Merge #11447: 0.15.1: Backports

20cdc2b Fix importmulti bug when importing an already imported key (Pedro Branco)
405e069 Update importprivkey named args documentation (Dusty Williams)
c94527a [Docs] Update Windows build instructions for using WSL and Ubuntu 17.04 (fanquake)
27e861a net: Improve and document SOCKS code (Wladimir J. van der Laan)
dea3b87 Add new step to clean $PATH var by removing /mnt specific Window's %PATH% paths that cause issues with the make system (Donal OConnor)
a43be5b rpc: Prevent `dumpwallet` from overwriting files (Wladimir J. van der Laan)
b6c0209 Fix validationinterface build on super old boost/clang (Matt Corallo)
6a62c74 qt: Backup former GUI settings on `-resetguisettings` (Wladimir J. van der Laan)
0fe2a9a when clearing addrman clear mapInfo and mapAddr (Gregory Sanders)
6b4d9f2 wallet: update stored witness in AddToWallet (Suhas Daftuar)
62d18cd doc: Prepare release notes for 0.15.1 (MarcoFalke)
8b61aee Put back inadvertently removed copyright notices (Paul Berg)
75997c3 Disallow uncompressed pubkeys in bitcoin-tx [multisig] output adds (Matt Corallo)
8d13b42 Replace save|restoreWindowGeometry with Qt functions (MeshCollider)
6642558 [Qt] Add delay before filtering transactions Fixes 3141 (Lucas Betschart)
19d63e8 Remove custom fee radio group (Andrew Chow)
b1a6c94 rpc: make estimatesmartfee argument naming consistent with documentation (Wladimir J. van der Laan)
921542e rpc: update cli for estimatefee argument rename (Wladimir J. van der Laan)
2e31b1d Fix division by zero in time remaining (MeshCollider)
47c02a8 qt: Use IsMine to validate custom change address (Chris Moore)
7310f1f [Qt] Fix display of package name on 'open config file' tooltip (Daniel Edgecumbe)
2cb720a Acquire cs_main lock before cs_wallet during wallet initialization (Russell Yanofsky)
b278a43 rpc: Write authcookie atomically (Wladimir J. van der Laan)
50bd3f6 Avoid returning a BIP9Stats object with uninitialized values (practicalswift)
9e8aae3 [wallet] Close DB on error. (Karl-Johan Alm)

Pull request description:

  This mostly backports various commits that fix(ed) bugs and issues.

  However, it also includes two patches for qt that only fix minor issues,
  as well as some doc patches.

Tree-SHA512: 5165e309faf6b4395fdf2f6662ccc0d58306971f3769e675504f17b2055efe29b2919f22d0dbf78c4c2dc7fd5c9d08a2c53345615e4a1df73914526687c9d571

25 files changed, 242 insertions, 141 deletions

diff --git a/src/addrman.h b/src/addrman.h
index 547088aedf..18f3062287 100644
--- a/src/addrman.h
+++ b/src/addrman.h
@@ -472,6 +472,8 @@ public:
         nTried = 0;
         nNew = 0;
         nLastGood = 1; //Initially at 1 so that "never" is strictly worse.
+        mapInfo.clear();
+        mapAddr.clear();
     }
 
     CAddrMan()
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
index cff90d13af..0f2c19bd5d 100644
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -310,6 +310,9 @@ static void MutateTxAddOutPubKey(CMutableTransaction& tx, const std::string& str
     }
 
     if (bSegWit) {
+        if (!pubkey.IsCompressed()) {
+            throw std::runtime_error("Uncompressed pubkeys are not useable for SegWit outputs");
+        }
         // Call GetScriptForWitness() to build a P2WSH scriptPubKey
         scriptPubKey = GetScriptForWitness(scriptPubKey);
     }
@@ -377,6 +380,11 @@ static void MutateTxAddOutMultiSig(CMutableTransaction& tx, const std::string& s
     CScript scriptPubKey = GetScriptForMultisig(required, pubkeys);
 
     if (bSegWit) {
+        for (CPubKey& pubkey : pubkeys) {
+            if (!pubkey.IsCompressed()) {
+                throw std::runtime_error("Uncompressed pubkeys are not useable for SegWit outputs");
+            }
+        }
         // Call GetScriptForWitness() to build a P2WSH scriptPubKey
         scriptPubKey = GetScriptForWitness(scriptPubKey);
     }
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 05f9f6961c..914124cb17 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -184,6 +184,48 @@ struct timeval MillisToTimeval(int64_t nTimeout)
     return timeout;
 }
 
+/** SOCKS version */
+enum SOCKSVersion: uint8_t {
+    SOCKS4 = 0x04,
+    SOCKS5 = 0x05
+};
+
+/** Values defined for METHOD in RFC1928 */
+enum SOCKS5Method: uint8_t {
+    NOAUTH = 0x00,        //! No authentication required
+    GSSAPI = 0x01,        //! GSSAPI
+    USER_PASS = 0x02,     //! Username/password
+    NO_ACCEPTABLE = 0xff, //! No acceptable methods
+};
+
+/** Values defined for CMD in RFC1928 */
+enum SOCKS5Command: uint8_t {
+    CONNECT = 0x01,
+    BIND = 0x02,
+    UDP_ASSOCIATE = 0x03
+};
+
+/** Values defined for REP in RFC1928 */
+enum SOCKS5Reply: uint8_t {
+    SUCCEEDED = 0x00,        //! Succeeded
+    GENFAILURE = 0x01,       //! General failure
+    NOTALLOWED = 0x02,       //! Connection not allowed by ruleset
+    NETUNREACHABLE = 0x03,   //! Network unreachable
+    HOSTUNREACHABLE = 0x04,  //! Network unreachable
+    CONNREFUSED = 0x05,      //! Connection refused
+    TTLEXPIRED = 0x06,       //! TTL expired
+    CMDUNSUPPORTED = 0x07,   //! Command not supported
+    ATYPEUNSUPPORTED = 0x08, //! Address type not supported
+};
+
+/** Values defined for ATYPE in RFC1928 */
+enum SOCKS5Atyp: uint8_t {
+    IPV4 = 0x01,
+    DOMAINNAME = 0x03,
+    IPV6 = 0x04,
+};
+
+/** Status codes that can be returned by InterruptibleRecv */
 enum class IntrRecvError {
     OK,
     Timeout,
@@ -203,7 +245,7 @@ enum class IntrRecvError {
  *
  * @note This function requires that hSocket is in non-blocking mode.
  */
-static IntrRecvError InterruptibleRecv(char* data, size_t len, int timeout, const SOCKET& hSocket)
+static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, int timeout, const SOCKET& hSocket)
 {
     int64_t curTime = GetTimeMillis();
     int64_t endTime = curTime + timeout;
@@ -211,7 +253,7 @@ static IntrRecvError InterruptibleRecv(char* data, size_t len, int timeout, cons
     // to break off in case of an interruption.
     const int64_t maxWait = 1000;
     while (len > 0 && curTime < endTime) {
-        ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
+        ssize_t ret = recv(hSocket, (char*)data, len, 0); // Optimistically try the recv first
         if (ret > 0) {
             len -= ret;
             data += ret;
@@ -242,24 +284,35 @@ static IntrRecvError InterruptibleRecv(char* data, size_t len, int timeout, cons
     return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout;
 }
 
+/** Credentials for proxy authentication */
 struct ProxyCredentials
 {
     std::string username;
     std::string password;
 };
 
-std::string Socks5ErrorString(int err)
+/** Convert SOCKS5 reply to a an error message */
+std::string Socks5ErrorString(uint8_t err)
 {
     switch(err) {
-        case 0x01: return "general failure";
-        case 0x02: return "connection not allowed";
-        case 0x03: return "network unreachable";
-        case 0x04: return "host unreachable";
-        case 0x05: return "connection refused";
-        case 0x06: return "TTL expired";
-        case 0x07: return "protocol error";
-        case 0x08: return "address type not supported";
-        default:   return "unknown";
+        case SOCKS5Reply::GENFAILURE:
+            return "general failure";
+        case SOCKS5Reply::NOTALLOWED:
+            return "connection not allowed";
+        case SOCKS5Reply::NETUNREACHABLE:
+            return "network unreachable";
+        case SOCKS5Reply::HOSTUNREACHABLE:
+            return "host unreachable";
+        case SOCKS5Reply::CONNREFUSED:
+            return "connection refused";
+        case SOCKS5Reply::TTLEXPIRED:
+            return "TTL expired";
+        case SOCKS5Reply::CMDUNSUPPORTED:
+            return "protocol error";
+        case SOCKS5Reply::ATYPEUNSUPPORTED:
+            return "address type not supported";
+        default:
+            return "unknown";
     }
 }
 
@@ -274,34 +327,34 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
     }
     // Accepted authentication methods
     std::vector<uint8_t> vSocks5Init;
-    vSocks5Init.push_back(0x05);
+    vSocks5Init.push_back(SOCKSVersion::SOCKS5);
     if (auth) {
-        vSocks5Init.push_back(0x02); // # METHODS
-        vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
-        vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
+        vSocks5Init.push_back(0x02); // Number of methods
+        vSocks5Init.push_back(SOCKS5Method::NOAUTH);
+        vSocks5Init.push_back(SOCKS5Method::USER_PASS);
     } else {
-        vSocks5Init.push_back(0x01); // # METHODS
-        vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
+        vSocks5Init.push_back(0x01); // Number of methods
+        vSocks5Init.push_back(SOCKS5Method::NOAUTH);
     }
     ssize_t ret = send(hSocket, (const char*)vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL);
     if (ret != (ssize_t)vSocks5Init.size()) {
         CloseSocket(hSocket);
         return error("Error sending to proxy");
     }
-    char pchRet1[2];
+    uint8_t pchRet1[2];
     if ((recvr = InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
         CloseSocket(hSocket);
         LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
         return false;
     }
-    if (pchRet1[0] != 0x05) {
+    if (pchRet1[0] != SOCKSVersion::SOCKS5) {
         CloseSocket(hSocket);
         return error("Proxy failed to initialize");
     }
-    if (pchRet1[1] == 0x02 && auth) {
+    if (pchRet1[1] == SOCKS5Method::USER_PASS && auth) {
         // Perform username/password authentication (as described in RFC1929)
         std::vector<uint8_t> vAuth;
-        vAuth.push_back(0x01);
+        vAuth.push_back(0x01); // Current (and only) version of user/pass subnegotiation
         if (auth->username.size() > 255 || auth->password.size() > 255)
             return error("Proxy username or password too long");
         vAuth.push_back(auth->username.size());
@@ -314,7 +367,7 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
             return error("Error sending authentication to proxy");
         }
         LogPrint(BCLog::PROXY, "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
-        char pchRetA[2];
+        uint8_t pchRetA[2];
         if ((recvr = InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
             CloseSocket(hSocket);
             return error("Error reading proxy authentication response");
@@ -323,17 +376,17 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
             CloseSocket(hSocket);
             return error("Proxy authentication unsuccessful");
         }
-    } else if (pchRet1[1] == 0x00) {
+    } else if (pchRet1[1] == SOCKS5Method::NOAUTH) {
         // Perform no authentication
     } else {
         CloseSocket(hSocket);
         return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
     }
     std::vector<uint8_t> vSocks5;
-    vSocks5.push_back(0x05); // VER protocol version
-    vSocks5.push_back(0x01); // CMD CONNECT
-    vSocks5.push_back(0x00); // RSV Reserved
-    vSocks5.push_back(0x03); // ATYP DOMAINNAME
+    vSocks5.push_back(SOCKSVersion::SOCKS5); // VER protocol version
+    vSocks5.push_back(SOCKS5Command::CONNECT); // CMD CONNECT
+    vSocks5.push_back(0x00); // RSV Reserved must be 0
+    vSocks5.push_back(SOCKS5Atyp::DOMAINNAME); // ATYP DOMAINNAME
     vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
     vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
     vSocks5.push_back((port >> 8) & 0xFF);
@@ -343,7 +396,7 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
         CloseSocket(hSocket);
         return error("Error sending to proxy");
     }
-    char pchRet2[4];
+    uint8_t pchRet2[4];
     if ((recvr = InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
         CloseSocket(hSocket);
         if (recvr == IntrRecvError::Timeout) {
@@ -355,26 +408,26 @@ static bool Socks5(const std::string& strDest, int port, const ProxyCredentials
             return error("Error while reading proxy response");
         }
     }
-    if (pchRet2[0] != 0x05) {
+    if (pchRet2[0] != SOCKSVersion::SOCKS5) {
         CloseSocket(hSocket);
         return error("Proxy failed to accept request");
     }
-    if (pchRet2[1] != 0x00) {
+    if (pchRet2[1] != SOCKS5Reply::SUCCEEDED) {
         // Failures to connect to a peer that are not proxy errors
         CloseSocket(hSocket);
         LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
         return false;
     }
-    if (pchRet2[2] != 0x00) {
+    if (pchRet2[2] != 0x00) { // Reserved field must be 0
         CloseSocket(hSocket);
         return error("Error: malformed proxy response");
     }
-    char pchRet3[256];
+    uint8_t pchRet3[256];
     switch (pchRet2[3])
     {
-        case 0x01: recvr = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
-        case 0x04: recvr = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
-        case 0x03:
+        case SOCKS5Atyp::IPV4: recvr = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
+        case SOCKS5Atyp::IPV6: recvr = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
+        case SOCKS5Atyp::DOMAINNAME:
         {
             recvr = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
             if (recvr != IntrRecvError::OK) {
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index e3970298e6..56373563b8 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -123,7 +123,11 @@ BitcoinGUI::BitcoinGUI(const PlatformStyle *_platformStyle, const NetworkStyle *
     spinnerFrame(0),
     platformStyle(_platformStyle)
 {
-    GUIUtil::restoreWindowGeometry("nWindow", QSize(850, 550), this);
+    QSettings settings;
+    if (!restoreGeometry(settings.value("MainWindowGeometry").toByteArray())) {
+        // Restore failed (perhaps missing setting), center the window
+        move(QApplication::desktop()->availableGeometry().center() - frameGeometry().center());
+    }
 
     QString windowTitle = tr(PACKAGE_NAME) + " - ";
 #ifdef ENABLE_WALLET
@@ -261,7 +265,8 @@ BitcoinGUI::~BitcoinGUI()
     // Unsubscribe from notifications from core
     unsubscribeFromCoreSignals();
 
-    GUIUtil::saveWindowGeometry("nWindow", this);
+    QSettings settings;
+    settings.setValue("MainWindowGeometry", saveGeometry());
     if(trayIcon) // Hide tray icon, as deleting will let it linger until quit (on Ubuntu)
         trayIcon->hide();
 #ifdef Q_OS_MAC
diff --git a/src/qt/forms/sendcoinsdialog.ui b/src/qt/forms/sendcoinsdialog.ui
index 1e2f2302b9..a0e48334c1 100644
--- a/src/qt/forms/sendcoinsdialog.ui
+++ b/src/qt/forms/sendcoinsdialog.ui
@@ -846,19 +846,13 @@
                <item>
                 <layout class="QHBoxLayout" name="horizontalLayoutFee13">
                  <item>
-                  <widget class="QRadioButton" name="radioCustomPerKilobyte">
+                  <widget class="QLabel" name="labelCustomPerKilobyte">
                    <property name="toolTip">
                     <string>If the custom fee is set to 1000 satoshis and the transaction is only 250 bytes, then &quot;per kilobyte&quot; only pays 250 satoshis in fee, while &quot;total at least&quot; pays 1000 satoshis. For transactions bigger than a kilobyte both pay by kilobyte.</string>
                    </property>
                    <property name="text">
                     <string>per kilobyte</string>
                    </property>
-                   <property name="checked">
-                    <bool>true</bool>
-                   </property>
-                   <attribute name="buttonGroup">
-                    <string notr="true">groupCustomFee</string>
-                   </attribute>
                   </widget>
                  </item>
                  <item>
@@ -1285,6 +1279,5 @@
  <connections/>
  <buttongroups>
   <buttongroup name="groupFee"/>
-  <buttongroup name="groupCustomFee"/>
  </buttongroups>
 </ui>
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index f3c5daebec..69c3e06869 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -842,32 +842,6 @@ bool SetStartOnSystemStartup(bool fAutoStart) { return false; }
 
 #endif
 
-void saveWindowGeometry(const QString& strSetting, QWidget *parent)
-{
-    QSettings settings;
-    settings.setValue(strSetting + "Pos", parent->pos());
-    settings.setValue(strSetting + "Size", parent->size());
-}
-
-void restoreWindowGeometry(const QString& strSetting, const QSize& defaultSize, QWidget *parent)
-{
-    QSettings settings;
-    QPoint pos = settings.value(strSetting + "Pos").toPoint();
-    QSize size = settings.value(strSetting + "Size", defaultSize).toSize();
-
-    parent->resize(size);
-    parent->move(pos);
-
-    if ((!pos.x() && !pos.y()) || (QApplication::desktop()->screenNumber(parent) == -1))
-    {
-        QRect screen = QApplication::desktop()->screenGeometry();
-        QPoint defaultPos((screen.width() - defaultSize.width()) / 2,
-                          (screen.height() - defaultSize.height()) / 2);
-        parent->resize(defaultSize);
-        parent->move(defaultPos);
-    }
-}
-
 void setClipboard(const QString& str)
 {
     QApplication::clipboard()->setText(str, QClipboard::Clipboard);
diff --git a/src/qt/guiutil.h b/src/qt/guiutil.h
index d6aa8c4ea6..d10818d0c8 100644
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -179,11 +179,6 @@ namespace GUIUtil
     bool GetStartOnSystemStartup();
     bool SetStartOnSystemStartup(bool fAutoStart);
 
-    /** Save window size and position */
-    void saveWindowGeometry(const QString& strSetting, QWidget *parent);
-    /** Restore window size and position */
-    void restoreWindowGeometry(const QString& strSetting, const QSize &defaultSizeIn, QWidget *parent);
-
     /* Convert QString to OS specific boost path through UTF-8 */
     fs::path qstringToBoostPath(const QString &path);
 
diff --git a/src/qt/modaloverlay.cpp b/src/qt/modaloverlay.cpp
index a83f285034..4f357e297d 100644
--- a/src/qt/modaloverlay.cpp
+++ b/src/qt/modaloverlay.cpp
@@ -99,15 +99,18 @@ void ModalOverlay::tipUpdate(int count, const QDateTime& blockDate, double nVeri
                 progressDelta = progressStart-sample.second;
                 timeDelta = blockProcessTime[0].first - sample.first;
                 progressPerHour = progressDelta/(double)timeDelta*1000*3600;
-                remainingMSecs = remainingProgress / progressDelta * timeDelta;
+                remainingMSecs = (progressDelta > 0) ? remainingProgress / progressDelta * timeDelta : -1;
                 break;
             }
         }
         // show progress increase per hour
         ui->progressIncreasePerH->setText(QString::number(progressPerHour*100, 'f', 2)+"%");
 
-        // show expected remaining time
-        ui->expectedTimeLeft->setText(GUIUtil::formatNiceTimeOffset(remainingMSecs/1000.0));
+        if(remainingMSecs >= 0) {	
+            ui->expectedTimeLeft->setText(GUIUtil::formatNiceTimeOffset(remainingMSecs / 1000.0));
+        } else {
+            ui->expectedTimeLeft->setText(QObject::tr("unknown"));
+        }
 
         static const int MAX_SAMPLES = 5000;
         if (blockProcessTime.count() > MAX_SAMPLES)
@@ -169,4 +172,4 @@ void ModalOverlay::closeClicked()
 {
     showHide(true);
     userClosed = true;
-}
+}
\ No newline at end of file
diff --git a/src/qt/optionsdialog.cpp b/src/qt/optionsdialog.cpp
index b80b6541dd..550884ed8e 100644
--- a/src/qt/optionsdialog.cpp
+++ b/src/qt/optionsdialog.cpp
@@ -80,6 +80,8 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
     ui->bitcoinAtStartup->setToolTip(ui->bitcoinAtStartup->toolTip().arg(tr(PACKAGE_NAME)));
     ui->bitcoinAtStartup->setText(ui->bitcoinAtStartup->text().arg(tr(PACKAGE_NAME)));
 
+    ui->openBitcoinConfButton->setToolTip(ui->openBitcoinConfButton->toolTip().arg(tr(PACKAGE_NAME)));
+
     ui->lang->setToolTip(ui->lang->toolTip().arg(tr(PACKAGE_NAME)));
     ui->lang->addItem(QString("(") + tr("default") + QString(")"), QVariant(""));
     for (const QString &langStr : translations.entryList())
diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp
index 77efef3e3c..a2dd52d9cb 100644
--- a/src/qt/optionsmodel.cpp
+++ b/src/qt/optionsmodel.cpp
@@ -151,10 +151,32 @@ void OptionsModel::Init(bool resetSettings)
     language = settings.value("language").toString();
 }
 
+/** Helper function to copy contents from one QSettings to another.
+ * By using allKeys this also covers nested settings in a hierarchy.
+ */
+static void CopySettings(QSettings& dst, const QSettings& src)
+{
+    for (const QString& key : src.allKeys()) {
+        dst.setValue(key, src.value(key));
+    }
+}
+
+/** Back up a QSettings to an ini-formatted file. */
+static void BackupSettings(const fs::path& filename, const QSettings& src)
+{
+    qWarning() << "Backing up GUI settings to" << GUIUtil::boostPathToQString(filename);
+    QSettings dst(GUIUtil::boostPathToQString(filename), QSettings::IniFormat);
+    dst.clear();
+    CopySettings(dst, src);
+}
+
 void OptionsModel::Reset()
 {
     QSettings settings;
 
+    // Backup old settings to chain-specific datadir for troubleshooting
+    BackupSettings(GetDataDir(true) / "guisettings.ini.bak", settings);
+
     // Save the strDataDir setting
     QString dataDir = Intro::getDefaultDataDirectory();
     dataDir = settings.value("strDataDir", dataDir).toString();
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 3590a98efa..d895fc1663 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -28,6 +28,7 @@
 #include <wallet/wallet.h>
 #endif
 
+#include <QDesktopWidget>
 #include <QKeyEvent>
 #include <QMenu>
 #include <QMessageBox>
@@ -428,7 +429,11 @@ RPCConsole::RPCConsole(const PlatformStyle *_platformStyle, QWidget *parent) :
     consoleFontSize(0)
 {
     ui->setupUi(this);
-    GUIUtil::restoreWindowGeometry("nRPCConsoleWindow", this->size(), this);
+    QSettings settings;
+    if (!restoreGeometry(settings.value("RPCConsoleWindowGeometry").toByteArray())) {
+        // Restore failed (perhaps missing setting), center the window
+        move(QApplication::desktop()->availableGeometry().center() - frameGeometry().center());
+    }
 
     ui->openDebugLogfileButton->setToolTip(ui->openDebugLogfileButton->toolTip().arg(tr(PACKAGE_NAME)));
 
@@ -466,14 +471,14 @@ RPCConsole::RPCConsole(const PlatformStyle *_platformStyle, QWidget *parent) :
     ui->detailWidget->hide();
     ui->peerHeading->setText(tr("Select a peer to view detailed information."));
 
-    QSettings settings;
     consoleFontSize = settings.value(fontSizeSettingsKey, QFontInfo(QFont()).pointSize()).toInt();
     clear();
 }
 
 RPCConsole::~RPCConsole()
 {
-    GUIUtil::saveWindowGeometry("nRPCConsoleWindow", this);
+    QSettings settings;
+    settings.setValue("RPCConsoleWindowGeometry", saveGeometry());
     RPCUnsetTimerInterface(rpcTimerInterface);
     delete rpcTimerInterface;
     delete ui;
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 38a475227e..96adae73da 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -114,10 +114,6 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
         settings.setValue("nFeeRadio", 1); // custom
     if (!settings.contains("nFeeRadio"))
         settings.setValue("nFeeRadio", 0); // recommended
-    if (!settings.contains("nCustomFeeRadio") && settings.contains("nTransactionFee") && settings.value("nTransactionFee").toLongLong() > 0) // compatibility
-        settings.setValue("nCustomFeeRadio", 1); // total at least
-    if (!settings.contains("nCustomFeeRadio"))
-        settings.setValue("nCustomFeeRadio", 0); // per kilobyte
     if (!settings.contains("nSmartFeeSliderPosition"))
         settings.setValue("nSmartFeeSliderPosition", 0);
     if (!settings.contains("nTransactionFee"))
@@ -127,8 +123,6 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->groupFee->setId(ui->radioSmartFee, 0);
     ui->groupFee->setId(ui->radioCustomFee, 1);
     ui->groupFee->button((int)std::max(0, std::min(1, settings.value("nFeeRadio").toInt())))->setChecked(true);
-    ui->groupCustomFee->setId(ui->radioCustomPerKilobyte, 0);
-    ui->groupCustomFee->button(0)->setChecked(true);
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     ui->checkBoxMinimumFee->setChecked(settings.value("fPayOnlyMinFee").toBool());
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
@@ -178,7 +172,6 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(updateFeeSectionControls()));
         connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(coinControlUpdateLabels()));
-        connect(ui->groupCustomFee, SIGNAL(buttonClicked(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->customFee, SIGNAL(valueChanged()), this, SLOT(coinControlUpdateLabels()));
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(setMinimumFee()));
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(updateFeeSectionControls()));
@@ -214,7 +207,6 @@ SendCoinsDialog::~SendCoinsDialog()
     QSettings settings;
     settings.setValue("fFeeSectionMinimized", fFeeMinimized);
     settings.setValue("nFeeRadio", ui->groupFee->checkedId());
-    settings.setValue("nCustomFeeRadio", ui->groupCustomFee->checkedId());
     settings.setValue("nConfTarget", getConfTargetForIndex(ui->confTargetSelector->currentIndex()));
     settings.setValue("nTransactionFee", (qint64)ui->customFee->value());
     settings.setValue("fPayOnlyMinFee", ui->checkBoxMinimumFee->isChecked());
@@ -609,7 +601,6 @@ void SendCoinsDialog::on_buttonMinimizeFee_clicked()
 
 void SendCoinsDialog::setMinimumFee()
 {
-    ui->radioCustomPerKilobyte->setChecked(true);
     ui->customFee->setValue(CWallet::GetRequiredFee(1000));
 }
 
@@ -622,7 +613,7 @@ void SendCoinsDialog::updateFeeSectionControls()
     ui->labelFeeEstimation      ->setEnabled(ui->radioSmartFee->isChecked());
     ui->checkBoxMinimumFee      ->setEnabled(ui->radioCustomFee->isChecked());
     ui->labelMinFeeWarning      ->setEnabled(ui->radioCustomFee->isChecked());
-    ui->radioCustomPerKilobyte  ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
+    ui->labelCustomPerKilobyte  ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
     ui->customFee               ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
 }
 
@@ -634,8 +625,7 @@ void SendCoinsDialog::updateFeeMinimizedLabel()
     if (ui->radioSmartFee->isChecked())
         ui->labelFeeMinimized->setText(ui->labelSmartFee->text());
     else {
-        ui->labelFeeMinimized->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), ui->customFee->value()) +
-            ((ui->radioCustomPerKilobyte->isChecked()) ? "/kB" : ""));
+        ui->labelFeeMinimized->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), ui->customFee->value()) + "/kB");
     }
 }
 
@@ -789,10 +779,8 @@ void SendCoinsDialog::coinControlChangeEdited(const QString& text)
         }
         else // Valid address
         {
-            CKeyID keyid;
-            addr.GetKeyID(keyid);
-            if (!model->havePrivKey(keyid)) // Unknown change address
-            {
+            const CTxDestination dest = addr.Get();
+            if (!model->IsSpendable(dest)) {
                 ui->labelCoinControlChangeLabel->setText(tr("Warning: Unknown change address"));
 
                 // confirmation dialog
@@ -800,7 +788,7 @@ void SendCoinsDialog::coinControlChangeEdited(const QString& text)
                     QMessageBox::Yes | QMessageBox::Cancel, QMessageBox::Cancel);
 
                 if(btnRetVal == QMessageBox::Yes)
-                    CoinControlDialog::coinControl->destChange = addr.Get();
+                    CoinControlDialog::coinControl->destChange = dest;
                 else
                 {
                     ui->lineEditCoinControlChange->setText("");
@@ -819,7 +807,7 @@ void SendCoinsDialog::coinControlChangeEdited(const QString& text)
                 else
                     ui->labelCoinControlChangeLabel->setText(tr("(no label)"));
 
-                CoinControlDialog::coinControl->destChange = addr.Get();
+                CoinControlDialog::coinControl->destChange = dest;
             }
         }
     }
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
index 53c38da9db..39dfdb587c 100644
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -33,6 +33,7 @@
 #include <QScrollBar>
 #include <QSignalMapper>
 #include <QTableView>
+#include <QTimer>
 #include <QUrl>
 #include <QVBoxLayout>
 
@@ -112,6 +113,17 @@ TransactionView::TransactionView(const PlatformStyle *platformStyle, QWidget *pa
     amountWidget->setValidator(new QDoubleValidator(0, 1e20, 8, this));
     hlayout->addWidget(amountWidget);
 
+    // Delay before filtering transactions in ms
+    static const int input_filter_delay = 200;
+
+    QTimer* amount_typing_delay = new QTimer(this);
+    amount_typing_delay->setSingleShot(true);
+    amount_typing_delay->setInterval(input_filter_delay);
+
+    QTimer* prefix_typing_delay = new QTimer(this);
+    prefix_typing_delay->setSingleShot(true);
+    prefix_typing_delay->setInterval(input_filter_delay);
+
     QVBoxLayout *vlayout = new QVBoxLayout(this);
     vlayout->setContentsMargins(0,0,0,0);
     vlayout->setSpacing(0);
@@ -173,8 +185,10 @@ TransactionView::TransactionView(const PlatformStyle *platformStyle, QWidget *pa
     connect(dateWidget, SIGNAL(activated(int)), this, SLOT(chooseDate(int)));
     connect(typeWidget, SIGNAL(activated(int)), this, SLOT(chooseType(int)));
     connect(watchOnlyWidget, SIGNAL(activated(int)), this, SLOT(chooseWatchonly(int)));
-    connect(addressWidget, SIGNAL(textChanged(QString)), this, SLOT(changedPrefix(QString)));
-    connect(amountWidget, SIGNAL(textChanged(QString)), this, SLOT(changedAmount(QString)));
+    connect(amountWidget, SIGNAL(textChanged(QString)), amount_typing_delay, SLOT(start()));
+    connect(amount_typing_delay, SIGNAL(timeout()), this, SLOT(changedAmount()));
+    connect(addressWidget, SIGNAL(textChanged(QString)), prefix_typing_delay, SLOT(start()));
+    connect(prefix_typing_delay, SIGNAL(timeout()), this, SLOT(changedPrefix()));
 
     connect(view, SIGNAL(doubleClicked(QModelIndex)), this, SIGNAL(doubleClicked(QModelIndex)));
     connect(view, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(contextualMenu(QPoint)));
@@ -312,20 +326,19 @@ void TransactionView::chooseWatchonly(int idx)
         (TransactionFilterProxy::WatchOnlyFilter)watchOnlyWidget->itemData(idx).toInt());
 }
 
-void TransactionView::changedPrefix(const QString &prefix)
+void TransactionView::changedPrefix()
 {
     if(!transactionProxyModel)
         return;
-    transactionProxyModel->setAddressPrefix(prefix);
+    transactionProxyModel->setAddressPrefix(addressWidget->text());
 }
 
-void TransactionView::changedAmount(const QString &amount)
+void TransactionView::changedAmount()
 {
     if(!transactionProxyModel)
         return;
     CAmount amount_parsed = 0;
-    if(BitcoinUnits::parse(model->getOptionsModel()->getDisplayUnit(), amount, &amount_parsed))
-    {
+    if (BitcoinUnits::parse(model->getOptionsModel()->getDisplayUnit(), amountWidget->text(), &amount_parsed)) {
         transactionProxyModel->setMinAmount(amount_parsed);
     }
     else
diff --git a/src/qt/transactionview.h b/src/qt/transactionview.h
index 52e57cae4c..5b4cfd4a88 100644
--- a/src/qt/transactionview.h
+++ b/src/qt/transactionview.h
@@ -112,8 +112,8 @@ public Q_SLOTS:
     void chooseDate(int idx);
     void chooseType(int idx);
     void chooseWatchonly(int idx);
-    void changedPrefix(const QString &prefix);
-    void changedAmount(const QString &amount);
+    void changedAmount();
+    void changedPrefix();
     void exportClicked();
     void focusTransaction(const QModelIndex&);
 
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 3ca726d0f9..aedbf22e4d 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -561,9 +561,9 @@ bool WalletModel::getPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
     return wallet->GetPubKey(address, vchPubKeyOut);
 }
 
-bool WalletModel::havePrivKey(const CKeyID &address) const
+bool WalletModel::IsSpendable(const CTxDestination& dest) const
 {
-    return wallet->HaveKey(address);
+    return IsMine(*wallet, dest) & ISMINE_SPENDABLE;
 }
 
 bool WalletModel::getPrivKey(const CKeyID &address, CKey& vchPrivKeyOut) const
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index 6be36a57e2..05733f8272 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -190,7 +190,7 @@ public:
     UnlockContext requestUnlock();
 
     bool getPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const;
-    bool havePrivKey(const CKeyID &address) const;
+    bool IsSpendable(const CTxDestination& dest) const;
     bool getPrivKey(const CKeyID &address, CKey& vchPrivKeyOut) const;
     void getOutputs(const std::vector<COutPoint>& vOutpoints, std::vector<COutput>& vOutputs);
     bool isSpent(const COutPoint& outpoint) const;
diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 4179453782..406ad2f6ec 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -115,8 +115,8 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "keypoolrefill", 0, "newsize" },
     { "getrawmempool", 0, "verbose" },
     { "estimatefee", 0, "nblocks" },
-    { "estimatesmartfee", 0, "nblocks" },
-    { "estimaterawfee", 0, "nblocks" },
+    { "estimatesmartfee", 0, "conf_target" },
+    { "estimaterawfee", 0, "conf_target" },
     { "estimaterawfee", 1, "threshold" },
     { "prioritisetransaction", 1, "dummy" },
     { "prioritisetransaction", 2, "fee_delta" },
diff --git a/src/rpc/protocol.cpp b/src/rpc/protocol.cpp
index db0626b5e1..dc6bcec382 100644
--- a/src/rpc/protocol.cpp
+++ b/src/rpc/protocol.cpp
@@ -66,9 +66,14 @@ static const std::string COOKIEAUTH_USER = "__cookie__";
 /** Default name for auth cookie file */
 static const std::string COOKIEAUTH_FILE = ".cookie";
 
-fs::path GetAuthCookieFile()
+/** Get name of RPC authentication cookie file */
+static fs::path GetAuthCookieFile(bool temp=false)
 {
-    fs::path path(gArgs.GetArg("-rpccookiefile", COOKIEAUTH_FILE));
+    std::string arg = gArgs.GetArg("-rpccookiefile", COOKIEAUTH_FILE);
+    if (temp) {
+        arg += ".tmp";
+    }
+    fs::path path(arg);
     if (!path.is_complete()) path = GetDataDir() / path;
     return path;
 }
@@ -84,14 +89,20 @@ bool GenerateAuthCookie(std::string *cookie_out)
      * these are set to 077 in init.cpp unless overridden with -sysperms.
      */
     std::ofstream file;
-    fs::path filepath = GetAuthCookieFile();
-    file.open(filepath.string().c_str());
+    fs::path filepath_tmp = GetAuthCookieFile(true);
+    file.open(filepath_tmp.string().c_str());
     if (!file.is_open()) {
-        LogPrintf("Unable to open cookie authentication file %s for writing\n", filepath.string());
+        LogPrintf("Unable to open cookie authentication file %s for writing\n", filepath_tmp.string());
         return false;
     }
     file << cookie;
     file.close();
+
+    fs::path filepath = GetAuthCookieFile(false);
+    if (!RenameOver(filepath_tmp, filepath)) {
+        LogPrintf("Unable to rename cookie authentication file %s to %s\n", filepath_tmp.string(), filepath.string());
+        return false;
+    }
     LogPrintf("Generated RPC authentication cookie %s\n", filepath.string());
 
     if (cookie_out)
diff --git a/src/rpc/protocol.h b/src/rpc/protocol.h
index 4bd4702d62..5c9c64f67d 100644
--- a/src/rpc/protocol.h
+++ b/src/rpc/protocol.h
@@ -91,8 +91,6 @@ UniValue JSONRPCReplyObj(const UniValue& result, const UniValue& error, const Un
 std::string JSONRPCReply(const UniValue& result, const UniValue& error, const UniValue& id);
 UniValue JSONRPCError(int code, const std::string& message);
 
-/** Get name of RPC authentication cookie file */
-fs::path GetAuthCookieFile();
 /** Generate a new RPC authentication cookie and write it to disk */
 bool GenerateAuthCookie(std::string *cookie_out);
 /** Read the RPC authentication cookie from disk */
diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index bf20d606f8..cd2fecd224 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -4,7 +4,9 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "validationinterface.h"
+
 #include "init.h"
+#include "primitives/block.h"
 #include "scheduler.h"
 #include "sync.h"
 #include "util.h"
diff --git a/src/versionbits.cpp b/src/versionbits.cpp
index 04a692d826..59588023ad 100644
--- a/src/versionbits.cpp
+++ b/src/versionbits.cpp
@@ -107,7 +107,7 @@ ThresholdState AbstractThresholdConditionChecker::GetStateFor(const CBlockIndex*
 // return the numerical statistics of blocks signalling the specified BIP9 condition in this current period
 BIP9Stats AbstractThresholdConditionChecker::GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params) const
 {
-    BIP9Stats stats;
+    BIP9Stats stats = {};
 
     stats.period = Period(params);
     stats.threshold = Threshold(params);
diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index b12d46e40a..d2fe4866fa 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -101,8 +101,10 @@ bool CDBEnv::Open(const fs::path& pathIn)
                              DB_RECOVER |
                              nEnvFlags,
                          S_IRUSR | S_IWUSR);
-    if (ret != 0)
+    if (ret != 0) {
+        dbenv->close(0);
         return error("CDBEnv::Open: Error %d opening database environment: %s\n", ret, DbEnv::strerror(ret));
+    }
 
     fDbEnvInit = true;
     fMockDb = false;
@@ -196,9 +198,9 @@ bool CDB::Recover(const std::string& filename, void *callbackDataIn, bool (*reco
                             DB_BTREE,           // Database type
                             DB_CREATE,          // Flags
                             0);
-    if (ret > 0)
-    {
+    if (ret > 0) {
         LogPrintf("Cannot create database file %s\n", filename);
+        pdbCopy->close(0);
         return false;
     }
 
@@ -536,8 +538,10 @@ bool CDB::Rewrite(CWalletDBWrapper& dbw, const char* pszSkip)
                         env->CloseDb(strFile);
                         if (pdbCopy->close(0))
                             fSuccess = false;
-                        delete pdbCopy;
+                    } else {
+                        pdbCopy->close(0);
                     }
+                    delete pdbCopy;
                 }
                 if (fSuccess) {
                     Db dbA(env->dbenv, 0);
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 67c6d9ec64..6c8ff7fc3b 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -79,10 +79,10 @@ UniValue importprivkey(const JSONRPCRequest& request)
 
     if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
         throw std::runtime_error(
-            "importprivkey \"bitcoinprivkey\" ( \"label\" ) ( rescan )\n"
+            "importprivkey \"privkey\" ( \"label\" ) ( rescan )\n"
             "\nAdds a private key (as returned by dumpprivkey) to your wallet.\n"
             "\nArguments:\n"
-            "1. \"bitcoinprivkey\"   (string, required) The private key (see dumpprivkey)\n"
+            "1. \"privkey\"          (string, required) The private key (see dumpprivkey)\n"
             "2. \"label\"            (string, optional, default=\"\") An optional label\n"
             "3. rescan               (boolean, optional, default=true) Rescan the wallet for transactions\n"
             "\nNote: This call can take minutes to complete if rescan is true.\n"
@@ -595,7 +595,7 @@ UniValue dumpwallet(const JSONRPCRequest& request)
     if (request.fHelp || request.params.size() != 1)
         throw std::runtime_error(
             "dumpwallet \"filename\"\n"
-            "\nDumps all wallet keys in a human-readable format.\n"
+            "\nDumps all wallet keys in a human-readable format to a server-side file. This does not allow overwriting existing files.\n"
             "\nArguments:\n"
             "1. \"filename\"    (string, required) The filename with path (either absolute or relative to bitcoind)\n"
             "\nResult:\n"
@@ -611,9 +611,19 @@ UniValue dumpwallet(const JSONRPCRequest& request)
 
     EnsureWalletIsUnlocked(pwallet);
 
-    std::ofstream file;
     boost::filesystem::path filepath = request.params[0].get_str();
     filepath = boost::filesystem::absolute(filepath);
+
+    /* Prevent arbitrary files from being overwritten. There have been reports
+     * that users have overwritten wallet files this way:
+     * https://github.com/bitcoin/bitcoin/issues/9934
+     * It may also avoid other security issues.
+     */
+    if (boost::filesystem::exists(filepath)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, filepath.string() + " already exists. If you are sure this is what you want, move it out of the way first");
+    }
+
+    std::ofstream file;
     file.open(filepath.string().c_str());
     if (!file.is_open())
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");
@@ -950,7 +960,7 @@ UniValue ProcessImport(CWallet * const pwallet, const UniValue& data, const int6
                 pwallet->SetAddressBook(vchAddress, label, "receive");
 
                 if (pwallet->HaveKey(vchAddress)) {
-                    return false;
+                    throw JSONRPCError(RPC_WALLET_ERROR, "The wallet already contains the private key for this address or script");
                 }
 
                 pwallet->mapKeyMetadata[vchAddress].nCreateTime = timestamp;
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 4a2cc9a139..5ebacd57d3 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -364,6 +364,12 @@ BOOST_AUTO_TEST_CASE(ApproximateBestSubset)
     empty_wallet();
 }
 
+static void AddKey(CWallet& wallet, const CKey& key)
+{
+    LOCK(wallet.cs_wallet);
+    wallet.AddKeyPubKey(key, key.GetPubKey());
+}
+
 BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup)
 {
     LOCK(cs_main);
@@ -379,8 +385,7 @@ BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup)
     // and new block files.
     {
         CWallet wallet;
-        LOCK(wallet.cs_wallet);
-        wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
+        AddKey(wallet, coinbaseKey);
         BOOST_CHECK_EQUAL(nullBlock, wallet.ScanForWalletTransactions(oldTip));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 100 * COIN);
     }
@@ -393,8 +398,7 @@ BOOST_FIXTURE_TEST_CASE(rescan, TestChain100Setup)
     // file.
     {
         CWallet wallet;
-        LOCK(wallet.cs_wallet);
-        wallet.AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
+        AddKey(wallet, coinbaseKey);
         BOOST_CHECK_EQUAL(oldTip, wallet.ScanForWalletTransactions(oldTip));
         BOOST_CHECK_EQUAL(wallet.GetImmatureBalance(), 50 * COIN);
     }
@@ -599,8 +603,7 @@ public:
         wallet.reset(new CWallet(std::unique_ptr<CWalletDBWrapper>(new CWalletDBWrapper(&bitdb, "wallet_test.dat"))));
         bool firstRun;
         wallet->LoadWallet(firstRun);
-        LOCK(wallet->cs_wallet);
-        wallet->AddKeyPubKey(coinbaseKey, coinbaseKey.GetPubKey());
+        AddKey(*wallet, coinbaseKey);
         wallet->ScanForWalletTransactions(chainActive.Genesis());
     }
 
@@ -635,7 +638,7 @@ public:
 BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup)
 {
     std::string coinbaseAddress = coinbaseKey.GetPubKey().GetID().ToString();
-    LOCK(wallet->cs_wallet);
+    LOCK2(cs_main, wallet->cs_wallet);
 
     // Confirm ListCoins initially returns 1 coin grouped under coinbaseKey
     // address.
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 318c159cfb..5e833ebee7 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -969,6 +969,15 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose)
             wtx.fFromMe = wtxIn.fFromMe;
             fUpdated = true;
         }
+        // If we have a witness-stripped version of this transaction, and we
+        // see a new version with a witness, then we must be upgrading a pre-segwit
+        // wallet.  Store the new version of the transaction with the witness,
+        // as the stripped-version must be invalid.
+        // TODO: Store all versions of the transaction, instead of just one.
+        if (wtxIn.tx->HasWitness() && !wtx.tx->HasWitness()) {
+            wtx.SetTx(wtxIn.tx);
+            fUpdated = true;
+        }
     }
 
     //// debug print
@@ -3101,13 +3110,14 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_c
 
 DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
 {
+    LOCK2(cs_main, cs_wallet);
+
     fFirstRunRet = false;
     DBErrors nLoadWalletRet = CWalletDB(*dbw,"cr+").LoadWallet(this);
     if (nLoadWalletRet == DB_NEED_REWRITE)
     {
         if (dbw->Rewrite("\x04pool"))
         {
-            LOCK(cs_wallet);
             setInternalKeyPool.clear();
             setExternalKeyPool.clear();
             m_pool_key_to_index.clear();