchain.py
index 0f7ae48c980c..b92877122d70 100755
--- a/test/functional/blockchain.py
+++ b/test/functional/blockchain.py
@@ -5,6 +5,7 @@
 """Test RPCs related to blockchainstate.
 
 Test the following RPCs:
+    - getblockchaininfo
     - gettxoutsetinfo
     - getdifficulty
     - getbestblockhash
@@ -67,6 +68,7 @@ def _test_getblockchaininfo(self):
             'chainwork',
             'difficulty',
             'headers',
+            'initialblockdownload',
             'mediantime',
             'pruned',
             'size_on_disk',
diff --git a/test/functional/receivedby.py b/test/functional/receivedby.py
index c06477c745cc..95e664366933 100755
--- a/test/functional/receivedby.py
+++ b/test/functional/receivedby.py
@@ -3,97 +3,83 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test the listreceivedbyaddress RPC."""
+from decimal import Decimal
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import *
-
-def get_sub_array_from_array(object_array, to_match):
-    '''
-        Finds and returns a sub array from an array of arrays.
-        to_match should be a unique idetifier of a sub array
-    '''
-    for item in object_array:
-        all_match = True
-        for key,value in to_match.items():
-            if item[key] != value:
-                all_match = False
-        if not all_match:
-            continue
-        return item
-    return []
+from test_framework.util import (assert_array_result,
+                                 assert_equal,
+                                 assert_raises_rpc_error,
+                                 )
 
 class ReceivedByTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
-        self.set_cache_mocktime()
 
     def run_test(self):
-        '''
-        listreceivedbyaddress Test
-        '''
+        # Generate block to get out of IBD
+        self.nodes[0].generate(1)
+
+        self.log.info("listreceivedbyaddress Test")
+
         # Send from node 0 to 1
         addr = self.nodes[1].getnewaddress()
         txid = self.nodes[0].sendtoaddress(addr, 0.1)
         self.sync_all()
 
-        #Check not listed in listreceivedbyaddress because has 0 confirmations
+        # Check not listed in listreceivedbyaddress because has 0 confirmations
         assert_array_result(self.nodes[1].listreceivedbyaddress(),
-                           {"address":addr},
-                           { },
-                           True)
-        #Bury Tx under 10 block so it will be returned by listreceivedbyaddress
+                            {"address": addr},
+                            {},
+                            True)
+        # Bury Tx under 10 block so it will be returned by listreceivedbyaddress
         self.nodes[1].generate(10)
         self.sync_all()
         assert_array_result(self.nodes[1].listreceivedbyaddress(),
-                           {"address":addr},
-                           {"address":addr, "account":"", "amount":Decimal("0.1"), "confirmations":10, "txids":[txid,]})
-        #With min confidence < 10
+                            {"address": addr},
+                            {"address": addr, "account": "", "amount": Decimal("0.1"), "confirmations": 10, "txids": [txid, ]})
+        # With min confidence < 10
         assert_array_result(self.nodes[1].listreceivedbyaddress(5),
-                           {"address":addr},
-                           {"address":addr, "account":"", "amount":Decimal("0.1"), "confirmations":10, "txids":[txid,]})
-        #With min confidence > 10, should not find Tx
-        assert_array_result(self.nodes[1].listreceivedbyaddress(11),{"address":addr},{ },True)
+                            {"address": addr},
+                            {"address": addr, "account": "", "amount": Decimal("0.1"), "confirmations": 10, "txids": [txid, ]})
+        # With min confidence > 10, should not find Tx
+        assert_array_result(self.nodes[1].listreceivedbyaddress(11), {"address": addr}, {}, True)
 
-        #Empty Tx
+        # Empty Tx
         addr = self.nodes[1].getnewaddress()
         assert_array_result(self.nodes[1].listreceivedbyaddress(0, False, True),
                            {"address":addr},
                            {"address":addr, "account":"", "amount":0, "confirmations":0, "txids":[]})
 
-        '''
-            getreceivedbyaddress Test
-        '''
+        self.log.info("getreceivedbyaddress Test")
+
         # Send from node 0 to 1
         addr = self.nodes[1].getnewaddress()
         txid = self.nodes[0].sendtoaddress(addr, 0.1)
         self.sync_all()
 
-        #Check balance is 0 because of 0 confirmations
+        # Check balance is 0 because of 0 confirmations
         balance = self.nodes[1].getreceivedbyaddress(addr)
-        if balance != Decimal("0.0"):
-            raise AssertionError("Wrong balance returned by getreceivedbyaddress, %0.2f"%(balance))
+        assert_equal(balance, Decimal("0.0"))
 
-        #Check balance is 0.1
-        balance = self.nodes[1].getreceivedbyaddress(addr,0)
-        if balance != Decimal("0.1"):
-            raise AssertionError("Wrong balance returned by getreceivedbyaddress, %0.2f"%(balance))
+        # Check balance is 0.1
+        balance = self.nodes[1].getreceivedbyaddress(addr, 0)
+        assert_equal(balance, Decimal("0.1"))
 
-        #Bury Tx under 10 block so it will be returned by the default getreceivedbyaddress
+        # Bury Tx under 10 block so it will be returned by the default getreceivedbyaddress
         self.nodes[1].generate(10)
         self.sync_all()
         balance = self.nodes[1].getreceivedbyaddress(addr)
-        if balance != Decimal("0.1"):
-            raise AssertionError("Wrong balance returned by getreceivedbyaddress, %0.2f"%(balance))
+        assert_equal(balance, Decimal("0.1"))
+
+        # Trying to getreceivedby for an address the wallet doesn't own should return an error
+        assert_raises_rpc_error(-4, "Address not found in wallet", self.nodes[0].getreceivedbyaddress, addr)
+
+        self.log.info("listreceivedbyaccount + getreceivedbyaccount Test")
 
-        '''
-            listreceivedbyaccount + getreceivedbyaccount Test
-        '''
-        #set pre-state
+        # set pre-state
         addrArr = self.nodes[1].getnewaddress()
         account = self.nodes[1].getaccount(addrArr)
-        received_by_account_json = get_sub_array_from_array(self.nodes[1].listreceivedbyaccount(),{"account":account})
-        if len(received_by_account_json) == 0:
-            raise AssertionError("No accounts found in node")
+        received_by_account_json = [r for r in self.nodes[1].listreceivedbyaccount() if r["account"] == account][0]
         balance_by_account = self.nodes[1].getreceivedbyaccount(account)
 
         txid = self.nodes[0].sendtoaddress(addr, 0.1)
@@ -101,40 +87,34 @@ def run_test(self):
 
         # listreceivedbyaccount should return received_by_account_json because of 0 confirmations
         assert_array_result(self.nodes[1].listreceivedbyaccount(),
-                           {"account":account},
-                           received_by_account_json)
+                            {"account": account},
+                            received_by_account_json)
 
         # getreceivedbyaddress should return same balance because of 0 confirmations
         balance = self.nodes[1].getreceivedbyaccount(account)
-        if balance != balance_by_account:
-            raise AssertionError("Wrong balance returned by getreceivedbyaccount, %0.2f"%(balance))
+        assert_equal(balance, balance_by_account)
 
         self.nodes[1].generate(10)
         self.sync_all()
         # listreceivedbyaccount should return updated account balance
         assert_array_result(self.nodes[1].listreceivedbyaccount(),
-                           {"account":account},
-                           {"account":received_by_account_json["account"], "amount":(received_by_account_json["amount"] + Decimal("0.1"))})
+                            {"account": account},
+                            {"account": received_by_account_json["account"], "amount": (received_by_account_json["amount"] + Decimal("0.1"))})
 
         # getreceivedbyaddress should return updates balance
         balance = self.nodes[1].getreceivedbyaccount(account)
-        if balance != balance_by_account + Decimal("0.1"):
-            raise AssertionError("Wrong balance returned by getreceivedbyaccount, %0.2f"%(balance))
+        assert_equal(balance, balance_by_account + Decimal("0.1"))
 
-        #Create a new account named "mynewaccount" that has a 0 balance
+        # Create a new account named "mynewaccount" that has a 0 balance
         self.nodes[1].getaccountaddress("mynewaccount")
-        received_by_account_json = get_sub_array_from_array(self.nodes[1].listreceivedbyaccount(0, False, True),{"account":"mynewaccount"})
-        if len(received_by_account_json) == 0:
-            raise AssertionError("No accounts found in node")
+        received_by_account_json = [r for r in self.nodes[1].listreceivedbyaccount(0, False, True) if r["account"] == "mynewaccount"][0]
 
         # Test includeempty of listreceivedbyaccount
-        if received_by_account_json["amount"] != Decimal("0.0"):
-            raise AssertionError("Wrong balance returned by listreceivedbyaccount, %0.2f"%(received_by_account_json["amount"]))
+        assert_equal(received_by_account_json["amount"], Decimal("0.0"))
 
         # Test getreceivedbyaccount for 0 amount accounts
         balance = self.nodes[1].getreceivedbyaccount("mynewaccount")
-        if balance != Decimal("0.0"):
-            raise AssertionError("Wrong balance returned by getreceivedbyaccount, %0.2f"%(balance))
+        assert_equal(balance, Decimal("0.0"))
 
 if __name__ == '__main__':
     ReceivedByTest().main()
diff --git a/test/functional/wallet-accounts.py b/test/functional/wallet-accounts.py
index e267dcfada0c..ea976a35437b 100755
--- a/test/functional/wallet-accounts.py
+++ b/test/functional/wallet-accounts.py
@@ -74,62 +74,135 @@ def run_test(self):
         # otherwise we're off by exactly the fee amount as that's mined
         # and matures in the next 100 blocks
         node.sendfrom("", common_address, fee)
-        accounts = ["a", "b", "c", "d", "e"]
         amount_to_send = 1.0
-        account_addresses = dict()
+
+        # Create accounts and make sure subsequent account API calls
+        # recognize the account/address associations.
+        accounts = [Account(name) for name in ("a", "b", "c", "d", "e")]
         for account in accounts:
-            address = node.getaccountaddress(account)
-            account_addresses[account] = address
-            
-            node.getnewaddress(account)
-            assert_equal(node.getaccount(address), account)
-            assert(address in node.getaddressesbyaccount(account))
-            
-            node.sendfrom("", address, amount_to_send)
-        
+            account.add_receive_address(node.getaccountaddress(account.name))
+            account.verify(node)
+
+        # Send a transaction to each account, and make sure this forces
+        # getaccountaddress to generate a new receiving address.
+        for account in accounts:
+            node.sendtoaddress(account.receive_address, amount_to_send)
+            account.add_receive_address(node.getaccountaddress(account.name))
+            account.verify(node)
+
+        # Check the amounts received.
         node.generate(1)
-        
-        for i in range(len(accounts)):
-            from_account = accounts[i]
+        for account in accounts:
+            assert_equal(
+                node.getreceivedbyaddress(account.addresses[0]), amount_to_send)
+            assert_equal(node.getreceivedbyaccount(account.name), amount_to_send)
+
+        # Check that sendfrom account reduces listaccounts balances.
+        for i, account in enumerate(accounts):
             to_account = accounts[(i+1) % len(accounts)]
-            to_address = account_addresses[to_account]
-            node.sendfrom(from_account, to_address, amount_to_send)
-        
+            node.sendfrom(account.name, to_account.receive_address, amount_to_send)
         node.generate(1)
-        
         for account in accounts:
-            address = node.getaccountaddress(account)
-            assert(address != account_addresses[account])
-            assert_equal(node.getreceivedbyaccount(account), 2)
-            node.move(account, "", node.getbalance(account))
-
+            account.add_receive_address(node.getaccountaddress(account.name))
+            account.verify(node)
+            assert_equal(node.getreceivedbyaccount(account.name), 2)
+            node.move(account.name, "", node.getbalance(account.name))
+            account.verify(node)
         node.generate(101)
-        
         expected_account_balances = {"": 52000}
         for account in accounts:
-            expected_account_balances[account] = 0
-        
+            expected_account_balances[account.name] = 0
         assert_equal(node.listaccounts(), expected_account_balances)
-        
         assert_equal(node.getbalance(""), 52000)
         
+        # Check that setaccount can assign an account to a new unused address.
         for account in accounts:
             address = node.getaccountaddress("")
-            node.setaccount(address, account)
-            assert(address in node.getaddressesbyaccount(account))
+            node.setaccount(address, account.name)
+            account.add_address(address)
+            account.verify(node)
             assert(address not in node.getaddressesbyaccount(""))
         
+        # Check that addmultisigaddress can assign accounts.
         for account in accounts:
             addresses = []
             for x in range(10):
                 addresses.append(node.getnewaddress())
-            multisig_address = node.addmultisigaddress(5, addresses, account)
+            multisig_address = node.addmultisigaddress(5, addresses, account.name)
+            account.add_address(multisig_address)
+            account.verify(node)
             node.sendfrom("", multisig_address, 50)
-        
         node.generate(101)
-        
         for account in accounts:
-            assert_equal(node.getbalance(account), 50)
+            assert_equal(node.getbalance(account.name), 50)
+
+        # Check that setaccount can change the account of an address from a
+        # different account.
+        change_account(node, accounts[0].addresses[0], accounts[0], accounts[1])
+
+        # Check that setaccount can change the account of an address which
+        # is the receiving address of a different account.
+        change_account(node, accounts[0].receive_address, accounts[0], accounts[1])
+
+        # Check that setaccount can set the account of an address already
+        # in the account. This is a no-op.
+        change_account(node, accounts[2].addresses[0], accounts[2], accounts[2])
+
+        # Check that setaccount can set the account of an address which is
+        # already the receiving address of the account. It would probably make
+        # sense for this to be a no-op, but right now it resets the receiving
+        # address, causing getaccountaddress to return a brand new address.
+        change_account(node, accounts[2].receive_address, accounts[2], accounts[2])
+
+class Account:
+    def __init__(self, name):
+        # Account name
+        self.name = name
+        # Current receiving address associated with this account.
+        self.receive_address = None
+        # List of all addresses assigned with this account
+        self.addresses = []
+
+    def add_address(self, address):
+        assert_equal(address not in self.addresses, True)
+        self.addresses.append(address)
+
+    def add_receive_address(self, address):
+        self.add_address(address)
+        self.receive_address = address
+
+    def verify(self, node):
+        if self.receive_address is not None:
+            assert self.receive_address in self.addresses
+            assert_equal(node.getaccountaddress(self.name), self.receive_address)
+
+        for address in self.addresses:
+            assert_equal(node.getaccount(address), self.name)
+
+        assert_equal(
+            set(node.getaddressesbyaccount(self.name)), set(self.addresses))
+
+
+def change_account(node, address, old_account, new_account):
+    assert_equal(address in old_account.addresses, True)
+    node.setaccount(address, new_account.name)
+
+    old_account.addresses.remove(address)
+    new_account.add_address(address)
+
+    # Calling setaccount on an address which was previously the receiving
+    # address of a different account should reset the receiving address of
+    # the old account, causing getaccountaddress to return a brand new
+    # address.
+    if address == old_account.receive_address:
+        new_address = node.getaccountaddress(old_account.name)
+        assert_equal(new_address not in old_account.addresses, True)
+        assert_equal(new_address not in new_account.addresses, True)
+        old_account.add_receive_address(new_address)
+
+    old_account.verify(node)
+    new_account.verify(node)
+
 
 if __name__ == '__main__':
     WalletAccountsTest().main()