Merge 5.6 into 5.6.2

Change-Id: I58b06ecd9c7d80f38ed4ebb36bde9e7c09486a20

37 files changed, 293 insertions, 440 deletions

diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index 0c64db4d48..fbd14e2d5d 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -576,7 +576,7 @@ void QMimeBinaryProvider::loadMimeTypePrivate(QMimeTypePrivate &data)
 
     QString comment;
     QString mainPattern;
-    const QString preferredLanguage = QLocale::system().name();
+    const QString preferredLanguage = QLocale().name();
 
     for (QStringList::const_reverse_iterator it = mimeFiles.crbegin(), end = mimeFiles.crend(); it != end; ++it) { // global first, then local.
         QFile qfile(*it);
diff --git a/src/corelib/mimetypes/qmimetype.cpp b/src/corelib/mimetypes/qmimetype.cpp
index e3b01bbb89..980e8c1e5e 100644
--- a/src/corelib/mimetypes/qmimetype.cpp
+++ b/src/corelib/mimetypes/qmimetype.cpp
@@ -232,15 +232,15 @@ QString QMimeType::name() const
 /*!
     Returns the description of the MIME type to be displayed on user interfaces.
 
-    The system language (QLocale::system().name()) is used to select the appropriate translation.
+    The default language (QLocale().name()) is used to select the appropriate translation.
  */
 QString QMimeType::comment() const
 {
     QMimeDatabasePrivate::instance()->provider()->loadMimeTypePrivate(*d);
 
     QStringList languageList;
-    languageList << QLocale::system().name();
-    languageList << QLocale::system().uiLanguages();
+    languageList << QLocale().name();
+    languageList << QLocale().uiLanguages();
     Q_FOREACH (const QString &language, languageList) {
         const QString lang = language == QLatin1String("C") ? QLatin1String("en_US") : language;
         const QString comm = d->localeComments.value(lang);
diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index e1e5367766..3531be412e 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -835,8 +835,11 @@ QPixmap QIcon::pixmap(QWindow *window, const QSize &size, Mode mode, State state
     qreal devicePixelRatio = qt_effective_device_pixel_ratio(window);
 
     // Handle the simple normal-dpi case:
-    if (!(devicePixelRatio > 1.0))
-        return d->engine->pixmap(size, mode, state);
+    if (!(devicePixelRatio > 1.0)) {
+        QPixmap pixmap = d->engine->pixmap(size, mode, state);
+        pixmap.setDevicePixelRatio(1.0);
+        return pixmap;
+    }
 
     // Try get a pixmap that is big enough to be displayed at device pixel resolution.
     QPixmap pixmap = d->engine->pixmap(size * devicePixelRatio, mode, state);
diff --git a/src/gui/kernel/qkeysequence.cpp b/src/gui/kernel/qkeysequence.cpp
index 1934342f96..ea71e34e4b 100644
--- a/src/gui/kernel/qkeysequence.cpp
+++ b/src/gui/kernel/qkeysequence.cpp
@@ -405,7 +405,7 @@ void Q_GUI_EXPORT qt_set_sequence_auto_mnemonic(bool b) { qt_sequence_no_mnemoni
 
 static const struct {
     int key;
-    const char* name;
+    const char name[25];
 } keyname[] = {
     //: This and all following "incomprehensible" strings in QShortcut context
     //: are key names. Please use the localized names appearing on actual
@@ -687,8 +687,8 @@ static const struct {
     { Qt::Key_TouchpadOn,  QT_TRANSLATE_NOOP("QShortcut", "Touchpad On") },
     { Qt::Key_TouchpadOff,  QT_TRANSLATE_NOOP("QShortcut", "Touchpad Off") },
 
-    { 0, 0 }
 };
+static Q_CONSTEXPR int numKeyNames = sizeof keyname / sizeof *keyname;
 
 /*!
     \enum QKeySequence::StandardKey
@@ -1172,7 +1172,7 @@ int QKeySequencePrivate::decodeString(const QString &str, QKeySequence::Sequence
         for (int tran = 0; tran < 2; ++tran) {
             if (!nativeText)
                 ++tran;
-            for (int i = 0; keyname[i].name; ++i) {
+            for (int i = 0; i < numKeyNames; ++i) {
                 QString keyName(tran == 0
                                 ? QCoreApplication::translate("QShortcut", keyname[i].name)
                                 : QString::fromLatin1(keyname[i].name));
@@ -1311,7 +1311,7 @@ QString QKeySequencePrivate::keyName(int key, QKeySequence::SequenceFormat forma
 #if defined(Q_OS_MACX)
 NonSymbol:
 #endif
-            while (keyname[i].name) {
+            while (i < numKeyNames) {
                 if (key == keyname[i].key) {
                     p = nativeText ? QCoreApplication::translate("QShortcut", keyname[i].name)
                                    : QString::fromLatin1(keyname[i].name);
@@ -1323,7 +1323,7 @@ NonSymbol:
             // fall back on the unicode representation of it...
             // Or else characters like Qt::Key_aring may not get displayed
             // (Really depends on you locale)
-            if (!keyname[i].name) {
+            if (i >= numKeyNames) {
                 if (!QChar::requiresSurrogates(key)) {
                     p = QChar(ushort(key)).toUpper();
                 } else {
diff --git a/src/gui/kernel/qoffscreensurface.cpp b/src/gui/kernel/qoffscreensurface.cpp
index 1a12ea4d32..056cc19f69 100644
--- a/src/gui/kernel/qoffscreensurface.cpp
+++ b/src/gui/kernel/qoffscreensurface.cpp
@@ -177,6 +177,7 @@ void QOffscreenSurface::create()
             if (QThread::currentThread() != qGuiApp->thread())
                 qWarning("Attempting to create QWindow-based QOffscreenSurface outside the gui thread. Expect failures.");
             d->offscreenWindow = new QWindow(d->screen);
+            d->offscreenWindow->setObjectName(QLatin1String("QOffscreenSurface"));
             // Remove this window from the global list since we do not want it to be destroyed when closing the app.
             // The QOffscreenSurface has to be usable even after exiting the event loop.
             QGuiApplicationPrivate::window_list.removeOne(d->offscreenWindow);
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 7f84706b6f..bcd29b6fe1 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -204,6 +204,8 @@ QWindow::~QWindow()
 {
     destroy();
     QGuiApplicationPrivate::window_list.removeAll(this);
+    if (!QGuiApplicationPrivate::is_app_closing)
+        QGuiApplicationPrivate::instance()->modalWindowList.removeOne(this);
 }
 
 void QWindowPrivate::init()
@@ -2158,6 +2160,9 @@ void QWindowPrivate::deliverUpdateRequest()
 */
 void QWindow::requestUpdate()
 {
+    Q_ASSERT_X(QThread::currentThread() == QCoreApplication::instance()->thread(),
+        "QWindow", "Updates can only be scheduled from the GUI (main) thread");
+
     Q_D(QWindow);
     if (d->updateRequestPending || !d->platformWindow)
         return;
diff --git a/src/gui/painting/qdrawhelper.cpp b/src/gui/painting/qdrawhelper.cpp
index a0f7155c67..ac22c7fc00 100644
--- a/src/gui/painting/qdrawhelper.cpp
+++ b/src/gui/painting/qdrawhelper.cpp
@@ -5754,9 +5754,9 @@ static inline void rgbBlendPixel(quint32 *dst, int coverage, int sr, int sg, int
     dg = gamma[dg];
     db = gamma[db];
 
-    int nr = qt_div_255((sr - dr) * mr) + dr;
-    int ng = qt_div_255((sg - dg) * mg) + dg;
-    int nb = qt_div_255((sb - db) * mb) + db;
+    int nr = qt_div_255(sr * mr + dr * (255 - mr));
+    int ng = qt_div_255(sg * mg + dg * (255 - mg));
+    int nb = qt_div_255(sb * mb + db * (255 - mb));
 
     nr = invgamma[nr];
     ng = invgamma[ng];
@@ -5781,9 +5781,9 @@ static inline void grayBlendPixel(quint32 *dst, int coverage, int sr, int sg, in
 
     int alpha = coverage;
     int ialpha = 255 - alpha;
-    int nr = (sr * alpha + ialpha * dr) / 255;
-    int ng = (sg * alpha + ialpha * dg) / 255;
-    int nb = (sb * alpha + ialpha * db) / 255;
+    int nr = qt_div_255(sr * alpha + dr * ialpha);
+    int ng = qt_div_255(sg * alpha + dg * ialpha);
+    int nb = qt_div_255(sb * alpha + db * ialpha);
 
     nr = invgamma[nr];
     ng = invgamma[ng];
diff --git a/src/gui/painting/qdrawhelper_p.h b/src/gui/painting/qdrawhelper_p.h
index ff98d186c5..d636eabe3f 100644
--- a/src/gui/painting/qdrawhelper_p.h
+++ b/src/gui/painting/qdrawhelper_p.h
@@ -705,6 +705,7 @@ static Q_ALWAYS_INLINE uint BYTE_MUL_RGB16_32(uint x, uint a) {
     return t;
 }
 
+// qt_div_255 is a fast rounded division by 255 using an approximation that is accurate for all positive 16-bit integers
 static Q_DECL_CONSTEXPR Q_ALWAYS_INLINE int qt_div_255(int x) { return (x + (x>>8) + 0x80) >> 8; }
 static Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_div_65535(uint x) { return (x + (x>>16) + 0x8000U) >> 16; }
 
diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index 5e8aac82b8..fa49b25073 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -1046,46 +1046,45 @@ QByteArray QFontEngine::getSfntTable(uint tag) const
     return table;
 }
 
-void QFontEngine::clearGlyphCache(const void *key)
+void QFontEngine::clearGlyphCache(const void *context)
 {
-    for (QLinkedList<GlyphCacheEntry>::iterator it = m_glyphCaches.begin(), end = m_glyphCaches.end(); it != end; ) {
-        if (it->context == key)
-            it = m_glyphCaches.erase(it);
-        else
-            ++it;
-    }
+    m_glyphCaches.remove(context);
 }
 
-void QFontEngine::setGlyphCache(const void *key, QFontEngineGlyphCache *data)
+void QFontEngine::setGlyphCache(const void *context, QFontEngineGlyphCache *cache)
 {
-    Q_ASSERT(data);
+    Q_ASSERT(cache);
 
-    GlyphCacheEntry entry;
-    entry.context = key;
-    entry.cache = data;
-    if (m_glyphCaches.contains(entry))
-        return;
+    GlyphCaches &caches = m_glyphCaches[context];
+    for (GlyphCaches::const_iterator it = caches.constBegin(), end = caches.constEnd(); it != end; ++it) {
+        if (cache == it->cache.data())
+            return;
+    }
 
-    // Limit the glyph caches to 4. This covers all 90 degree rotations and limits
-    // memory use when there is continuous or random rotation
-    if (m_glyphCaches.size() == 4)
-        m_glyphCaches.removeLast();
+    // Limit the glyph caches to 4 per context. This covers all 90 degree rotations,
+    // and limits memory use when there is continuous or random rotation
+    if (caches.size() == 4)
+        caches.removeLast();
 
-    m_glyphCaches.push_front(entry);
+    GlyphCacheEntry entry;
+    entry.cache = cache;
+    caches.push_front(entry);
 
 }
 
-QFontEngineGlyphCache *QFontEngine::glyphCache(const void *key, GlyphFormat format, const QTransform &transform) const
+QFontEngineGlyphCache *QFontEngine::glyphCache(const void *context, GlyphFormat format, const QTransform &transform) const
 {
-    for (QLinkedList<GlyphCacheEntry>::const_iterator it = m_glyphCaches.constBegin(), end = m_glyphCaches.constEnd(); it != end; ++it) {
-        QFontEngineGlyphCache *c = it->cache.data();
-        if (key == it->context
-            && format == c->glyphFormat()
-            && qtransform_equals_no_translate(c->m_transform, transform)) {
-            return c;
-        }
+    const QHash<const void*, GlyphCaches>::const_iterator caches = m_glyphCaches.constFind(context);
+    if (caches == m_glyphCaches.cend())
+        return Q_NULLPTR;
+
+    for (GlyphCaches::const_iterator it = caches->begin(), end = caches->end(); it != end; ++it) {
+        QFontEngineGlyphCache *cache = it->cache.data();
+        if (format == cache->glyphFormat() && qtransform_equals_no_translate(cache->m_transform, transform))
+            return cache;
     }
-    return 0;
+
+    return Q_NULLPTR;
 }
 
 static inline QFixed kerning(int left, int right, const QFontEngine::KernPair *pairs, int numPairs)
@@ -1565,12 +1564,11 @@ QFixed QFontEngine::lastRightBearing(const QGlyphLayout &glyphs, bool round)
 
 
 QFontEngine::GlyphCacheEntry::GlyphCacheEntry()
-    : context(0)
 {
 }
 
 QFontEngine::GlyphCacheEntry::GlyphCacheEntry(const GlyphCacheEntry &o)
-    : context(o.context), cache(o.cache)
+    : cache(o.cache)
 {
 }
 
@@ -1580,7 +1578,6 @@ QFontEngine::GlyphCacheEntry::~GlyphCacheEntry()
 
 QFontEngine::GlyphCacheEntry &QFontEngine::GlyphCacheEntry::operator=(const GlyphCacheEntry &o)
 {
-    context = o.context;
     cache = o.cache;
     return *this;
 }
diff --git a/src/gui/text/qfontengine_p.h b/src/gui/text/qfontengine_p.h
index 7ddc5c0c32..39cf826ee2 100644
--- a/src/gui/text/qfontengine_p.h
+++ b/src/gui/text/qfontengine_p.h
@@ -316,12 +316,11 @@ private:
 
         GlyphCacheEntry &operator=(const GlyphCacheEntry &);
 
-        const void *context;
         QExplicitlySharedDataPointer<QFontEngineGlyphCache> cache;
-        bool operator==(const GlyphCacheEntry &other) const { return context == other.context && cache == other.cache; }
+        bool operator==(const GlyphCacheEntry &other) const { return cache == other.cache; }
     };
-
-    mutable QLinkedList<GlyphCacheEntry> m_glyphCaches;
+    typedef QLinkedList<GlyphCacheEntry> GlyphCaches;
+    mutable QHash<const void *, GlyphCaches> m_glyphCaches;
 
 private:
     QVariant m_userData;
diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index 3edf652f35..6cccf417c7 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -1309,7 +1309,7 @@ QTextCursor QTextDocument::find(const QString &subString, int from, FindFlags op
     //do not include the character given in the position.
     if (options & FindBackward) {
         --pos ;
-        if (pos < subString.size())
+        if (pos < 0)
             return QTextCursor();
     }
 
diff --git a/src/network/socket/qabstractsocket.cpp b/src/network/socket/qabstractsocket.cpp
index 9c1e7a6a49..3d665270fd 100644
--- a/src/network/socket/qabstractsocket.cpp
+++ b/src/network/socket/qabstractsocket.cpp
@@ -103,12 +103,12 @@
     To close the socket, call disconnectFromHost(). QAbstractSocket enters
     QAbstractSocket::ClosingState. After all pending data has been written to
     the socket, QAbstractSocket actually closes the socket, enters
-    QAbstractSocket::ClosedState, and emits disconnected(). If you want to
-    abort a connection immediately, discarding all pending data, call abort()
-    instead. If the remote host closes the connection, QAbstractSocket will
-    emit error(QAbstractSocket::RemoteHostClosedError), during which the socket
-    state will still be ConnectedState, and then the disconnected() signal
-    will be emitted.
+    QAbstractSocket::UnconnectedState, and emits disconnected(). If you want
+    to abort a connection immediately, discarding all pending data, call
+    abort() instead. If the remote host closes the connection,
+    QAbstractSocket will emit error(QAbstractSocket::RemoteHostClosedError),
+    during which the socket state will still be ConnectedState, and then the
+    disconnected() signal will be emitted.
 
     The port and address of the connected peer is fetched by calling
     peerPort() and peerAddress(). peerName() returns the host name of
diff --git a/src/platformsupport/cglconvenience/cglconvenience.mm b/src/platformsupport/cglconvenience/cglconvenience.mm
index 6b0a91e13f..fb609ae485 100644
--- a/src/platformsupport/cglconvenience/cglconvenience.mm
+++ b/src/platformsupport/cglconvenience/cglconvenience.mm
@@ -81,8 +81,11 @@ void *qcgl_createNSOpenGLPixelFormat(const QSurfaceFormat &format)
 
     QVector<NSOpenGLPixelFormatAttribute> attrs;
 
-    if (format.swapBehavior() != QSurfaceFormat::SingleBuffer)
+    if (format.swapBehavior() == QSurfaceFormat::DoubleBuffer
+        || format.swapBehavior() == QSurfaceFormat::DefaultSwapBehavior)
         attrs.append(NSOpenGLPFADoubleBuffer);
+    else if (format.swapBehavior() == QSurfaceFormat::TripleBuffer)
+        attrs.append(NSOpenGLPFATripleBuffer);
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
     if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_7) {
diff --git a/src/plugins/bearer/networkmanager/qnetworkmanagerengine.cpp b/src/plugins/bearer/networkmanager/qnetworkmanagerengine.cpp
index 13b64a556c..1b1034817e 100644
--- a/src/plugins/bearer/networkmanager/qnetworkmanagerengine.cpp
+++ b/src/plugins/bearer/networkmanager/qnetworkmanagerengine.cpp
@@ -123,6 +123,9 @@ void QNetworkManagerEngine::setupConfigurations()
     // Get active connections.
     foreach (const QDBusObjectPath &acPath, managerInterface->activeConnections()) {
 
+        if (activeConnectionsList.contains(acPath.path()))
+            continue;
+
         QNetworkManagerConnectionActive *activeConnection =
                 new QNetworkManagerConnectionActive(acPath.path(),this);
         activeConnectionsList.insert(acPath.path(), activeConnection);
@@ -135,14 +138,6 @@ void QNetworkManagerEngine::setupConfigurations()
             connectionInterfaces.insert(activeConnection->connection().path(),device.networkInterface());
         }
     }
-
-        // Get current list of access points.
-    foreach (const QDBusObjectPath &devicePath, managerInterface->getDevices()) {
-        locker.unlock();
-        deviceAdded(devicePath); //add all accesspoints
-        locker.relock();
-    }
-
     // Get connections.
     foreach (const QDBusObjectPath &settingsPath, systemSettings->listConnections()) {
         locker.unlock();
@@ -251,11 +246,6 @@ void QNetworkManagerEngine::requestUpdate()
     QMetaObject::invokeMethod(this, "updateCompleted", Qt::QueuedConnection);
 }
 
-void QNetworkManagerEngine::scanFinished()
-{
-    QMetaObject::invokeMethod(this, "updateCompleted", Qt::QueuedConnection);
-}
-
 void QNetworkManagerEngine::interfacePropertiesChanged(const QMap<QString, QVariant> &properties)
 {
     QMutexLocker locker(&mutex);
@@ -397,57 +387,6 @@ void QNetworkManagerEngine::deviceConnectionsChanged(const QStringList &connecti
     }
 }
 
-void QNetworkManagerEngine::deviceAdded(const QDBusObjectPath &path)
-{
-    QNetworkManagerInterfaceDevice *iDevice;
-    iDevice = new QNetworkManagerInterfaceDevice(path.path(),this);
-    connect(iDevice,SIGNAL(connectionsChanged(QStringList)),
-            this,SLOT(deviceConnectionsChanged(QStringList)));
-
-    interfaceDevices.insert(path.path(),iDevice);
-    if (iDevice->deviceType() == DEVICE_TYPE_WIFI) {
-        QNetworkManagerInterfaceDeviceWireless *wirelessDevice =
-            new QNetworkManagerInterfaceDeviceWireless(iDevice->path(),this);
-
-        connect(wirelessDevice, SIGNAL(accessPointAdded(QString)),
-                this, SLOT(newAccessPoint(QString)));
-        connect(wirelessDevice, SIGNAL(accessPointRemoved(QString)),
-                this, SLOT(removeAccessPoint(QString)));
-        connect(wirelessDevice,SIGNAL(scanDone()),this,SLOT(scanFinished()));
-        wirelessDevice->setConnections();
-
-        wirelessDevices.insert(path.path(), wirelessDevice);
-    }
-
-    if (iDevice->deviceType() == DEVICE_TYPE_ETHERNET) {
-        QNetworkManagerInterfaceDeviceWired *wiredDevice =
-                new QNetworkManagerInterfaceDeviceWired(iDevice->path(),this);
-        connect(wiredDevice,SIGNAL(carrierChanged(bool)),this,SLOT(wiredCarrierChanged(bool)));
-        wiredDevices.insert(iDevice->path(), wiredDevice);
-    }
-}
-
-void QNetworkManagerEngine::deviceRemoved(const QDBusObjectPath &path)
-{
-    QMutexLocker locker(&mutex);
-
-    if (interfaceDevices.contains(path.path())) {
-        locker.unlock();
-        delete interfaceDevices.take(path.path());
-        locker.relock();
-    }
-    if (wirelessDevices.contains(path.path())) {
-        locker.unlock();
-        delete wirelessDevices.take(path.path());
-        locker.relock();
-    }
-    if (wiredDevices.contains(path.path())) {
-        locker.unlock();
-        delete wiredDevices.take(path.path());
-        locker.relock();
-    }
-}
-
 void QNetworkManagerEngine::wiredCarrierChanged(bool carrier)
 {
     QNetworkManagerInterfaceDeviceWired *deviceWired = qobject_cast<QNetworkManagerInterfaceDeviceWired *>(sender());
@@ -538,7 +477,7 @@ void QNetworkManagerEngine::newConnection(const QDBusObjectPath &path,
              if (i.value()->deviceType() == deviceType) {
                 QNetworkManagerInterfaceDeviceWired *wiredDevice
                         = wiredDevices.value(i.value()->path());
-                 if (wiredDevice->carrier()) {
+                 if (wiredDevice && wiredDevice->carrier()) {
                      cpPriv->state |= QNetworkConfiguration::Discovered;
                  }
              }
@@ -596,15 +535,10 @@ void QNetworkManagerEngine::removeConnection(const QString &path)
         emit configurationRemoved(ptr);
         locker.relock();
     }
+
     // add base AP back into configurations
-    QMapIterator<QString, QString> i(configuredAccessPoints);
-    while (i.hasNext()) {
-        i.next();
-        if (i.value() == path) {
-            configuredAccessPoints.remove(i.key());
-            newAccessPoint(i.key());
-        }
-    }
+
+    // removed along with all AP props code...
 }
 
 void QNetworkManagerEngine::updateConnection()
@@ -678,114 +612,6 @@ void QNetworkManagerEngine::activationFinished(QDBusPendingCallWatcher *watcher)
     }
 }
 
-void QNetworkManagerEngine::newAccessPoint(const QString &path)
-{
-    QMutexLocker locker(&mutex);
-    QNetworkManagerInterfaceAccessPoint *accessPoint =
-        new QNetworkManagerInterfaceAccessPoint(path,this);
-
-    bool okToAdd = true;
-    for (int i = 0; i < accessPoints.count(); ++i) {
-        if (accessPoints.at(i)->path() == path) {
-            okToAdd = false;
-        }
-    }
-    if (okToAdd) {
-        accessPoints.append(accessPoint);
-    }
-    // Check if configuration exists for connection.
-    if (!accessPoint->ssid().isEmpty()) {
-
-        for (int i = 0; i < connections.count(); ++i) {
-            QNetworkManagerSettingsConnection *connection = connections.at(i);
-            const QString settingsPath = connection->path();
-
-            if (accessPoint->ssid() == connection->getSsid()) {
-                if (!configuredAccessPoints.contains(path)) {
-                    configuredAccessPoints.insert(path,settingsPath);
-                }
-
-                QNetworkConfigurationPrivatePointer ptr =
-                    accessPointConfigurations.value(settingsPath);
-                ptr->mutex.lock();
-                QNetworkConfiguration::StateFlags flag = QNetworkConfiguration::Defined;
-                ptr->state = (flag | QNetworkConfiguration::Discovered);
-
-                if (isConnectionActive(settingsPath))
-                    ptr->state = (flag | QNetworkConfiguration::Active);
-                ptr->mutex.unlock();
-
-                locker.unlock();
-                emit configurationChanged(ptr);
-                return;
-            }
-        }
-    }
-
-    // New access point.
-    QNetworkConfigurationPrivatePointer ptr(new QNetworkConfigurationPrivate);
-
-    ptr->name = accessPoint->ssid();
-    ptr->isValid = true;
-    ptr->id = path;
-    ptr->type = QNetworkConfiguration::InternetAccessPoint;
-    ptr->purpose = QNetworkConfiguration::PublicPurpose;
-    ptr->state = QNetworkConfiguration::Undefined;
-    ptr->bearerType = QNetworkConfiguration::BearerWLAN;
-
-    accessPointConfigurations.insert(ptr->id, ptr);
-
-    locker.unlock();
-    emit configurationAdded(ptr);
-}
-
-void QNetworkManagerEngine::removeAccessPoint(const QString &path)
-{
-    QMutexLocker locker(&mutex);
-    for (int i = 0; i < accessPoints.count(); ++i) {
-        QNetworkManagerInterfaceAccessPoint *accessPoint = accessPoints.at(i);
-        if (accessPoint->path() == path) {
-            accessPoints.removeOne(accessPoint);
-
-            if (configuredAccessPoints.contains(accessPoint->path())) {
-                // find connection and change state to Defined
-                configuredAccessPoints.remove(accessPoint->path());
-
-                for (int i = 0; i < connections.count(); ++i) {
-                    QNetworkManagerSettingsConnection *connection = connections.at(i);
-
-                    if (accessPoint->ssid() == connection->getSsid()) {//might not have bssid yet
-                        const QString settingsPath = connection->path();
-                        const QString connectionId = settingsPath;
-
-                        QNetworkConfigurationPrivatePointer ptr =
-                            accessPointConfigurations.value(connectionId);
-                        ptr->mutex.lock();
-                        ptr->state = QNetworkConfiguration::Defined;
-                        ptr->mutex.unlock();
-
-                        locker.unlock();
-                        emit configurationChanged(ptr);
-                        locker.relock();
-                        break;
-                    }
-                }
-            } else {
-                QNetworkConfigurationPrivatePointer ptr =
-                    accessPointConfigurations.take(path);
-
-                if (ptr) {
-                    locker.unlock();
-                    emit configurationRemoved(ptr);
-                    locker.relock();
-                }
-            }
-            delete accessPoint;
-            break;
-        }
-    }
-}
-
 QNetworkConfigurationPrivate *QNetworkManagerEngine::parseConnection(const QString &settingsPath,
                                                                      const QNmSettingsMap &map)
 {
@@ -808,7 +634,7 @@ QNetworkConfigurationPrivate *QNetworkManagerEngine::parseConnection(const QStri
             QNetworkManagerInterfaceDevice device(devicePath.path(),this);
             if (device.deviceType() == DEVICE_TYPE_ETHERNET) {
                 QNetworkManagerInterfaceDeviceWired *wiredDevice = wiredDevices.value(device.path());
-                if (wiredDevice->carrier()) {
+                if (wiredDevice && wiredDevice->carrier()) {
                     cpPriv->state |= QNetworkConfiguration::Discovered;
                     break;
                 }
@@ -1078,10 +904,6 @@ void QNetworkManagerEngine::nmRegistered(const QString &)
     managerInterface = new QNetworkManagerInterface(this);
     systemSettings = new QNetworkManagerSettings(NM_DBUS_SERVICE, this);
 
-    connect(managerInterface, SIGNAL(deviceAdded(QDBusObjectPath)),
-            this, SLOT(deviceAdded(QDBusObjectPath)));
-    connect(managerInterface, SIGNAL(deviceRemoved(QDBusObjectPath)),
-            this, SLOT(deviceRemoved(QDBusObjectPath)));
     connect(managerInterface, SIGNAL(activationFinished(QDBusPendingCallWatcher*)),
             this, SLOT(activationFinished(QDBusPendingCallWatcher*)));
     connect(managerInterface, SIGNAL(propertiesChanged(QMap<QString,QVariant>)),
diff --git a/src/plugins/bearer/networkmanager/qnetworkmanagerengine.h b/src/plugins/bearer/networkmanager/qnetworkmanagerengine.h
index 1f578890dc..b859318a5b 100644
--- a/src/plugins/bearer/networkmanager/qnetworkmanagerengine.h
+++ b/src/plugins/bearer/networkmanager/qnetworkmanagerengine.h
@@ -93,19 +93,12 @@ private Q_SLOTS:
     void interfacePropertiesChanged(const QMap<QString, QVariant> &properties);
     void activeConnectionPropertiesChanged(const QMap<QString, QVariant> &properties);
 
-    void deviceAdded(const QDBusObjectPath &path);
-    void deviceRemoved(const QDBusObjectPath &path);
-
     void newConnection(const QDBusObjectPath &path, QNetworkManagerSettings *settings = 0);
     void removeConnection(const QString &path);
     void updateConnection();
     void activationFinished(QDBusPendingCallWatcher *watcher);
     void deviceConnectionsChanged(const QStringList &activeConnectionsList);
 
-    void newAccessPoint(const QString &path);
-    void removeAccessPoint(const QString &path);
-    void scanFinished();
-
     void wiredCarrierChanged(bool);
 
     void nmRegistered(const QString &serviceName = QString());
diff --git a/src/plugins/bearer/networkmanager/qnetworkmanagerservice.cpp b/src/plugins/bearer/networkmanager/qnetworkmanagerservice.cpp
index d550887ba6..7506b768f2 100644
--- a/src/plugins/bearer/networkmanager/qnetworkmanagerservice.cpp
+++ b/src/plugins/bearer/networkmanager/qnetworkmanagerservice.cpp
@@ -95,6 +95,21 @@ QNetworkManagerInterface::QNetworkManagerInterface(QObject *parent)
 
 QNetworkManagerInterface::~QNetworkManagerInterface()
 {
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  QLatin1String(NM_DBUS_PATH),
+                                  QLatin1String(NM_DBUS_INTERFACE),
+                                  QLatin1String("PropertiesChanged"),
+                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  QLatin1String(NM_DBUS_PATH),
+                                  QLatin1String(NM_DBUS_INTERFACE),
+                                  QLatin1String("DeviceAdded"),
+                                  this,SIGNAL(deviceAdded(QDBusObjectPath)));
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  QLatin1String(NM_DBUS_PATH),
+                                  QLatin1String(NM_DBUS_INTERFACE),
+                                  QLatin1String("DeviceRemoved"),
+                                  this,SIGNAL(deviceRemoved(QDBusObjectPath)));
 }
 
 bool QNetworkManagerInterface::setConnections()
@@ -235,28 +250,6 @@ QNetworkManagerInterfaceAccessPoint::QNetworkManagerInterfaceAccessPoint(const Q
                   NM_DBUS_INTERFACE_ACCESS_POINT,
                   QDBusConnection::systemBus(),parent)
 {
-    if (!isValid()) {
-        return;
-    }
-    PropertiesDBusInterface *accessPointPropertiesInterface = new PropertiesDBusInterface(QLatin1String(NM_DBUS_SERVICE),
-                                                  dbusPathName,
-                                                  DBUS_PROPERTIES_INTERFACE,
-                                                  QDBusConnection::systemBus());
-
-    QList<QVariant> argumentList;
-    argumentList << QLatin1String(NM_DBUS_INTERFACE_ACCESS_POINT);
-    QDBusPendingReply<QVariantMap> propsReply
-            = accessPointPropertiesInterface->callWithArgumentList(QDBus::Block,QLatin1String("GetAll"),
-                                                                       argumentList);
-    if (!propsReply.isError()) {
-        propertyMap = propsReply.value();
-    }
-
-    QDBusConnection::systemBus().connect(QLatin1String(NM_DBUS_SERVICE),
-                                  dbusPathName,
-                                  QLatin1String(NM_DBUS_INTERFACE_ACCESS_POINT),
-                                  QLatin1String("PropertiesChanged"),
-                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
 }
 
 QNetworkManagerInterfaceAccessPoint::~QNetworkManagerInterfaceAccessPoint()
@@ -369,6 +362,11 @@ QNetworkManagerInterfaceDevice::QNetworkManagerInterfaceDevice(const QString &de
 
 QNetworkManagerInterfaceDevice::~QNetworkManagerInterfaceDevice()
 {
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  path(),
+                                  QLatin1String(NM_DBUS_INTERFACE_DEVICE),
+                                  QLatin1String("PropertiesChanged"),
+                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
 }
 
 QString QNetworkManagerInterfaceDevice::udi() const
@@ -468,6 +466,11 @@ QNetworkManagerInterfaceDeviceWired::QNetworkManagerInterfaceDeviceWired(const Q
 
 QNetworkManagerInterfaceDeviceWired::~QNetworkManagerInterfaceDeviceWired()
 {
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  path(),
+                                  QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRED),
+                                  QLatin1String("PropertiesChanged"),
+                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
 }
 
 QString QNetworkManagerInterfaceDeviceWired::hwAddress() const
@@ -557,77 +560,20 @@ QNetworkManagerInterfaceDeviceWireless::QNetworkManagerInterfaceDeviceWireless(c
                                   QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRELESS),
                                   QLatin1String("PropertiesChanged"),
                                   this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
-
-    QDBusPendingReply<QList<QDBusObjectPath> > reply
-            = asyncCall(QLatin1String("GetAccessPoints"));
-
-    QDBusPendingCallWatcher *callWatcher = new QDBusPendingCallWatcher(reply);
-    connect(callWatcher, SIGNAL(finished(QDBusPendingCallWatcher*)),
-                     this, SLOT(accessPointsFinished(QDBusPendingCallWatcher*)));
 }
 
 QNetworkManagerInterfaceDeviceWireless::~QNetworkManagerInterfaceDeviceWireless()
 {
-}
-
-void QNetworkManagerInterfaceDeviceWireless::slotAccessPointAdded(QDBusObjectPath path)
-{
-    if (path.path().length() > 2)
-        Q_EMIT accessPointAdded(path.path());
-}
-
-void QNetworkManagerInterfaceDeviceWireless::slotAccessPointRemoved(QDBusObjectPath path)
-{
-    if (path.path().length() > 2)
-        Q_EMIT accessPointRemoved(path.path());
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  path(),
+                                  QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRELESS),
+                                  QLatin1String("PropertiesChanged"),
+                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
 }
 
 bool QNetworkManagerInterfaceDeviceWireless::setConnections()
 {
-    if (!isValid())
-        return false;
-
-    QDBusConnection dbusConnection = QDBusConnection::systemBus();
-    bool allOk = true;
-
-    if (!dbusConnection.connect(QLatin1String(NM_DBUS_SERVICE),
-                               interfacePath,
-                                QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRELESS),
-                                QLatin1String("AccessPointAdded"),
-                                this, SLOT(slotAccessPointAdded(QDBusObjectPath)))) {
-        allOk = false;
-    }
-
-
-    if (!dbusConnection.connect(QLatin1String(NM_DBUS_SERVICE),
-                              interfacePath,
-                              QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRELESS),
-                              QLatin1String("AccessPointRemoved"),
-                              this, SLOT(slotAccessPointRemoved(QDBusObjectPath)))) {
-        allOk = false;
-    }
-
-    if (!dbusConnection.connect(QLatin1String(NM_DBUS_SERVICE),
-                               interfacePath,
-                               QLatin1String(NM_DBUS_INTERFACE_DEVICE_WIRELESS),
-                               QLatin1String("ScanDone"),
-                               this, SLOT(scanIsDone()))) {
-        allOk = false;
-    }
-    return allOk;
-}
-
-void QNetworkManagerInterfaceDeviceWireless::accessPointsFinished(QDBusPendingCallWatcher *watcher)
-{
-    QDBusPendingReply<QList<QDBusObjectPath> > reply(*watcher);
-    watcher->deleteLater();
-    if (!reply.isError()) {
-        accessPointsList = reply.value();
-    }
-
-    for (int i = 0; i < accessPointsList.size(); i++) {
-        Q_EMIT accessPointAdded(accessPointsList.at(i).path());
-    }
+    return true;
 }
 
 QList <QDBusObjectPath> QNetworkManagerInterfaceDeviceWireless::getAccessPoints()
@@ -676,11 +622,6 @@ quint32 QNetworkManagerInterfaceDeviceWireless::wirelessCapabilities() const
     return 0;
 }
 
-void QNetworkManagerInterfaceDeviceWireless::scanIsDone()
-{
-    Q_EMIT scanDone();
-}
-
 void QNetworkManagerInterfaceDeviceWireless::requestScan()
 {
     asyncCall(QLatin1String("RequestScan"));
@@ -729,6 +670,12 @@ QNetworkManagerInterfaceDeviceModem::QNetworkManagerInterfaceDeviceModem(const Q
 
 QNetworkManagerInterfaceDeviceModem::~QNetworkManagerInterfaceDeviceModem()
 {
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  path(),
+                                  QLatin1String(NM_DBUS_PATH_SETTINGS),
+                                  QLatin1String(NM_DBUS_IFACE_SETTINGS),
+                                  QLatin1String("NewConnection"),
+                                  this, SIGNAL(newConnection(QDBusObjectPath)));
 }
 
 QNetworkManagerInterfaceDeviceModem::ModemCapabilities QNetworkManagerInterfaceDeviceModem::modemCapabilities() const
@@ -833,6 +780,16 @@ QNetworkManagerSettingsConnection::QNetworkManagerSettingsConnection(const QStri
 
 QNetworkManagerSettingsConnection::~QNetworkManagerSettingsConnection()
 {
+    QDBusConnection::systemBus().disconnect(service(),
+                                  path(),
+                                  QLatin1String(NM_DBUS_IFACE_SETTINGS_CONNECTION),
+                                  QLatin1String("Updated"),
+                                  this, SIGNAL(updated()));
+    QDBusConnection::systemBus().disconnect(service(),
+                                  path(),
+                                  QLatin1String(NM_DBUS_IFACE_SETTINGS_CONNECTION),
+                                  QLatin1String("Removed"),
+                                  this, SIGNAL(slotSettingsRemoved()));
 }
 
 bool QNetworkManagerSettingsConnection::setConnections()
@@ -989,6 +946,11 @@ QNetworkManagerConnectionActive::QNetworkManagerConnectionActive(const QString &
 
 QNetworkManagerConnectionActive::~QNetworkManagerConnectionActive()
 {
+    QDBusConnection::systemBus().disconnect(QLatin1String(NM_DBUS_SERVICE),
+                                  path(),
+                                  QLatin1String(NM_DBUS_INTERFACE_ACTIVE_CONNECTION),
+                                  QLatin1String("PropertiesChanged"),
+                                  this,SLOT(propertiesSwap(QMap<QString,QVariant>)));
 }
 
 QDBusObjectPath QNetworkManagerConnectionActive::connection() const
diff --git a/src/plugins/bearer/networkmanager/qnetworkmanagerservice.h b/src/plugins/bearer/networkmanager/qnetworkmanagerservice.h
index 7956705789..4b810caf4a 100644
--- a/src/plugins/bearer/networkmanager/qnetworkmanagerservice.h
+++ b/src/plugins/bearer/networkmanager/qnetworkmanagerservice.h
@@ -322,7 +322,6 @@ public:
                                                     QObject *parent = 0);
     ~QNetworkManagerInterfaceDeviceWireless();
 
-    QDBusObjectPath path() const;
     QList <QDBusObjectPath> getAccessPoints();
 
     QString hwAddress() const;
@@ -335,21 +334,11 @@ public:
     void requestScan();
 Q_SIGNALS:
     void propertiesChanged(QMap<QString,QVariant>);
-    void accessPointAdded(const QString &);
-    void accessPointRemoved(const QString &);
-    void scanDone();
     void propertiesReady();
-    void accessPointsReady();
 
 private Q_SLOTS:
-    void scanIsDone();
     void propertiesSwap(QMap<QString,QVariant>);
 
-    void slotAccessPointAdded(QDBusObjectPath);
-    void slotAccessPointRemoved(QDBusObjectPath);
-
-    void accessPointsFinished(QDBusPendingCallWatcher *watcher);
-
 private:
     QVariantMap propertyMap;
     QList <QDBusObjectPath> accessPointsList;
diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.mm b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
index 0f9b8b900d..b77ca07141 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.mm
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
@@ -305,8 +305,16 @@ void QCocoaGLContext::updateSurfaceFormat()
         m_format.setSamples(samples);
 
     int doubleBuffered = -1;
+    int tripleBuffered = -1;
     [pixelFormat getValues:&doubleBuffered forAttribute:NSOpenGLPFADoubleBuffer forVirtualScreen:0];
-    m_format.setSwapBehavior(doubleBuffered == 1 ? QSurfaceFormat::DoubleBuffer : QSurfaceFormat::SingleBuffer);
+    [pixelFormat getValues:&tripleBuffered forAttribute:NSOpenGLPFATripleBuffer forVirtualScreen:0];
+
+    if (tripleBuffered == 1)
+        m_format.setSwapBehavior(QSurfaceFormat::TripleBuffer);
+    else if (doubleBuffered == 1)
+        m_format.setSwapBehavior(QSurfaceFormat::DoubleBuffer);
+    else
+        m_format.setSwapBehavior(QSurfaceFormat::SingleBuffer);
 
     int steroBuffers = -1;
     [pixelFormat getValues:&steroBuffers forAttribute:NSOpenGLPFAStereo forVirtualScreen:0];
diff --git a/src/plugins/platforms/ios/qiostextresponder.mm b/src/plugins/platforms/ios/qiostextresponder.mm
index 0cf505930f..4bef968de1 100644
--- a/src/plugins/platforms/ios/qiostextresponder.mm
+++ b/src/plugins/platforms/ios/qiostextresponder.mm
@@ -908,7 +908,7 @@
     UIFont *uifont = [UIFont fontWithName:qfont.family().toNSString() size:qfont.pointSize()];
     if (!uifont)
         return [NSDictionary dictionary];
-    return [NSDictionary dictionaryWithObject:uifont forKey:UITextInputTextFontKey];
+    return [NSDictionary dictionaryWithObject:uifont forKey:NSFontAttributeName];
 }
 
 - (NSDictionary *)markedTextStyle
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 6e8df340df..94bb71e429 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -1044,12 +1044,15 @@ void QWindowsNativeFileDialogBase::setDirectory(const QUrl &directory)
 
 QString QWindowsNativeFileDialogBase::directory() const
 {
+    QString result;
 #ifndef Q_OS_WINCE
     IShellItem *item = 0;
-    if (m_fileDialog && SUCCEEDED(m_fileDialog->GetFolder(&item)) && item)
-        return QWindowsNativeFileDialogBase::itemPath(item);
+    if (m_fileDialog && SUCCEEDED(m_fileDialog->GetFolder(&item)) && item) {
+        result = QWindowsNativeFileDialogBase::itemPath(item);
+        item->Release();
+    }
 #endif
-    return QString();
+    return result;
 }
 
 void QWindowsNativeFileDialogBase::doExec(HWND owner)
@@ -1514,8 +1517,10 @@ QList<QUrl> QWindowsNativeSaveFileDialog::selectedFiles() const
     QList<QUrl> result;
     IShellItem *item = 0;
     const HRESULT hr = fileDialog()->GetCurrentSelection(&item);
-    if (SUCCEEDED(hr) && item)
+    if (SUCCEEDED(hr) && item) {
         result.push_back(QUrl::fromLocalFile(QWindowsNativeSaveFileDialog::itemPath(item)));
+        item->Release();
+    }
     return result;
 }
 
diff --git a/src/plugins/platforms/winrt/qwinrtclipboard.cpp b/src/plugins/platforms/winrt/qwinrtclipboard.cpp
index c385018239..14443f380c 100644
--- a/src/plugins/platforms/winrt/qwinrtclipboard.cpp
+++ b/src/plugins/platforms/winrt/qwinrtclipboard.cpp
@@ -56,6 +56,7 @@ typedef IEventHandler<IInspectable *> ContentChangedHandler;
 QT_BEGIN_NAMESPACE
 
 QWinRTClipboard::QWinRTClipboard()
+    : m_mimeData(Q_NULLPTR)
 {
 #ifndef Q_OS_WINPHONE
     QEventDispatcherWinRT::runOnXamlThread([this]() {
@@ -100,9 +101,16 @@ QMimeData *QWinRTClipboard::mimeData(QClipboard::Mode mode)
     const wchar_t *textStr = result.GetRawBuffer(&size);
     QString text = QString::fromWCharArray(textStr, size);
     text.replace(QStringLiteral("\r\n"), QStringLiteral("\n"));
-    m_mimeData.setText(text);
 
-    return &m_mimeData;
+    if (m_mimeData) {
+        if (m_mimeData->text() == text)
+            return m_mimeData;
+        delete m_mimeData;
+    }
+    m_mimeData = new QMimeData();
+    m_mimeData->setText(text);
+
+    return m_mimeData;
 #else // Q_OS_WINPHONE
     return QPlatformClipboard::mimeData(mode);
 #endif // Q_OS_WINPHONE
@@ -143,6 +151,12 @@ void QWinRTClipboard::setMimeData(QMimeData *data, QClipboard::Mode mode)
         return;
 
 #ifndef Q_OS_WINPHONE
+    const bool newData = !m_mimeData || m_mimeData != data;
+    if (newData) {
+        if (m_mimeData)
+            delete m_mimeData;
+        m_mimeData = data;
+    }
     const QString text = data ? data->text() : QString();
     HRESULT hr = QEventDispatcherWinRT::runOnXamlThread([this, text]() {
         HRESULT hr;
@@ -161,7 +175,6 @@ void QWinRTClipboard::setMimeData(QMimeData *data, QClipboard::Mode mode)
         return S_OK;
     });
     RETURN_VOID_IF_FAILED("Could not set clipboard text.");
-    emitChanged(mode);
 #else // Q_OS_WINPHONE
     QPlatformClipboard::setMimeData(data, mode);
 #endif // Q_OS_WINPHONE
diff --git a/src/plugins/platforms/winrt/qwinrtclipboard.h b/src/plugins/platforms/winrt/qwinrtclipboard.h
index 1fb10bdfc0..fc3d50ce59 100644
--- a/src/plugins/platforms/winrt/qwinrtclipboard.h
+++ b/src/plugins/platforms/winrt/qwinrtclipboard.h
@@ -70,7 +70,7 @@ private:
 #ifndef Q_OS_WINPHONE
     Microsoft::WRL::ComPtr<ABI::Windows::ApplicationModel::DataTransfer::IClipboardStatics> m_nativeClipBoard;
 #endif
-    QMimeData m_mimeData;
+    QMimeData *m_mimeData;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/winrt/qwinrtmessagedialoghelper.cpp b/src/plugins/platforms/winrt/qwinrtmessagedialoghelper.cpp
index bad15126d4..42fe030b23 100644
--- a/src/plugins/platforms/winrt/qwinrtmessagedialoghelper.cpp
+++ b/src/plugins/platforms/winrt/qwinrtmessagedialoghelper.cpp
@@ -108,6 +108,9 @@ bool QWinRTMessageDialogHelper::show(Qt::WindowFlags windowFlags, Qt::WindowModa
     Q_D(QWinRTMessageDialogHelper);
 
     QSharedPointer<QMessageDialogOptions> options = this->options();
+    if (!options.data())
+        return false;
+
     const QString informativeText = options->informativeText();
     const QString title = options->windowTitle();
     const QString text = informativeText.isEmpty() ? options->text() : (options->text() + QLatin1Char('\n') + informativeText);
diff --git a/src/plugins/platforms/xcb/gl_integrations/gl_integrations_plugin_base.pri b/src/plugins/platforms/xcb/gl_integrations/gl_integrations_plugin_base.pri
index c2d3849d8e..68cb91ff3d 100644
--- a/src/plugins/platforms/xcb/gl_integrations/gl_integrations_plugin_base.pri
+++ b/src/plugins/platforms/xcb/gl_integrations/gl_integrations_plugin_base.pri
@@ -3,6 +3,8 @@ QT += core-private gui-private platformsupport-private xcb_qpa_lib-private
 INCLUDEPATH += $$PWD
 INCLUDEPATH += $$PWD/../
 
+load(qt_build_paths)
+
 # needed by Xcursor ...
 contains(QT_CONFIG, xcb-xlib) {
     DEFINES += XCB_USE_XLIB
diff --git a/src/plugins/platforms/xcb/xcb_qpa_lib.pro b/src/plugins/platforms/xcb/xcb_qpa_lib.pro
index db9ea32cd8..9ca8872cb2 100644
--- a/src/plugins/platforms/xcb/xcb_qpa_lib.pro
+++ b/src/plugins/platforms/xcb/xcb_qpa_lib.pro
@@ -38,6 +38,8 @@ HEADERS = \
         qxcbxsettings.h \
         qxcbsystemtraytracker.h
 
+load(qt_build_paths)
+
 DEFINES += QT_BUILD_XCB_PLUGIN
 # needed by Xcursor ...
 contains(QT_CONFIG, xcb-xlib) {
diff --git a/src/printsupport/kernel/qprintengine_win.cpp b/src/printsupport/kernel/qprintengine_win.cpp
index a9d316095c..1c02d389fe 100644
--- a/src/printsupport/kernel/qprintengine_win.cpp
+++ b/src/printsupport/kernel/qprintengine_win.cpp
@@ -918,14 +918,14 @@ void QWin32PrintEnginePrivate::initialize()
     Q_ASSERT(hPrinter);
     Q_ASSERT(pInfo);
 
+    initHDC();
+
     if (devMode) {
         num_copies = devMode->dmCopies;
         devMode->dmCollate = DMCOLLATE_TRUE;
         updatePageLayout();
     }
 
-    initHDC();
-
 #if defined QT_DEBUG_DRAW || defined QT_DEBUG_METRICS
     qDebug() << "QWin32PrintEngine::initialize()";
     debugMetrics();
diff --git a/src/printsupport/kernel/qprintengine_win_p.h b/src/printsupport/kernel/qprintengine_win_p.h
index c1d7b452f9..74b78ae2b1 100644
--- a/src/printsupport/kernel/qprintengine_win_p.h
+++ b/src/printsupport/kernel/qprintengine_win_p.h
@@ -124,10 +124,14 @@ public:
         state(QPrinter::Idle),
         resolution(0),
         m_pageLayout(QPageLayout(QPageSize(QPageSize::A4), QPageLayout::Portrait, QMarginsF(0, 0, 0, 0))),
+        stretch_x(1), stretch_y(1), origin_x(0), origin_y(0),
+        dpi_x(96), dpi_y(96), dpi_display(96),
         num_copies(1),
         printToFile(false),
         reinit(false),
-        embed_fonts(true)
+        complex_xform(false), has_pen(false), has_brush(false), has_custom_paper_size(false),
+        embed_fonts(true),
+        txop(0 /* QTransform::TxNone */)
     {
     }
 
diff --git a/src/widgets/dialogs/qcolordialog.cpp b/src/widgets/dialogs/qcolordialog.cpp
index 547a55f19e..c4cc21cbe5 100644
--- a/src/widgets/dialogs/qcolordialog.cpp
+++ b/src/widgets/dialogs/qcolordialog.cpp
@@ -2173,7 +2173,8 @@ QColor QColorDialog::getColor(const QColor &initial, QWidget *parent, const QStr
 
 QRgb QColorDialog::getRgba(QRgb initial, bool *ok, QWidget *parent)
 {
-    QColor color(getColor(QColor(initial), parent, QString(), ShowAlphaChannel));
+    const QColor color = getColor(QColor::fromRgba(initial), parent, QString(),
+                                  ShowAlphaChannel);
     QRgb result = color.isValid() ? color.rgba() : initial;
     if (ok)
         *ok = color.isValid();
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 6729969024..b1d80d7b8f 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -10340,14 +10340,13 @@ void QWidgetPrivate::setWindowFlags(Qt::WindowFlags flags)
         // the old type was a window and/or the new type is a window
         QPoint oldPos = q->pos();
         bool visible = q->isVisible();
+        const bool windowFlagChanged = (q->data->window_flags ^ flags) & Qt::Window;
         q->setParent(q->parentWidget(), flags);
 
         // if both types are windows or neither of them are, we restore
         // the old position
-        if (!((q->data->window_flags ^ flags) & Qt::Window)
-            && (visible || q->testAttribute(Qt::WA_Moved))) {
+        if (!windowFlagChanged && (visible || q->testAttribute(Qt::WA_Moved)))
             q->move(oldPos);
-        }
         // for backward-compatibility we change Qt::WA_QuitOnClose attribute value only when the window was recreated.
         adjustQuitOnCloseAttribute();
     } else {
diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index cb3c2a410b..568a4755e4 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -996,15 +996,17 @@ QRenderRule::QRenderRule(const QVector<Declaration> &declarations, const QObject
         }
     }
 
-    if (const QWidget *widget = qobject_cast<const QWidget *>(object)) {
-        QStyleSheetStyle *style = const_cast<QStyleSheetStyle *>(globalStyleSheetStyle);
-        if (!style)
-            style = qobject_cast<QStyleSheetStyle *>(widget->style());
-        if (style)
-            fixupBorder(style->nativeFrameWidth(widget));
+    if (hasBorder()) {
+        if (const QWidget *widget = qobject_cast<const QWidget *>(object)) {
+            QStyleSheetStyle *style = const_cast<QStyleSheetStyle *>(globalStyleSheetStyle);
+            if (!style)
+                style = qobject_cast<QStyleSheetStyle *>(widget->style());
+            if (style)
+                fixupBorder(style->nativeFrameWidth(widget));
+        }
+        if (border()->hasBorderImage())
+            defaultBackground = QBrush();
     }
-    if (hasBorder() && border()->hasBorderImage())
-        defaultBackground = QBrush();
 }
 
 QRect QRenderRule::borderRect(const QRect& r) const
diff --git a/src/widgets/styles/qwindowsvistastyle.cpp b/src/widgets/styles/qwindowsvistastyle.cpp
index fe9684a25f..52006815ed 100644
--- a/src/widgets/styles/qwindowsvistastyle.cpp
+++ b/src/widgets/styles/qwindowsvistastyle.cpp
@@ -1175,9 +1175,9 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
     case CE_MenuItem:
         if (const QStyleOptionMenuItem *menuitem = qstyleoption_cast<const QStyleOptionMenuItem *>(option)) {
             // windows always has a check column, regardless whether we have an icon or not
-            const qreal devicePixelRatio = QWindowsXPStylePrivate::devicePixelRatio(widget);
-            int checkcol = qRound(qreal(25) / devicePixelRatio);
-            const int gutterWidth = qRound(qreal(3) / devicePixelRatio);
+            const qreal factor = QWindowsXPStylePrivate::nativeMetricScaleFactor(widget);
+            int checkcol = qRound(qreal(25) * factor);
+            const int gutterWidth = qRound(qreal(3) * factor);
             {
                 XPThemeData theme(widget, 0, QWindowsXPStylePrivate::MenuTheme,
                                   MENU_POPUPCHECKBACKGROUND, MBI_HOT);
@@ -2166,8 +2166,9 @@ QRect QWindowsVistaStyle::subControlRect(ComplexControl control, const QStyleOpt
             const bool isToolTitle = false;
             const int height = tb->rect.height();
             const int width = tb->rect.width();
-            int buttonWidth = GetSystemMetrics(SM_CXSIZE) / QWindowsStylePrivate::devicePixelRatio(widget)
-                - int(QStyleHelper::dpiScaled(4));
+            const int buttonWidth =
+                qRound(qreal(GetSystemMetrics(SM_CXSIZE)) * QWindowsStylePrivate::nativeMetricScaleFactor(widget)
+                       - QStyleHelper::dpiScaled(4));
 
             const int frameWidth = proxy()->pixelMetric(PM_MdiSubWindowFrameWidth, option, widget);
             const bool sysmenuHint  = (tb->titleBarFlags & Qt::WindowSystemMenuHint) != 0;
diff --git a/src/widgets/styles/qwindowsxpstyle.cpp b/src/widgets/styles/qwindowsxpstyle.cpp
index f2ee8e0b47..3017707117 100644
--- a/src/widgets/styles/qwindowsxpstyle.cpp
+++ b/src/widgets/styles/qwindowsxpstyle.cpp
@@ -2098,7 +2098,7 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
             themeNumber = QWindowsXPStylePrivate::StatusTheme;
             partId = SP_GRIPPER;
             XPThemeData theme(0, p, themeNumber, partId, 0);
-            QSize size = (theme.size() / QWindowsStylePrivate::devicePixelRatio(widget)).toSize();
+            QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
             size.rheight()--;
             if (const QStyleOptionSizeGrip *sg = qstyleoption_cast<const QStyleOptionSizeGrip *>(option)) {
                 switch (sg->corner) {
@@ -2169,7 +2169,7 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
                                   QWindowsXPStylePrivate::ToolBarTheme,
                                   TP_SPLITBUTTONDROPDOWN);
                 if (theme.isValid()) {
-                    const QSize size = (theme.size() / QWindowsStylePrivate::devicePixelRatio(widget)).toSize();
+                    const QSize size = (theme.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                     mbiw = size.width();
                     mbih = size.height();
                 }
@@ -2632,10 +2632,11 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
 QRect QWindowsXPStylePrivate::scrollBarGripperBounds(QStyle::State flags, const QWidget *widget, XPThemeData *theme)
 {
     const bool horizontal = flags & QStyle::State_Horizontal;
-    const QMargins contentsMargin = (theme->margins(theme->rect, TMT_SIZINGMARGINS)
-                                     / QWindowsStylePrivate::devicePixelRatio(widget)).toMargins();
+    const qreal factor = QWindowsStylePrivate::nativeMetricScaleFactor(widget);
+    const QMargins contentsMargin =
+        (theme->margins(theme->rect, TMT_SIZINGMARGINS) * factor).toMargins();
     theme->partId = horizontal ? SBP_GRIPPERHORZ : SBP_GRIPPERVERT;
-    const QSize size = (theme->size() / QWindowsStylePrivate::devicePixelRatio(widget)).toSize();
+    const QSize size = (theme->size() * factor).toSize();
 
     const int hSpace = theme->rect.width() - size.width();
     const int vSpace = theme->rect.height() - size.height();
@@ -3793,12 +3794,13 @@ QSize QWindowsXPStyle::sizeFromContents(ContentsType ct, const QStyleOption *opt
         {
             XPThemeData buttontheme(widget, 0, QWindowsXPStylePrivate::ButtonTheme, BP_PUSHBUTTON, PBS_NORMAL);
             if (buttontheme.isValid()) {
-                const qreal devicePixelRatio = QWindowsXPStylePrivate::devicePixelRatio(widget);
-                const QMarginsF borderSize = buttontheme.margins() / devicePixelRatio;
+                const qreal factor = QWindowsXPStylePrivate::nativeMetricScaleFactor(widget);
+                const QMarginsF borderSize = buttontheme.margins() * factor;
                 if (!borderSize.isNull()) {
-                    const qreal margin = qreal(2) / devicePixelRatio;
+                    const qreal margin = qreal(2) * factor;
                     sz.rwidth() += qRound(borderSize.left() + borderSize.right() - margin);
-                    sz.rheight() += int(borderSize.bottom() + borderSize.top() - margin + devicePixelRatio - 1);
+                    sz.rheight() += int(borderSize.bottom() + borderSize.top() - margin
+                        + qreal(1) / factor - 1);
                 }
                 const int textMargins = 2*(proxy()->pixelMetric(PM_FocusFrameHMargin) + 1);
                 sz += QSize(qMax(pixelMetric(QStyle::PM_ScrollBarExtent, option, widget)
@@ -4072,7 +4074,7 @@ QIcon QWindowsXPStyle::standardIcon(StandardPixmap standardIcon,
                 XPThemeData theme(0, 0, QWindowsXPStylePrivate::WindowTheme,
                                   WP_RESTOREBUTTON, RBS_NORMAL);
                 if (theme.isValid()) {
-                    const QSize size = (themeSize.size() / QWindowsStylePrivate::devicePixelRatio(widget)).toSize();
+                    const QSize size = (themeSize.size() * QWindowsStylePrivate::nativeMetricScaleFactor(widget)).toSize();
                     QPixmap pm(size);
                     pm.fill(Qt::transparent);
                     QPainter p(&pm);
diff --git a/src/widgets/widgets/qabstractspinbox.cpp b/src/widgets/widgets/qabstractspinbox.cpp
index 854befd265..881db81ad4 100644
--- a/src/widgets/widgets/qabstractspinbox.cpp
+++ b/src/widgets/widgets/qabstractspinbox.cpp
@@ -1083,6 +1083,8 @@ void QAbstractSpinBox::keyPressEvent(QKeyEvent *event)
     }
 
     d->edit->event(event);
+    if (!d->edit->text().isEmpty())
+        d->cleared = false;
     if (!isVisible())
         d->ignoreUpdateEdit = true;
 }
diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index d22e89c6e1..1d10de904d 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -2604,6 +2604,21 @@ void QDockAreaLayout::remove(const QList<int> &path)
     docks[index].remove(path.mid(1));
 }
 
+void QDockAreaLayout::removePlaceHolder(const QString &name)
+{
+    QList<int> index = indexOfPlaceHolder(name);
+    if (!index.isEmpty())
+        remove(index);
+    foreach (QDockWidgetGroupWindow *dwgw, mainWindow->findChildren<QDockWidgetGroupWindow *>(
+                                               QString(), Qt::FindDirectChildrenOnly)) {
+        index = dwgw->layoutInfo()->indexOfPlaceHolder(name);
+        if (!index.isEmpty()) {
+            dwgw->layoutInfo()->remove(index);
+            dwgw->destroyOrHideIfEmpty();
+        }
+    }
+}
+
 static inline int qMax(int i1, int i2, int i3) { return qMax(i1, qMax(i2, i3)); }
 
 void QDockAreaLayout::getGrid(QVector<QLayoutStruct> *_ver_struct_list,
@@ -3030,15 +3045,27 @@ QRect QDockAreaLayout::constrainedRect(QRect rect, QWidget* widget)
 
 bool QDockAreaLayout::restoreDockWidget(QDockWidget *dockWidget)
 {
-    QList<int> index = indexOfPlaceHolder(dockWidget->objectName());
-    if (index.isEmpty())
-        return false;
+    QDockAreaLayoutItem *item = 0;
+    foreach (QDockWidgetGroupWindow *dwgw, mainWindow->findChildren<QDockWidgetGroupWindow *>(
+                                               QString(), Qt::FindDirectChildrenOnly)) {
+        QList<int> index = dwgw->layoutInfo()->indexOfPlaceHolder(dockWidget->objectName());
+        if (!index.isEmpty()) {
+            dockWidget->setParent(dwgw);
+            item = const_cast<QDockAreaLayoutItem *>(&dwgw->layoutInfo()->item(index));
+            break;
+        }
+    }
+    if (!item) {
+        QList<int> index = indexOfPlaceHolder(dockWidget->objectName());
+        if (index.isEmpty())
+            return false;
+        item = const_cast<QDockAreaLayoutItem *>(&this->item(index));
+    }
 
-    QDockAreaLayoutItem &item = this->item(index);
-    QPlaceHolderItem *placeHolder = item.placeHolderItem;
+    QPlaceHolderItem *placeHolder = item->placeHolderItem;
     Q_ASSERT(placeHolder != 0);
 
-    item.widgetItem = new QDockWidgetItem(dockWidget);
+    item->widgetItem = new QDockWidgetItem(dockWidget);
 
     if (placeHolder->window) {
         const QRect r = constrainedRect(placeHolder->topLevelRect, dockWidget);
@@ -3050,7 +3077,7 @@ bool QDockAreaLayout::restoreDockWidget(QDockWidget *dockWidget)
         dockWidget->d_func()->setWindowState(true);
 #endif
 
-    item.placeHolderItem = 0;
+    item->placeHolderItem = 0;
     delete placeHolder;
 
     return true;
@@ -3086,9 +3113,7 @@ void QDockAreaLayout::addDockWidget(QInternal::DockPosition pos, QDockWidget *do
         info = new_info;
     }
 
-    QList<int> index = indexOfPlaceHolder(dockWidget->objectName());
-    if (!index.isEmpty())
-        remove(index);
+    removePlaceHolder(dockWidget->objectName());
 }
 
 void QDockAreaLayout::tabifyDockWidget(QDockWidget *first, QDockWidget *second)
@@ -3101,9 +3126,7 @@ void QDockAreaLayout::tabifyDockWidget(QDockWidget *first, QDockWidget *second)
     Q_ASSERT(info != 0);
     info->tab(path.last(), new QDockWidgetItem(second));
 
-    QList<int> index = indexOfPlaceHolder(second->objectName());
-    if (!index.isEmpty())
-        remove(index);
+    removePlaceHolder(second->objectName());
 }
 
 void QDockAreaLayout::resizeDocks(const QList<QDockWidget *> &docks,
@@ -3165,9 +3188,7 @@ void QDockAreaLayout::splitDockWidget(QDockWidget *after,
     Q_ASSERT(info != 0);
     info->split(path.last(), orientation, new QDockWidgetItem(dockWidget));
 
-    QList<int> index = indexOfPlaceHolder(dockWidget->objectName());
-    if (!index.isEmpty())
-        remove(index);
+    removePlaceHolder(dockWidget->objectName());
 }
 
 void QDockAreaLayout::apply(bool animate)
diff --git a/src/widgets/widgets/qdockarealayout_p.h b/src/widgets/widgets/qdockarealayout_p.h
index 5d352f0124..8a35d8b035 100644
--- a/src/widgets/widgets/qdockarealayout_p.h
+++ b/src/widgets/widgets/qdockarealayout_p.h
@@ -255,6 +255,7 @@ public:
     QLayoutItem *plug(const QList<int> &path);
     QLayoutItem *unplug(const QList<int> &path);
     void remove(const QList<int> &path);
+    void removePlaceHolder(const QString &name);
 
     void fitLayout();
 
diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index 6b247d8d11..f581fe4d88 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -215,11 +215,10 @@ public:
     }
     void setGeometry(const QRect&r) Q_DECL_OVERRIDE
     {
+        static_cast<QDockWidgetGroupWindow *>(parent())->destroyOrHideIfEmpty();
         QDockAreaLayoutInfo *li = layoutInfo();
-        if (li->isEmpty()) {
-            static_cast<QDockWidgetGroupWindow *>(parent())->destroyIfEmpty();
+        if (li->isEmpty())
             return;
-        }
         int fw = frameWidth();
         li->reparentWidgets(parentWidget());
         li->rect = r.adjusted(fw, fw, -fw, -fw);
@@ -272,6 +271,10 @@ bool QDockWidgetGroupWindow::event(QEvent *e)
         if (qobject_cast<QDockWidget *>(static_cast<QChildEvent*>(e)->child()))
             adjustFlags();
         break;
+    case QEvent::LayoutRequest:
+        // We might need to show the widget again
+        destroyOrHideIfEmpty();
+        break;
     default:
         break;
     }
@@ -325,34 +328,43 @@ QDockWidget *QDockWidgetGroupWindow::topDockWidget() const
 }
 
 /*! \internal
-    Destroy this window if there is no more QDockWidget in it.
+    Destroy or hide this window if there is no more QDockWidget in it.
+    Otherwise make sure it is shown.
  */
-void QDockWidgetGroupWindow::destroyIfEmpty()
-{
-    if (layoutInfo()->isEmpty()) {
-        // Make sure to reparent the possibly floating or hidden QDockWidgets to the parent
-        foreach (QDockWidget *dw,
-                 findChildren<QDockWidget *>(QString(), Qt::FindDirectChildrenOnly)) {
-            bool wasFloating = dw->isFloating();
-            bool wasHidden = dw->isHidden();
-            dw->setParent(parentWidget());
-            if (wasFloating) {
-                dw->setFloating(true);
-            } else {
-                // maybe it was hidden, we still have to put it back in the main layout.
-                QMainWindowLayout *ml = qt_mainwindow_layout(static_cast<QMainWindow*>(parentWidget()));
-                Qt::DockWidgetArea area = ml->dockWidgetArea(this);
-                if (area == Qt::NoDockWidgetArea)
-                    area = Qt::LeftDockWidgetArea;
-                static_cast<QMainWindow*>(parentWidget())->addDockWidget(area, dw);
-            }
-            if (!wasHidden)
-                dw->show();
+void QDockWidgetGroupWindow::destroyOrHideIfEmpty()
+{
+    if (!layoutInfo()->isEmpty()) {
+        show(); // It might have been hidden,
+        return;
+    }
+    // There might still be placeholders
+    if (!layoutInfo()->item_list.isEmpty()) {
+        hide();
+        return;
+    }
+
+    // Make sure to reparent the possibly floating or hidden QDockWidgets to the parent
+    foreach (QDockWidget *dw, findChildren<QDockWidget *>(QString(), Qt::FindDirectChildrenOnly)) {
+        bool wasFloating = dw->isFloating();
+        bool wasHidden = dw->isHidden();
+        dw->setParent(parentWidget());
+        if (wasFloating) {
+            dw->setFloating(true);
+        } else {
+            // maybe it was hidden, we still have to put it back in the main layout.
+            QMainWindowLayout *ml =
+                qt_mainwindow_layout(static_cast<QMainWindow *>(parentWidget()));
+            Qt::DockWidgetArea area = ml->dockWidgetArea(this);
+            if (area == Qt::NoDockWidgetArea)
+                area = Qt::LeftDockWidgetArea;
+            static_cast<QMainWindow *>(parentWidget())->addDockWidget(area, dw);
         }
-        foreach (QTabBar *tb, findChildren<QTabBar *>(QString(), Qt::FindDirectChildrenOnly))
-            tb->setParent(parentWidget());
-        deleteLater();
+        if (!wasHidden)
+            dw->show();
     }
+    foreach (QTabBar *tb, findChildren<QTabBar *>(QString(), Qt::FindDirectChildrenOnly))
+        tb->setParent(parentWidget());
+    deleteLater();
 }
 
 /*! \internal
@@ -2075,7 +2087,7 @@ void QMainWindowLayout::animationFinished(QWidget *widget)
                 item.subinfo->reparentWidgets(parentWidget());
                 item.subinfo->setTabBarShape(parentInfo->tabBarShape);
             }
-            dwgw->destroyIfEmpty();
+            dwgw->destroyOrHideIfEmpty();
         }
 
         if (QDockWidget *dw = qobject_cast<QDockWidget*>(widget)) {
diff --git a/src/widgets/widgets/qmainwindowlayout_p.h b/src/widgets/widgets/qmainwindowlayout_p.h
index 9a13e5f5ce..7475da8bdc 100644
--- a/src/widgets/widgets/qmainwindowlayout_p.h
+++ b/src/widgets/widgets/qmainwindowlayout_p.h
@@ -86,7 +86,7 @@ public:
         : QWidget(parent, f) {}
     QDockAreaLayoutInfo *layoutInfo() const;
     QDockWidget *topDockWidget() const;
-    void destroyIfEmpty();
+    void destroyOrHideIfEmpty();
     void adjustFlags();
 protected:
     bool event(QEvent *) Q_DECL_OVERRIDE;