QNetworkAccessManager: delay IPv4 or IPv6 based on getaddrinfo order

Instead of always delaying IPv4 when we have both Ipv4 and IPv6 we
should use the order we get from getaddrinfo to descide which one
that should be delayed.

Task-number: QTBUG-23066
Change-Id: Ibe8c4d7000abd6e57fe8c6afac8a4a843e17ff27
Reviewed-by: Peter Hartmann <peter.hartmann@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>

3 files changed, 35 insertions, 18 deletions

diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index b43f2b9bcd..b4004eae14 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -81,7 +81,7 @@ const int QHttpNetworkConnectionPrivate::defaultRePipelineLength = 2;
 QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(const QString &hostName, quint16 port, bool encrypt)
 : state(RunningState),
   networkLayerState(Unknown),
-  hostName(hostName), port(port), encrypt(encrypt),
+  hostName(hostName), port(port), encrypt(encrypt), delayIpv4(true),
   channelCount(defaultChannelCount)
 #ifndef QT_NO_NETWORKPROXY
   , networkProxy(QNetworkProxy::NoProxy)
@@ -92,7 +92,7 @@ QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(const QString &host
 
 QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(quint16 channelCount, const QString &hostName, quint16 port, bool encrypt)
 : state(RunningState), networkLayerState(Unknown),
-  hostName(hostName), port(port), encrypt(encrypt),
+  hostName(hostName), port(port), encrypt(encrypt), delayIpv4(true),
   channelCount(channelCount)
 #ifndef QT_NO_NETWORKPROXY
   , networkProxy(QNetworkProxy::NoProxy)
@@ -126,8 +126,8 @@ void QHttpNetworkConnectionPrivate::init()
 #endif
         channels[i].init();
     }
-    ipv4ConnectTimer.setSingleShot(true);
-    QObject::connect(&ipv4ConnectTimer, SIGNAL(timeout()), q, SLOT(_q_connectIPv4Channel()));
+    delayedConnectionTimer.setSingleShot(true);
+    QObject::connect(&delayedConnectionTimer, SIGNAL(timeout()), q, SLOT(_q_connectDelayedChannel()));
 }
 
 void QHttpNetworkConnectionPrivate::pauseConnection()
@@ -189,9 +189,9 @@ bool QHttpNetworkConnectionPrivate::shouldEmitChannelError(QAbstractSocket *sock
     int otherSocket = (i == 0 ? 1 : 0);
 
     // If the IPv4 connection still isn't started we need to start it now.
-    if (ipv4ConnectTimer.isActive()) {
-        ipv4ConnectTimer.stop();
-        channels[0].ensureConnection();
+    if (delayedConnectionTimer.isActive()) {
+        delayedConnectionTimer.stop();
+        channels[otherSocket].ensureConnection();
     }
 
     if (channelCount == 1) {
@@ -974,12 +974,22 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(QHostInfo info)
 {
     bool bIpv4 = false;
     bool bIpv6 = false;
+    bool foundAddress = false;
 
     foreach (QHostAddress address, info.addresses()) {
-        if (address.protocol() == QAbstractSocket::IPv4Protocol)
+        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+            if (!foundAddress) {
+                foundAddress = true;
+                delayIpv4 = false;
+            }
             bIpv4 = true;
-        else if (address.protocol() == QAbstractSocket::IPv6Protocol)
+        } else if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+            if (!foundAddress) {
+                foundAddress = true;
+                delayIpv4 = true;
+            }
             bIpv6 = true;
+        }
     }
 
     if (bIpv4 && bIpv6)
@@ -1030,8 +1040,11 @@ void QHttpNetworkConnectionPrivate::startNetworkLayerStateLookup()
         else if (networkSession->configuration().bearerType() == QNetworkConfiguration::BearerHSPA)
             timeout = 400;
 #endif
-        ipv4ConnectTimer.start(timeout);
-        channels[1].ensureConnection();
+        delayedConnectionTimer.start(timeout);
+        if (delayIpv4)
+            channels[1].ensureConnection();
+        else
+            channels[0].ensureConnection();
     } else {
         networkLayerState = InProgress;
         channels[0].networkLayerPreference = QAbstractSocket::AnyIPProtocol;
@@ -1039,9 +1052,12 @@ void QHttpNetworkConnectionPrivate::startNetworkLayerStateLookup()
     }
 }
 
-void QHttpNetworkConnectionPrivate::_q_connectIPv4Channel()
+void QHttpNetworkConnectionPrivate::_q_connectDelayedChannel()
 {
-    channels[0].ensureConnection();
+    if (delayIpv4)
+        channels[0].ensureConnection();
+    else
+        channels[1].ensureConnection();
 }
 
 #ifndef QT_NO_BEARERMANAGEMENT
diff --git a/src/network/access/qhttpnetworkconnection_p.h b/src/network/access/qhttpnetworkconnection_p.h
index 18ec92a07a..75da382145 100644
--- a/src/network/access/qhttpnetworkconnection_p.h
+++ b/src/network/access/qhttpnetworkconnection_p.h
@@ -135,7 +135,7 @@ private:
 
     Q_PRIVATE_SLOT(d_func(), void _q_startNextRequest())
     Q_PRIVATE_SLOT(d_func(), void _q_hostLookupFinished(QHostInfo))
-    Q_PRIVATE_SLOT(d_func(), void _q_connectIPv4Channel())
+    Q_PRIVATE_SLOT(d_func(), void _q_connectDelayedChannel())
 };
 
 
@@ -198,7 +198,7 @@ public:
     void _q_startNextRequest(); // send the next request from the queue
 
     void _q_hostLookupFinished(QHostInfo info);
-    void _q_connectIPv4Channel();
+    void _q_connectDelayedChannel();
 
     void createAuthorization(QAbstractSocket *socket, QHttpNetworkRequest &request);
 
@@ -210,9 +210,10 @@ public:
     QString hostName;
     quint16 port;
     bool encrypt;
+    bool delayIpv4;
 
     const int channelCount;
-    QTimer ipv4ConnectTimer;
+    QTimer delayedConnectionTimer;
     QHttpNetworkConnectionChannel *channels; // parallel connections to the server
     bool shouldEmitChannelError(QAbstractSocket *socket);
 
diff --git a/src/network/access/qhttpnetworkconnectionchannel.cpp b/src/network/access/qhttpnetworkconnectionchannel.cpp
index edf66ff1aa..ab178be582 100644
--- a/src/network/access/qhttpnetworkconnectionchannel.cpp
+++ b/src/network/access/qhttpnetworkconnectionchannel.cpp
@@ -954,8 +954,8 @@ void QHttpNetworkConnectionChannel::_q_connected()
     // For the Happy Eyeballs we need to check if this is the first channel to connect.
     if (!pendingEncrypt) {
         if (connection->d_func()->networkLayerState == QHttpNetworkConnectionPrivate::InProgress) {
-            if (connection->d_func()->ipv4ConnectTimer.isActive())
-                connection->d_func()->ipv4ConnectTimer.stop();
+            if (connection->d_func()->delayedConnectionTimer.isActive())
+                connection->d_func()->delayedConnectionTimer.stop();
             if (networkLayerPreference == QAbstractSocket::IPv4Protocol)
                 connection->d_func()->networkLayerState = QHttpNetworkConnectionPrivate::IPv4;
             else if (networkLayerPreference == QAbstractSocket::IPv6Protocol)