[Qt] let OptionsModel::getProxySettings() directly query proxy

- as a proxy set via GUI can be overridden via -proxy, directly query the
  core to get active proxy
- give a warning, if active proxy is not SOCKS5 (needs to be SOCKS5 for
  the Qt networking code to work)
- also remove an obsolete connect() call from optionsdialog.cpp and a
  reference to Bitcoin-Qt (now just GUI)

src/qt/optionsdialog.cpp

@@ -53,7 +53,6 @@ OptionsDialog::OptionsDialog(QWidget *parent) :
     connect(ui->connectSocks, SIGNAL(toggled(bool)), ui->proxyIp, SLOT(setEnabled(bool)));
     connect(ui->connectSocks, SIGNAL(toggled(bool)), ui->proxyPort, SLOT(setEnabled(bool)));
     connect(ui->connectSocks, SIGNAL(toggled(bool)), ui->socksVersion, SLOT(setEnabled(bool)));
-    connect(ui->connectSocks, SIGNAL(clicked(bool)), this, SLOT(showRestartWarning_Proxy()));
 
     ui->proxyIp->installEventFilter(this);
 
@@ -204,7 +203,7 @@ void OptionsDialog::on_resetButton_clicked()
         if(btnRetVal == QMessageBox::Cancel)
             return;
 
-        /* reset all options and close Bitcoin-Qt */
+        /* reset all options and close GUI */
         model->Reset();
         QApplication::quit();
     }

src/qt/optionsmodel.cpp

@@ -19,6 +19,7 @@
 #include "walletdb.h"
 #endif
 
+#include <QNetworkProxy>
 #include <QSettings>
 #include <QStringList>
 
@@ -375,14 +376,25 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
     return successful;
 }
 
-bool OptionsModel::getProxySettings(QString& proxyIP, quint16 &proxyPort) const
+bool OptionsModel::getProxySettings(QNetworkProxy& proxy) const
 {
-    std::string proxy = GetArg("-proxy", "");
-    if (proxy.empty()) return false;
+    // Directly query current base proxy, because
+    // GUI settings can be overridden with -proxy.
+    proxyType curProxy;
+    if (GetProxy(NET_IPV4, curProxy)) {
+        if (curProxy.second == 5) {
+            proxy.setType(QNetworkProxy::Socks5Proxy);
+            proxy.setHostName(QString::fromStdString(curProxy.first.ToStringIP()));
+            proxy.setPort(curProxy.first.GetPort());
+
+            return true;
+        }
+        else
+            return false;
+    }
+    else
+        proxy.setType(QNetworkProxy::NoProxy);
 
-    CService addrProxy(proxy);
-    proxyIP = QString(addrProxy.ToStringIP().c_str());
-    proxyPort = addrProxy.GetPort();
     return true;
 }
 

src/qt/optionsmodel.h

@@ -7,6 +7,10 @@
 
 #include <QAbstractListModel>
 
+QT_BEGIN_NAMESPACE
+class QNetworkProxy;
+QT_END_NAMESPACE
+
 /** Interface from Qt to configuration data structure for Bitcoin client.
    To Qt, the options are presented as a list with the different options
    laid out vertically.
@@ -54,7 +58,7 @@ public:
     bool getMinimizeOnClose() { return fMinimizeOnClose; }
     int getDisplayUnit() { return nDisplayUnit; }
     bool getDisplayAddresses() { return bDisplayAddresses; }
-    bool getProxySettings(QString& proxyIP, quint16 &proxyPort) const;
+    bool getProxySettings(QNetworkProxy& proxy) const;
     bool getCoinControlFeatures() { return fCoinControlFeatures; }
     const QString& getOverriddenByCommandLine() { return strOverriddenByCommandLine; }
 

src/qt/paymentserver.cpp

@@ -335,17 +335,22 @@ void PaymentServer::initNetManager()
     // netManager is used to fetch paymentrequests given in bitcoin: URIs
     netManager = new QNetworkAccessManager(this);
 
-    // Use proxy settings from optionsModel
-    QString proxyIP;
-    quint16 proxyPort;
-    if (optionsModel->getProxySettings(proxyIP, proxyPort))
-    {
-        QNetworkProxy proxy;
-        proxy.setType(QNetworkProxy::Socks5Proxy);
-        proxy.setHostName(proxyIP);
-        proxy.setPort(proxyPort);
-        netManager->setProxy(proxy);
+    QNetworkProxy proxy;
+
+    // Query active proxy (fails if no SOCKS5 proxy)
+    if (optionsModel->getProxySettings(proxy)) {
+        if (proxy.type() == QNetworkProxy::Socks5Proxy) {
+            netManager->setProxy(proxy);
+
+            qDebug() << "PaymentServer::initNetManager : Using SOCKS5 proxy" << proxy.hostName() << ":" << proxy.port();
+        }
+        else
+            qDebug() << "PaymentServer::initNetManager : No active proxy server found.";
     }
+    else
+        emit message(tr("Net manager warning"),
+            tr("Your active proxy doesn't support SOCKS5, which is required for payment requests via proxy."),
+            CClientUIInterface::MSG_WARNING);
 
     connect(netManager, SIGNAL(finished(QNetworkReply*)),
             this, SLOT(netRequestFinished(QNetworkReply*)));