Don't listen on IPv6 address by default. Prevents network connectivity problems. Closes #1880.

Conflicts:
	src/preferences/advancedsettings.h
	src/preferences/preferences.cpp
	src/preferences/preferences.h
	src/qtlibtorrent/qbtsession.cpp

src/preferences/advancedsettings.h

@@ -17,7 +17,7 @@ enum AdvSettingsRows {DISK_CACHE,
                     #if LIBTORRENT_VERSION_NUM >= 1610
                       DISK_CACHE_TTL,
                     #endif
-                      OS_CACHE, OUTGOING_PORT_MIN, OUTGOING_PORT_MAX, IGNORE_LIMIT_LAN, RECHECK_COMPLETED, LIST_REFRESH, RESOLVE_COUNTRIES, RESOLVE_HOSTS, MAX_HALF_OPEN, SUPER_SEEDING, NETWORK_IFACE, NETWORK_ADDRESS, PROGRAM_NOTIFICATIONS, TRACKER_STATUS, TRACKER_PORT,
+                      OS_CACHE, OUTGOING_PORT_MIN, OUTGOING_PORT_MAX, IGNORE_LIMIT_LAN, RECHECK_COMPLETED, LIST_REFRESH, RESOLVE_COUNTRIES, RESOLVE_HOSTS, MAX_HALF_OPEN, SUPER_SEEDING, NETWORK_IFACE, NETWORK_LISTEN_IPV6, NETWORK_ADDRESS, PROGRAM_NOTIFICATIONS, TRACKER_STATUS, TRACKER_PORT,
                     #if defined(Q_WS_WIN) || defined(Q_WS_MAC)
                       UPDATE_CHECK,
                     #endif
@@ -35,7 +35,7 @@ private:
   QSpinBox spin_cache, outgoing_ports_min, outgoing_ports_max, spin_list_refresh, spin_maxhalfopen, spin_tracker_port;
   QCheckBox cb_os_cache, cb_ignore_limits_lan, cb_recheck_completed, cb_resolve_countries, cb_resolve_hosts,
   cb_super_seeding, cb_program_notifications, cb_tracker_status, cb_confirm_torrent_deletion,
-  cb_enable_tracker_ext;
+  cb_enable_tracker_ext, cb_listen_ipv6;
   QComboBox combo_iface;
 #if LIBTORRENT_VERSION_NUM >= 1610
   QSpinBox spin_cache_ttl;
@@ -106,6 +106,8 @@ public slots:
       pref.setNetworkInterface(combo_iface.itemData(combo_iface.currentIndex()).toString());
       pref.setNetworkInterfaceName(combo_iface.currentText());
     }
+    // Listen on IPv6 address
+    pref.setListenIPv6(cb_listen_ipv6.isChecked());
     // Network address
     QHostAddress addr(txt_network_address.text().trimmed());
     if (addr.isNull())
@@ -259,6 +261,9 @@ private slots:
       combo_iface.setCurrentIndex(i);
     }
     setRow(NETWORK_IFACE, tr("Network Interface (requires restart)"), &combo_iface);
+    // Listen on IPv6 address
+    cb_listen_ipv6.setChecked(pref.getListenIPv6());
+    setRow(NETWORK_LISTEN_IPV6, tr("Listen on IPv6 address (requires restart)"), &cb_listen_ipv6);
     // Network address
     txt_network_address.setText(pref.getNetworkAddress());
     setRow(NETWORK_ADDRESS, tr("IP Address to report to trackers (requires restart)"), &txt_network_address);

src/preferences/preferences.h

@@ -1130,7 +1130,15 @@ public:
   QString getNetworkInterface() const {
     return value(QString::fromUtf8("Preferences/Connection/Interface"), QString()).toString();
   }
-  
+
+  bool getListenIPv6() const {
+    return value("Preferences/Connection/InterfaceListenIPv6", false).toBool();
+  }
+
+  void setListenIPv6(bool enable) {
+    setValue("Preferences/Connection/InterfaceListenIPv6", enable);
+  }
+
   void setNetworkInterfaceName(const QString& iface) {
     setValue(QString::fromUtf8("Preferences/Connection/InterfaceName"), iface);
   }

src/qtlibtorrent/qbtsession.cpp

@@ -1983,13 +1983,25 @@ void QBtSession::setListeningPort(int port) {
   libtorrent::error_code ec;
 #endif
   const QString iface_name = pref.getNetworkInterface();
+  const bool listen_ipv6 = pref.getListenIPv6();
   if (iface_name.isEmpty()) {
     addConsoleMessage(tr("qBittorrent is trying to listen on any interface port: TCP/%1", "e.g: qBittorrent is trying to listen on any interface port: TCP/6881").arg(QString::number(port)), "blue");
+    if (listen_ipv6)
 #if LIBTORRENT_VERSION_NUM >= 1600
-    s->listen_on(ports, ec, 0, session::listen_no_system_port);
+      s->listen_on(ports, ec, "::", session::listen_no_system_port);
 #else
-    s->listen_on(ports);
+      s->listen_on(ports, "::");
 #endif
+    else
+#if LIBTORRENT_VERSION_NUM >= 1600
+      s->listen_on(ports, ec, "0.0.0.0", session::listen_no_system_port);
+#else
+      s->listen_on(ports, "0.0.0.0");
+#endif
+
+    if (ec)
+      addConsoleMessage(tr("qBittorrent failed to listen on any interface port: %1. Reason: %2", "e.g: qBittorrent failed to listen on any interface port: TCP/6881. Reason: no such interface" ).arg(QString::number(port)).arg(misc::toQStringU(ec.message())), "red");
+
     return;
   }
   // Attempt to listen on provided interface
@@ -2002,6 +2014,8 @@ void QBtSession::setListeningPort(int port) {
   QString ip;
   qDebug("This network interface has %d IP addresses", network_iface.addressEntries().size());
   foreach (const QNetworkAddressEntry &entry, network_iface.addressEntries()) {
+    if (!listen_ipv6 && (entry.ip().protocol() == QAbstractSocket::IPv6Protocol))
+      continue;
     qDebug("Trying to listen on IP %s (%s)", qPrintable(entry.ip().toString()), qPrintable(iface_name));
 #if LIBTORRENT_VERSION_NUM >= 1600
     s->listen_on(ports, ec, entry.ip().toString().toAscii().constData(), session::listen_no_system_port);