Merge branch 'master' of scm.dev.nokia.troll.no:qt/mobility-staging into master-integration

* 'master' of scm.dev.nokia.troll.no:qt/mobility-staging: (165 commits)
  Add 'We mean it.' header.
  Use provided typedef for QNetworkConfigurationPrivatePointer.
  Fix public includes.
  Document networkSessionOnline() signal and mark as internal.
  Tag new classes as since 4.7.
  Fix documentation.
  Remove debug.
  Update copyright year to 2010.
  We don't need to migrate cached replies.
  Fix after reworking to use signals/slots.
  Remove debug.
  Rename and remove unused private slots.
  Add comments to private state enums.
  Revert "(ODBC) Use wchar_t instead of assuming 2 bytes."
  Move check for range header support to before deleting backend.
  Don't try to migrate finished or aborted requests.
  Clarify TemporaryNetworkFailureError docs.
  Remove functions used for testing.
  Connect signals between QNAM and QNetworkReplyImpl.
  Fix networkAccessEnabled implementation.
  ...

13 files changed, 487 insertions, 35 deletions

diff --git a/src/network/access/qhttpnetworkconnectionchannel.cpp b/src/network/access/qhttpnetworkconnectionchannel.cpp
index 70a301d..5bd972c 100644
--- a/src/network/access/qhttpnetworkconnectionchannel.cpp
+++ b/src/network/access/qhttpnetworkconnectionchannel.cpp
@@ -305,9 +305,12 @@ void QHttpNetworkConnectionChannel::_q_receiveReply()
     while (socket->bytesAvailable()) {
         QHttpNetworkReplyPrivate::ReplyState state = reply ? reply->d_func()->state : QHttpNetworkReplyPrivate::AllDoneState;
         switch (state) {
-        case QHttpNetworkReplyPrivate::NothingDoneState:
-        case QHttpNetworkReplyPrivate::ReadingStatusState: {
+        case QHttpNetworkReplyPrivate::NothingDoneState: {
+            // only eat whitespace on the first call
             eatWhitespace();
+            state = reply->d_func()->state = QHttpNetworkReplyPrivate::ReadingStatusState;
+        }
+        case QHttpNetworkReplyPrivate::ReadingStatusState: {
             qint64 statusBytes = reply->d_func()->readStatus(socket);
             if (statusBytes == -1 && reconnectAttempts <= 0) {
                 // too many errors reading/receiving/parsing the status, close the socket and emit error
diff --git a/src/network/access/qhttpnetworkreply.cpp b/src/network/access/qhttpnetworkreply.cpp
index a5223d1..512c045 100644
--- a/src/network/access/qhttpnetworkreply.cpp
+++ b/src/network/access/qhttpnetworkreply.cpp
@@ -423,13 +423,26 @@ int QHttpNetworkReplyPrivate::gunzipBodyPartially(QByteArray &compressed, QByteA
 
 qint64 QHttpNetworkReplyPrivate::readStatus(QAbstractSocket *socket)
 {
+    if (fragment.isEmpty()) {
+        // reserve bytes for the status line. This is better than always append() which reallocs the byte array
+        fragment.reserve(32);
+    }
+
     qint64 bytes = 0;
     char c;
+    qint64 haveRead = 0;
+
+    do {
+        haveRead = socket->read(&c, 1);
+        if (haveRead == -1)
+            return -1; // unexpected EOF
+        else if (haveRead == 0)
+            break; // read more later
+
+        bytes++;
 
-    while (socket->bytesAvailable()) {
         // allow both CRLF & LF (only) line endings
-        if (socket->peek(&c, 1) == 1 && c == '\n') {
-            bytes += socket->read(&c, 1); // read the "n"
+        if (c == '\n') {
             // remove the CR at the end
             if (fragment.endsWith('\r')) {
                 fragment.truncate(fragment.length()-1);
@@ -442,11 +455,6 @@ qint64 QHttpNetworkReplyPrivate::readStatus(QAbstractSocket *socket)
             }
             break;
         } else {
-            c = 0;
-            int haveRead = socket->read(&c, 1);
-            if (haveRead == -1)
-                return -1;
-            bytes += haveRead;
             fragment.append(c);
         }
 
@@ -456,8 +464,7 @@ qint64 QHttpNetworkReplyPrivate::readStatus(QAbstractSocket *socket)
             fragment.clear();
             return -1;
         }
-
-    }
+    } while (haveRead == 1);
 
     return bytes;
 }
@@ -500,20 +507,41 @@ bool QHttpNetworkReplyPrivate::parseStatus(const QByteArray &status)
 
 qint64 QHttpNetworkReplyPrivate::readHeader(QAbstractSocket *socket)
 {
+    if (fragment.isEmpty()) {
+        // according to http://dev.opera.com/articles/view/mama-http-headers/ the average size of the header
+        // block is 381 bytes.
+        // reserve bytes. This is better than always append() which reallocs the byte array.
+        fragment.reserve(512);
+    }
+
     qint64 bytes = 0;
     char c = 0;
     bool allHeaders = false;
-    while (!allHeaders && socket->bytesAvailable()) {
-        if (socket->peek(&c, 1) == 1 && c == '\n') {
-            // check for possible header endings. As per HTTP rfc,
-            // the header endings will be marked by CRLFCRLF. But
-            // we will allow CRLFLF, LFLF & CRLFCRLF
-            if (fragment.endsWith("\n\r") || fragment.endsWith('\n'))
-                allHeaders = true;
+    qint64 haveRead = 0;
+    do {
+        haveRead = socket->read(&c, 1);
+        if (haveRead == 0) {
+            // read more later
+            break;
+        } else if (haveRead == -1) {
+            // connection broke down
+            return -1;
+        } else {
+            fragment.append(c);
+            bytes++;
+
+            if (c == '\n') {
+                // check for possible header endings. As per HTTP rfc,
+                // the header endings will be marked by CRLFCRLF. But
+                // we will allow CRLFCRLF, CRLFLF, LFLF
+                if (fragment.endsWith("\r\n\r\n")
+                    || fragment.endsWith("\r\n\n")
+                    || fragment.endsWith("\n\n"))
+                    allHeaders = true;
+            }
         }
-        bytes += socket->read(&c, 1);
-        fragment.append(c);
-    }
+    } while (!allHeaders && haveRead > 0);
+
     // we received all headers now parse them
     if (allHeaders) {
         parseHeader(fragment);
diff --git a/src/network/access/qnetworkaccessbackend.cpp b/src/network/access/qnetworkaccessbackend.cpp
index 8ac64d2..1d23cdc 100644
--- a/src/network/access/qnetworkaccessbackend.cpp
+++ b/src/network/access/qnetworkaccessbackend.cpp
@@ -49,6 +49,7 @@
 
 #include "qnetworkaccesscachebackend_p.h"
 #include "qabstractnetworkcache.h"
+#include "qhostinfo.h"
 
 #include "private/qnoncontiguousbytedevice_p.h"
 
@@ -341,4 +342,35 @@ void QNetworkAccessBackend::sslErrors(const QList<QSslError> &errors)
 #endif
 }
 
+/*!
+    Starts the backend.  Returns true if the backend is started.  Returns false if the backend
+    could not be started due to an unopened or roaming session.  The caller should recall this
+    function once the session has been opened or the roaming process has finished.
+*/
+bool QNetworkAccessBackend::start()
+{
+    if (!manager->networkSession) {
+        open();
+        return true;
+    }
+
+    // This is not ideal.
+    const QString host = reply->url.host();
+    if (host == QLatin1String("localhost") ||
+        QHostAddress(host) == QHostAddress::LocalHost ||
+        QHostAddress(host) == QHostAddress::LocalHostIPv6) {
+        // Don't need an open session for localhost access.
+        open();
+        return true;
+    }
+
+    if (manager->networkSession->isOpen() &&
+        manager->networkSession->state() == QNetworkSession::Connected) {
+        open();
+        return true;
+    }
+
+    return false;
+}
+
 QT_END_NAMESPACE
diff --git a/src/network/access/qnetworkaccessbackend_p.h b/src/network/access/qnetworkaccessbackend_p.h
index 43d993c..830ec7e 100644
--- a/src/network/access/qnetworkaccessbackend_p.h
+++ b/src/network/access/qnetworkaccessbackend_p.h
@@ -54,6 +54,7 @@
 //
 
 #include "qnetworkreplyimpl_p.h"
+#include "QtNetwork/qnetworksession.h"
 #include "QtCore/qobject.h"
 
 QT_BEGIN_NAMESPACE
@@ -111,6 +112,7 @@ public:
     //   socket).
 
     virtual void open() = 0;
+    virtual bool start();
     virtual void closeDownstreamChannel() = 0;
     virtual bool waitForDownstreamReadyRead(int msecs) = 0;
 
@@ -190,6 +192,7 @@ private:
     friend class QNetworkAccessManager;
     friend class QNetworkAccessManagerPrivate;
     friend class QNetworkAccessBackendUploadIODevice;
+    friend class QNetworkReplyImplPrivate;
     QNetworkAccessManagerPrivate *manager;
     QNetworkReplyImplPrivate *reply;
 };
diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index e16aedc..9a351dc 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -59,6 +59,8 @@
 #include "QtCore/qvector.h"
 #include "QtNetwork/qauthenticator.h"
 #include "QtNetwork/qsslconfiguration.h"
+#include "QtNetwork/qnetworkconfigmanager.h"
+#include "QtNetwork/qnetworksession.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -160,6 +162,43 @@ static void ensureInitialized()
 */
 
 /*!
+    \property QNetworkAccessManager::networkAccess
+    \brief states whether network access is enabled or disabled through this network access
+    manager.
+
+    \since 4.7
+
+    Network access is enabled by default.
+
+    When network access is disabled the network access manager will not process any new network
+    requests, all such requests will fail with an error. Requests with URLs with the file:// scheme
+    will still be processed.
+
+    This property can be used to enable and disable network access for all clients of a single
+    network access manager instance.
+*/
+
+/*!
+    \fn void QNetworkAccessManager::networkAccessChanged(bool enabled)
+
+    This signal is emitted when the value of the \l networkAccess property changes. If \a enabled
+    is true new requests that access the network will be processed; otherwise new network requests
+    that require network access will fail with an error.
+*/
+
+/*!
+    \fn void QNetworkAccessManager::networkSessionOnline()
+
+    \since 4.7
+
+    \internal
+
+    This signal is emitted when the status of the network session changes into a usable state.
+    It is used to signal QNetworkReply's to start or migrate their network operation once the
+    network session has been opened / roamed.
+*/
+
+/*!
     \fn void QNetworkAccessManager::proxyAuthenticationRequired(const QNetworkProxy &proxy, QAuthenticator *authenticator)
 
     This signal is emitted whenever a proxy requests authentication
@@ -346,6 +385,9 @@ QNetworkAccessManager::QNetworkAccessManager(QObject *parent)
     : QObject(*new QNetworkAccessManagerPrivate, parent)
 {
     ensureInitialized();
+
+    QNetworkConfigurationManager manager;
+    d_func()->createSession(manager.defaultConfiguration());
 }
 
 /*!
@@ -665,6 +707,85 @@ QNetworkReply *QNetworkAccessManager::deleteResource(const QNetworkRequest &requ
 }
 
 /*!
+    \since 4.7
+
+    Sets the network configuration that will be used when creating a network session to \a config.
+
+    \sa configuration()
+*/
+void QNetworkAccessManager::setConfiguration(const QNetworkConfiguration &config)
+{
+    d_func()->createSession(config);
+}
+
+/*!
+    \since 4.7
+
+    Returns the network configuration.
+
+    \sa setConfiguration()
+*/
+QNetworkConfiguration QNetworkAccessManager::configuration() const
+{
+    Q_D(const QNetworkAccessManager);
+
+    if (d->networkSession)
+        return d->networkSession->configuration();
+    else
+        return QNetworkConfiguration();
+}
+
+/*!
+    \since 4.7
+
+    Returns the current active network configuration.
+
+    \sa configuration()
+*/
+QNetworkConfiguration QNetworkAccessManager::activeConfiguration() const
+{
+    Q_D(const QNetworkAccessManager);
+
+    if (d->networkSession) {
+        QNetworkConfigurationManager manager;
+
+        return manager.configurationFromIdentifier(
+            d->networkSession->sessionProperty(QLatin1String("ActiveConfiguration")).toString());
+    } else {
+        return QNetworkConfiguration();
+    }
+}
+
+/*!
+    \since 4.7
+
+    Enables network access via this QNetworkAccessManager if \a enabled is true; otherwise disables
+    access.
+*/
+void QNetworkAccessManager::setNetworkAccessEnabled(bool enabled)
+{
+    Q_D(QNetworkAccessManager);
+
+    if (d->networkAccessEnabled != enabled) {
+        d->networkAccessEnabled = enabled;
+        emit networkAccessChanged(enabled);
+    }
+}
+
+/*!
+    \since 4.7
+
+    Returns true if network access via this QNetworkAccessManager is enabled; otherwise returns
+    false.
+*/
+bool QNetworkAccessManager::networkAccessEnabled() const
+{
+    Q_D(const QNetworkAccessManager);
+
+    return d->networkAccessEnabled;
+}
+
+/*!
     Returns a new QNetworkReply object to handle the operation \a op
     and request \a req. The device \a outgoingData is always 0 for Get and
     Head requests, but is the value passed to post() and put() in
@@ -693,6 +814,13 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
         return new QFileNetworkReply(this, req, op);
     }
 
+    // Return a disabled network reply if network access is disabled.
+    // Except if the scheme is empty or file://.
+    if (!d->networkAccessEnabled && !(req.url().scheme() == QLatin1String("file") ||
+                                      req.url().scheme().isEmpty())) {
+        return new QDisabledNetworkReply(this, req, op);
+    }
+
     QNetworkRequest request = req;
     if (!request.header(QNetworkRequest::ContentLengthHeader).isValid() &&
         outgoingData && !outgoingData->isSequential()) {
@@ -709,6 +837,8 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
     // first step: create the reply
     QUrl url = request.url();
     QNetworkReplyImpl *reply = new QNetworkReplyImpl(this);
+    if (req.url().scheme() != QLatin1String("file") && !req.url().scheme().isEmpty())
+        connect(this, SIGNAL(networkSessionOnline()), reply, SLOT(_q_networkSessionOnline()));
     QNetworkReplyImplPrivate *priv = reply->d_func();
     priv->manager = this;
 
@@ -743,6 +873,7 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
 void QNetworkAccessManagerPrivate::_q_replyFinished()
 {
     Q_Q(QNetworkAccessManager);
+
     QNetworkReply *reply = qobject_cast<QNetworkReply *>(q->sender());
     if (reply)
         emit q->finished(reply);
@@ -998,6 +1129,45 @@ QNetworkAccessManagerPrivate::~QNetworkAccessManagerPrivate()
 {
 }
 
+void QNetworkAccessManagerPrivate::createSession(const QNetworkConfiguration &config)
+{
+    Q_Q(QNetworkAccessManager);
+
+    if (networkSession)
+        delete networkSession;
+
+    if (!config.isValid()) {
+        networkSession = 0;
+        return;
+    }
+
+    networkSession = new QNetworkSession(config, q);
+
+    QObject::connect(networkSession, SIGNAL(opened()), q, SIGNAL(networkSessionOnline()));
+    QObject::connect(networkSession, SIGNAL(newConfigurationActivated()),
+                     q, SLOT(_q_networkSessionNewConfigurationActivated()));
+    QObject::connect(networkSession,
+                     SIGNAL(preferredConfigurationChanged(QNetworkConfiguration,bool)),
+                     q,
+                     SLOT(_q_networkSessionPreferredConfigurationChanged(QNetworkConfiguration,bool)));
+}
+
+void QNetworkAccessManagerPrivate::_q_networkSessionNewConfigurationActivated()
+{
+    Q_Q(QNetworkAccessManager);
+
+    networkSession->accept();
+
+    emit q->networkSessionOnline();
+}
+
+void QNetworkAccessManagerPrivate::_q_networkSessionPreferredConfigurationChanged(const QNetworkConfiguration &, bool)
+{
+    Q_Q(QNetworkAccessManager);
+
+    networkSession->migrate();
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qnetworkaccessmanager.cpp"
diff --git a/src/network/access/qnetworkaccessmanager.h b/src/network/access/qnetworkaccessmanager.h
index d2fe527..6fdb678 100644
--- a/src/network/access/qnetworkaccessmanager.h
+++ b/src/network/access/qnetworkaccessmanager.h
@@ -62,12 +62,16 @@ class QNetworkReply;
 class QNetworkProxy;
 class QNetworkProxyFactory;
 class QSslError;
+class QNetworkConfiguration;
 
 class QNetworkReplyImplPrivate;
 class QNetworkAccessManagerPrivate;
 class Q_NETWORK_EXPORT QNetworkAccessManager: public QObject
 {
     Q_OBJECT
+
+    Q_PROPERTY(bool networkAccess READ networkAccessEnabled WRITE setNetworkAccessEnabled NOTIFY networkAccessChanged)
+
 public:
     enum Operation {
         HeadOperation = 1,
@@ -103,6 +107,13 @@ public:
     QNetworkReply *put(const QNetworkRequest &request, const QByteArray &data);
     QNetworkReply *deleteResource(const QNetworkRequest &request);
 
+    void setConfiguration(const QNetworkConfiguration &config);
+    QNetworkConfiguration configuration() const;
+    QNetworkConfiguration activeConfiguration() const;
+
+    void setNetworkAccessEnabled(bool enabled);
+    bool networkAccessEnabled() const;
+
 Q_SIGNALS:
 #ifndef QT_NO_NETWORKPROXY
     void proxyAuthenticationRequired(const QNetworkProxy &proxy, QAuthenticator *authenticator);
@@ -113,6 +124,10 @@ Q_SIGNALS:
     void sslErrors(QNetworkReply *reply, const QList<QSslError> &errors);
 #endif
 
+    void networkSessionOnline();
+
+    void networkAccessChanged(bool enabled);
+
 protected:
     virtual QNetworkReply *createRequest(Operation op, const QNetworkRequest &request,
                                          QIODevice *outgoingData = 0);
@@ -122,6 +137,8 @@ private:
     Q_DECLARE_PRIVATE(QNetworkAccessManager)
     Q_PRIVATE_SLOT(d_func(), void _q_replyFinished())
     Q_PRIVATE_SLOT(d_func(), void _q_replySslErrors(QList<QSslError>))
+    Q_PRIVATE_SLOT(d_func(), void _q_networkSessionNewConfigurationActivated())
+    Q_PRIVATE_SLOT(d_func(), void _q_networkSessionPreferredConfigurationChanged(QNetworkConfiguration,bool))
 };
 
 QT_END_NAMESPACE
diff --git a/src/network/access/qnetworkaccessmanager_p.h b/src/network/access/qnetworkaccessmanager_p.h
index 1749373..568894c 100644
--- a/src/network/access/qnetworkaccessmanager_p.h
+++ b/src/network/access/qnetworkaccessmanager_p.h
@@ -65,6 +65,7 @@ class QAuthenticator;
 class QAbstractNetworkCache;
 class QNetworkAuthenticationCredential;
 class QNetworkCookieJar;
+class QNetworkSession;
 
 class QNetworkAccessManagerPrivate: public QObjectPrivate
 {
@@ -74,7 +75,9 @@ public:
 #ifndef QT_NO_NETWORKPROXY
           proxyFactory(0),
 #endif
-          cookieJarCreated(false)
+          cookieJarCreated(false),
+          networkSession(0),
+          networkAccessEnabled(true)
     { }
     ~QNetworkAccessManagerPrivate();
 
@@ -99,6 +102,12 @@ public:
 
     QNetworkAccessBackend *findBackend(QNetworkAccessManager::Operation op, const QNetworkRequest &request);
 
+    void createSession(const QNetworkConfiguration &config);
+
+    void _q_networkSessionNewConfigurationActivated();
+    void _q_networkSessionPreferredConfigurationChanged(const QNetworkConfiguration &config,
+                                                        bool isSeamless);
+
     // this is the cache for storing downloaded files
     QAbstractNetworkCache *networkCache;
 
@@ -112,6 +121,8 @@ public:
 
     bool cookieJarCreated;
 
+    QNetworkSession *networkSession;
+    bool networkAccessEnabled;
 
     // this cache can be used by individual backends to cache e.g. their TCP connections to a server
     // and use the connections for multiple requests.
diff --git a/src/network/access/qnetworkcookie.h b/src/network/access/qnetworkcookie.h
index f34396f..3cc4cee 100644
--- a/src/network/access/qnetworkcookie.h
+++ b/src/network/access/qnetworkcookie.h
@@ -114,7 +114,7 @@ Q_NETWORK_EXPORT QDebug operator<<(QDebug, const QNetworkCookie &);
 QT_END_NAMESPACE
 
 // ### Qt5 remove this include
-#include "qnetworkcookiejar.h"
+#include <QtNetwork/QNetworkCookieJar>
 
 Q_DECLARE_METATYPE(QNetworkCookie)
 Q_DECLARE_METATYPE(QList<QNetworkCookie>)
diff --git a/src/network/access/qnetworkcookiejar.h b/src/network/access/qnetworkcookiejar.h
index 813bf3e..8086f38 100644
--- a/src/network/access/qnetworkcookiejar.h
+++ b/src/network/access/qnetworkcookiejar.h
@@ -46,7 +46,7 @@
 #include <QtCore/QUrl>
 
 // ### Qt5 remove this include
-#include "qnetworkcookie.h"
+#include <QtNetwork/QNetworkCookie>
 
 QT_BEGIN_HEADER
 
diff --git a/src/network/access/qnetworkreply.cpp b/src/network/access/qnetworkreply.cpp
index 15748fe..c8b8c1f 100644
--- a/src/network/access/qnetworkreply.cpp
+++ b/src/network/access/qnetworkreply.cpp
@@ -125,6 +125,11 @@ QNetworkReplyPrivate::QNetworkReplyPrivate()
     encrypted channel could not be established. The sslErrors() signal
     should have been emitted.
 
+    \value TemporaryNetworkFailureError the connection was broken due
+    to disconnection from the network, however the system has initiated
+    roaming to another access point. The request should be resubmitted
+    and will be processed as soon as the connection is re-established.
+
     \value ProxyConnectionRefusedError the connection to the proxy
     server was refused (the proxy server is not accepting requests)
 
diff --git a/src/network/access/qnetworkreply.h b/src/network/access/qnetworkreply.h
index 5db4985..acb7379 100644
--- a/src/network/access/qnetworkreply.h
+++ b/src/network/access/qnetworkreply.h
@@ -77,6 +77,7 @@ public:
         TimeoutError,
         OperationCanceledError,
         SslHandshakeFailedError,
+        TemporaryNetworkFailureError,
         UnknownNetworkError = 99,
 
         // proxy errors (101-199):
diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index 59c7d76..7f66b25 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -47,6 +47,7 @@
 #include "QtCore/qdatetime.h"
 #include "QtNetwork/qsslconfiguration.h"
 #include "qnetworkaccesshttpbackend_p.h"
+#include "qnetworkaccessmanager_p.h"
 
 #include <QtCore/QCoreApplication>
 
@@ -57,7 +58,7 @@ inline QNetworkReplyImplPrivate::QNetworkReplyImplPrivate()
       copyDevice(0),
       cacheEnabled(false), cacheSaveDevice(0),
       notificationHandlingPaused(false),
-      bytesDownloaded(0), lastBytesDownloaded(-1), bytesUploaded(-1),
+      bytesDownloaded(0), lastBytesDownloaded(-1), bytesUploaded(-1), preMigrationDownloaded(-1),
       httpStatusCode(0),
       state(Idle)
 {
@@ -82,7 +83,24 @@ void QNetworkReplyImplPrivate::_q_startOperation()
         return;
     }
 
-    backend->open();
+    if (!backend->start()) {
+        // backend failed to start because the session state is not Connected.
+        // QNetworkAccessManager will call reply->backend->start() again for us when the session
+        // state changes.
+        state = WaitingForSession;
+
+        QNetworkSession *session = manager->d_func()->networkSession;
+
+        if (session) {
+            if (!session->isOpen())
+                session->open();
+        } else {
+            qWarning("Backend is waiting for QNetworkSession to connect, but there is none!");
+        }
+
+        return;
+    }
+
     if (state != Finished) {
         if (operation == QNetworkAccessManager::GetOperation)
             pendingNotifications.append(NotifyDownstreamReadyWrite);
@@ -134,6 +152,8 @@ void QNetworkReplyImplPrivate::_q_copyReadyRead()
 
     lastBytesDownloaded = bytesDownloaded;
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    if (preMigrationDownloaded != Q_INT64_C(-1))
+        totalSize = totalSize.toLongLong() + preMigrationDownloaded;
     pauseNotificationHandling();
     emit q->downloadProgress(bytesDownloaded,
                              totalSize.isNull() ? Q_INT64_C(-1) : totalSize.toLongLong());
@@ -206,6 +226,26 @@ void QNetworkReplyImplPrivate::_q_bufferOutgoingData()
     }
 }
 
+void QNetworkReplyImplPrivate::_q_networkSessionOnline()
+{
+    Q_Q(QNetworkReplyImpl);
+
+    switch (state) {
+    case QNetworkReplyImplPrivate::Buffering:
+    case QNetworkReplyImplPrivate::Working:
+    case QNetworkReplyImplPrivate::Reconnecting:
+        // Migrate existing downloads to new network connection.
+        migrateBackend();
+        break;
+    case QNetworkReplyImplPrivate::WaitingForSession:
+        // Start waiting requests.
+        QMetaObject::invokeMethod(q, "_q_startOperation", Qt::QueuedConnection);
+        break;
+    default:
+        ;
+    }
+}
+
 void QNetworkReplyImplPrivate::setup(QNetworkAccessManager::Operation op, const QNetworkRequest &req,
                                      QIODevice *data)
 {
@@ -457,6 +497,17 @@ void QNetworkReplyImplPrivate::appendDownstreamData(QByteDataBuffer &data)
     QPointer<QNetworkReplyImpl> qq = q;
 
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    if (totalSize.isNull()) {
+        RawHeadersList::ConstIterator it = findRawHeader("Content-Range");
+        if (it != rawHeaders.constEnd()) {
+            int index = it->second.lastIndexOf('/');
+            if (index != -1)
+                totalSize = it->second.mid(index + 1).toLongLong() - preMigrationDownloaded;
+        }
+    }
+
+    if (preMigrationDownloaded != Q_INT64_C(-1))
+        totalSize = totalSize.toLongLong() + preMigrationDownloaded;
     pauseNotificationHandling();
     emit q->downloadProgress(bytesDownloaded,
                              totalSize.isNull() ? Q_INT64_C(-1) : totalSize.toLongLong());
@@ -498,14 +549,39 @@ void QNetworkReplyImplPrivate::appendDownstreamData(QIODevice *data)
 void QNetworkReplyImplPrivate::finished()
 {
     Q_Q(QNetworkReplyImpl);
-    if (state == Finished || state == Aborted)
+
+    if (state == Finished || state == Aborted || state == WaitingForSession)
         return;
 
+    pauseNotificationHandling();
+    QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    if (preMigrationDownloaded != Q_INT64_C(-1))
+        totalSize = totalSize.toLongLong() + preMigrationDownloaded;
+    QNetworkSession *session = manager->d_func()->networkSession;
+    if (session && session->state() == QNetworkSession::Roaming &&
+        state == Working && errorCode != QNetworkReply::OperationCanceledError) {
+        // only content with a known size will fail with a temporary network failure error
+        if (!totalSize.isNull()) {
+            if (bytesDownloaded != totalSize) {
+                if (migrateBackend()) {
+                    // either we are migrating or the request is finished/aborted
+                    if (state == Reconnecting || state == WaitingForSession) {
+                        resumeNotificationHandling();
+                        return; // exit early if we are migrating.
+                    }
+                } else {
+                    error(QNetworkReply::TemporaryNetworkFailureError,
+                          q->tr("Temporary network failure."));
+                }
+            }
+        }
+    }
+    resumeNotificationHandling();
+
     state = Finished;
     pendingNotifications.clear();
 
     pauseNotificationHandling();
-    QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
     if (totalSize.isNull() || totalSize == -1) {
         emit q->downloadProgress(bytesDownloaded, bytesDownloaded);
     }
@@ -514,7 +590,9 @@ void QNetworkReplyImplPrivate::finished()
         emit q->uploadProgress(0, 0);
     resumeNotificationHandling();
 
-    completeCacheSave();
+    // if we don't know the total size of or we received everything save the cache
+    if (totalSize.isNull() || totalSize == -1 || bytesDownloaded == totalSize)
+        completeCacheSave();
 
     // note: might not be a good idea, since users could decide to delete us
     // which would delete the backend too...
@@ -722,6 +800,89 @@ bool QNetworkReplyImpl::event(QEvent *e)
     return QObject::event(e);
 }
 
+/*
+    Migrates the backend of the QNetworkReply to a new network connection if required.  Returns
+    true if the reply is migrated or it is not required; otherwise returns false.
+*/
+bool QNetworkReplyImplPrivate::migrateBackend()
+{
+    Q_Q(QNetworkReplyImpl);
+
+    // Network reply is already finished or aborted, don't need to migrate.
+    if (state == Finished || state == Aborted)
+        return true;
+
+    // Resume only supported by http backend, not migrating.
+    if (!qobject_cast<QNetworkAccessHttpBackend *>(backend))
+        return false;
+
+    // Request has outgoing data, not migrating.
+    if (outgoingData)
+        return false;
+
+    // Request is serviced from the cache, don't need to migrate.
+    if (copyDevice)
+        return true;
+
+    // Range header is not supported by server/resource, can't migrate.
+    RawHeadersList::ConstIterator it = findRawHeader("Accept-Ranges");
+    if (it == rawHeaders.constEnd() || it->second == "none")
+        return false;
+
+    state = QNetworkReplyImplPrivate::Reconnecting;
+
+    if (backend) {
+        delete backend;
+        backend = 0;
+    }
+
+    cookedHeaders.clear();
+    rawHeaders.clear();
+
+    preMigrationDownloaded = bytesDownloaded;
+
+    request.setRawHeader("Range", "bytes=" + QByteArray::number(preMigrationDownloaded) + '-');
+
+    backend = manager->d_func()->findBackend(operation, request);
+
+    if (backend) {
+        backend->setParent(q);
+        backend->reply = this;
+    }
+
+    if (qobject_cast<QNetworkAccessHttpBackend *>(backend)) {
+        _q_startOperation();
+    } else {
+        QMetaObject::invokeMethod(q, "_q_startOperation", Qt::QueuedConnection);
+    }
+
+    return true;
+}
+
+QDisabledNetworkReply::QDisabledNetworkReply(QObject *parent,
+                                             const QNetworkRequest &req,
+                                             QNetworkAccessManager::Operation op)
+:   QNetworkReply(parent)
+{
+    setRequest(req);
+    setUrl(req.url());
+    setOperation(op);
+
+    qRegisterMetaType<QNetworkReply::NetworkError>("QNetworkReply::NetworkError");
+
+    QString msg = QCoreApplication::translate("QNetworkAccessManager",
+                                              "Network access is disabled.");
+    setError(UnknownNetworkError, msg);
+
+    QMetaObject::invokeMethod(this, "error", Qt::QueuedConnection,
+        Q_ARG(QNetworkReply::NetworkError, UnknownNetworkError));
+    QMetaObject::invokeMethod(this, "finished", Qt::QueuedConnection);
+}
+
+QDisabledNetworkReply::~QDisabledNetworkReply()
+{
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qnetworkreplyimpl_p.cpp"
diff --git a/src/network/access/qnetworkreplyimpl_p.h b/src/network/access/qnetworkreplyimpl_p.h
index 168e5cf..ec413cc 100644
--- a/src/network/access/qnetworkreplyimpl_p.h
+++ b/src/network/access/qnetworkreplyimpl_p.h
@@ -98,6 +98,7 @@ public:
     Q_PRIVATE_SLOT(d_func(), void _q_copyReadChannelFinished())
     Q_PRIVATE_SLOT(d_func(), void _q_bufferOutgoingData())
     Q_PRIVATE_SLOT(d_func(), void _q_bufferOutgoingDataFinished())
+    Q_PRIVATE_SLOT(d_func(), void _q_networkSessionOnline())
 };
 
 class QNetworkReplyImplPrivate: public QNetworkReplyPrivate
@@ -110,11 +111,13 @@ public:
     };
 
     enum State {
-        Idle,
-        Buffering,
-        Working,
-        Finished,
-        Aborted
+        Idle,               // The reply is idle.
+        Buffering,          // The reply is buffering outgoing data.
+        Working,            // The reply is uploading/downloading data.
+        Finished,           // The reply has finished.
+        Aborted,            // The reply has been aborted.
+        WaitingForSession,  // The reply is waiting for the session to open before connecting.
+        Reconnecting        // The reply will reconnect to once roaming has completed.
     };
 
     typedef QQueue<InternalNotifications> NotificationQueue;
@@ -128,6 +131,7 @@ public:
     void _q_copyReadChannelFinished();
     void _q_bufferOutgoingData();
     void _q_bufferOutgoingDataFinished();
+    void _q_networkSessionOnline();
 
     void setup(QNetworkAccessManager::Operation op, const QNetworkRequest &request,
                QIODevice *outgoingData);
@@ -161,6 +165,8 @@ public:
     QIODevice *copyDevice;
     QAbstractNetworkCache *networkCache() const;
 
+    bool migrateBackend();
+
     bool cacheEnabled;
     QIODevice *cacheSaveDevice;
 
@@ -177,6 +183,7 @@ public:
     qint64 bytesDownloaded;
     qint64 lastBytesDownloaded;
     qint64 bytesUploaded;
+    qint64 preMigrationDownloaded;
 
     QString httpReasonPhrase;
     int httpStatusCode;
@@ -186,6 +193,20 @@ public:
     Q_DECLARE_PUBLIC(QNetworkReplyImpl)
 };
 
+class QDisabledNetworkReply : public QNetworkReply
+{
+    Q_OBJECT
+
+public:
+    QDisabledNetworkReply(QObject *parent, const QNetworkRequest &req,
+                          const QNetworkAccessManager::Operation op);
+    ~QDisabledNetworkReply();
+
+    void abort() { }
+protected:
+    qint64 readData(char *, qint64) { return -1; }
+};
+
 QT_END_NAMESPACE
 
 #endif