Merge remote-tracking branch 'origin/dev' into merge-dev

Change-Id: I31b761cfd5ea01373c60d02a5da8c33398d34739

142 files changed, 1975 insertions, 903 deletions

diff --git a/src/plugins/platforms/android/qandroidassetsfileenginehandler.cpp b/src/plugins/platforms/android/qandroidassetsfileenginehandler.cpp
index 26e72a480f..fcc08ea00d 100644
--- a/src/plugins/platforms/android/qandroidassetsfileenginehandler.cpp
+++ b/src/plugins/platforms/android/qandroidassetsfileenginehandler.cpp
@@ -72,9 +72,10 @@ static inline QString prefixedPath(QString path)
 struct AssetItem {
     enum class Type {
         File,
-        Folder
+        Folder,
+        Invalid
     };
-
+    AssetItem() = default;
     AssetItem (const QString &rawName)
         : name(rawName)
     {
@@ -92,21 +93,47 @@ using AssetItemList = QVector<AssetItem>;
 class FolderIterator : public AssetItemList
 {
 public:
-    static QSharedPointer<FolderIterator> fromCache(const QString &path)
+    static QSharedPointer<FolderIterator> fromCache(const QString &path, bool clone)
     {
         QMutexLocker lock(&m_assetsCacheMutex);
         QSharedPointer<FolderIterator> *folder = m_assetsCache.object(path);
         if (!folder) {
             folder = new QSharedPointer<FolderIterator>{new FolderIterator{path}};
-            if (!m_assetsCache.insert(path, folder)) {
+            if ((*folder)->empty() || !m_assetsCache.insert(path, folder)) {
                 QSharedPointer<FolderIterator> res = *folder;
                 delete folder;
                 return res;
             }
         }
-        return *folder;
+        return clone ? QSharedPointer<FolderIterator>{new FolderIterator{*(*folder)}} : *folder;
+    }
+
+    static AssetItem::Type fileType(const QString &filePath)
+    {
+        const QStringList paths = filePath.split(QLatin1Char('/'));
+        QString fullPath;
+        AssetItem::Type res = AssetItem::Type::Invalid;
+        for (const auto &path: paths) {
+            auto folder = fromCache(fullPath, false);
+            auto it = std::lower_bound(folder->begin(), folder->end(), AssetItem{path}, [](const AssetItem &val, const AssetItem &assetItem) {
+                return val.name < assetItem.name;
+            });
+            if (it == folder->end() || it->name != path)
+                return AssetItem::Type::Invalid;
+            if (!fullPath.isEmpty())
+                fullPath.append(QLatin1Char('/'));
+            fullPath += path;
+            res = it->type;
+        }
+        return res;
     }
 
+    FolderIterator(const FolderIterator &other)
+        : AssetItemList(other)
+        , m_index(-1)
+        , m_path(other.m_path)
+    {}
+
     FolderIterator(const QString &path)
         : m_path(path)
     {
@@ -118,8 +145,12 @@ public:
             QJNIEnvironmentPrivate env;
             jobjectArray jFiles = static_cast<jobjectArray>(files.object());
             const jint nFiles = env->GetArrayLength(jFiles);
-            for (int i = 0; i < nFiles; ++i)
-                push_back({QJNIObjectPrivate(env->GetObjectArrayElement(jFiles, i)).toString()});
+            for (int i = 0; i < nFiles; ++i) {
+                AssetItem item{QJNIObjectPrivate(env->GetObjectArrayElement(jFiles, i)).toString()};
+                insert(std::upper_bound(begin(), end(), item, [](const auto &a, const auto &b){
+                    return a.name < b.name;
+                }), item);
+            }
         }
         m_path = assetsPrefix + QLatin1Char('/') + m_path + QLatin1Char('/');
         m_path.replace(QLatin1String("//"), QLatin1String("/"));
@@ -169,7 +200,7 @@ public:
                                       const QString &path)
         : QAbstractFileEngineIterator(filters, nameFilters)
     {
-        m_stack.push_back(FolderIterator::fromCache(cleanedAssetPath(path)));
+        m_stack.push_back(FolderIterator::fromCache(cleanedAssetPath(path), true));
         if (m_stack.last()->empty())
             m_stack.pop_back();
     }
@@ -215,7 +246,7 @@ public:
         if (!res)
             return {};
         if (res->second.type == AssetItem::Type::Folder) {
-            m_stack.push_back(FolderIterator::fromCache(cleanedAssetPath(currentFilePath())));
+            m_stack.push_back(FolderIterator::fromCache(cleanedAssetPath(currentFilePath()), true));
             if (m_stack.last()->empty())
                 m_stack.pop_back();
         }
@@ -257,6 +288,7 @@ public:
             m_assetFile = 0;
             return true;
         }
+        m_isFolder = false;
         return false;
     }
 
@@ -305,12 +337,12 @@ public:
 
     FileFlags fileFlags(FileFlags type = FileInfoAll) const override
     {
-        FileFlags flags(ReadOwnerPerm|ReadUserPerm|ReadGroupPerm|ReadOtherPerm|ExistsFlag);
+        FileFlags commonFlags(ReadOwnerPerm|ReadUserPerm|ReadGroupPerm|ReadOtherPerm|ExistsFlag);
+        FileFlags flags;
         if (m_assetFile)
-            flags |= FileType;
+            flags = FileType | commonFlags;
         else if (m_isFolder)
-            flags |= DirectoryType;
-
+            flags = DirectoryType | commonFlags;
         return type & flags;
     }
 
@@ -341,9 +373,20 @@ public:
 
     void setFileName(const QString &file) override
     {
+        if (m_fileName == cleanedAssetPath(file))
+            return;
         close();
         m_fileName = cleanedAssetPath(file);
-        m_isFolder = !open(QIODevice::ReadOnly) && !FolderIterator::fromCache(m_fileName)->empty();
+        switch (FolderIterator::fileType(m_fileName)) {
+        case AssetItem::Type::File:
+            open(QIODevice::ReadOnly);
+            break;
+        case AssetItem::Type::Folder:
+            m_isFolder = true;
+            break;
+        case AssetItem::Type::Invalid:
+            break;
+        }
     }
 
     Iterator *beginEntryList(QDir::Filters filters, const QStringList &filterNames) override
@@ -355,9 +398,9 @@ public:
 
 private:
     AAsset *m_assetFile = nullptr;
-    AAssetManager *m_assetManager;
+    AAssetManager *m_assetManager = nullptr;
     QString m_fileName;
-    bool m_isFolder;
+    bool m_isFolder = false;
 };
 
 
diff --git a/src/plugins/platforms/cocoa/cocoa.pro b/src/plugins/platforms/cocoa/cocoa.pro
index 4cf9e64447..a919963cf4 100644
--- a/src/plugins/platforms/cocoa/cocoa.pro
+++ b/src/plugins/platforms/cocoa/cocoa.pro
@@ -25,7 +25,6 @@ SOURCES += main.mm \
     qcocoaclipboard.mm \
     qcocoadrag.mm \
     qmacclipboard.mm \
-    qcocoasystemsettings.mm \
     qcocoainputcontext.mm \
     qcocoaservices.mm \
     qcocoasystemtrayicon.mm \
@@ -59,7 +58,6 @@ HEADERS += qcocoaintegration.h \
     qcocoaclipboard.h \
     qcocoadrag.h \
     qmacclipboard.h \
-    qcocoasystemsettings.h \
     qcocoainputcontext.h \
     qcocoaservices.h \
     qcocoasystemtrayicon.h \
@@ -87,6 +85,11 @@ qtConfig(accessibility) {
         qcocoaaccessibility.h
 }
 
+qtConfig(sessionmanager) {
+    SOURCES += qcocoasessionmanager.cpp
+    HEADERS += qcocoasessionmanager.h
+}
+
 RESOURCES += qcocoaresources.qrc
 
 LIBS += -framework AppKit -framework CoreServices -framework Carbon -framework IOKit -framework QuartzCore -framework CoreVideo -framework Metal -framework IOSurface -lcups
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
index db4ec251ae..106c226adc 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
@@ -133,7 +133,7 @@ static void populateRoleMap()
     roleMap[QAccessible::SpinBox] = NSAccessibilityIncrementorRole;
     roleMap[QAccessible::Slider] = NSAccessibilitySliderRole;
     roleMap[QAccessible::ProgressBar] = NSAccessibilityProgressIndicatorRole;
-    roleMap[QAccessible::ComboBox] = NSAccessibilityPopUpButtonRole;
+    roleMap[QAccessible::ComboBox] = NSAccessibilityComboBoxRole;
     roleMap[QAccessible::RadioButton] = NSAccessibilityRadioButtonRole;
     roleMap[QAccessible::CheckBox] = NSAccessibilityCheckBoxRole;
     roleMap[QAccessible::StaticText] = NSAccessibilityStaticTextRole;
diff --git a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
index 9b0a6b1b86..3fb9e83d35 100644
--- a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
+++ b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
@@ -79,11 +79,14 @@
 #include "qcocoamenuitem.h"
 #include "qcocoansmenu.h"
 
+#if QT_CONFIG(sessionmanager)
+#  include "qcocoasessionmanager.h"
+#endif
+
 #include <qevent.h>
 #include <qurl.h>
 #include <qdebug.h>
 #include <qguiapplication.h>
-#include <private/qguiapplication_p.h>
 #include "qt_mac_p.h"
 #include <qpa/qwindowsysteminterface.h>
 #include <qwindowdefs.h>
@@ -149,7 +152,7 @@ QT_USE_NAMESPACE
     if ([reflectionDelegate respondsToSelector:_cmd])
         return [reflectionDelegate applicationShouldTerminate:sender];
 
-    if (QGuiApplicationPrivate::instance()->threadData->eventLoops.isEmpty()) {
+    if (QGuiApplicationPrivate::instance()->threadData.loadRelaxed()->eventLoops.isEmpty()) {
         // No event loop is executing. This probably means that Qt is used as a plugin,
         // or as a part of a native Cocoa application. In any case it should be fine to
         // terminate now.
@@ -157,6 +160,17 @@ QT_USE_NAMESPACE
         return NSTerminateNow;
     }
 
+#if QT_CONFIG(sessionmanager)
+    QCocoaSessionManager *cocoaSessionManager = QCocoaSessionManager::instance();
+    cocoaSessionManager->resetCancellation();
+    cocoaSessionManager->appCommitData();
+
+    if (cocoaSessionManager->wasCanceled()) {
+        qCDebug(lcQpaApplication) << "Session management canceled application termination";
+        return NSTerminateCancel;
+    }
+#endif
+
     if (!QWindowSystemInterface::handleApplicationTermination<QWindowSystemInterface::SynchronousDelivery>()) {
         qCDebug(lcQpaApplication) << "Application termination canceled";
         return NSTerminateCancel;
@@ -359,7 +373,7 @@ QT_USE_NAMESPACE
     if (!platformItem || platformItem->menu())
         return;
 
-    QScopedScopeLevelCounter scopeLevelCounter(QGuiApplicationPrivate::instance()->threadData);
+    QScopedScopeLevelCounter scopeLevelCounter(QGuiApplicationPrivate::instance()->threadData.loadRelaxed());
     QGuiApplicationPrivate::modifier_buttons = [QNSView convertKeyModifiers:[NSEvent modifierFlags]];
 
     static QMetaMethod activatedSignal = QMetaMethod::fromSignal(&QCocoaMenuItem::activated);
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.h b/src/plugins/platforms/cocoa/qcocoabackingstore.h
index a874936ce6..b57deacb57 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.h
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.h
@@ -54,8 +54,6 @@ class QCocoaBackingStore : public QRasterBackingStore
 protected:
     QCocoaBackingStore(QWindow *window);
     QCFType<CGColorSpaceRef> colorSpace() const;
-    QMacNotificationObserver m_backingPropertiesObserver;
-    virtual void backingPropertiesChanged() = 0;
 };
 
 class QNSWindowBackingStore : public QCocoaBackingStore
@@ -71,7 +69,6 @@ private:
     bool windowHasUnifiedToolbar() const;
     QImage::Format format() const override;
     void redrawRoundedBottomCorners(CGRect) const;
-    void backingPropertiesChanged() override;
 };
 
 class QCALayerBackingStore : public QCocoaBackingStore
@@ -118,7 +115,8 @@ private:
     bool recreateBackBufferIfNeeded();
     bool prepareForFlush();
 
-    void backingPropertiesChanged() override;
+    void backingPropertiesChanged();
+    QMacNotificationObserver m_backingPropertiesObserver;
 
     std::list<std::unique_ptr<GraphicsBuffer>> m_buffers;
 };
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.mm b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index b17302a640..2e15d11564 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -51,17 +51,6 @@ QT_BEGIN_NAMESPACE
 QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
     : QRasterBackingStore(window)
 {
-    // Ideally this would be plumbed from the platform layer to QtGui, and
-    // the QBackingStore would be recreated, but we don't have that code yet,
-    // so at least make sure we invalidate our backingstore when the backing
-    // properties (color space e.g.) are changed.
-    NSView *view = static_cast<QCocoaWindow *>(window->handle())->view();
-    m_backingPropertiesObserver = QMacNotificationObserver(view.window,
-        NSWindowDidChangeBackingPropertiesNotification, [this]() {
-            qCDebug(lcQpaBackingStore) << "Backing properties for"
-                << this->window() << "did change";
-            backingPropertiesChanged();
-        });
 }
 
 QCFType<CGColorSpaceRef> QCocoaBackingStore::colorSpace() const
@@ -341,11 +330,6 @@ void QNSWindowBackingStore::redrawRoundedBottomCorners(CGRect windowRect) const
 #endif
 }
 
-void QNSWindowBackingStore::backingPropertiesChanged()
-{
-    m_image = QImage();
-}
-
 // ----------------------------------------------------------------------------
 
 QCALayerBackingStore::QCALayerBackingStore(QWindow *window)
@@ -353,6 +337,18 @@ QCALayerBackingStore::QCALayerBackingStore(QWindow *window)
 {
     qCDebug(lcQpaBackingStore) << "Creating QCALayerBackingStore for" << window;
     m_buffers.resize(1);
+
+    // Ideally this would be plumbed from the platform layer to QtGui, and
+    // the QBackingStore would be recreated, but we don't have that code yet,
+    // so at least make sure we update our backingstore when the backing
+    // properties (color space e.g.) are changed.
+    NSView *view = static_cast<QCocoaWindow *>(window->handle())->view();
+    m_backingPropertiesObserver = QMacNotificationObserver(view.window,
+        NSWindowDidChangeBackingPropertiesNotification, [this]() {
+            qCDebug(lcQpaBackingStore) << "Backing properties for"
+                << this->window() << "did change";
+            backingPropertiesChanged();
+        });
 }
 
 QCALayerBackingStore::~QCALayerBackingStore()
@@ -620,8 +616,11 @@ QImage QCALayerBackingStore::toImage() const
 
 void QCALayerBackingStore::backingPropertiesChanged()
 {
-    m_buffers.clear();
-    m_buffers.resize(1);
+    qCDebug(lcQpaBackingStore) << "Updating color space of existing buffers";
+    for (auto &buffer : m_buffers) {
+        if (buffer)
+            buffer->setColorSpace(colorSpace());
+    }
 }
 
 QPlatformGraphicsBuffer *QCALayerBackingStore::graphicsBuffer() const
@@ -698,10 +697,11 @@ bool QCALayerBackingStore::prepareForFlush()
 
 QCALayerBackingStore::GraphicsBuffer::GraphicsBuffer(const QSize &size, qreal devicePixelRatio,
                                 const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace)
-    : QIOSurfaceGraphicsBuffer(size, format, colorSpace)
+    : QIOSurfaceGraphicsBuffer(size, format)
     , dirtyRegion(0, 0, size.width() / devicePixelRatio, size.height() / devicePixelRatio)
     , m_devicePixelRatio(devicePixelRatio)
 {
+    setColorSpace(colorSpace);
 }
 
 QImage *QCALayerBackingStore::GraphicsBuffer::asImage()
diff --git a/src/plugins/platforms/cocoa/qcocoaclipboard.mm b/src/plugins/platforms/cocoa/qcocoaclipboard.mm
index a35c153084..141940cc50 100644
--- a/src/plugins/platforms/cocoa/qcocoaclipboard.mm
+++ b/src/plugins/platforms/cocoa/qcocoaclipboard.mm
@@ -67,7 +67,7 @@ void QCocoaClipboard::setMimeData(QMimeData *data, QClipboard::Mode mode)
         }
 
         pasteBoard->sync();
-        pasteBoard->setMimeData(data);
+        pasteBoard->setMimeData(data, QMacPasteboard::LazyRequest);
         emitChanged(mode);
     }
 }
diff --git a/src/plugins/platforms/cocoa/qcocoacursor.h b/src/plugins/platforms/cocoa/qcocoacursor.h
index 58b9ef2151..5b008eff35 100644
--- a/src/plugins/platforms/cocoa/qcocoacursor.h
+++ b/src/plugins/platforms/cocoa/qcocoacursor.h
@@ -56,6 +56,9 @@ public:
     void changeCursor(QCursor *cursor, QWindow *window) override;
     QPoint pos() const override;
     void setPos(const QPoint &position) override;
+
+    QSize size() const override;
+
 private:
     QHash<Qt::CursorShape, NSCursor *> m_cursors;
     NSCursor *convertCursor(QCursor *cursor);
diff --git a/src/plugins/platforms/cocoa/qcocoacursor.mm b/src/plugins/platforms/cocoa/qcocoacursor.mm
index 87a57c78c8..e0d623fc4c 100644
--- a/src/plugins/platforms/cocoa/qcocoacursor.mm
+++ b/src/plugins/platforms/cocoa/qcocoacursor.mm
@@ -85,6 +85,31 @@ void QCocoaCursor::setPos(const QPoint &position)
     CFRelease(e);
 }
 
+
+QSize QCocoaCursor::size() const
+{
+    NSCursor *cocoaCursor = NSCursor.currentSystemCursor;
+    if (!cocoaCursor)
+        return QPlatformCursor::size();
+    NSImage *cursorImage = cocoaCursor.image;
+    if (!cursorImage)
+        return QPlatformCursor::size();
+
+    QSizeF size = QSizeF::fromCGSize(cursorImage.size);
+    NSUserDefaults *defaults = NSUserDefaults.standardUserDefaults;
+    NSDictionary *accessSettings = [defaults persistentDomainForName:@"com.apple.universalaccess"];
+    if (accessSettings == nil)
+        return size.toSize();
+
+    float sizeScale = [accessSettings[@"mouseDriverCursorSize"] floatValue];
+    if (sizeScale > 0) {
+        size.rwidth() *= sizeScale;
+        size.rheight() *= sizeScale;
+    }
+
+    return size.toSize();
+}
+
 NSCursor *QCocoaCursor::convertCursor(QCursor *cursor)
 {
     if (!cursor)
diff --git a/src/plugins/platforms/cocoa/qcocoadrag.mm b/src/plugins/platforms/cocoa/qcocoadrag.mm
index 09433194a6..95808b8a11 100644
--- a/src/plugins/platforms/cocoa/qcocoadrag.mm
+++ b/src/plugins/platforms/cocoa/qcocoadrag.mm
@@ -134,7 +134,7 @@ Qt::DropAction QCocoaDrag::drag(QDrag *o)
     NSImage *nsimage = qt_mac_create_nsimage(pm);
     [nsimage setSize:NSSizeFromCGSize(pmDeviceIndependentSize.toCGSize())];
 
-    QMacPasteboard dragBoard((CFStringRef) NSDragPboard, QMacInternalPasteboardMime::MIME_DND);
+    QMacPasteboard dragBoard(CFStringRef(NSPasteboardNameDrag), QMacInternalPasteboardMime::MIME_DND);
     m_drag->mimeData()->setData(QLatin1String("application/x-qt-mime-type-name"), QByteArray("dummy"));
     dragBoard.setMimeData(m_drag->mimeData(), QMacPasteboard::LazyRequest);
 
@@ -145,7 +145,7 @@ Qt::DropAction QCocoaDrag::drag(QDrag *o)
     CGFloat flippedY = pmDeviceIndependentSize.height() - hotSpot.y();
     event_location.y -= flippedY;
     NSSize mouseOffset_unused = NSMakeSize(0.0, 0.0);
-    NSPasteboard *pboard = [NSPasteboard pasteboardWithName:NSDragPboard];
+    NSPasteboard *pboard = [NSPasteboard pasteboardWithName:NSPasteboardNameDrag];
 
     [theWindow dragImage:nsimage
         at:event_location
diff --git a/src/plugins/platforms/cocoa/qcocoaeventdispatcher.h b/src/plugins/platforms/cocoa/qcocoaeventdispatcher.h
index 69587a24be..b8d2532b8e 100644
--- a/src/plugins/platforms/cocoa/qcocoaeventdispatcher.h
+++ b/src/plugins/platforms/cocoa/qcocoaeventdispatcher.h
@@ -186,6 +186,7 @@ public:
     QAtomicInt serialNumber;
     int lastSerial;
     bool interrupt;
+    bool propagateInterrupt = false;
 
     static void postedEventsSourceCallback(void *info);
     static void waitingObserverCallback(CFRunLoopObserverRef observer,
diff --git a/src/plugins/platforms/cocoa/qcocoaeventdispatcher.mm b/src/plugins/platforms/cocoa/qcocoaeventdispatcher.mm
index b3ce9e45dc..94b9e62eab 100644
--- a/src/plugins/platforms/cocoa/qcocoaeventdispatcher.mm
+++ b/src/plugins/platforms/cocoa/qcocoaeventdispatcher.mm
@@ -84,13 +84,12 @@
 #include "private/qthread_p.h"
 #include "private/qguiapplication_p.h"
 #include <qdebug.h>
+#include <qscopeguard.h>
 
 #include <AppKit/AppKit.h>
 
 QT_BEGIN_NAMESPACE
 
-QT_USE_NAMESPACE
-
 static inline CFRunLoopRef mainRunLoop()
 {
     return CFRunLoopGetMain();
@@ -348,6 +347,16 @@ static inline void qt_mac_waitForMoreEvents(NSString *runLoopMode = NSDefaultRun
 bool QCocoaEventDispatcher::processEvents(QEventLoop::ProcessEventsFlags flags)
 {
     Q_D(QCocoaEventDispatcher);
+
+    // In rare rather corner cases a user's application messes with
+    // QEventLoop::exec()/exit() and QCoreApplication::processEvents(),
+    // we have to undo what bool blocker normally does.
+    d->propagateInterrupt = false;
+    const auto boolBlockerUndo = qScopeGuard([d](){
+        if (d->propagateInterrupt)
+            d->interrupt = true;
+        d->propagateInterrupt = false;
+    });
     QBoolBlocker interruptBlocker(d->interrupt, false);
 
     bool interruptLater = false;
@@ -496,7 +505,16 @@ bool QCocoaEventDispatcher::processEvents(QEventLoop::ProcessEventsFlags flags)
 
             if ((d->processEventsFlags & QEventLoop::EventLoopExec) == 0) {
                 // When called "manually", always process posted events and timers
+                bool oldInterrupt = d->interrupt;
                 d->processPostedEvents();
+                if (!oldInterrupt && d->interrupt && !d->currentModalSession()) {
+                    // We had direct processEvent call, coming not from QEventLoop::exec().
+                    // One of the posted events triggered an application to interrupt the loop.
+                    // But bool blocker will reset d->interrupt to false, so the real event
+                    // loop will never notice it was interrupted. Now we'll have to fix it by
+                    // enforcing the value of d->interrupt.
+                    d->propagateInterrupt = true;
+                }
                 retVal = d->processTimers() || retVal;
             }
 
@@ -511,7 +529,7 @@ bool QCocoaEventDispatcher::processEvents(QEventLoop::ProcessEventsFlags flags)
             if (hadModalSession && !d->currentModalSessionCached)
                 interruptLater = true;
         }
-        bool canWait = (d->threadData->canWait
+        bool canWait = (d->threadData.loadRelaxed()->canWait
                 && !retVal
                 && !d->interrupt
                 && (d->processEventsFlags & QEventLoop::WaitForMoreEvents));
@@ -878,7 +896,7 @@ void QCocoaEventDispatcherPrivate::processPostedEvents()
     }
 
     int serial = serialNumber.loadRelaxed();
-    if (!threadData->canWait || (serial != lastSerial)) {
+    if (!threadData.loadRelaxed()->canWait || (serial != lastSerial)) {
         lastSerial = serial;
         QCoreApplication::sendPostedEvents();
         QWindowSystemInterface::sendWindowSystemEvents(QEventLoop::AllEvents);
diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.h b/src/plugins/platforms/cocoa/qcocoaglcontext.h
index 4210a4ed3f..238067568b 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.h
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.h
@@ -86,6 +86,10 @@ private:
     QSurfaceFormat m_format;
     QVarLengthArray<QMacNotificationObserver, 3> m_updateObservers;
     QAtomicInt m_needsUpdate = false;
+
+#ifndef QT_NO_DEBUG_STREAM
+    friend QDebug operator<<(QDebug debug, const QCocoaGLContext *screen);
+#endif
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoaglcontext.mm b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
index b312e033cd..6db4bdb9fd 100644
--- a/src/plugins/platforms/cocoa/qcocoaglcontext.mm
+++ b/src/plugins/platforms/cocoa/qcocoaglcontext.mm
@@ -158,6 +158,8 @@ void QCocoaGLContext::initialize()
     [m_context setValues:&order forParameter:NSOpenGLCPSurfaceOrder];
 
     updateSurfaceFormat();
+
+    qCDebug(lcQpaOpenGLContext).verbosity(3) << "Created" << this << "based on requested" << context()->format();
 }
 
 NSOpenGLPixelFormat *QCocoaGLContext::pixelFormatForSurfaceFormat(const QSurfaceFormat &format)
@@ -355,7 +357,7 @@ QCocoaGLContext::~QCocoaGLContext()
 
 bool QCocoaGLContext::makeCurrent(QPlatformSurface *surface)
 {
-    qCDebug(lcQpaOpenGLContext) << "Making" << m_context << "current"
+    qCDebug(lcQpaOpenGLContext) << "Making" << this << "current"
         << "in" << QThread::currentThread() << "for" << surface;
 
     Q_ASSERT(surface->surface()->supportsOpenGL());
@@ -555,4 +557,20 @@ QFunctionPointer QCocoaGLContext::getProcAddress(const char *procName)
     return (QFunctionPointer)dlsym(RTLD_DEFAULT, procName);
 }
 
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug debug, const QCocoaGLContext *context)
+{
+    QDebugStateSaver saver(debug);
+    debug.nospace();
+    debug << "QCocoaGLContext(" << (const void *)context;
+    if (context) {
+        if (debug.verbosity() > QDebug::DefaultVerbosity)
+            debug << ", " << context->format();
+        debug << ", " << context->nativeContext();
+    }
+    debug << ')';
+    return debug;
+}
+#endif // !QT_NO_DEBUG_STREAM
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.h b/src/plugins/platforms/cocoa/qcocoaintegration.h
index 0e2656e046..30838ba254 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.h
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.h
@@ -92,6 +92,10 @@ public:
     QCocoaVulkanInstance *getCocoaVulkanInstance() const;
 #endif
 
+#if QT_CONFIG(sessionmanager)
+    QPlatformSessionManager *createPlatformSessionManager(const QString &id, const QString &key) const override;
+#endif
+
     QCoreTextFontDatabase *fontDatabase() const override;
     QCocoaNativeInterface *nativeInterface() const override;
     QPlatformInputContext *inputContext() const override;
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 67ad0b3492..a77b97f538 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -52,6 +52,9 @@
 #include "qcocoamimetypes.h"
 #include "qcocoaaccessibility.h"
 #include "qcocoascreen.h"
+#if QT_CONFIG(sessionmanager)
+#  include "qcocoasessionmanager.h"
+#endif
 
 #include <qpa/qplatforminputcontextfactory_p.h>
 #include <qpa/qplatformaccessibility.h>
@@ -197,16 +200,6 @@ QCocoaIntegration::QCocoaIntegration(const QStringList &paramList)
         [cocoaApplication setMenu:[qtMenuLoader menu]];
     }
 
-    // The presentation options such as whether or not the dock and/or menu bar is
-    // hidden (automatically by the system) affects the main screen's available
-    // geometry. Since we're initializing the screens synchronously at application
-    // startup we need to ensure that the presentation options have been propagated
-    // to the screen before we read out its properties. Normally OS X does this in
-    // an asynchronous callback, but that's too late for us. We force the propagation
-    // by explicitly setting the presentation option to the magic 'default value',
-    // which will resolve to an actual value and result in screen invalidation.
-    cocoaApplication.presentationOptions = NSApplicationPresentationDefault;
-
     QCocoaScreen::initializeScreens();
 
     QMacInternalPasteboardMime::initializeMimeTypes();
@@ -255,6 +248,13 @@ QCocoaIntegration::Options QCocoaIntegration::options() const
     return mOptions;
 }
 
+#if QT_CONFIG(sessionmanager)
+QPlatformSessionManager *QCocoaIntegration::createPlatformSessionManager(const QString &id, const QString &key) const
+{
+    return new QCocoaSessionManager(id, key);
+}
+#endif
+
 bool QCocoaIntegration::hasCapability(QPlatformIntegration::Capability cap) const
 {
     switch (cap) {
diff --git a/src/plugins/platforms/cocoa/qcocoascreen.h b/src/plugins/platforms/cocoa/qcocoascreen.h
index 7ec9a2b5af..dcf6f1c753 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.h
+++ b/src/plugins/platforms/cocoa/qcocoascreen.h
@@ -53,9 +53,6 @@ class QCocoaIntegration;
 class QCocoaScreen : public QPlatformScreen
 {
 public:
-    static void initializeScreens();
-    static void cleanupScreens();
-
     ~QCocoaScreen();
 
     // ----------------------------------------------------
@@ -79,7 +76,6 @@ public:
     // ----------------------------------------------------
 
     NSScreen *nativeScreen() const;
-    void updateProperties();
 
     void requestUpdate();
     void deliverUpdateRequests();
@@ -88,6 +84,7 @@ public:
     static QCocoaScreen *primaryScreen();
     static QCocoaScreen *get(NSScreen *nsScreen);
     static QCocoaScreen *get(CGDirectDisplayID displayId);
+    static QCocoaScreen *get(CFUUIDRef uuid);
 
     static CGPoint mapToNative(const QPointF &pos, QCocoaScreen *screen = QCocoaScreen::primaryScreen());
     static CGRect mapToNative(const QRectF &rect, QCocoaScreen *screen = QCocoaScreen::primaryScreen());
@@ -95,11 +92,23 @@ public:
     static QRectF mapFromNative(CGRect rect, QCocoaScreen *screen = QCocoaScreen::primaryScreen());
 
 private:
-    QCocoaScreen(CGDirectDisplayID displayId);
+    static void initializeScreens();
+    static void updateScreens();
+    static void cleanupScreens();
+
+    static bool updateScreensIfNeeded();
+    static NSArray *s_screenConfigurationBeforeUpdate;
+
     static void add(CGDirectDisplayID displayId);
+    QCocoaScreen(CGDirectDisplayID displayId);
+    void update(CGDirectDisplayID displayId);
     void remove();
 
+    bool isOnline() const;
+    bool isMirroring() const;
+
     CGDirectDisplayID m_displayId = kCGNullDirectDisplay;
+    CGDirectDisplayID displayId() const { return m_displayId; }
 
     QRect m_geometry;
     QRect m_availableGeometry;
@@ -116,6 +125,8 @@ private:
     dispatch_source_t m_displayLinkSource = nullptr;
     QAtomicInt m_pendingUpdates;
 
+    friend class QCocoaIntegration;
+    friend class QCocoaWindow;
     friend QDebug operator<<(QDebug debug, const QCocoaScreen *screen);
 };
 
diff --git a/src/plugins/platforms/cocoa/qcocoascreen.mm b/src/plugins/platforms/cocoa/qcocoascreen.mm
index bd5c95b9d0..e4dd4cf6c6 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.mm
+++ b/src/plugins/platforms/cocoa/qcocoascreen.mm
@@ -57,6 +57,7 @@ QT_BEGIN_NAMESPACE
 namespace CoreGraphics {
     Q_NAMESPACE
     enum DisplayChange {
+        ReconfiguredWithFlagsMissing = 0,
         Moved = kCGDisplayMovedFlag,
         SetMain = kCGDisplaySetMainFlag,
         SetMode = kCGDisplaySetModeFlag,
@@ -71,73 +72,165 @@ namespace CoreGraphics {
     Q_ENUM_NS(DisplayChange)
 }
 
+NSArray *QCocoaScreen::s_screenConfigurationBeforeUpdate = nil;
+
 void QCocoaScreen::initializeScreens()
 {
-    uint32_t displayCount = 0;
-    if (CGGetActiveDisplayList(0, nullptr, &displayCount) != kCGErrorSuccess)
-        qFatal("Failed to get number of active displays");
-
-    CGDirectDisplayID activeDisplays[displayCount];
-    if (CGGetActiveDisplayList(displayCount, &activeDisplays[0], &displayCount) != kCGErrorSuccess)
-        qFatal("Failed to get active displays");
-
-    for (CGDirectDisplayID displayId : activeDisplays)
-        QCocoaScreen::add(displayId);
+    updateScreens();
 
     CGDisplayRegisterReconfigurationCallback([](CGDirectDisplayID displayId, CGDisplayChangeSummaryFlags flags, void *userInfo) {
-        if (flags & kCGDisplayBeginConfigurationFlag)
-            return; // Wait for changes to apply
-
         Q_UNUSED(userInfo);
 
-        qCDebug(lcQpaScreen).verbosity(0).nospace() << "Display reconfiguration"
-            << " (" << QFlags<CoreGraphics::DisplayChange>(flags) << ")"
-            << " for displayId=" << displayId;
-
-        QCocoaScreen *cocoaScreen = QCocoaScreen::get(displayId);
+        // Displays are reconfigured in batches, and we want to update our screens
+        // once a batch ends, so that all the states of the displays are up to date.
+        static int displayReconfigurationsInProgress = 0;
+
+        const bool beforeReconfigure = flags & kCGDisplayBeginConfigurationFlag;
+        qCDebug(lcQpaScreen).verbosity(0).nospace() << "Display " << displayId
+                << (beforeReconfigure ? " about to reconfigure" : " was ")
+                << QFlags<CoreGraphics::DisplayChange>(flags)
+                << " with " << displayReconfigurationsInProgress
+                << " display configuration(s) in progress";
+
+        if (!flags) {
+            // CGDisplayRegisterReconfigurationCallback has been observed to be called
+            // with flags unset. This seems like a bug. The callback is not paired with
+            // a matching "completion" callback either, so we don't know whether to treat
+            // it as a begin or end of reconfigure.
+            return;
+        }
 
-        if ((flags & kCGDisplayAddFlag) || !cocoaScreen) {
-            if (!CGDisplayIsActive(displayId)) {
-                qCDebug(lcQpaScreen) << "Not adding inactive display" << displayId;
-                return; // Will be added when activated
+        if (beforeReconfigure) {
+            if (!displayReconfigurationsInProgress++) {
+                // There might have been a screen reconfigure before this that
+                // we didn't process yet, so do that now if that's the case.
+                updateScreensIfNeeded();
+
+                Q_ASSERT(!s_screenConfigurationBeforeUpdate);
+                s_screenConfigurationBeforeUpdate = NSScreen.screens;
+                qCDebug(lcQpaScreen, "Display reconfigure transaction started"
+                    " with screen configuration %p", s_screenConfigurationBeforeUpdate);
+
+                static void (^tryScreenUpdate)();
+                tryScreenUpdate = ^void () {
+                    qCDebug(lcQpaScreen) << "Attempting screen update from runloop block";
+                    if (!updateScreensIfNeeded())
+                        CFRunLoopPerformBlock(CFRunLoopGetMain(), kCFRunLoopCommonModes, tryScreenUpdate);
+                };
+                CFRunLoopPerformBlock(CFRunLoopGetMain(), kCFRunLoopCommonModes, tryScreenUpdate);
             }
-            QCocoaScreen::add(displayId);
-        } else if ((flags & kCGDisplayRemoveFlag) || !CGDisplayIsActive(displayId)) {
-            cocoaScreen->remove();
         } else {
-            // Detect changes to the primary screen immediately, instead of
-            // waiting for a display reconfigure with kCGDisplaySetMainFlag.
-            // This ensures that any property updates to the other screens
-            // will be in reference to the correct primary screen.
-            QCocoaScreen *mainDisplay = QCocoaScreen::get(CGMainDisplayID());
-            if (QGuiApplication::primaryScreen()->handle() != mainDisplay) {
-                mainDisplay->updateProperties();
-                qCInfo(lcQpaScreen) << "Primary screen changed to" << mainDisplay;
-                QWindowSystemInterface::handlePrimaryScreenChanged(mainDisplay);
-                if (cocoaScreen == mainDisplay)
-                    return; // Already reconfigured
-            }
+            Q_ASSERT_X(displayReconfigurationsInProgress, "QCococaScreen",
+                "Display configuration transactions are expected to be balanced");
 
-            cocoaScreen->updateProperties();
-            qCInfo(lcQpaScreen).nospace() << "Reconfigured " <<
-                (primaryScreen() == cocoaScreen ? "primary " : "")
-                << cocoaScreen;
+            if (!--displayReconfigurationsInProgress) {
+                qCDebug(lcQpaScreen) << "Display reconfigure transaction completed";
+                // We optimistically update now, in case the NSScreens have changed
+                updateScreensIfNeeded();
+            }
         }
     }, nullptr);
+
+    static QMacNotificationObserver screenParameterObserver(NSApplication.sharedApplication,
+        NSApplicationDidChangeScreenParametersNotification, [&]() {
+            qCDebug(lcQpaScreen) << "Received screen parameter change notification";
+            updateScreensIfNeeded(); // As a last resort we update screens here
+        });
+}
+
+bool QCocoaScreen::updateScreensIfNeeded()
+{
+    if (!s_screenConfigurationBeforeUpdate) {
+        qCDebug(lcQpaScreen) << "QScreens have already been updated, all good";
+        return true;
+    }
+
+    if (s_screenConfigurationBeforeUpdate == NSScreen.screens) {
+        qCDebug(lcQpaScreen) << "Still waiting for NSScreen configuration change";
+        return false;
+    }
+
+    qCDebug(lcQpaScreen, "NSScreen configuration changed to %p", NSScreen.screens);
+    updateScreens();
+
+    s_screenConfigurationBeforeUpdate = nil;
+    return true;
+}
+
+/*
+    Update the list of available QScreens, and the properties of existing screens.
+
+    At this point we rely on the NSScreen.screens to be up to date.
+*/
+void QCocoaScreen::updateScreens()
+{
+    uint32_t displayCount = 0;
+    if (CGGetOnlineDisplayList(0, nullptr, &displayCount) != kCGErrorSuccess)
+        qFatal("Failed to get number of online displays");
+
+    QVector<CGDirectDisplayID> onlineDisplays(displayCount);
+    if (CGGetOnlineDisplayList(displayCount, onlineDisplays.data(), &displayCount) != kCGErrorSuccess)
+        qFatal("Failed to get online displays");
+
+    qCInfo(lcQpaScreen) << "Updating screens with" << displayCount
+        << "online displays:" << onlineDisplays;
+
+    // TODO: Verify whether we can always assume the main display is first
+    int mainDisplayIndex = onlineDisplays.indexOf(CGMainDisplayID());
+    if (mainDisplayIndex < 0) {
+        qCWarning(lcQpaScreen) << "Main display not in list of online displays!";
+    } else if (mainDisplayIndex > 0) {
+        qCWarning(lcQpaScreen) << "Main display not first display, making sure it is";
+        onlineDisplays.move(mainDisplayIndex, 0);
+    }
+
+    for (CGDirectDisplayID displayId : onlineDisplays) {
+        Q_ASSERT(CGDisplayIsOnline(displayId));
+
+        if (CGDisplayMirrorsDisplay(displayId))
+            continue;
+
+        // A single physical screen can map to multiple displays IDs,
+        // depending on which GPU is in use or which physical port the
+        // screen is connected to. By mapping the display ID to a UUID,
+        // which are shared between displays that target the same screen,
+        // we can pick an existing QScreen to update instead of needlessly
+        // adding and removing QScreens.
+        QCFType<CFUUIDRef> uuid = CGDisplayCreateUUIDFromDisplayID(displayId);
+        Q_ASSERT(uuid);
+
+        if (QCocoaScreen *existingScreen = QCocoaScreen::get(uuid)) {
+            existingScreen->update(displayId);
+            qCInfo(lcQpaScreen) << "Updated" << existingScreen;
+            if (CGDisplayIsMain(displayId) && existingScreen != qGuiApp->primaryScreen()->handle()) {
+                qCInfo(lcQpaScreen) << "Primary screen changed to" << existingScreen;
+                QWindowSystemInterface::handlePrimaryScreenChanged(existingScreen);
+            }
+        } else {
+            QCocoaScreen::add(displayId);
+        }
+    }
+
+    for (QScreen *screen : QGuiApplication::screens()) {
+        QCocoaScreen *platformScreen = static_cast<QCocoaScreen*>(screen->handle());
+        if (!platformScreen->isOnline() || platformScreen->isMirroring())
+            platformScreen->remove();
+    }
 }
 
 void QCocoaScreen::add(CGDirectDisplayID displayId)
 {
     const bool isPrimary = CGDisplayIsMain(displayId);
     QCocoaScreen *cocoaScreen = new QCocoaScreen(displayId);
-    qCInfo(lcQpaScreen).nospace() << "Adding " << (isPrimary ? "new primary " : "") << cocoaScreen;
+    qCInfo(lcQpaScreen) << "Adding" << cocoaScreen
+        << (isPrimary ? "as new primary screen" : "");
     QWindowSystemInterface::handleScreenAdded(cocoaScreen, isPrimary);
 }
 
 QCocoaScreen::QCocoaScreen(CGDirectDisplayID displayId)
     : QPlatformScreen(), m_displayId(displayId)
 {
-    updateProperties();
+    update(m_displayId);
     m_cursor = new QCocoaCursor;
 }
 
@@ -150,8 +243,6 @@ void QCocoaScreen::cleanupScreens()
 
 void QCocoaScreen::remove()
 {
-    m_displayId = kCGNullDirectDisplay; // Prevent stale references during removal
-
     // This may result in the application responding to QGuiApplication::screenRemoved
     // by moving the window to another screen, either by setGeometry, or by setScreen.
     // If the window isn't moved by the application, Qt will as a fallback move it to
@@ -163,7 +254,7 @@ void QCocoaScreen::remove()
     // QCocoaWindow::windowDidChangeScreen. At that point the window will appear to have
     // already changed its screen, but that's only true if comparing the Qt screens,
     // not when comparing the NSScreens.
-    qCInfo(lcQpaScreen).nospace() << "Removing " << (primaryScreen() == this ? "current primary " : "") << this;
+    qCInfo(lcQpaScreen) << "Removing " << this;
     QWindowSystemInterface::handleScreenRemoved(this);
 }
 
@@ -210,9 +301,14 @@ static QString displayName(CGDirectDisplayID displayID)
     return QString();
 }
 
-void QCocoaScreen::updateProperties()
+void QCocoaScreen::update(CGDirectDisplayID displayId)
 {
-    Q_ASSERT(m_displayId);
+    if (displayId != m_displayId) {
+        qCDebug(lcQpaScreen) << "Reconnecting" << this << "as display" << displayId;
+        m_displayId = displayId;
+    }
+
+    Q_ASSERT(isOnline());
 
     const QRect previousGeometry = m_geometry;
     const QRect previousAvailableGeometry = m_availableGeometry;
@@ -350,8 +446,8 @@ struct DeferredDebugHelper
 
 void QCocoaScreen::deliverUpdateRequests()
 {
-    if (!m_displayId)
-        return; // Screen removed
+    if (!isOnline())
+        return;
 
     QMacAutoReleasePool pool;
 
@@ -562,6 +658,29 @@ QPixmap QCocoaScreen::grabWindow(WId view, int x, int y, int width, int height)
     return windowPixmap;
 }
 
+bool QCocoaScreen::isOnline() const
+{
+    // When a display is disconnected CGDisplayIsOnline and other CGDisplay
+    // functions that take a displayId will not return false, but will start
+    // returning -1 to signal that the displayId is invalid. Some functions
+    // will also assert or even crash in this case, so it's important that
+    // we double check if a display is online before calling other functions.
+    auto isOnline = CGDisplayIsOnline(m_displayId);
+    static const uint32_t kCGDisplayIsDisconnected = int32_t(-1);
+    return isOnline != kCGDisplayIsDisconnected && isOnline;
+}
+
+/*
+    Returns true if a screen is mirroring another screen
+*/
+bool QCocoaScreen::isMirroring() const
+{
+    if (!isOnline())
+        return false;
+
+    return CGDisplayMirrorsDisplay(m_displayId);
+}
+
 /*!
     The screen used as a reference for global window geometry
 */
@@ -586,6 +705,12 @@ QList<QPlatformScreen*> QCocoaScreen::virtualSiblings() const
 
 QCocoaScreen *QCocoaScreen::get(NSScreen *nsScreen)
 {
+    if (s_screenConfigurationBeforeUpdate) {
+        qCWarning(lcQpaScreen) << "Trying to resolve screen while waiting for screen reconfigure!";
+        if (!updateScreensIfNeeded())
+            qCWarning(lcQpaScreen) << "Failed to do last minute screen update. Expect crashes.";
+    }
+
     return get(nsScreen.qt_displayId);
 }
 
@@ -600,23 +725,34 @@ QCocoaScreen *QCocoaScreen::get(CGDirectDisplayID displayId)
     return nullptr;
 }
 
+QCocoaScreen *QCocoaScreen::get(CFUUIDRef uuid)
+{
+    for (QScreen *screen : QGuiApplication::screens()) {
+        auto *platformScreen = static_cast<QCocoaScreen*>(screen->handle());
+        if (!platformScreen->isOnline())
+            continue;
+
+        auto displayId = platformScreen->displayId();
+        QCFType<CFUUIDRef> candidateUuid(CGDisplayCreateUUIDFromDisplayID(displayId));
+        Q_ASSERT(candidateUuid);
+
+        if (candidateUuid == uuid)
+            return platformScreen;
+    }
+
+    return nullptr;
+}
+
 NSScreen *QCocoaScreen::nativeScreen() const
 {
     if (!m_displayId)
         return nil; // The display has been disconnected
 
-    // A single display may have different displayIds depending on
-    // which GPU is in use or which physical port the display is
-    // connected to. By comparing UUIDs instead of display IDs we
-    // ensure that we always pick up the appropriate NSScreen.
-    QCFType<CFUUIDRef> uuid = CGDisplayCreateUUIDFromDisplayID(m_displayId);
-
-    for (NSScreen *screen in [NSScreen screens]) {
-        if (QCFType<CFUUIDRef>(CGDisplayCreateUUIDFromDisplayID(screen.qt_displayId)) == uuid)
+    for (NSScreen *screen in NSScreen.screens) {
+        if (screen.qt_displayId == m_displayId)
             return screen;
     }
 
-    qCWarning(lcQpaScreen) << "Could not find NSScreen for display ID" << m_displayId;
     return nil;
 }
 
@@ -651,11 +787,21 @@ QDebug operator<<(QDebug debug, const QCocoaScreen *screen)
     debug.nospace();
     debug << "QCocoaScreen(" << (const void *)screen;
     if (screen) {
-        debug << ", geometry=" << screen->geometry();
+        debug << ", " << screen->name();
+        if (screen->isOnline()) {
+            if (CGDisplayIsAsleep(screen->displayId()))
+                debug << ", Sleeping";
+            if (auto mirroring = CGDisplayMirrorsDisplay(screen->displayId()))
+                debug << ", mirroring=" << mirroring;
+        } else {
+            debug << ", Offline";
+        }
+        debug << ", " << screen->geometry();
         debug << ", dpr=" << screen->devicePixelRatio();
-        debug << ", name=" << screen->name();
-        debug << ", displayId=" << screen->m_displayId;
-        debug << ", native=" << screen->nativeScreen();
+        debug << ", displayId=" << screen->displayId();
+
+        if (auto nativeScreen = screen->nativeScreen())
+            debug << ", " << nativeScreen;
     }
     debug << ')';
     return debug;
diff --git a/src/plugins/platforms/cocoa/qcocoasessionmanager.cpp b/src/plugins/platforms/cocoa/qcocoasessionmanager.cpp
new file mode 100644
index 0000000000..74e318b5be
--- /dev/null
+++ b/src/plugins/platforms/cocoa/qcocoasessionmanager.cpp
@@ -0,0 +1,88 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Samuel Gaist <samuel.gaist@idiap.ch>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT_NO_SESSIONMANAGER
+#include <private/qsessionmanager_p.h>
+#include <private/qguiapplication_p.h>
+
+#include <qcocoasessionmanager.h>
+#include <qstring.h>
+
+QT_BEGIN_NAMESPACE
+
+QCocoaSessionManager::QCocoaSessionManager(const QString &id, const QString &key)
+    : QPlatformSessionManager(id, key),
+      m_canceled(false)
+{
+}
+
+QCocoaSessionManager::~QCocoaSessionManager()
+{
+}
+
+bool QCocoaSessionManager::allowsInteraction()
+{
+    return false;
+}
+
+void QCocoaSessionManager::resetCancellation()
+{
+    m_canceled = false;
+}
+
+void QCocoaSessionManager::cancel()
+{
+    m_canceled = true;
+}
+
+bool QCocoaSessionManager::wasCanceled() const
+{
+    return m_canceled;
+}
+
+QCocoaSessionManager *QCocoaSessionManager::instance()
+{
+    auto *qGuiAppPriv = QGuiApplicationPrivate::instance();
+    auto *managerPrivate = static_cast<QSessionManagerPrivate*>(QObjectPrivate::get(qGuiAppPriv->session_manager));
+    return static_cast<QCocoaSessionManager *>(managerPrivate->platformSessionManager);
+}
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_SESSIONMANAGER
diff --git a/src/plugins/platforms/cocoa/qcocoasystemsettings.h b/src/plugins/platforms/cocoa/qcocoasessionmanager.h
index cf5688bbed..89ab7bd157 100644
--- a/src/plugins/platforms/cocoa/qcocoasystemsettings.h
+++ b/src/plugins/platforms/cocoa/qcocoasessionmanager.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2019 Samuel Gaist <samuel.gaist@idiap.ch>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the plugins of the Qt Toolkit.
@@ -37,18 +37,45 @@
 **
 ****************************************************************************/
 
-#ifndef QCOCOASYSTEMSETTINGS_H
-#define QCOCOASYSTEMSETTINGS_H
+#ifndef QCOCOASESSIONMANAGER_H
+#define QCOCOASESSIONMANAGER_H
 
-#include <QtCore/qhash.h>
-#include <QtGui/qpalette.h>
-#include <qpa/qplatformtheme.h>
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is part of the QPA API and is not meant to be used
+// in applications. Usage of this API may make your code
+// source and binary incompatible with future versions of Qt.
+//
+
+#ifndef QT_NO_SESSIONMANAGER
+
+#include <qpa/qplatformsessionmanager.h>
 
 QT_BEGIN_NAMESPACE
 
-QPalette * qt_mac_createSystemPalette();
-QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes();
+class QCocoaSessionManager : public QPlatformSessionManager
+{
+public:
+    QCocoaSessionManager(const QString &id, const QString &key);
+    virtual ~QCocoaSessionManager();
+
+    bool allowsInteraction() override;
+    void cancel() override;
+    void resetCancellation();
+    bool wasCanceled() const;
+
+    static QCocoaSessionManager *instance();
+
+private:
+    bool m_canceled;
+
+    Q_DISABLE_COPY(QCocoaSessionManager)
+};
 
 QT_END_NAMESPACE
 
-#endif
+#endif // QT_NO_SESSIONMANAGER
+
+#endif // QCOCOASESSIONMANAGER_H
diff --git a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm b/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
deleted file mode 100644
index cb25bd7d81..0000000000
--- a/src/plugins/platforms/cocoa/qcocoasystemsettings.mm
+++ /dev/null
@@ -1,245 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2019 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the plugins of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qcocoasystemsettings.h"
-
-#include "qcocoahelpers.h"
-
-#include <QtCore/private/qcore_mac_p.h>
-#include <QtGui/qfont.h>
-#include <QtGui/private/qcoregraphics_p.h>
-
-#if !QT_MACOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__MAC_10_14)
-@interface NSColor (MojaveForwardDeclarations)
-@property (class, strong, readonly) NSColor *selectedContentBackgroundColor NS_AVAILABLE_MAC(10_14);
-@property (class, strong, readonly) NSColor *unemphasizedSelectedTextBackgroundColor NS_AVAILABLE_MAC(10_14);
-@property (class, strong, readonly) NSColor *unemphasizedSelectedTextColor NS_AVAILABLE_MAC(10_14);
-@property (class, strong, readonly) NSColor *unemphasizedSelectedContentBackgroundColor NS_AVAILABLE_MAC(10_14);
-@property (class, strong, readonly) NSArray<NSColor *> *alternatingContentBackgroundColors NS_AVAILABLE_MAC(10_14);
-// Missing from non-Mojave SDKs, even if introduced in 10.10
-@property (class, strong, readonly) NSColor *linkColor NS_AVAILABLE_MAC(10_10);
-@end
-#endif
-
-QT_BEGIN_NAMESPACE
-
-QPalette * qt_mac_createSystemPalette()
-{
-    QColor qc;
-
-    // Standard palette initialization (copied from Qt 4 styles)
-    QBrush backgroundBrush = qt_mac_toQBrush([NSColor windowBackgroundColor]);
-    QColor background = backgroundBrush.color();
-    QColor light(background.lighter(110));
-    QColor dark(background.darker(160));
-    QColor mid(background.darker(140));
-    QPalette *palette = new QPalette(Qt::black, background, light, dark, mid, Qt::black, Qt::white);
-
-    palette->setBrush(QPalette::Window, backgroundBrush);
-
-    palette->setBrush(QPalette::Disabled, QPalette::WindowText, dark);
-    palette->setBrush(QPalette::Disabled, QPalette::Text, dark);
-    palette->setBrush(QPalette::Disabled, QPalette::ButtonText, dark);
-    palette->setBrush(QPalette::Disabled, QPalette::Base, backgroundBrush);
-    QBrush textBackgroundBrush = qt_mac_toQBrush([NSColor textBackgroundColor]);
-    palette->setBrush(QPalette::Active, QPalette::Base, textBackgroundBrush);
-    palette->setBrush(QPalette::Inactive, QPalette::Base, textBackgroundBrush);
-    palette->setColor(QPalette::Disabled, QPalette::Dark, QColor(191, 191, 191));
-    palette->setColor(QPalette::Active, QPalette::Dark, QColor(191, 191, 191));
-    palette->setColor(QPalette::Inactive, QPalette::Dark, QColor(191, 191, 191));
-
-    // System palette initialization:
-    QBrush br = qt_mac_toQBrush([NSColor selectedControlColor]);
-    palette->setBrush(QPalette::Active, QPalette::Highlight, br);
-    if (__builtin_available(macOS 10.14, *)) {
-        const auto inactiveHighlight = qt_mac_toQBrush([NSColor unemphasizedSelectedContentBackgroundColor]);
-        palette->setBrush(QPalette::Inactive, QPalette::Highlight, inactiveHighlight);
-        palette->setBrush(QPalette::Disabled, QPalette::Highlight, inactiveHighlight);
-    } else {
-        palette->setBrush(QPalette::Inactive, QPalette::Highlight, br);
-        palette->setBrush(QPalette::Disabled, QPalette::Highlight, br);
-    }
-
-    palette->setBrush(QPalette::Shadow, qt_mac_toQColor([NSColor shadowColor]));
-
-    qc = qt_mac_toQColor([NSColor controlTextColor]);
-    palette->setColor(QPalette::Active, QPalette::Text, qc);
-    palette->setColor(QPalette::Active, QPalette::WindowText, qc);
-    palette->setColor(QPalette::Active, QPalette::HighlightedText, qc);
-    palette->setColor(QPalette::Inactive, QPalette::Text, qc);
-    palette->setColor(QPalette::Inactive, QPalette::WindowText, qc);
-    palette->setColor(QPalette::Inactive, QPalette::HighlightedText, qc);
-
-    qc = qt_mac_toQColor([NSColor disabledControlTextColor]);
-    palette->setColor(QPalette::Disabled, QPalette::Text, qc);
-    palette->setColor(QPalette::Disabled, QPalette::WindowText, qc);
-    palette->setColor(QPalette::Disabled, QPalette::HighlightedText, qc);
-
-    palette->setBrush(QPalette::ToolTipBase, qt_mac_toQBrush([NSColor controlColor]));
-
-    palette->setColor(QPalette::Normal, QPalette::Link, qt_mac_toQColor([NSColor linkColor]));
-
-    return palette;
-}
-
-struct QMacPaletteMap {
-    inline QMacPaletteMap(QPlatformTheme::Palette p, NSColor *a, NSColor *i) :
-        active(a), inactive(i), paletteRole(p) { }
-
-    NSColor *active;
-    NSColor *inactive;
-    QPlatformTheme::Palette paletteRole;
-};
-
-#define MAC_PALETTE_ENTRY(pal, active, inactive) \
-    QMacPaletteMap(pal, [NSColor active], [NSColor inactive])
-static QMacPaletteMap mac_widget_colors[] = {
-    MAC_PALETTE_ENTRY(QPlatformTheme::ToolButtonPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::ButtonPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::HeaderPalette, headerTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::ComboBoxPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::ItemViewPalette, textColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::MessageBoxLabelPalette, textColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::TabBarPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::LabelPalette, textColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::GroupBoxPalette, textColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::MenuPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::MenuBarPalette, controlTextColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::TextEditPalette, textColor, disabledControlTextColor),
-    MAC_PALETTE_ENTRY(QPlatformTheme::TextLineEditPalette, textColor, disabledControlTextColor)
-};
-#undef MAC_PALETTE_ENTRY
-
-static const int mac_widget_colors_count = sizeof(mac_widget_colors) / sizeof(mac_widget_colors[0]);
-
-QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
-{
-    QHash<QPlatformTheme::Palette, QPalette*> palettes;
-    QColor qc;
-    for (int i = 0; i < mac_widget_colors_count; i++) {
-        QPalette &pal = *qt_mac_createSystemPalette();
-        if (mac_widget_colors[i].active) {
-            qc = qt_mac_toQColor(mac_widget_colors[i].active);
-            pal.setColor(QPalette::Active, QPalette::Text, qc);
-            pal.setColor(QPalette::Inactive, QPalette::Text, qc);
-            pal.setColor(QPalette::Active, QPalette::WindowText, qc);
-            pal.setColor(QPalette::Inactive, QPalette::WindowText, qc);
-            pal.setColor(QPalette::Active, QPalette::HighlightedText, qc);
-            pal.setColor(QPalette::Inactive, QPalette::HighlightedText, qc);
-            pal.setColor(QPalette::Active, QPalette::ButtonText, qc);
-            pal.setColor(QPalette::Inactive, QPalette::ButtonText, qc);
-            qc = qt_mac_toQColor(mac_widget_colors[i].inactive);
-            pal.setColor(QPalette::Disabled, QPalette::Text, qc);
-            pal.setColor(QPalette::Disabled, QPalette::WindowText, qc);
-            pal.setColor(QPalette::Disabled, QPalette::HighlightedText, qc);
-            pal.setColor(QPalette::Disabled, QPalette::ButtonText, qc);
-        }
-        if (mac_widget_colors[i].paletteRole == QPlatformTheme::MenuPalette
-                || mac_widget_colors[i].paletteRole == QPlatformTheme::MenuBarPalette) {
-            NSColor *selectedMenuItemColor = nil;
-            if (__builtin_available(macOS 10.14, *)) {
-                // Cheap approximation for NSVisualEffectView (see deprecation note for selectedMenuItemTextColor)
-                selectedMenuItemColor = [[NSColor selectedContentBackgroundColor] highlightWithLevel:0.4];
-            } else {
-                // selectedMenuItemColor would presumably be the correct color to use as the background
-                // for selected menu items. But that color is always blue, and doesn't follow the
-                // appearance color in system preferences. So we therefore deliberatly choose to use
-                // keyboardFocusIndicatorColor instead, which appears to have the same color value.
-                selectedMenuItemColor = [NSColor keyboardFocusIndicatorColor];
-            }
-            pal.setBrush(QPalette::Highlight, qt_mac_toQColor(selectedMenuItemColor));
-            qc = qt_mac_toQColor([NSColor labelColor]);
-            pal.setBrush(QPalette::ButtonText, qc);
-            pal.setBrush(QPalette::Text, qc);
-            qc = qt_mac_toQColor([NSColor selectedMenuItemTextColor]);
-            pal.setBrush(QPalette::HighlightedText, qc);
-            qc = qt_mac_toQColor([NSColor disabledControlTextColor]);
-            pal.setBrush(QPalette::Disabled, QPalette::Text, qc);
-        } else if ((mac_widget_colors[i].paletteRole == QPlatformTheme::ButtonPalette)
-                || (mac_widget_colors[i].paletteRole == QPlatformTheme::HeaderPalette)
-                || (mac_widget_colors[i].paletteRole == QPlatformTheme::TabBarPalette)) {
-            pal.setColor(QPalette::Disabled, QPalette::ButtonText,
-                         pal.color(QPalette::Disabled, QPalette::Text));
-            pal.setColor(QPalette::Inactive, QPalette::ButtonText,
-                         pal.color(QPalette::Inactive, QPalette::Text));
-            pal.setColor(QPalette::Active, QPalette::ButtonText,
-                         pal.color(QPalette::Active, QPalette::Text));
-        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::ItemViewPalette) {
-            NSArray<NSColor *> *baseColors = nil;
-            NSColor *activeHighlightColor = nil;
-            if (__builtin_available(macOS 10.14, *)) {
-                baseColors = [NSColor alternatingContentBackgroundColors];
-                activeHighlightColor = [NSColor selectedContentBackgroundColor];
-                pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
-                             qt_mac_toQBrush([NSColor unemphasizedSelectedTextColor]));
-            } else {
-                baseColors = [NSColor controlAlternatingRowBackgroundColors];
-                activeHighlightColor = [NSColor alternateSelectedControlColor];
-                pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
-                             pal.brush(QPalette::Active, QPalette::Text));
-            }
-            pal.setBrush(QPalette::Base, qt_mac_toQBrush(baseColors[0]));
-            pal.setBrush(QPalette::AlternateBase, qt_mac_toQBrush(baseColors[1]));
-            pal.setBrush(QPalette::Active, QPalette::Highlight,
-                         qt_mac_toQBrush(activeHighlightColor));
-            pal.setBrush(QPalette::Active, QPalette::HighlightedText,
-                         qt_mac_toQBrush([NSColor alternateSelectedControlTextColor]));
-            pal.setBrush(QPalette::Inactive, QPalette::Text,
-                         pal.brush(QPalette::Active, QPalette::Text));
-        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::TextEditPalette) {
-            pal.setBrush(QPalette::Active, QPalette::Base, qt_mac_toQColor([NSColor textBackgroundColor]));
-            pal.setBrush(QPalette::Inactive, QPalette::Text,
-                          pal.brush(QPalette::Active, QPalette::Text));
-            pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
-                          pal.brush(QPalette::Active, QPalette::Text));
-        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::TextLineEditPalette
-                   || mac_widget_colors[i].paletteRole == QPlatformTheme::ComboBoxPalette) {
-            pal.setBrush(QPalette::Active, QPalette::Base, qt_mac_toQColor([NSColor textBackgroundColor]));
-            pal.setBrush(QPalette::Disabled, QPalette::Base,
-                         pal.brush(QPalette::Active, QPalette::Base));
-        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::LabelPalette) {
-            qc = qt_mac_toQColor([NSColor labelColor]);
-            pal.setBrush(QPalette::Inactive, QPalette::ToolTipText, qc);
-        }
-        palettes.insert(mac_widget_colors[i].paletteRole, &pal);
-    }
-    return palettes;
-}
-
-QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.h b/src/plugins/platforms/cocoa/qcocoatheme.h
index a00cbdfea3..50e56ef1bf 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.h
+++ b/src/plugins/platforms/cocoa/qcocoatheme.h
@@ -70,7 +70,7 @@ public:
     const QPalette *palette(Palette type = SystemPalette) const override;
     const QFont *font(Font type = SystemFont) const override;
     QPixmap standardPixmap(StandardPixmap sp, const QSizeF &size) const override;
-    QIcon fileIcon(const QFileInfo &fileInfo, QPlatformTheme::IconOptions options = 0) const override;
+    QIcon fileIcon(const QFileInfo &fileInfo, QPlatformTheme::IconOptions options = {}) const override;
 
     QVariant themeHint(ThemeHint hint) const override;
     QString standardButtonText(int button) const override;
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index 7c10456824..a76ba300e9 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -45,7 +45,6 @@
 #include <QtCore/QOperatingSystemVersion>
 #include <QtCore/QVariant>
 
-#include "qcocoasystemsettings.h"
 #include "qcocoasystemtrayicon.h"
 #include "qcocoamenuitem.h"
 #include "qcocoamenu.h"
@@ -80,8 +79,203 @@
 
 #include <CoreServices/CoreServices.h>
 
+#if !QT_MACOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__MAC_10_14)
+@interface NSColor (MojaveForwardDeclarations)
+@property (class, strong, readonly) NSColor *selectedContentBackgroundColor NS_AVAILABLE_MAC(10_14);
+@property (class, strong, readonly) NSColor *unemphasizedSelectedTextBackgroundColor NS_AVAILABLE_MAC(10_14);
+@property (class, strong, readonly) NSColor *unemphasizedSelectedTextColor NS_AVAILABLE_MAC(10_14);
+@property (class, strong, readonly) NSColor *unemphasizedSelectedContentBackgroundColor NS_AVAILABLE_MAC(10_14);
+@property (class, strong, readonly) NSArray<NSColor *> *alternatingContentBackgroundColors NS_AVAILABLE_MAC(10_14);
+// Missing from non-Mojave SDKs, even if introduced in 10.10
+@property (class, strong, readonly) NSColor *linkColor NS_AVAILABLE_MAC(10_10);
+@end
+#endif
+
 QT_BEGIN_NAMESPACE
 
+static QPalette *qt_mac_createSystemPalette()
+{
+    QColor qc;
+
+    // Standard palette initialization (copied from Qt 4 styles)
+    QBrush backgroundBrush = qt_mac_toQBrush([NSColor windowBackgroundColor]);
+    QColor background = backgroundBrush.color();
+    QColor light(background.lighter(110));
+    QColor dark(background.darker(160));
+    QColor mid(background.darker(140));
+    QPalette *palette = new QPalette(Qt::black, background, light, dark, mid, Qt::black, Qt::white);
+
+    palette->setBrush(QPalette::Window, backgroundBrush);
+
+    palette->setBrush(QPalette::Disabled, QPalette::WindowText, dark);
+    palette->setBrush(QPalette::Disabled, QPalette::Text, dark);
+    palette->setBrush(QPalette::Disabled, QPalette::ButtonText, dark);
+    palette->setBrush(QPalette::Disabled, QPalette::Base, backgroundBrush);
+    QBrush textBackgroundBrush = qt_mac_toQBrush([NSColor textBackgroundColor]);
+    palette->setBrush(QPalette::Active, QPalette::Base, textBackgroundBrush);
+    palette->setBrush(QPalette::Inactive, QPalette::Base, textBackgroundBrush);
+    palette->setColor(QPalette::Disabled, QPalette::Dark, QColor(191, 191, 191));
+    palette->setColor(QPalette::Active, QPalette::Dark, QColor(191, 191, 191));
+    palette->setColor(QPalette::Inactive, QPalette::Dark, QColor(191, 191, 191));
+
+    // System palette initialization:
+    QBrush br = qt_mac_toQBrush([NSColor selectedControlColor]);
+    palette->setBrush(QPalette::Active, QPalette::Highlight, br);
+    if (__builtin_available(macOS 10.14, *)) {
+        const auto inactiveHighlight = qt_mac_toQBrush([NSColor unemphasizedSelectedContentBackgroundColor]);
+        palette->setBrush(QPalette::Inactive, QPalette::Highlight, inactiveHighlight);
+        palette->setBrush(QPalette::Disabled, QPalette::Highlight, inactiveHighlight);
+    } else {
+        palette->setBrush(QPalette::Inactive, QPalette::Highlight, br);
+        palette->setBrush(QPalette::Disabled, QPalette::Highlight, br);
+    }
+
+    palette->setBrush(QPalette::Shadow, qt_mac_toQColor([NSColor shadowColor]));
+
+    qc = qt_mac_toQColor([NSColor controlTextColor]);
+    palette->setColor(QPalette::Active, QPalette::Text, qc);
+    palette->setColor(QPalette::Active, QPalette::WindowText, qc);
+    palette->setColor(QPalette::Active, QPalette::HighlightedText, qc);
+    palette->setColor(QPalette::Inactive, QPalette::Text, qc);
+    palette->setColor(QPalette::Inactive, QPalette::WindowText, qc);
+    palette->setColor(QPalette::Inactive, QPalette::HighlightedText, qc);
+
+    qc = qt_mac_toQColor([NSColor disabledControlTextColor]);
+    palette->setColor(QPalette::Disabled, QPalette::Text, qc);
+    palette->setColor(QPalette::Disabled, QPalette::WindowText, qc);
+    palette->setColor(QPalette::Disabled, QPalette::HighlightedText, qc);
+
+    palette->setBrush(QPalette::ToolTipBase, qt_mac_toQBrush([NSColor controlColor]));
+
+    palette->setColor(QPalette::Normal, QPalette::Link, qt_mac_toQColor([NSColor linkColor]));
+
+    return palette;
+}
+
+struct QMacPaletteMap {
+    inline QMacPaletteMap(QPlatformTheme::Palette p, NSColor *a, NSColor *i) :
+        active(a), inactive(i), paletteRole(p) { }
+
+    NSColor *active;
+    NSColor *inactive;
+    QPlatformTheme::Palette paletteRole;
+};
+
+#define MAC_PALETTE_ENTRY(pal, active, inactive) \
+    QMacPaletteMap(pal, [NSColor active], [NSColor inactive])
+static QMacPaletteMap mac_widget_colors[] = {
+    MAC_PALETTE_ENTRY(QPlatformTheme::ToolButtonPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::ButtonPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::HeaderPalette, headerTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::ComboBoxPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::ItemViewPalette, textColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::MessageBoxLabelPalette, textColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::TabBarPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::LabelPalette, textColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::GroupBoxPalette, textColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::MenuPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::MenuBarPalette, controlTextColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::TextEditPalette, textColor, disabledControlTextColor),
+    MAC_PALETTE_ENTRY(QPlatformTheme::TextLineEditPalette, textColor, disabledControlTextColor)
+};
+#undef MAC_PALETTE_ENTRY
+
+static const int mac_widget_colors_count = sizeof(mac_widget_colors) / sizeof(mac_widget_colors[0]);
+
+static QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
+{
+    QHash<QPlatformTheme::Palette, QPalette*> palettes;
+    QColor qc;
+    for (int i = 0; i < mac_widget_colors_count; i++) {
+        QPalette &pal = *qt_mac_createSystemPalette();
+        if (mac_widget_colors[i].active) {
+            qc = qt_mac_toQColor(mac_widget_colors[i].active);
+            pal.setColor(QPalette::Active, QPalette::Text, qc);
+            pal.setColor(QPalette::Inactive, QPalette::Text, qc);
+            pal.setColor(QPalette::Active, QPalette::WindowText, qc);
+            pal.setColor(QPalette::Inactive, QPalette::WindowText, qc);
+            pal.setColor(QPalette::Active, QPalette::HighlightedText, qc);
+            pal.setColor(QPalette::Inactive, QPalette::HighlightedText, qc);
+            pal.setColor(QPalette::Active, QPalette::ButtonText, qc);
+            pal.setColor(QPalette::Inactive, QPalette::ButtonText, qc);
+            qc = qt_mac_toQColor(mac_widget_colors[i].inactive);
+            pal.setColor(QPalette::Disabled, QPalette::Text, qc);
+            pal.setColor(QPalette::Disabled, QPalette::WindowText, qc);
+            pal.setColor(QPalette::Disabled, QPalette::HighlightedText, qc);
+            pal.setColor(QPalette::Disabled, QPalette::ButtonText, qc);
+        }
+        if (mac_widget_colors[i].paletteRole == QPlatformTheme::MenuPalette
+                || mac_widget_colors[i].paletteRole == QPlatformTheme::MenuBarPalette) {
+            NSColor *selectedMenuItemColor = nil;
+            if (__builtin_available(macOS 10.14, *)) {
+                // Cheap approximation for NSVisualEffectView (see deprecation note for selectedMenuItemTextColor)
+                selectedMenuItemColor = [[NSColor selectedContentBackgroundColor] highlightWithLevel:0.4];
+            } else {
+                // selectedMenuItemColor would presumably be the correct color to use as the background
+                // for selected menu items. But that color is always blue, and doesn't follow the
+                // appearance color in system preferences. So we therefore deliberatly choose to use
+                // keyboardFocusIndicatorColor instead, which appears to have the same color value.
+                selectedMenuItemColor = [NSColor keyboardFocusIndicatorColor];
+            }
+            pal.setBrush(QPalette::Highlight, qt_mac_toQColor(selectedMenuItemColor));
+            qc = qt_mac_toQColor([NSColor labelColor]);
+            pal.setBrush(QPalette::ButtonText, qc);
+            pal.setBrush(QPalette::Text, qc);
+            qc = qt_mac_toQColor([NSColor selectedMenuItemTextColor]);
+            pal.setBrush(QPalette::HighlightedText, qc);
+            qc = qt_mac_toQColor([NSColor disabledControlTextColor]);
+            pal.setBrush(QPalette::Disabled, QPalette::Text, qc);
+        } else if ((mac_widget_colors[i].paletteRole == QPlatformTheme::ButtonPalette)
+                || (mac_widget_colors[i].paletteRole == QPlatformTheme::HeaderPalette)
+                || (mac_widget_colors[i].paletteRole == QPlatformTheme::TabBarPalette)) {
+            pal.setColor(QPalette::Disabled, QPalette::ButtonText,
+                         pal.color(QPalette::Disabled, QPalette::Text));
+            pal.setColor(QPalette::Inactive, QPalette::ButtonText,
+                         pal.color(QPalette::Inactive, QPalette::Text));
+            pal.setColor(QPalette::Active, QPalette::ButtonText,
+                         pal.color(QPalette::Active, QPalette::Text));
+        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::ItemViewPalette) {
+            NSArray<NSColor *> *baseColors = nil;
+            NSColor *activeHighlightColor = nil;
+            if (__builtin_available(macOS 10.14, *)) {
+                baseColors = [NSColor alternatingContentBackgroundColors];
+                activeHighlightColor = [NSColor selectedContentBackgroundColor];
+                pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
+                             qt_mac_toQBrush([NSColor unemphasizedSelectedTextColor]));
+            } else {
+                baseColors = [NSColor controlAlternatingRowBackgroundColors];
+                activeHighlightColor = [NSColor alternateSelectedControlColor];
+                pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
+                             pal.brush(QPalette::Active, QPalette::Text));
+            }
+            pal.setBrush(QPalette::Base, qt_mac_toQBrush(baseColors[0]));
+            pal.setBrush(QPalette::AlternateBase, qt_mac_toQBrush(baseColors[1]));
+            pal.setBrush(QPalette::Active, QPalette::Highlight,
+                         qt_mac_toQBrush(activeHighlightColor));
+            pal.setBrush(QPalette::Active, QPalette::HighlightedText,
+                         qt_mac_toQBrush([NSColor alternateSelectedControlTextColor]));
+            pal.setBrush(QPalette::Inactive, QPalette::Text,
+                         pal.brush(QPalette::Active, QPalette::Text));
+        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::TextEditPalette) {
+            pal.setBrush(QPalette::Active, QPalette::Base, qt_mac_toQColor([NSColor textBackgroundColor]));
+            pal.setBrush(QPalette::Inactive, QPalette::Text,
+                          pal.brush(QPalette::Active, QPalette::Text));
+            pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
+                          pal.brush(QPalette::Active, QPalette::Text));
+        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::TextLineEditPalette
+                   || mac_widget_colors[i].paletteRole == QPlatformTheme::ComboBoxPalette) {
+            pal.setBrush(QPalette::Active, QPalette::Base, qt_mac_toQColor([NSColor textBackgroundColor]));
+            pal.setBrush(QPalette::Disabled, QPalette::Base,
+                         pal.brush(QPalette::Active, QPalette::Base));
+        } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::LabelPalette) {
+            qc = qt_mac_toQColor([NSColor labelColor]);
+            pal.setBrush(QPalette::Inactive, QPalette::ToolTipText, qc);
+        }
+        palettes.insert(mac_widget_colors[i].paletteRole, &pal);
+    }
+    return palettes;
+}
+
 const char *QCocoaTheme::name = "cocoa";
 
 QCocoaTheme::QCocoaTheme()
@@ -129,7 +323,7 @@ void QCocoaTheme::handleSystemThemeChange()
         QFontCache::instance()->clear();
     }
 
-    QWindowSystemInterface::handleThemeChange(nullptr);
+    QWindowSystemInterface::handleThemeChange<QWindowSystemInterface::SynchronousDelivery>(nullptr);
 }
 
 bool QCocoaTheme::usePlatformNativeDialog(DialogType dialogType) const
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 21366b4f67..ad232d6d80 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -559,7 +559,10 @@ void QCocoaWindow::setWindowFlags(Qt::WindowFlags flags)
     Qt::WindowType type = static_cast<Qt::WindowType>(int(flags & Qt::WindowType_Mask));
     if ((type & Qt::Popup) != Qt::Popup && (type & Qt::Dialog) != Qt::Dialog) {
         NSWindowCollectionBehavior behavior = m_view.window.collectionBehavior;
-        if ((flags & Qt::WindowFullscreenButtonHint) || m_view.window.qt_fullScreen) {
+        const bool enableFullScreen = m_view.window.qt_fullScreen
+                                    || !(flags & Qt::CustomizeWindowHint)
+                                    || (flags & Qt::WindowFullscreenButtonHint);
+        if (enableFullScreen) {
             behavior |= NSWindowCollectionBehaviorFullScreenPrimary;
             behavior &= ~NSWindowCollectionBehaviorFullScreenAuxiliary;
         } else {
@@ -1689,9 +1692,9 @@ void QCocoaWindow::registerTouch(bool enable)
 {
     m_registerTouchCount += enable ? 1 : -1;
     if (enable && m_registerTouchCount == 1)
-        [m_view setAcceptsTouchEvents:YES];
+        m_view.allowedTouchTypes |= NSTouchTypeMaskIndirect;
     else if (m_registerTouchCount == 0)
-        [m_view setAcceptsTouchEvents:NO];
+        m_view.allowedTouchTypes &= ~NSTouchTypeMaskIndirect;
 }
 
 void QCocoaWindow::setContentBorderThickness(int topThickness, int bottomThickness)
diff --git a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
index 872773cb7a..e070ba977d 100644
--- a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
+++ b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
@@ -48,9 +48,11 @@ QT_BEGIN_NAMESPACE
 class QIOSurfaceGraphicsBuffer : public QPlatformGraphicsBuffer
 {
 public:
-    QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace);
+    QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format);
     ~QIOSurfaceGraphicsBuffer();
 
+    void setColorSpace(QCFType<CGColorSpaceRef> colorSpace);
+
     const uchar *data() const override;
     uchar *data() override;
     int bytesPerLine() const override;
diff --git a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
index a367487e85..fc187e0f51 100644
--- a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
+++ b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
@@ -53,7 +53,7 @@ QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(lcQpaIOSurface, "qt.qpa.backingstore.iosurface");
 
-QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace)
+QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format)
     : QPlatformGraphicsBuffer(size, format)
 {
     const size_t width = size.width();
@@ -81,17 +81,26 @@ QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPix
 
     Q_ASSERT(size_t(bytesPerLine()) == bytesPerRow);
     Q_ASSERT(size_t(byteCount()) == totalBytes);
-
-    if (colorSpace) {
-        IOSurfaceSetValue(m_surface, CFSTR("IOSurfaceColorSpace"),
-            QCFType<CFPropertyListRef>(CGColorSpaceCopyPropertyList(colorSpace)));
-    }
 }
 
 QIOSurfaceGraphicsBuffer::~QIOSurfaceGraphicsBuffer()
 {
 }
 
+void QIOSurfaceGraphicsBuffer::setColorSpace(QCFType<CGColorSpaceRef> colorSpace)
+{
+    static const auto kIOSurfaceColorSpace = CFSTR("IOSurfaceColorSpace");
+
+    qCDebug(lcQpaIOSurface) << "Tagging" << this << "with color space" << colorSpace;
+
+    if (colorSpace) {
+        IOSurfaceSetValue(m_surface, kIOSurfaceColorSpace,
+            QCFType<CFPropertyListRef>(CGColorSpaceCopyPropertyList(colorSpace)));
+    } else {
+        IOSurfaceRemoveValue(m_surface, kIOSurfaceColorSpace);
+    }
+}
+
 const uchar *QIOSurfaceGraphicsBuffer::data() const
 {
     return (const uchar *)IOSurfaceGetBaseAddress(m_surface);
diff --git a/src/plugins/platforms/cocoa/qmacclipboard.mm b/src/plugins/platforms/cocoa/qmacclipboard.mm
index 358a6b49fd..654647b35a 100644
--- a/src/plugins/platforms/cocoa/qmacclipboard.mm
+++ b/src/plugins/platforms/cocoa/qmacclipboard.mm
@@ -138,8 +138,12 @@ QMacPasteboard::QMacPasteboard(CFStringRef name, uchar mt)
 
 QMacPasteboard::~QMacPasteboard()
 {
-    // commit all promises for paste after exit close
-    resolvingBeforeDestruction = true;
+    /*
+        Commit all promises for paste when shutting down,
+        unless we are the stack-allocated clipboard used by QCocoaDrag.
+    */
+    if (mime_type == QMacInternalPasteboardMime::MIME_DND)
+        resolvingBeforeDestruction = true;
     PasteboardResolvePromises(paste);
     if (paste)
         CFRelease(paste);
diff --git a/src/plugins/platforms/eglfs/api/qeglfscontext.cpp b/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
index c5cef34d8e..48fafbda8d 100644
--- a/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfscontext.cpp
@@ -52,7 +52,7 @@ QT_BEGIN_NAMESPACE
 QEglFSContext::QEglFSContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share, EGLDisplay display,
                              EGLConfig *config, const QVariant &nativeHandle)
     : QEGLPlatformContext(format, share, display, config, nativeHandle,
-                          qt_egl_device_integration()->supportsSurfacelessContexts() ? Flags(0) : QEGLPlatformContext::NoSurfaceless),
+                          qt_egl_device_integration()->supportsSurfacelessContexts() ? Flags() : QEGLPlatformContext::NoSurfaceless),
       m_tempWindow(0)
 {
 }
@@ -78,7 +78,7 @@ EGLSurface QEglFSContext::createTemporaryOffscreenSurface()
         }
     }
     EGLConfig config = q_configFromGLFormat(eglDisplay(), format());
-    return eglCreateWindowSurface(eglDisplay(), config, m_tempWindow, 0);
+    return eglCreateWindowSurface(eglDisplay(), config, m_tempWindow, nullptr);
 }
 
 void QEglFSContext::destroyTemporaryOffscreenSurface(EGLSurface surface)
diff --git a/src/plugins/platforms/eglfs/api/qeglfscursor.cpp b/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
index 22319fcc66..98e05195ee 100644
--- a/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfscursor.cpp
@@ -62,7 +62,7 @@ QEglFSCursor::QEglFSCursor(QPlatformScreen *screen)
   : m_visible(true),
     m_screen(static_cast<QEglFSScreen *>(screen)),
     m_activeScreen(nullptr),
-    m_deviceListener(0),
+    m_deviceListener(nullptr),
     m_updateRequested(false)
 {
     QByteArray hideCursorVal = qgetenv("QT_QPA_EGLFS_HIDECURSOR");
diff --git a/src/plugins/platforms/eglfs/api/qeglfsintegration.cpp b/src/plugins/platforms/eglfs/api/qeglfsintegration.cpp
index 674f579b4f..d9a3545a95 100644
--- a/src/plugins/platforms/eglfs/api/qeglfsintegration.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfsintegration.cpp
@@ -109,10 +109,10 @@ QT_BEGIN_NAMESPACE
 
 QEglFSIntegration::QEglFSIntegration()
     : m_display(EGL_NO_DISPLAY),
-      m_inputContext(0),
+      m_inputContext(nullptr),
       m_fontDb(new QGenericUnixFontDatabase),
       m_services(new QGenericUnixServices),
-      m_kbdMgr(0),
+      m_kbdMgr(nullptr),
       m_disableInputHandlers(false)
 {
     m_disableInputHandlers = qEnvironmentVariableIntValue("QT_QPA_EGLFS_DISABLE_INPUT");
@@ -223,7 +223,7 @@ QPlatformOpenGLContext *QEglFSIntegration::createPlatformOpenGLContext(QOpenGLCo
         EGLConfig config = QEglFSDeviceIntegration::chooseConfig(dpy, adjustedFormat);
         ctx = new QEglFSContext(adjustedFormat, share, dpy, &config, QVariant());
     } else {
-        ctx = new QEglFSContext(adjustedFormat, share, dpy, 0, nativeHandle);
+        ctx = new QEglFSContext(adjustedFormat, share, dpy, nullptr, nativeHandle);
     }
     nativeHandle = QVariant::fromValue<QEGLNativeContext>(QEGLNativeContext(ctx->eglContext(), dpy));
 
@@ -236,7 +236,7 @@ QPlatformOffscreenSurface *QEglFSIntegration::createPlatformOffscreenSurface(QOf
     EGLDisplay dpy = surface->screen() ? static_cast<QEglFSScreen *>(surface->screen()->handle())->display() : display();
     QSurfaceFormat fmt = qt_egl_device_integration()->surfaceFormatFor(surface->requestedFormat());
     if (qt_egl_device_integration()->supportsPBuffers()) {
-        QEGLPlatformContext::Flags flags = 0;
+        QEGLPlatformContext::Flags flags;
         if (!qt_egl_device_integration()->supportsSurfacelessContexts())
             flags |= QEGLPlatformContext::NoSurfaceless;
         return new QEGLPbuffer(dpy, fmt, surface, flags);
@@ -307,7 +307,7 @@ static int resourceType(const QByteArray &key)
 
 void *QEglFSIntegration::nativeResourceForIntegration(const QByteArray &resource)
 {
-    void *result = 0;
+    void *result = nullptr;
 
     switch (resourceType(resource)) {
     case EglDisplay:
@@ -329,7 +329,7 @@ void *QEglFSIntegration::nativeResourceForIntegration(const QByteArray &resource
 
 void *QEglFSIntegration::nativeResourceForScreen(const QByteArray &resource, QScreen *screen)
 {
-    void *result = 0;
+    void *result = nullptr;
 
     switch (resourceType(resource)) {
     case XlibDisplay:
@@ -347,7 +347,7 @@ void *QEglFSIntegration::nativeResourceForScreen(const QByteArray &resource, QSc
 
 void *QEglFSIntegration::nativeResourceForWindow(const QByteArray &resource, QWindow *window)
 {
-    void *result = 0;
+    void *result = nullptr;
 
     switch (resourceType(resource)) {
     case EglDisplay:
@@ -374,7 +374,7 @@ void *QEglFSIntegration::nativeResourceForWindow(const QByteArray &resource, QWi
 #ifndef QT_NO_OPENGL
 void *QEglFSIntegration::nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context)
 {
-    void *result = 0;
+    void *result = nullptr;
 
     switch (resourceType(resource)) {
     case EglContext:
@@ -402,7 +402,7 @@ static void *eglContextForContext(QOpenGLContext *context)
 
     QEglFSContext *handle = static_cast<QEglFSContext *>(context->handle());
     if (!handle)
-        return 0;
+        return nullptr;
 
     return handle->eglContext();
 }
@@ -416,7 +416,7 @@ QPlatformNativeInterface::NativeResourceForContextFunction QEglFSIntegration::na
 #else
     Q_UNUSED(resource);
 #endif
-    return 0;
+    return nullptr;
 }
 
 QFunctionPointer QEglFSIntegration::platformFunction(const QByteArray &function) const
diff --git a/src/plugins/platforms/eglfs/api/qeglfsoffscreenwindow.cpp b/src/plugins/platforms/eglfs/api/qeglfsoffscreenwindow.cpp
index 864271cd3a..c96e329816 100644
--- a/src/plugins/platforms/eglfs/api/qeglfsoffscreenwindow.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfsoffscreenwindow.cpp
@@ -67,7 +67,7 @@ QEglFSOffscreenWindow::QEglFSOffscreenWindow(EGLDisplay display, const QSurfaceF
         return;
     }
     EGLConfig config = q_configFromGLFormat(m_display, m_format);
-    m_surface = eglCreateWindowSurface(m_display, config, m_window, 0);
+    m_surface = eglCreateWindowSurface(m_display, config, m_window, nullptr);
     if (m_surface != EGL_NO_SURFACE)
         m_format = q_glFormatFromConfig(m_display, config);
 }
diff --git a/src/plugins/platforms/eglfs/api/qeglfsscreen.cpp b/src/plugins/platforms/eglfs/api/qeglfsscreen.cpp
index 11b68c0589..8a8e8cd563 100644
--- a/src/plugins/platforms/eglfs/api/qeglfsscreen.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfsscreen.cpp
@@ -54,7 +54,7 @@ QT_BEGIN_NAMESPACE
 QEglFSScreen::QEglFSScreen(EGLDisplay dpy)
     : m_dpy(dpy),
       m_surface(EGL_NO_SURFACE),
-      m_cursor(0)
+      m_cursor(nullptr)
 {
     m_cursor = qt_egl_device_integration()->createCursor(this);
 }
@@ -164,7 +164,7 @@ void QEglFSScreen::handleCursorMove(const QPoint &pos)
         return;
     }
 
-    QWindow *enter = 0, *leave = 0;
+    QWindow *enter = nullptr, *leave = nullptr;
     for (int i = windows.count() - 1; i >= 0; --i) {
         QWindow *window = windows[i]->sourceWindow();
         const QRect geom = window->geometry();
diff --git a/src/plugins/platforms/eglfs/api/qeglfswindow.cpp b/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
index 1fed182882..f7e116eb88 100644
--- a/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
+++ b/src/plugins/platforms/eglfs/api/qeglfswindow.cpp
@@ -61,13 +61,12 @@ QT_BEGIN_NAMESPACE
 QEglFSWindow::QEglFSWindow(QWindow *w)
     : QPlatformWindow(w),
 #ifndef QT_NO_OPENGL
-      m_backingStore(0),
-      m_rasterCompositingContext(0),
+      m_backingStore(nullptr),
+      m_rasterCompositingContext(nullptr),
 #endif
       m_winId(0),
       m_surface(EGL_NO_SURFACE),
-      m_window(0),
-      m_flags(0)
+      m_window(0)
 {
 }
 
@@ -186,7 +185,7 @@ void QEglFSWindow::destroy()
 #endif
     }
 
-    m_flags = 0;
+    m_flags = { };
 }
 
 void QEglFSWindow::invalidateSurface()
@@ -208,7 +207,7 @@ void QEglFSWindow::resetSurface()
     m_format = q_glFormatFromConfig(display, m_config, platformFormat);
     const QSize surfaceSize = screen()->rawGeometry().size();
     m_window = qt_egl_device_integration()->createNativeWindow(this, surfaceSize, m_format);
-    m_surface = eglCreateWindowSurface(display, m_config, m_window, NULL);
+    m_surface = eglCreateWindowSurface(display, m_config, m_window, nullptr);
 }
 
 void QEglFSWindow::setVisible(bool visible)
@@ -338,7 +337,7 @@ const QPlatformTextureList *QEglFSWindow::textures() const
     if (m_backingStore)
         return m_backingStore->textures();
 
-    return 0;
+    return nullptr;
 }
 
 void QEglFSWindow::endCompositing()
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
index 4d0cf0c47e..dc98cdce4b 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.cpp
@@ -69,7 +69,7 @@ QEglFSKmsGbmCursor::QEglFSKmsGbmCursor(QEglFSKmsGbmScreen *screen)
     : m_screen(screen)
     , m_cursorSize(64, 64) // 64x64 is the old standard size, we now try to query the real size below
     , m_bo(nullptr)
-    , m_cursorImage(0, 0, 0, 0, 0, 0)
+    , m_cursorImage(nullptr, nullptr, 0, 0, 0, 0)
     , m_state(CursorPendingVisible)
     , m_deviceListener(nullptr)
 {
@@ -102,7 +102,7 @@ QEglFSKmsGbmCursor::QEglFSKmsGbmCursor(QEglFSKmsGbmScreen *screen)
 
 #ifndef QT_NO_CURSOR
     QCursor cursor(Qt::ArrowCursor);
-    changeCursor(&cursor, 0);
+    changeCursor(&cursor, nullptr);
 #endif
     setPos(QPoint(0, 0));
 }
@@ -214,7 +214,8 @@ void QEglFSKmsGbmCursor::changeCursor(QCursor *windowCursor, QWindow *window)
 
     Q_FOREACH (QPlatformScreen *screen, m_screen->virtualSiblings()) {
         QEglFSKmsScreen *kmsScreen = static_cast<QEglFSKmsScreen *>(screen);
-
+        if (kmsScreen->isCursorOutOfRange())
+            continue;
         int status = drmModeSetCursor(kmsScreen->device()->fd(), kmsScreen->output().crtc_id, handle,
                                       m_cursorSize.width(), m_cursorSize.height());
         if (status != 0)
@@ -232,17 +233,36 @@ void QEglFSKmsGbmCursor::setPos(const QPoint &pos)
 {
     Q_FOREACH (QPlatformScreen *screen, m_screen->virtualSiblings()) {
         QEglFSKmsScreen *kmsScreen = static_cast<QEglFSKmsScreen *>(screen);
-        QPoint origin = kmsScreen->geometry().topLeft();
-        QPoint localPos = pos - origin;
-        QPoint adjustedPos = localPos - m_cursorImage.hotspot();
-
-        int ret = drmModeMoveCursor(kmsScreen->device()->fd(), kmsScreen->output().crtc_id, adjustedPos.x(), adjustedPos.y());
-        if (ret == 0)
-            m_pos = pos;
-        else
-            qWarning("Failed to move cursor on screen %s: %d", kmsScreen->name().toLatin1().constData(), ret);
-
-        kmsScreen->handleCursorMove(pos);
+        const QRect screenGeom = kmsScreen->geometry();
+        const QPoint origin = screenGeom.topLeft();
+        const QPoint localPos = pos - origin;
+        const QPoint adjustedLocalPos = localPos - m_cursorImage.hotspot();
+
+        if (localPos.x() < 0 || localPos.y() < 0
+            || localPos.x() >= screenGeom.width() || localPos.y() >= screenGeom.height())
+        {
+            if (!kmsScreen->isCursorOutOfRange()) {
+                kmsScreen->setCursorOutOfRange(true);
+                drmModeSetCursor(kmsScreen->device()->fd(), kmsScreen->output().crtc_id, 0, 0, 0);
+            }
+        } else {
+            int ret;
+            if (kmsScreen->isCursorOutOfRange()) {
+                kmsScreen->setCursorOutOfRange(false);
+                uint32_t handle = gbm_bo_get_handle(m_bo).u32;
+                ret = drmModeSetCursor(kmsScreen->device()->fd(), kmsScreen->output().crtc_id,
+                                       handle, m_cursorSize.width(), m_cursorSize.height());
+            } else {
+                ret = drmModeMoveCursor(kmsScreen->device()->fd(), kmsScreen->output().crtc_id,
+                                        adjustedLocalPos.x(), adjustedLocalPos.y());
+            }
+            if (ret == 0)
+                m_pos = pos;
+            else
+                qWarning("Failed to move cursor on screen %s: %d", kmsScreen->name().toLatin1().constData(), ret);
+
+            kmsScreen->handleCursorMove(pos);
+        }
     }
 }
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.h
index d47b579238..5d2dfedba2 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmcursor.h
@@ -85,6 +85,8 @@ public:
 
     void updateMouseStatus();
 
+    void reevaluateVisibilityForScreens() { setPos(pos()); }
+
 private:
     void initCursorAtlas();
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
index 20127ae7f7..503419cf91 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.cpp
@@ -83,6 +83,8 @@ bool QEglFSKmsGbmDevice::open()
 
     setFd(fd);
 
+    m_eventReader.create(this);
+
     return true;
 }
 
@@ -90,6 +92,8 @@ void QEglFSKmsGbmDevice::close()
 {
     // Note: screens are gone at this stage.
 
+    m_eventReader.destroy();
+
     if (m_gbm_device) {
         gbm_device_destroy(m_gbm_device);
         m_gbm_device = nullptr;
@@ -155,4 +159,14 @@ void QEglFSKmsGbmDevice::registerScreenCloning(QPlatformScreen *screen,
     gbmScreen->initCloning(screenThisScreenClones, screensCloningThisScreen);
 }
 
+void QEglFSKmsGbmDevice::registerScreen(QPlatformScreen *screen,
+                                        bool isPrimary,
+                                        const QPoint &virtualPos,
+                                        const QList<QPlatformScreen *> &virtualSiblings)
+{
+    QEglFSKmsDevice::registerScreen(screen, isPrimary, virtualPos, virtualSiblings);
+    if (screenConfig()->hwCursor() && m_globalCursor)
+        m_globalCursor->reevaluateVisibilityForScreens();
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.h
index 518e2ce58b..f1476f8ffa 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmdevice.h
@@ -70,6 +70,10 @@ public:
     void registerScreenCloning(QPlatformScreen *screen,
                                QPlatformScreen *screenThisScreenClones,
                                const QVector<QPlatformScreen *> &screensCloningThisScreen) override;
+    void registerScreen(QPlatformScreen *screen,
+                        bool isPrimary,
+                        const QPoint &virtualPos,
+                        const QList<QPlatformScreen *> &virtualSiblings) override;
 
 private:
     Q_DISABLE_COPY(QEglFSKmsGbmDevice)
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
index f154520669..caa1187b40 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
@@ -54,8 +54,6 @@
 
 QT_BEGIN_NAMESPACE
 
-QMutex QEglFSKmsGbmScreen::m_waitForFlipMutex;
-
 QEglFSKmsGbmIntegration::QEglFSKmsGbmIntegration()
 {
     qCDebug(qLcEglfsKmsDebug, "New DRM/KMS via GBM integration created");
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
index 16dbfe1522..6f5c3b6953 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
@@ -110,7 +110,7 @@ QEglFSKmsGbmScreen::FrameBuffer *QEglFSKmsGbmScreen::framebufferForBufferObject(
     return fb.take();
 }
 
-QEglFSKmsGbmScreen::QEglFSKmsGbmScreen(QKmsDevice *device, const QKmsOutput &output, bool headless)
+QEglFSKmsGbmScreen::QEglFSKmsGbmScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless)
     : QEglFSKmsScreen(device, output, headless)
     , m_gbm_surface(nullptr)
     , m_gbm_bo_current(nullptr)
@@ -243,7 +243,7 @@ void QEglFSKmsGbmScreen::ensureModeSet(uint32_t fb)
 
             if (device()->hasAtomicSupport()) {
 #if QT_CONFIG(drm_atomic)
-                drmModeAtomicReq *request = device()->atomic_request();
+                drmModeAtomicReq *request = device()->threadLocalAtomicRequest();
                 if (request) {
                     drmModeAtomicAddProperty(request, op.connector_id, op.crtcIdPropertyId, op.crtc_id);
                     drmModeAtomicAddProperty(request, op.crtc_id, op.modeIdPropertyId, op.mode_blob_id);
@@ -276,19 +276,15 @@ void QEglFSKmsGbmScreen::waitForFlip()
     if (!m_gbm_bo_next)
         return;
 
-    QMutexLocker lock(&m_waitForFlipMutex);
-    while (m_gbm_bo_next) {
-        drmEventContext drmEvent;
-        memset(&drmEvent, 0, sizeof(drmEvent));
-        drmEvent.version = 2;
-        drmEvent.vblank_handler = nullptr;
-        drmEvent.page_flip_handler = pageFlipHandler;
-        drmHandleEvent(device()->fd(), &drmEvent);
-    }
+    m_flipMutex.lock();
+    device()->eventReader()->startWaitFlip(this, &m_flipMutex, &m_flipCond);
+    m_flipCond.wait(&m_flipMutex);
+    m_flipMutex.unlock();
+
+    flipFinished();
 
 #if QT_CONFIG(drm_atomic)
-    if (device()->hasAtomicSupport())
-        device()->atomicReset();
+    device()->threadLocalAtomicReset();
 #endif
 }
 
@@ -324,16 +320,16 @@ void QEglFSKmsGbmScreen::flip()
 
     if (device()->hasAtomicSupport()) {
 #if QT_CONFIG(drm_atomic)
-        drmModeAtomicReq *request = device()->atomic_request();
+        drmModeAtomicReq *request = device()->threadLocalAtomicRequest();
         if (request) {
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->framebufferPropertyId, fb->fb);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->crtcPropertyId, op.crtc_id);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->srcwidthPropertyId,
-                                     output().size.width() << 16);
+                                     op.size.width() << 16);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->srcXPropertyId, 0);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->srcYPropertyId, 0);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->srcheightPropertyId,
-                                     output().size.height() << 16);
+                                     op.size.height() << 16);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->crtcXPropertyId, 0);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->crtcYPropertyId, 0);
             drmModeAtomicAddProperty(request, op.eglfs_plane->id, op.eglfs_plane->crtcwidthPropertyId,
@@ -371,7 +367,7 @@ void QEglFSKmsGbmScreen::flip()
 
             if (device()->hasAtomicSupport()) {
 #if QT_CONFIG(drm_atomic)
-                drmModeAtomicReq *request = device()->atomic_request();
+                drmModeAtomicReq *request = device()->threadLocalAtomicRequest();
                 if (request) {
                     drmModeAtomicAddProperty(request, d.screen->output().eglfs_plane->id,
                                                       d.screen->output().eglfs_plane->framebufferPropertyId, fb->fb);
@@ -394,22 +390,10 @@ void QEglFSKmsGbmScreen::flip()
     }
 
 #if QT_CONFIG(drm_atomic)
-    if (device()->hasAtomicSupport())
-         device()->atomicCommit(this);
+    device()->threadLocalAtomicCommit(this);
 #endif
 }
 
-void QEglFSKmsGbmScreen::pageFlipHandler(int fd, unsigned int sequence, unsigned int tv_sec, unsigned int tv_usec, void *user_data)
-{
-    Q_UNUSED(fd);
-    Q_UNUSED(sequence);
-    Q_UNUSED(tv_sec);
-    Q_UNUSED(tv_usec);
-
-    QEglFSKmsGbmScreen *screen = static_cast<QEglFSKmsGbmScreen *>(user_data);
-    screen->flipFinished();
-}
-
 void QEglFSKmsGbmScreen::flipFinished()
 {
     if (m_cloneSource) {
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
index b94f44b7b1..69feeee703 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.h
@@ -43,7 +43,8 @@
 #define QEGLFSKMSGBMSCREEN_H
 
 #include "qeglfskmsscreen.h"
-#include <QtCore/QMutex>
+#include <QMutex>
+#include <QWaitCondition>
 
 #include <gbm.h>
 
@@ -54,7 +55,7 @@ class QEglFSKmsGbmCursor;
 class QEglFSKmsGbmScreen : public QEglFSKmsScreen
 {
 public:
-    QEglFSKmsGbmScreen(QKmsDevice *device, const QKmsOutput &output, bool headless);
+    QEglFSKmsGbmScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless);
     ~QEglFSKmsGbmScreen();
 
     QPlatformCursor *cursor() const override;
@@ -75,18 +76,15 @@ private:
     void cloneDestFlipFinished(QEglFSKmsGbmScreen *cloneDestScreen);
     void updateFlipStatus();
 
-    static void pageFlipHandler(int fd,
-                                unsigned int sequence,
-                                unsigned int tv_sec,
-                                unsigned int tv_usec,
-                                void *user_data);
-
     gbm_surface *m_gbm_surface;
 
     gbm_bo *m_gbm_bo_current;
     gbm_bo *m_gbm_bo_next;
     bool m_flipPending;
 
+    QMutex m_flipMutex;
+    QWaitCondition m_flipCond;
+
     QScopedPointer<QEglFSKmsGbmCursor> m_cursor;
 
     struct FrameBuffer {
@@ -101,8 +99,6 @@ private:
         bool cloneFlipPending = false;
     };
     QVector<CloneDestination> m_cloneDests;
-
-    static QMutex m_waitForFlipMutex;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
index 1626c86239..5a62e437c4 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.cpp
@@ -47,7 +47,7 @@ QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(qLcEglfsKmsDebug)
 
-QEglFSKmsEglDeviceScreen::QEglFSKmsEglDeviceScreen(QKmsDevice *device, const QKmsOutput &output)
+QEglFSKmsEglDeviceScreen::QEglFSKmsEglDeviceScreen(QEglFSKmsDevice *device, const QKmsOutput &output)
     : QEglFSKmsScreen(device, output)
 {
 }
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
index 5efe35f8b3..961398ba3e 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldevicescreen.h
@@ -47,7 +47,7 @@ QT_BEGIN_NAMESPACE
 class QEglFSKmsEglDeviceScreen : public QEglFSKmsScreen
 {
 public:
-    QEglFSKmsEglDeviceScreen(QKmsDevice *device, const QKmsOutput &output);
+    QEglFSKmsEglDeviceScreen(QEglFSKmsDevice *device, const QKmsOutput &output);
     ~QEglFSKmsEglDeviceScreen();
 
     QPlatformCursor *cursor() const override;
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/eglfs_kms_support.pro b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/eglfs_kms_support.pro
index 40806b6a9b..e51903ed96 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/eglfs_kms_support.pro
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/eglfs_kms_support.pro
@@ -14,9 +14,11 @@ CONFIG += egl
 
 SOURCES += $$PWD/qeglfskmsintegration.cpp \
            $$PWD/qeglfskmsdevice.cpp \
-           $$PWD/qeglfskmsscreen.cpp
+           $$PWD/qeglfskmsscreen.cpp \
+           $$PWD/qeglfskmseventreader.cpp
 
 HEADERS += $$PWD/qeglfskmsintegration.h \
            $$PWD/qeglfskmsdevice.h \
            $$PWD/qeglfskmsscreen.h \
-           $$PWD/qeglfskmshelpers.h
+           $$PWD/qeglfskmshelpers.h \
+           $$PWD/qeglfskmseventreader.h
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsdevice.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsdevice.h
index fc83a620d9..34908aa60f 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsdevice.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsdevice.h
@@ -42,6 +42,7 @@
 #define QEGLFSKMSDEVICE_H
 
 #include "private/qeglfsglobal_p.h"
+#include "qeglfskmseventreader.h"
 #include <QtKmsSupport/private/qkmsdevice_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -55,6 +56,11 @@ public:
                         bool isPrimary,
                         const QPoint &virtualPos,
                         const QList<QPlatformScreen *> &virtualSiblings) override;
+
+    QEglFSKmsEventReader *eventReader() { return &m_eventReader; }
+
+protected:
+    QEglFSKmsEventReader m_eventReader;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.cpp
new file mode 100644
index 0000000000..645a0ae2e9
--- /dev/null
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.cpp
@@ -0,0 +1,218 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qeglfskmseventreader.h"
+#include "qeglfskmsdevice.h"
+#include <QSocketNotifier>
+#include <QCoreApplication>
+#include <QLoggingCategory>
+
+QT_BEGIN_NAMESPACE
+
+Q_DECLARE_LOGGING_CATEGORY(qLcEglfsKmsDebug)
+
+static void pageFlipHandler(int fd, unsigned int sequence, unsigned int tv_sec, unsigned int tv_usec, void *user_data)
+{
+    Q_UNUSED(fd);
+    Q_UNUSED(sequence);
+    Q_UNUSED(tv_sec);
+    Q_UNUSED(tv_usec);
+
+    QEglFSKmsEventReaderThread *t = static_cast<QEglFSKmsEventReaderThread *>(QThread::currentThread());
+    t->eventHost()->handlePageFlipCompleted(user_data);
+}
+
+class RegisterWaitFlipEvent : public QEvent
+{
+public:
+    static const QEvent::Type TYPE = QEvent::Type(QEvent::User + 1);
+    RegisterWaitFlipEvent(void *key, QMutex *mutex, QWaitCondition *cond)
+        : QEvent(TYPE), key(key), mutex(mutex), cond(cond)
+    { }
+    void *key;
+    QMutex *mutex;
+    QWaitCondition *cond;
+};
+
+bool QEglFSKmsEventHost::event(QEvent *event)
+{
+    if (event->type() == RegisterWaitFlipEvent::TYPE) {
+        RegisterWaitFlipEvent *e = static_cast<RegisterWaitFlipEvent *>(event);
+        PendingFlipWait *p = &pendingFlipWaits[0];
+        PendingFlipWait *end = p + MAX_FLIPS;
+        while (p < end) {
+            if (!p->key) {
+                p->key = e->key;
+                p->mutex = e->mutex;
+                p->cond = e->cond;
+                updateStatus();
+                return true;
+            }
+            ++p;
+        }
+        qWarning("Cannot queue page flip wait (more than %d screens?)", MAX_FLIPS);
+        e->mutex->lock();
+        e->cond->wakeOne();
+        e->mutex->unlock();
+        return true;
+    }
+    return QObject::event(event);
+}
+
+void QEglFSKmsEventHost::updateStatus()
+{
+    void **begin = &completedFlips[0];
+    void **end = begin + MAX_FLIPS;
+
+    for (int i = 0; i < MAX_FLIPS; ++i) {
+        PendingFlipWait *w = pendingFlipWaits + i;
+        if (!w->key)
+            continue;
+
+        void **p = begin;
+        while (p < end) {
+            if (*p == w->key) {
+                *p = nullptr;
+                w->key = nullptr;
+                w->mutex->lock();
+                w->cond->wakeOne();
+                w->mutex->unlock();
+                return;
+            }
+            ++p;
+        }
+    }
+}
+
+void QEglFSKmsEventHost::handlePageFlipCompleted(void *key)
+{
+    void **begin = &completedFlips[0];
+    void **end = begin + MAX_FLIPS;
+    void **p = begin;
+    while (p < end) {
+        if (*p == key) {
+            updateStatus();
+            return;
+        }
+        ++p;
+    }
+    p = begin;
+    while (p < end) {
+        if (!*p) {
+            *p = key;
+            updateStatus();
+            return;
+        }
+        ++p;
+    }
+    qWarning("Cannot store page flip status (more than %d screens?)", MAX_FLIPS);
+}
+
+void QEglFSKmsEventReaderThread::run()
+{
+    qCDebug(qLcEglfsKmsDebug, "Event reader thread: entering event loop");
+
+    QSocketNotifier notifier(m_fd, QSocketNotifier::Read);
+    QObject::connect(&notifier, &QSocketNotifier::activated, &notifier, [this] {
+        drmEventContext drmEvent;
+        memset(&drmEvent, 0, sizeof(drmEvent));
+        drmEvent.version = 2;
+        drmEvent.vblank_handler = nullptr;
+        drmEvent.page_flip_handler = pageFlipHandler;
+        drmHandleEvent(m_fd, &drmEvent);
+    });
+
+    exec();
+
+    m_ev.moveToThread(thread()); // move back to the thread where m_ev was created
+
+    qCDebug(qLcEglfsKmsDebug, "Event reader thread: event loop stopped");
+}
+
+QEglFSKmsEventReader::~QEglFSKmsEventReader()
+{
+    destroy();
+}
+
+void QEglFSKmsEventReader::create(QEglFSKmsDevice *device)
+{
+    destroy();
+
+    if (!device)
+        return;
+
+    m_device = device;
+
+    qCDebug(qLcEglfsKmsDebug, "Initalizing event reader for device %p fd %d",
+            m_device, m_device->fd());
+
+    m_thread = new QEglFSKmsEventReaderThread(m_device->fd());
+    m_thread->start();
+
+    // Change thread affinity for the event host, so that postEvent()
+    // goes through the event reader thread's event loop for that object.
+    m_thread->eventHost()->moveToThread(m_thread);
+}
+
+void QEglFSKmsEventReader::destroy()
+{
+    if (!m_device)
+        return;
+
+    qCDebug(qLcEglfsKmsDebug, "Stopping event reader for device %p", m_device);
+
+    if (m_thread) {
+        m_thread->quit();
+        m_thread->wait();
+        delete m_thread;
+        m_thread = nullptr;
+    }
+
+    m_device = nullptr;
+}
+
+void QEglFSKmsEventReader::startWaitFlip(void *key, QMutex *mutex, QWaitCondition *cond)
+{
+    if (m_thread) {
+        QCoreApplication::postEvent(m_thread->eventHost(),
+                                    new RegisterWaitFlipEvent(key, mutex, cond));
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.h
new file mode 100644
index 0000000000..4aa285b0fe
--- /dev/null
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmseventreader.h
@@ -0,0 +1,99 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QEGLFSKKMSEVENTREADER_H
+#define QEGLFSKKMSEVENTREADER_H
+
+#include "private/qeglfsglobal_p.h"
+#include <QObject>
+#include <QThread>
+#include <QMutex>
+#include <QWaitCondition>
+
+QT_BEGIN_NAMESPACE
+
+class QEglFSKmsDevice;
+
+struct QEglFSKmsEventHost : public QObject
+{
+    struct PendingFlipWait {
+        void *key;
+        QMutex *mutex;
+        QWaitCondition *cond;
+    };
+
+    static const int MAX_FLIPS = 32;
+    void *completedFlips[MAX_FLIPS] = {};
+    QEglFSKmsEventHost::PendingFlipWait pendingFlipWaits[MAX_FLIPS] = {};
+
+    bool event(QEvent *event) override;
+    void updateStatus();
+    void handlePageFlipCompleted(void *key);
+};
+
+class QEglFSKmsEventReaderThread : public QThread
+{
+public:
+    QEglFSKmsEventReaderThread(int fd) : m_fd(fd) { }
+    void run() override;
+    QEglFSKmsEventHost *eventHost() { return &m_ev; }
+
+private:
+    int m_fd;
+    QEglFSKmsEventHost m_ev;
+};
+
+class Q_EGLFS_EXPORT QEglFSKmsEventReader
+{
+public:
+    ~QEglFSKmsEventReader();
+
+    void create(QEglFSKmsDevice *device);
+    void destroy();
+
+    void startWaitFlip(void *key, QMutex *mutex, QWaitCondition *cond);
+
+private:
+    QEglFSKmsDevice *m_device = nullptr;
+    QEglFSKmsEventReaderThread *m_thread = nullptr;
+};
+
+QT_END_NAMESPACE
+
+#endif // QEGLFSKKMSEVENTREADER_H
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
index a6aac61506..28b6b7df63 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsintegration.cpp
@@ -140,7 +140,7 @@ void *QEglFSKmsIntegration::nativeResourceForIntegration(const QByteArray &name)
 
 #if QT_CONFIG(drm_atomic)
     if (name == QByteArrayLiteral("dri_atomic_request") && m_device)
-        return (void *) (qintptr) m_device->atomic_request();
+        return (void *) (qintptr) m_device->threadLocalAtomicRequest();
 #endif
     return nullptr;
 }
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
index e5354d97bd..959f17eba3 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "qeglfskmsscreen.h"
+#include "qeglfskmsdevice.h"
 #include "qeglfsintegration_p.h"
 
 #include <QtCore/QLoggingCategory>
@@ -68,10 +69,11 @@ private:
     QEglFSKmsScreen *m_screen;
 };
 
-QEglFSKmsScreen::QEglFSKmsScreen(QKmsDevice *device, const QKmsOutput &output, bool headless)
+QEglFSKmsScreen::QEglFSKmsScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless)
     : QEglFSScreen(static_cast<QEglFSIntegration *>(QGuiApplicationPrivate::platformIntegration())->display())
     , m_device(device)
     , m_output(output)
+    , m_cursorOutOfRange(false)
     , m_powerState(PowerStateOn)
     , m_interruptHandler(new QEglFSKmsInterruptHandler(this))
     , m_headless(headless)
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.h
index 7f395aacb7..a5c8f5b4e8 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.h
@@ -51,12 +51,13 @@
 
 QT_BEGIN_NAMESPACE
 
+class QEglFSKmsDevice;
 class QEglFSKmsInterruptHandler;
 
 class Q_EGLFS_EXPORT QEglFSKmsScreen : public QEglFSScreen
 {
 public:
-    QEglFSKmsScreen(QKmsDevice *device, const QKmsOutput &output, bool headless = false);
+    QEglFSKmsScreen(QEglFSKmsDevice *device, const QKmsOutput &output, bool headless = false);
     ~QEglFSKmsScreen();
 
     void setVirtualPosition(const QPoint &pos);
@@ -87,7 +88,7 @@ public:
     int currentMode() const override;
     int preferredMode() const override;
 
-    QKmsDevice *device() const { return m_device; }
+    QEglFSKmsDevice *device() const { return m_device; }
 
     virtual void waitForFlip();
 
@@ -99,12 +100,16 @@ public:
     QPlatformScreen::PowerState powerState() const override;
     void setPowerState(QPlatformScreen::PowerState state) override;
 
+    bool isCursorOutOfRange() const { return m_cursorOutOfRange; }
+    void setCursorOutOfRange(bool b) { m_cursorOutOfRange = b; }
+
 protected:
-    QKmsDevice *m_device;
+    QEglFSKmsDevice *m_device;
 
     QKmsOutput m_output;
     QEdidParser m_edid;
     QPoint m_pos;
+    bool m_cursorOutOfRange;
 
     QList<QPlatformScreen *> m_siblings;
 
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.cpp
index 475d9d55dd..c255bc84b7 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.cpp
@@ -99,7 +99,7 @@ QEglFSKmsVsp2Screen::DmaBuffer *QEglFSKmsVsp2Screen::dmaBufferForGbmBuffer(gbm_b
     return fb.take();
 }
 
-QEglFSKmsVsp2Screen::QEglFSKmsVsp2Screen(QKmsDevice *device, const QKmsOutput &output)
+QEglFSKmsVsp2Screen::QEglFSKmsVsp2Screen(QEglFSKmsDevice *device, const QKmsOutput &output)
     : QEglFSKmsScreen(device, output)
     , m_blender(new Blender(this))
 {
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.h
index 7618510333..378786643d 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_vsp2/qeglfskmsvsp2screen.h
@@ -53,7 +53,7 @@ QT_BEGIN_NAMESPACE
 class QEglFSKmsVsp2Screen : public QEglFSKmsScreen
 {
 public:
-    QEglFSKmsVsp2Screen(QKmsDevice *device, const QKmsOutput &output);
+    QEglFSKmsVsp2Screen(QEglFSKmsDevice *device, const QKmsOutput &output);
 
     gbm_surface *createSurface();
     void resetSurface();
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.cpp
index 07b2de7c58..ce5a721906 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.cpp
@@ -75,7 +75,7 @@ void EventReader::run()
             if (client->format == 32
                 && client->type == atoms[Atoms::WM_PROTOCOLS]
                 && client->data.data32[0] == atoms[Atoms::WM_DELETE_WINDOW]) {
-                QWindow *window = m_integration->platformWindow() ? m_integration->platformWindow()->window() : 0;
+                QWindow *window = m_integration->platformWindow() ? m_integration->platformWindow()->window() : nullptr;
                 if (window)
                     QWindowSystemInterface::handleCloseEvent(window);
             }
@@ -106,7 +106,7 @@ void QEglFSX11Integration::sendConnectionEvent(xcb_atom_t a)
 
 void QEglFSX11Integration::platformInit()
 {
-    m_display = XOpenDisplay(0);
+    m_display = XOpenDisplay(nullptr);
     if (Q_UNLIKELY(!m_display))
         qFatal("Could not open display");
 
@@ -121,7 +121,7 @@ void QEglFSX11Integration::platformInit()
     xcb_create_window(m_connection, XCB_COPY_FROM_PARENT,
                       m_connectionEventListener, it.data->root,
                       0, 0, 1, 1, 0, XCB_WINDOW_CLASS_INPUT_ONLY,
-                      it.data->root_visual, 0, 0);
+                      it.data->root_visual, 0, nullptr);
 
     m_eventReader = new EventReader(this);
     m_eventReader->start();
@@ -135,11 +135,11 @@ void QEglFSX11Integration::platformDestroy()
 
     m_eventReader->wait();
     delete m_eventReader;
-    m_eventReader = 0;
+    m_eventReader = nullptr;
 
     XCloseDisplay(DISPLAY);
-    m_display = 0;
-    m_connection = 0;
+    m_display = nullptr;
+    m_connection = nullptr;
 }
 
 EGLNativeDisplayType QEglFSX11Integration::platformDisplay() const
@@ -175,7 +175,7 @@ EGLNativeWindowType QEglFSX11Integration::createNativeWindow(QPlatformWindow *pl
     xcb_create_window(m_connection, XCB_COPY_FROM_PARENT, m_window, it.data->root,
                       0, 0, size.width(), size.height(), 0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT, it.data->root_visual,
-                      0, 0);
+                      0, nullptr);
 
     xcb_intern_atom_cookie_t cookies[Atoms::N_ATOMS];
     static const char *atomNames[Atoms::N_ATOMS] = {
@@ -189,7 +189,7 @@ EGLNativeWindowType QEglFSX11Integration::createNativeWindow(QPlatformWindow *pl
 
     for (int i = 0; i < Atoms::N_ATOMS; ++i) {
         cookies[i] = xcb_intern_atom(m_connection, false, strlen(atomNames[i]), atomNames[i]);
-        xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(m_connection, cookies[i], 0);
+        xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(m_connection, cookies[i], nullptr);
         m_atoms[i] = reply->atom;
         free(reply);
     }
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.h b/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.h
index bf431caaac..ebcc19b682 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.h
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_x11/qeglfsx11integration.h
@@ -67,7 +67,7 @@ class EventReader;
 class QEglFSX11Integration : public QEglFSDeviceIntegration
 {
 public:
-    QEglFSX11Integration() : m_connection(0), m_window(0), m_eventReader(0) {}
+    QEglFSX11Integration() : m_connection(nullptr), m_window(0), m_eventReader(nullptr) {}
 
     void platformInit() override;
     void platformDestroy() override;
diff --git a/src/plugins/platforms/eglfs/qeglfsmain.cpp b/src/plugins/platforms/eglfs/qeglfsmain.cpp
index 4f77b7cd17..b41bbec27d 100644
--- a/src/plugins/platforms/eglfs/qeglfsmain.cpp
+++ b/src/plugins/platforms/eglfs/qeglfsmain.cpp
@@ -56,7 +56,7 @@ QPlatformIntegration* QEglFSIntegrationPlugin::create(const QString& system, con
     if (!system.compare(QLatin1String("eglfs"), Qt::CaseInsensitive))
         return new QEglFSIntegration;
 
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileengineassetslibrary.mm b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileengineassetslibrary.mm
index 54152aebf7..c5244a51ad 100644
--- a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileengineassetslibrary.mm
+++ b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileengineassetslibrary.mm
@@ -373,7 +373,7 @@ bool QIOSFileEngineAssetsLibrary::close()
 
 QAbstractFileEngine::FileFlags QIOSFileEngineAssetsLibrary::fileFlags(QAbstractFileEngine::FileFlags type) const
 {
-    QAbstractFileEngine::FileFlags flags = 0;
+    QAbstractFileEngine::FileFlags flags;
     const bool isDir = (m_assetUrl == QLatin1String("assets-library://"));
     const bool exists = isDir || m_assetUrl == g_iteratorCurrentUrl.localData() || loadAsset();
 
diff --git a/src/plugins/platforms/ios/qioscontext.mm b/src/plugins/platforms/ios/qioscontext.mm
index c9509ae599..cb1a8a96f8 100644
--- a/src/plugins/platforms/ios/qioscontext.mm
+++ b/src/plugins/platforms/ios/qioscontext.mm
@@ -332,11 +332,8 @@ bool QIOSContext::verifyGraphicsHardwareAvailability()
         );
     });
 
-    if (applicationBackgrounded) {
-        static const char warning[] = "OpenGL ES calls are not allowed while an application is backgrounded";
-        Q_ASSERT_X(!applicationBackgrounded, "QIOSContext", warning);
-        qCWarning(lcQpaGLContext, warning);
-    }
+    if (applicationBackgrounded)
+        qCWarning(lcQpaGLContext, "OpenGL ES calls are not allowed while an application is backgrounded");
 
     return !applicationBackgrounded;
 }
diff --git a/src/plugins/platforms/ios/qiostextresponder.mm b/src/plugins/platforms/ios/qiostextresponder.mm
index 396c769be8..a3350bda87 100644
--- a/src/plugins/platforms/ios/qiostextresponder.mm
+++ b/src/plugins/platforms/ios/qiostextresponder.mm
@@ -745,7 +745,11 @@
 - (UITextPosition *)positionFromPosition:(UITextPosition *)position offset:(NSInteger)offset
 {
     int p = static_cast<QUITextPosition *>(position).index;
-    return [QUITextPosition positionWithIndex:p + offset];
+    const int posWithIndex = p + offset;
+    const int textLength = [self currentImeState:Qt::ImSurroundingText].toString().length();
+    if (posWithIndex < 0 || posWithIndex > textLength)
+        return nil;
+    return [QUITextPosition positionWithIndex:posWithIndex];
 }
 
 - (UITextPosition *)positionFromPosition:(UITextPosition *)position inDirection:(UITextLayoutDirection)direction offset:(NSInteger)offset
@@ -781,12 +785,16 @@
 
 - (UIView *)textInputView
 {
+    auto *focusWindow = QGuiApplication::focusWindow();
+    if (!focusWindow)
+        return nil;
+
     // iOS expects rects we return from other UITextInput methods
     // to be relative to the view this method returns.
     // Since QInputMethod returns rects relative to the top level
     // QWindow, that is also the view we need to return.
-    Q_ASSERT(qApp->focusWindow()->handle());
-    QPlatformWindow *topLevel = qApp->focusWindow()->handle();
+    Q_ASSERT(focusWindow->handle());
+    QPlatformWindow *topLevel = focusWindow->handle();
     while (QPlatformWindow *p = topLevel->parent())
         topLevel = p;
     return reinterpret_cast<UIView *>(topLevel->winId());
diff --git a/src/plugins/platforms/ios/qioswindow.mm b/src/plugins/platforms/ios/qioswindow.mm
index cdec57de71..1b6a802ca2 100644
--- a/src/plugins/platforms/ios/qioswindow.mm
+++ b/src/plugins/platforms/ios/qioswindow.mm
@@ -51,6 +51,9 @@
 #include <qpa/qplatformintegration.h>
 
 #import <QuartzCore/CAEAGLLayer.h>
+#ifdef Q_OS_IOS
+#import <QuartzCore/CAMetalLayer.h>
+#endif
 
 #include <QtDebug>
 
@@ -58,9 +61,15 @@ QT_BEGIN_NAMESPACE
 
 QIOSWindow::QIOSWindow(QWindow *window)
     : QPlatformWindow(window)
-    , m_view([[QUIView alloc] initWithQIOSWindow:this])
     , m_windowLevel(0)
 {
+#ifdef Q_OS_IOS
+    if (window->surfaceType() == QSurface::MetalSurface)
+        m_view = [[QUIMetalView alloc] initWithQIOSWindow:this];
+    else
+#endif
+        m_view = [[QUIView alloc] initWithQIOSWindow:this];
+
     connect(qGuiApp, &QGuiApplication::applicationStateChanged, this, &QIOSWindow::applicationStateChanged);
 
     setParent(QPlatformWindow::parent());
diff --git a/src/plugins/platforms/ios/quiview.h b/src/plugins/platforms/ios/quiview.h
index e1d5d5af0c..1ab9481dd6 100644
--- a/src/plugins/platforms/ios/quiview.h
+++ b/src/plugins/platforms/ios/quiview.h
@@ -70,3 +70,7 @@ QT_END_NAMESPACE
 @property (nonatomic, readonly) UIEdgeInsets qt_safeAreaInsets;
 @end
 
+#ifdef Q_OS_IOS
+@interface QUIMetalView : QUIView
+@end
+#endif
diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index e64c05d099..59eae07388 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -100,13 +100,15 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 - (instancetype)initWithFrame:(CGRect)frame
 {
     if ((self = [super initWithFrame:frame])) {
-        // Set up EAGL layer
-        CAEAGLLayer *eaglLayer = static_cast<CAEAGLLayer *>(self.layer);
-        eaglLayer.opaque = TRUE;
-        eaglLayer.drawableProperties = @{
-            kEAGLDrawablePropertyRetainedBacking: @(YES),
-            kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8
-        };
+        if ([self.layer isKindOfClass:[CAEAGLLayer class]]) {
+            // Set up EAGL layer
+            CAEAGLLayer *eaglLayer = static_cast<CAEAGLLayer *>(self.layer);
+            eaglLayer.opaque = TRUE;
+            eaglLayer.drawableProperties = @{
+                kEAGLDrawablePropertyRetainedBacking: @(YES),
+                kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8
+            };
+        }
 
         if (isQtApplication())
             self.hidden = YES;
@@ -628,6 +630,14 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 #endif
 }
 
+- (void)addInteraction:(id<UIInteraction>)interaction
+{
+    if ([NSStringFromClass(interaction.class) isEqualToString:@"UITextInteraction"])
+        return;
+
+    [super addInteraction:interaction];
+}
+
 @end
 
 @implementation UIView (QtHelpers)
@@ -667,6 +677,25 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
 @end
 
+#ifdef Q_OS_IOS
+@implementation QUIMetalView
+
++ (Class)layerClass
+{
+#ifdef TARGET_IPHONE_SIMULATOR
+    if (@available(ios 13.0, *))
+#endif
+
+    return [CAMetalLayer class];
+
+#ifdef TARGET_IPHONE_SIMULATOR
+    return nil;
+#endif
+}
+
+@end
+#endif
+
 #ifndef QT_NO_ACCESSIBILITY
 // Include category as an alternative to using -ObjC (Apple QA1490)
 #include "quiview_accessibility.mm"
diff --git a/src/plugins/platforms/offscreen/main.cpp b/src/plugins/platforms/offscreen/main.cpp
index 207db60f3a..f364d9f004 100644
--- a/src/plugins/platforms/offscreen/main.cpp
+++ b/src/plugins/platforms/offscreen/main.cpp
@@ -57,7 +57,7 @@ QPlatformIntegration *QOffscreenIntegrationPlugin::create(const QString& system,
     if (!system.compare(QLatin1String("offscreen"), Qt::CaseInsensitive))
         return QOffscreenIntegration::createOffscreenIntegration();
 
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/offscreen/qoffscreencommon.cpp b/src/plugins/platforms/offscreen/qoffscreencommon.cpp
index eae25012c1..de75a3e012 100644
--- a/src/plugins/platforms/offscreen/qoffscreencommon.cpp
+++ b/src/plugins/platforms/offscreen/qoffscreencommon.cpp
@@ -48,7 +48,7 @@
 
 QT_BEGIN_NAMESPACE
 
-QPlatformWindow *QOffscreenScreen::windowContainingCursor = 0;
+QPlatformWindow *QOffscreenScreen::windowContainingCursor = nullptr;
 
 class QOffscreenCursor : public QPlatformCursor
 {
@@ -60,7 +60,7 @@ public:
     {
         m_pos = pos;
         const QWindowList wl = QGuiApplication::topLevelWindows();
-        QWindow *containing = 0;
+        QWindow *containing = nullptr;
         for (QWindow *w : wl) {
             if (w->type() != Qt::Desktop && w->isExposed() && w->geometry().contains(pos)) {
                 containing = w;
@@ -72,7 +72,7 @@ public:
         if (containing)
             local -= containing->position();
 
-        QWindow *previous = QOffscreenScreen::windowContainingCursor ? QOffscreenScreen::windowContainingCursor->window() : 0;
+        QWindow *previous = QOffscreenScreen::windowContainingCursor ? QOffscreenScreen::windowContainingCursor->window() : nullptr;
 
         if (containing != previous)
             QWindowSystemInterface::handleEnterLeaveEvent(containing, previous, local, pos);
@@ -80,7 +80,7 @@ public:
         QWindowSystemInterface::handleMouseEvent(containing, local, pos, QGuiApplication::mouseButtons(), Qt::NoButton,
                                                  QEvent::MouseMove, QGuiApplication::keyboardModifiers(), Qt::MouseEventSynthesizedByQt);
 
-        QOffscreenScreen::windowContainingCursor = containing ? containing->handle() : 0;
+        QOffscreenScreen::windowContainingCursor = containing ? containing->handle() : nullptr;
     }
 #ifndef QT_NO_CURSOR
     void changeCursor(QCursor *windowCursor, QWindow *window) override
@@ -106,7 +106,7 @@ QPixmap QOffscreenScreen::grabWindow(WId id, int x, int y, int width, int height
     QOffscreenWindow *window = QOffscreenWindow::windowForWinId(id);
     if (!window || window->window()->type() == Qt::Desktop) {
         const QWindowList wl = QGuiApplication::topLevelWindows();
-        QWindow *containing = 0;
+        QWindow *containing = nullptr;
         for (QWindow *w : wl) {
             if (w->type() != Qt::Desktop && w->isExposed() && w->geometry().contains(rect)) {
                 containing = w;
diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration.cpp b/src/plugins/platforms/offscreen/qoffscreenintegration.cpp
index 869e9228cd..3a4494fc2e 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration.cpp
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration.cpp
@@ -79,7 +79,7 @@ template <typename BaseEventDispatcher>
 class QOffscreenEventDispatcher : public BaseEventDispatcher
 {
 public:
-    explicit QOffscreenEventDispatcher(QObject *parent = 0)
+    explicit QOffscreenEventDispatcher(QObject *parent = nullptr)
         : BaseEventDispatcher(parent)
     {
     }
diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
index 92fc8aa57a..84991d751f 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
@@ -206,7 +206,7 @@ QOffscreenX11GLXContext::QOffscreenX11GLXContext(QOffscreenX11Info *x11, QOpenGL
     if (d->format.renderableType() != QSurfaceFormat::OpenGL)
         return;
 
-    d->shareContext = 0;
+    d->shareContext = nullptr;
     if (context->shareHandle())
         d->shareContext = static_cast<QOffscreenX11GLXContext *>(context->shareHandle())->d->context;
 
@@ -216,9 +216,9 @@ QOffscreenX11GLXContext::QOffscreenX11GLXContext(QOffscreenX11Info *x11, QOpenGL
     if (config) {
         d->context = glXCreateNewContext(x11->display(), config, GLX_RGBA_TYPE, d->shareContext, true);
         if (!d->context && d->shareContext) {
-            d->shareContext = 0;
+            d->shareContext = nullptr;
             // re-try without a shared glx context
-            d->context = glXCreateNewContext(x11->display(), config, GLX_RGBA_TYPE, 0, true);
+            d->context = glXCreateNewContext(x11->display(), config, GLX_RGBA_TYPE, nullptr, true);
         }
 
         // Get the basic surface format details
@@ -234,8 +234,8 @@ QOffscreenX11GLXContext::QOffscreenX11GLXContext(QOffscreenX11Info *x11, QOpenGL
         d->context = glXCreateContext(x11->display(), visualInfo, d->shareContext, true);
         if (!d->context && d->shareContext) {
             // re-try without a shared glx context
-            d->shareContext = 0;
-            d->context = glXCreateContext(x11->display(), visualInfo, 0, true);
+            d->shareContext = nullptr;
+            d->context = glXCreateContext(x11->display(), visualInfo, nullptr, true);
         }
 
         d->window = createDummyWindow(x11, visualInfo);
@@ -269,7 +269,7 @@ bool QOffscreenX11GLXContext::makeCurrent(QPlatformSurface *surface)
 
 void QOffscreenX11GLXContext::doneCurrent()
 {
-    glXMakeCurrent(d->x11->display(), 0, 0);
+    glXMakeCurrent(d->x11->display(), 0, nullptr);
 }
 
 void QOffscreenX11GLXContext::swapBuffers(QPlatformSurface *)
diff --git a/src/plugins/platforms/offscreen/qoffscreenwindow.cpp b/src/plugins/platforms/offscreen/qoffscreenwindow.cpp
index 832e94034d..53880c877e 100644
--- a/src/plugins/platforms/offscreen/qoffscreenwindow.cpp
+++ b/src/plugins/platforms/offscreen/qoffscreenwindow.cpp
@@ -69,7 +69,7 @@ QOffscreenWindow::QOffscreenWindow(QWindow *window)
 QOffscreenWindow::~QOffscreenWindow()
 {
     if (QOffscreenScreen::windowContainingCursor == this)
-        QOffscreenScreen::windowContainingCursor = 0;
+        QOffscreenScreen::windowContainingCursor = nullptr;
     m_windowForWinIdHash.remove(m_winId);
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxglcontext.cpp b/src/plugins/platforms/qnx/qqnxglcontext.cpp
index 1d030ba1aa..69391c4fec 100644
--- a/src/plugins/platforms/qnx/qqnxglcontext.cpp
+++ b/src/plugins/platforms/qnx/qqnxglcontext.cpp
@@ -58,8 +58,6 @@
 
 QT_BEGIN_NAMESPACE
 
-EGLDisplay QQnxGLContext::ms_eglDisplay = EGL_NO_DISPLAY;
-
 static QEGLPlatformContext::Flags makeFlags()
 {
     QEGLPlatformContext::Flags result = 0;
@@ -71,7 +69,8 @@ static QEGLPlatformContext::Flags makeFlags()
 }
 
 QQnxGLContext::QQnxGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share)
-    : QEGLPlatformContext(format, share, ms_eglDisplay, 0, QVariant(), makeFlags())
+    : QEGLPlatformContext(format, share, QQnxIntegration::instance()->eglDisplay(), 0, QVariant(),
+                          makeFlags())
 {
 }
 
@@ -79,28 +78,6 @@ QQnxGLContext::~QQnxGLContext()
 {
 }
 
-void QQnxGLContext::initializeContext()
-{
-    qGLContextDebug();
-
-    // Initialize connection to EGL
-    ms_eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-    if (Q_UNLIKELY(ms_eglDisplay == EGL_NO_DISPLAY))
-        qFatal("QQnxGLContext: failed to obtain EGL display: %x", eglGetError());
-
-    EGLBoolean eglResult = eglInitialize(ms_eglDisplay, 0, 0);
-    if (Q_UNLIKELY(eglResult != EGL_TRUE))
-        qFatal("QQnxGLContext: failed to initialize EGL display, err=%d", eglGetError());
-}
-
-void QQnxGLContext::shutdownContext()
-{
-    qGLContextDebug();
-
-    // Close connection to EGL
-    eglTerminate(ms_eglDisplay);
-}
-
 EGLSurface QQnxGLContext::eglSurfaceForPlatformSurface(QPlatformSurface *surface)
 {
     QQnxEglWindow *window = static_cast<QQnxEglWindow *>(surface);
diff --git a/src/plugins/platforms/qnx/qqnxglcontext.h b/src/plugins/platforms/qnx/qqnxglcontext.h
index 19179a80e2..5d807ee9e4 100644
--- a/src/plugins/platforms/qnx/qqnxglcontext.h
+++ b/src/plugins/platforms/qnx/qqnxglcontext.h
@@ -58,19 +58,12 @@ public:
     QQnxGLContext(const QSurfaceFormat &format, QPlatformOpenGLContext *share);
     virtual ~QQnxGLContext();
 
-    static void initializeContext();
-    static void shutdownContext();
-
     bool makeCurrent(QPlatformSurface *surface) override;
     void swapBuffers(QPlatformSurface *surface) override;
     void doneCurrent() override;
 
 protected:
     EGLSurface eglSurfaceForPlatformSurface(QPlatformSurface *surface) override;
-
-private:
-    //Can be static because different displays returne the same handle
-    static EGLDisplay ms_eglDisplay;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/qnx/qqnxintegration.cpp b/src/plugins/platforms/qnx/qqnxintegration.cpp
index f479e94988..84baa6ec44 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.cpp
+++ b/src/plugins/platforms/qnx/qqnxintegration.cpp
@@ -170,6 +170,9 @@ QQnxIntegration::QQnxIntegration(const QStringList &paramList)
 #if QT_CONFIG(draganddrop)
     , m_drag(new QSimpleDrag())
 #endif
+#if QT_CONFIG(opengl)
+    , m_eglDisplay(EGL_NO_DISPLAY)
+#endif
 {
     ms_instance = this;
     m_options = parseOptions(paramList);
@@ -195,9 +198,8 @@ QQnxIntegration::QQnxIntegration(const QStringList &paramList)
     QMetaObject::invokeMethod(m_navigatorEventNotifier, "start", Qt::QueuedConnection);
 #endif
 
-#if !defined(QT_NO_OPENGL)
-    // Initialize global OpenGL resources
-    QQnxGLContext::initializeContext();
+#if QT_CONFIG(opengl)
+    createEglDisplay();
 #endif
 
     // Create/start event thread
@@ -284,9 +286,8 @@ QQnxIntegration::~QQnxIntegration()
     // Close connection to QNX composition manager
     screen_destroy_context(m_screenContext);
 
-#if !defined(QT_NO_OPENGL)
-    // Cleanup global OpenGL resources
-    QQnxGLContext::shutdownContext();
+#if QT_CONFIG(opengl)
+    destroyEglDisplay();
 #endif
 
 #if QT_CONFIG(qqnx_pps)
@@ -741,4 +742,28 @@ bool QQnxIntegration::supportsNavigatorEvents() const
     return m_navigator != 0;
 }
 
+#if QT_CONFIG(opengl)
+void QQnxIntegration::createEglDisplay()
+{
+    qIntegrationDebug();
+
+    // Initialize connection to EGL
+    m_eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+    if (Q_UNLIKELY(m_eglDisplay == EGL_NO_DISPLAY))
+        qFatal("QQnxiIntegration: failed to obtain EGL display: %x", eglGetError());
+
+    EGLBoolean eglResult = eglInitialize(m_eglDisplay, 0, 0);
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
+        qFatal("QQnxIntegration: failed to initialize EGL display, err=%d", eglGetError());
+}
+
+void QQnxIntegration::destroyEglDisplay()
+{
+    qIntegrationDebug();
+
+    // Close connection to EGL
+    eglTerminate(m_eglDisplay);
+}
+#endif
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/qnx/qqnxintegration.h b/src/plugins/platforms/qnx/qqnxintegration.h
index 0bf37880d1..2596af3c45 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.h
+++ b/src/plugins/platforms/qnx/qqnxintegration.h
@@ -46,6 +46,10 @@
 
 #include <screen/screen.h>
 
+#if QT_CONFIG(opengl)
+#include <EGL/egl.h>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 class QQnxScreenEventThread;
@@ -96,7 +100,8 @@ public:
     QPlatformWindow *createPlatformWindow(QWindow *window) const override;
     QPlatformBackingStore *createPlatformBackingStore(QWindow *window) const override;
 
-#if !defined(QT_NO_OPENGL)
+#if QT_CONFIG(opengl)
+    EGLDisplay eglDisplay() const { return m_eglDisplay; }
     QPlatformOpenGLContext *createPlatformOpenGLContext(QOpenGLContext *context) const override;
 #endif
 
@@ -175,6 +180,12 @@ private:
 
     Options m_options;
 
+#if QT_CONFIG(opengl)
+    EGLDisplay m_eglDisplay;
+    void createEglDisplay();
+    void destroyEglDisplay();
+#endif
+
     static QQnxIntegration *ms_instance;
 
     friend class QQnxWindow;
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
index a9b5860187..e3a6aea99f 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
@@ -257,7 +257,7 @@ void QQnxScreenEventHandler::injectKeyboardEvent(int flags, int sym, int modifie
                                                capKeyString(cap, modifiers, key);
 
     QWindowSystemInterface::handleExtendedKeyEvent(QGuiApplication::focusWindow(), type, key, qtMod,
-            scan, virtualKey, modifiers, keyStr);
+            scan, virtualKey, modifiers, keyStr, flags & KEY_REPEAT);
     qScreenEventDebug() << "Qt key t=" << type << ", k=" << key << ", s=" << keyStr;
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp b/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
index 1b5f3b4954..491c314488 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
@@ -60,6 +60,18 @@ static const int c_screenCode = _PULSE_CODE_MINAVAIL + 0;
 static const int c_armCode = _PULSE_CODE_MINAVAIL + 1;
 static const int c_quitCode = _PULSE_CODE_MINAVAIL + 2;
 
+#if !defined(screen_register_event)
+int screen_register_event(screen_context_t, struct sigevent *event)
+{
+    return MsgRegisterEvent(event, -1);
+}
+
+int screen_unregister_event(struct sigevent *event)
+{
+    return MsgUnregisterEvent(event);
+}
+#endif
+
 QQnxScreenEventThread::QQnxScreenEventThread(screen_context_t context)
     : QThread()
     , m_screenContext(context)
@@ -75,10 +87,14 @@ QQnxScreenEventThread::QQnxScreenEventThread(screen_context_t context)
         qFatal("QQnxScreenEventThread: Can't continue without a channel connection");
     }
 
-    struct sigevent screenEvent;
-    SIGEV_PULSE_INIT(&screenEvent, m_connectionId, SIGEV_PULSE_PRIO_INHERIT, c_screenCode, 0);
+    SIGEV_PULSE_INIT(&m_screenEvent, m_connectionId, SIGEV_PULSE_PRIO_INHERIT, c_screenCode, 0);
+    if (screen_register_event(m_screenContext, &m_screenEvent) == -1) {
+        ConnectDetach(m_connectionId);
+        ChannelDestroy(m_channelId);
+        qFatal("QQnxScreenEventThread: Can't continue without a registered event");
+    }
 
-    screen_notify(m_screenContext, SCREEN_NOTIFY_EVENT, nullptr, &screenEvent);
+    screen_notify(m_screenContext, SCREEN_NOTIFY_EVENT, nullptr, &m_screenEvent);
 }
 
 QQnxScreenEventThread::~QQnxScreenEventThread()
@@ -86,6 +102,8 @@ QQnxScreenEventThread::~QQnxScreenEventThread()
     // block until thread terminates
     shutdown();
 
+    screen_notify(m_screenContext, SCREEN_NOTIFY_EVENT, nullptr, nullptr);
+    screen_unregister_event(&m_screenEvent);
     ConnectDetach(m_connectionId);
     ChannelDestroy(m_channelId);
 }
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventthread.h b/src/plugins/platforms/qnx/qqnxscreeneventthread.h
index 3c8d197545..e5b762369c 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventthread.h
+++ b/src/plugins/platforms/qnx/qqnxscreeneventthread.h
@@ -45,6 +45,7 @@
 #include <QtCore/QMutex>
 
 #include <screen/screen.h>
+#include <sys/siginfo.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -73,6 +74,7 @@ private:
 
     int m_channelId;
     int m_connectionId;
+    struct sigevent m_screenEvent;
     screen_context_t m_screenContext;
     bool m_emitNeededOnNextScreenPulse = true;
     int m_screenPulsesSinceLastArmPulse = 0;
diff --git a/src/plugins/platforms/vnc/main.cpp b/src/plugins/platforms/vnc/main.cpp
index 3ec0f0b78d..ac7e18e03f 100644
--- a/src/plugins/platforms/vnc/main.cpp
+++ b/src/plugins/platforms/vnc/main.cpp
@@ -56,7 +56,7 @@ QPlatformIntegration* QVncIntegrationPlugin::create(const QString& system, const
     if (!system.compare(QLatin1String("vnc"), Qt::CaseInsensitive))
         return new QVncIntegration(paramList);
 
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/vnc/qvnc.cpp b/src/plugins/platforms/vnc/qvnc.cpp
index 32114c6443..8390fa19cd 100644
--- a/src/plugins/platforms/vnc/qvnc.cpp
+++ b/src/plugins/platforms/vnc/qvnc.cpp
@@ -537,7 +537,7 @@ QVncClientCursor::QVncClientCursor()
 {
     QWindow *w = QGuiApplication::focusWindow();
     QCursor c = w ? w->cursor() : QCursor(Qt::ArrowCursor);
-    changeCursor(&c, 0);
+    changeCursor(&c, nullptr);
 }
 
 QVncClientCursor::~QVncClientCursor()
@@ -595,7 +595,7 @@ void QVncClientCursor::changeCursor(QCursor *widgetCursor, QWindow *window)
         cursor = widgetCursor->pixmap().toImage();
     } else {
         // system cursor
-        QPlatformCursorImage platformImage(0, 0, 0, 0, 0, 0);
+        QPlatformCursorImage platformImage(nullptr, nullptr, 0, 0, 0, 0);
         platformImage.set(shape);
         cursor = *platformImage.image();
         hotspot = platformImage.hotspot();
diff --git a/src/plugins/platforms/vnc/qvncclient.cpp b/src/plugins/platforms/vnc/qvncclient.cpp
index 3a373a5e4b..c5caddc58d 100644
--- a/src/plugins/platforms/vnc/qvncclient.cpp
+++ b/src/plugins/platforms/vnc/qvncclient.cpp
@@ -65,7 +65,6 @@ QVncClient::QVncClient(QTcpSocket *clientSocket, QVncServer *server)
     , m_cutTextPending(0)
     , m_supportHextile(false)
     , m_wantUpdate(false)
-    , m_keymod(0)
     , m_dirtyCursor(false)
     , m_updatePending(false)
     , m_protocolVersion(V3_3)
@@ -618,7 +617,7 @@ void QVncClient::keyEvent()
             m_keymod = ev.down ? m_keymod | Qt::AltModifier :
                                  m_keymod & ~Qt::AltModifier;
         if (ev.unicode || ev.keycode)
-            QWindowSystemInterface::handleKeyEvent(0, ev.down ? QEvent::KeyPress : QEvent::KeyRelease, ev.keycode, m_keymod, QString(ev.unicode));
+            QWindowSystemInterface::handleKeyEvent(nullptr, ev.down ? QEvent::KeyPress : QEvent::KeyRelease, ev.keycode, m_keymod, QString(ev.unicode));
         m_handleMsg = false;
     }
 }
diff --git a/src/plugins/platforms/vnc/qvncscreen.cpp b/src/plugins/platforms/vnc/qvncscreen.cpp
index 2eca18fb4d..5dc3919ff5 100644
--- a/src/plugins/platforms/vnc/qvncscreen.cpp
+++ b/src/plugins/platforms/vnc/qvncscreen.cpp
@@ -101,7 +101,7 @@ bool QVncScreen::initialize()
     default:
         qWarning("QVNCScreen::initDevice: No support for screen depth %d",
                  depth());
-        dirty = 0;
+        dirty = nullptr;
         return false;
     }
 
diff --git a/src/plugins/platforms/wasm/qwasmclipboard.cpp b/src/plugins/platforms/wasm/qwasmclipboard.cpp
index d4a1e4dd50..fb46f1534f 100644
--- a/src/plugins/platforms/wasm/qwasmclipboard.cpp
+++ b/src/plugins/platforms/wasm/qwasmclipboard.cpp
@@ -198,7 +198,9 @@ void QWasmClipboard::installEventHandlers(const QString &canvasId)
         return;
 
     // Fallback path for browsers which do not support direct clipboard access
-    val canvas = val::global(canvasId.toUtf8().constData());
+    val document = val::global("document");
+    val canvas = document.call<val>("getElementById", val(canvasId.toUtf8().constData()));
+
     canvas.call<void>("addEventListener", std::string("cut"),
                       val::module_property("qtClipboardCutTo"));
     canvas.call<void>("addEventListener", std::string("copy"),
diff --git a/src/plugins/platforms/wasm/qwasmcompositor.cpp b/src/plugins/platforms/wasm/qwasmcompositor.cpp
index a810880c43..e9c4559971 100644
--- a/src/plugins/platforms/wasm/qwasmcompositor.cpp
+++ b/src/plugins/platforms/wasm/qwasmcompositor.cpp
@@ -694,7 +694,7 @@ void QWasmCompositor::frame()
 
     if (m_context.isNull()) {
         m_context.reset(new QOpenGLContext());
-        //mContext->setFormat(mScreen->format());
+        m_context->setFormat(someWindow->window()->requestedFormat());
         m_context->setScreen(screen()->screen());
         m_context->create();
     }
diff --git a/src/plugins/platforms/wasm/qwasmcursor.cpp b/src/plugins/platforms/wasm/qwasmcursor.cpp
index 2b3f37300d..c04fa6441a 100644
--- a/src/plugins/platforms/wasm/qwasmcursor.cpp
+++ b/src/plugins/platforms/wasm/qwasmcursor.cpp
@@ -36,6 +36,8 @@
 #include <emscripten/emscripten.h>
 #include <emscripten/bind.h>
 
+using namespace emscripten;
+
 void QWasmCursor::changeCursor(QCursor *windowCursor, QWindow *window)
 {
     if (!windowCursor || !window)
@@ -54,8 +56,10 @@ void QWasmCursor::changeCursor(QCursor *windowCursor, QWindow *window)
         htmlCursorName = "auto";
 
     // Set cursor on the canvas
-    QString canvasId = QWasmScreen::get(screen)->canvasId();
-    emscripten::val canvasStyle = emscripten::val::global(canvasId.toUtf8().constData())["style"];
+    QByteArray canvasId = QWasmScreen::get(screen)->canvasId().toUtf8();
+    val document = val::global("document");
+    val canvas = document.call<val>("getElementById", val(canvasId.constData()));
+    val canvasStyle = canvas["style"];
     canvasStyle.set("cursor", emscripten::val(htmlCursorName.constData()));
 }
 
@@ -68,6 +72,7 @@ QByteArray QWasmCursor::cursorShapeToHtml(Qt::CursorShape shape)
         cursorName = "default";
         break;
     case Qt::UpArrowCursor:
+        cursorName = "n-resize";
         break;
     case Qt::CrossCursor:
         cursorName = "crosshair";
@@ -91,7 +96,8 @@ QByteArray QWasmCursor::cursorShapeToHtml(Qt::CursorShape shape)
         cursorName = "nwse-resize";
         break;
     case Qt::SizeAllCursor:
-        break; // no equivalent?
+        cursorName = "move";
+        break;
     case Qt::BlankCursor:
         cursorName = "none";
         break;
@@ -111,18 +117,23 @@ QByteArray QWasmCursor::cursorShapeToHtml(Qt::CursorShape shape)
         cursorName = "help";
         break;
     case Qt::BusyCursor:
-        cursorName = "wait";
+        cursorName = "progress";
         break;
     case Qt::OpenHandCursor:
-        break; // no equivalent?
+        cursorName = "grab";
+        break;
     case Qt::ClosedHandCursor:
-        break; // no equivalent?
+        cursorName = "grabbing";
+        break;
     case Qt::DragCopyCursor:
-        break; // no equivalent?
+        cursorName = "copy";
+        break;
     case Qt::DragMoveCursor:
-        break; // no equivalent?
+        cursorName = "default";
+        break;
     case Qt::DragLinkCursor:
-        break; // no equivalent?
+        cursorName = "alias";
+        break;
     default:
         break;
     }
diff --git a/src/plugins/platforms/wasm/qwasmeventdispatcher.cpp b/src/plugins/platforms/wasm/qwasmeventdispatcher.cpp
index 41355d72ae..d89cd78b28 100644
--- a/src/plugins/platforms/wasm/qwasmeventdispatcher.cpp
+++ b/src/plugins/platforms/wasm/qwasmeventdispatcher.cpp
@@ -33,6 +33,14 @@
 
 #include <emscripten.h>
 
+#if (__EMSCRIPTEN_major__ > 1 || __EMSCRIPTEN_minor__ > 38 || __EMSCRIPTEN_minor__ == 38 && __EMSCRIPTEN_tiny__ >= 22)
+#  define EMSCRIPTEN_HAS_ASYNC_RUN_IN_MAIN_RUNTIME_THREAD
+#endif
+
+#ifdef EMSCRIPTEN_HAS_ASYNC_RUN_IN_MAIN_RUNTIME_THREAD
+#include <emscripten/threading.h>
+#endif
+
 class QWasmEventDispatcherPrivate : public QEventDispatcherUNIXPrivate
 {
 
@@ -179,3 +187,18 @@ void QWasmEventDispatcher::doMaintainTimers()
     emscripten_async_call(callback, this, toWaitDuration);
     m_currentTargetTime = newTargetTime;
 }
+
+void QWasmEventDispatcher::wakeUp()
+{
+#ifdef EMSCRIPTEN_HAS_ASYNC_RUN_IN_MAIN_RUNTIME_THREAD
+    if (!emscripten_is_main_runtime_thread())
+        emscripten_async_run_in_main_runtime_thread_(EM_FUNC_SIG_VI, (void*)(&QWasmEventDispatcher::mainThreadWakeUp), this);
+#endif
+    QEventDispatcherUNIX::wakeUp();
+}
+
+void QWasmEventDispatcher::mainThreadWakeUp(void *eventDispatcher)
+{
+    emscripten_resume_main_loop(); // Service possible requestUpdate Calls
+    static_cast<QWasmEventDispatcher *>(eventDispatcher)->processEvents(QEventLoop::AllEvents);
+}
diff --git a/src/plugins/platforms/wasm/qwasmeventdispatcher.h b/src/plugins/platforms/wasm/qwasmeventdispatcher.h
index 5300b3de73..f72d92ce07 100644
--- a/src/plugins/platforms/wasm/qwasmeventdispatcher.h
+++ b/src/plugins/platforms/wasm/qwasmeventdispatcher.h
@@ -51,6 +51,8 @@ public:
 protected:
     bool processEvents(QEventLoop::ProcessEventsFlags flags) override;
     void doMaintainTimers();
+    void wakeUp() override;
+    static void mainThreadWakeUp(void *eventDispatcher);
 
 private:
     bool m_hasMainLoop = false;
diff --git a/src/plugins/platforms/wasm/qwasmeventtranslator.cpp b/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
index ad94ba9c77..d6ea147ccf 100644
--- a/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
+++ b/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
@@ -47,9 +47,10 @@
 
 #include <iostream>
 
-QT_BEGIN_NAMESPACE
 using namespace emscripten;
 
+QT_BEGIN_NAMESPACE
+
 typedef struct emkb2qt {
     const char *em;
     unsigned int qt;
@@ -353,10 +354,11 @@ void QWasmEventTranslator::initEventHandlers()
         g_useNaturalScrolling = false; // make this !default on macOS
 
         if (emscripten::val::global("window")["safari"].isUndefined()) {
-
-            emscripten::val::global(canvasId).call<void>("addEventListener",
-                                                         std::string("wheel"),
-                                                         val::module_property("qtMouseWheelEvent"));
+            val document = val::global("document");
+            val canvas = document.call<val>("getElementById", val(canvasId));
+            canvas.call<void>("addEventListener",
+                              std::string("wheel"),
+                              val::module_property("qtMouseWheelEvent"));
         }
     }
 
@@ -544,7 +546,7 @@ void resizeWindow(QWindow *window, QWasmWindow::ResizeMode mode,
 
 void QWasmEventTranslator::processMouse(int eventType, const EmscriptenMouseEvent *mouseEvent)
 {
-    auto timestamp = mouseEvent->timestamp;
+    auto timestamp = emscripten_date_now();
     QPoint targetPoint(mouseEvent->targetX, mouseEvent->targetY);
     QPoint globalPoint = screen()->geometry().topLeft() + targetPoint;
 
@@ -670,7 +672,7 @@ int QWasmEventTranslator::wheel_cb(int eventType, const EmscriptenWheelEvent *wh
 
     QWasmEventTranslator *translator = (QWasmEventTranslator*)userData;
     Qt::KeyboardModifiers modifiers = translator->translateMouseEventModifier(&mouseEvent);
-    auto timestamp = mouseEvent.timestamp;
+    auto timestamp = emscripten_date_now();
     QPoint targetPoint(mouseEvent.targetX, mouseEvent.targetY);
     QPoint globalPoint = eventTranslator->screen()->geometry().topLeft() + targetPoint;
 
diff --git a/src/plugins/platforms/wasm/qwasmopenglcontext.cpp b/src/plugins/platforms/wasm/qwasmopenglcontext.cpp
index 62087f54bd..501ab99116 100644
--- a/src/plugins/platforms/wasm/qwasmopenglcontext.cpp
+++ b/src/plugins/platforms/wasm/qwasmopenglcontext.cpp
@@ -30,6 +30,7 @@
 #include "qwasmopenglcontext.h"
 #include "qwasmintegration.h"
 #include <EGL/egl.h>
+#include <emscripten/val.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -50,7 +51,13 @@ QWasmOpenGLContext::QWasmOpenGLContext(const QSurfaceFormat &format)
 QWasmOpenGLContext::~QWasmOpenGLContext()
 {
     if (m_context) {
+        // Destroy GL context. Work around bug in emscripten_webgl_destroy_context
+        // which removes all event handlers on the canvas by temporarily removing
+        // emscripten's JSEvents global object.
+        emscripten::val jsEvents = emscripten::val::global("window")["JSEvents"];
+        emscripten::val::global("window").set("JSEvents", emscripten::val::undefined());
         emscripten_webgl_destroy_context(m_context);
+        emscripten::val::global("window").set("JSEvents", jsEvents);
         m_context = 0;
     }
 }
@@ -99,7 +106,7 @@ EMSCRIPTEN_WEBGL_CONTEXT_HANDLE QWasmOpenGLContext::createEmscriptenContext(cons
     attributes.depth = useDepthStencil;
     attributes.stencil = useDepthStencil;
 
-    EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context = emscripten_webgl_create_context(canvasId.toLocal8Bit().constData(), &attributes);
+    EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context = emscripten_webgl_create_context(canvasId.toUtf8().constData(), &attributes);
 
     return context;
 }
diff --git a/src/plugins/platforms/wasm/qwasmscreen.cpp b/src/plugins/platforms/wasm/qwasmscreen.cpp
index e536bc0ee3..d50765e3fb 100644
--- a/src/plugins/platforms/wasm/qwasmscreen.cpp
+++ b/src/plugins/platforms/wasm/qwasmscreen.cpp
@@ -44,6 +44,7 @@
 #include <QtGui/qguiapplication.h>
 #include <private/qhighdpiscaling_p.h>
 
+using namespace emscripten;
 
 QT_BEGIN_NAMESPACE
 
@@ -54,6 +55,8 @@ QWasmScreen::QWasmScreen(const QString &canvasId)
     m_compositor = new QWasmCompositor(this);
     m_eventTranslator = new QWasmEventTranslator(this);
     updateQScreenAndCanvasRenderSize();
+    emscripten::val canvas = emscripten::val::global(m_canvasId.toUtf8().constData());
+    canvas.call<void>("focus");
 }
 
 QWasmScreen::~QWasmScreen()
@@ -182,12 +185,18 @@ void QWasmScreen::updateQScreenAndCanvasRenderSize()
     QSizeF cssSize(css_width, css_height);
 
     QSizeF canvasSize = cssSize * devicePixelRatio();
-    emscripten::val canvas = emscripten::val::global(canvasId.constData());
+    val document = val::global("document");
+    val canvas = document.call<val>("getElementById", val(canvasId.constData()));
+
     canvas.set("width", canvasSize.width());
     canvas.set("height", canvasSize.height());
 
+    QPoint offset;
+    offset.setX(canvas["offsetTop"].as<int>());
+    offset.setY(canvas["offsetLeft"].as<int>());
+
     emscripten::val rect = canvas.call<emscripten::val>("getBoundingClientRect");
-    QPoint position(rect["left"].as<int>(), rect["top"].as<int>());
+    QPoint position(rect["left"].as<int>() - offset.x(), rect["top"].as<int>() - offset.y());
 
     setGeometry(QRect(position, cssSize.toSize()));
     m_compositor->redrawWindowContent();
diff --git a/src/plugins/platforms/windows/qwindowsclipboard.cpp b/src/plugins/platforms/windows/qwindowsclipboard.cpp
index 4e6d3306e1..ccd4e50a8b 100644
--- a/src/plugins/platforms/windows/qwindowsclipboard.cpp
+++ b/src/plugins/platforms/windows/qwindowsclipboard.cpp
@@ -82,7 +82,7 @@ static QDebug operator<<(QDebug d, const QMimeData *mimeData)
     d << "QMimeData(";
     if (mimeData) {
         const QStringList formats = mimeData->formats();
-        d << "formats=" << formats.join(QLatin1String(", "));
+        d << "formats=" << formats.join(u", ");
         if (mimeData->hasText())
             d << ", text=" << mimeData->text();
         if (mimeData->hasHtml())
@@ -339,7 +339,7 @@ void QWindowsClipboard::setMimeData(QMimeData *mimeData, QClipboard::Mode mode)
 
     if (src != S_OK) {
         QString mimeDataFormats = mimeData ?
-            mimeData->formats().join(QLatin1String(", ")) : QString(QStringLiteral("NULL"));
+            mimeData->formats().join(u", ") : QString(QStringLiteral("NULL"));
         qErrnoWarning("OleSetClipboard: Failed to set mime data (%s) on clipboard: %s",
                       qPrintable(mimeDataFormats),
                       QWindowsContext::comErrorString(src).constData());
diff --git a/src/plugins/platforms/windows/qwindowscombase.h b/src/plugins/platforms/windows/qwindowscombase.h
index 45cba9c68b..bb4b295395 100644
--- a/src/plugins/platforms/windows/qwindowscombase.h
+++ b/src/plugins/platforms/windows/qwindowscombase.h
@@ -107,6 +107,9 @@ private:
     ULONG m_ref;
 };
 
+// Clang does not consider __declspec(nothrow) as nothrow
+QT_WARNING_DISABLE_CLANG("-Wmicrosoft-exception-spec")
+
 QT_END_NAMESPACE
 
 #endif // QWINDOWSCOMBASE_H
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 9757fa5f3f..88d3131de2 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -274,6 +274,8 @@ struct QWindowsContextPrivate {
     const HRESULT m_oleInitializeResult;
     QWindow *m_lastActiveWindow = nullptr;
     bool m_asyncExpose = false;
+    HPOWERNOTIFY m_powerNotification = nullptr;
+    HWND m_powerDummyWindow = nullptr;
 };
 
 QWindowsContextPrivate::QWindowsContextPrivate()
@@ -314,6 +316,13 @@ QWindowsContext::~QWindowsContext()
 #if QT_CONFIG(tabletevent)
     d->m_tabletSupport.reset(); // Destroy internal window before unregistering classes.
 #endif
+
+    if (d->m_powerNotification)
+        UnregisterPowerSettingNotification(d->m_powerNotification);
+
+    if (d->m_powerDummyWindow)
+        DestroyWindow(d->m_powerDummyWindow);
+
     unregisterWindowClasses();
     if (d->m_oleInitializeResult == S_OK || d->m_oleInitializeResult == S_FALSE)
         OleUninitialize();
@@ -381,6 +390,55 @@ bool QWindowsContext::initPointer(unsigned integrationOptions)
     return true;
 }
 
+extern "C" LRESULT QT_WIN_CALLBACK qWindowsPowerWindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    if (message != WM_POWERBROADCAST || wParam != PBT_POWERSETTINGCHANGE)
+        return DefWindowProc(hwnd, message, wParam, lParam);
+
+    static bool initialized = false; // ignore the initial change
+    if (!initialized) {
+        initialized = true;
+        return DefWindowProc(hwnd, message, wParam, lParam);
+    }
+
+    auto setting = reinterpret_cast<const POWERBROADCAST_SETTING *>(lParam);
+    if (setting) {
+        auto data = reinterpret_cast<const DWORD *>(&setting->Data);
+        if (*data == 1) {
+            // Repaint the windows when returning from sleeping display mode.
+            const auto tlw = QGuiApplication::topLevelWindows();
+            for (auto w : tlw) {
+                if (w->isVisible() && w->windowState() != Qt::WindowMinimized) {
+                    if (auto tw = QWindowsWindow::windowsWindowOf(w)) {
+                        if (HWND hwnd = tw->handle()) {
+                            InvalidateRect(hwnd, nullptr, false);
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return DefWindowProc(hwnd, message, wParam, lParam);
+}
+
+bool QWindowsContext::initPowerNotificationHandler()
+{
+    if (d->m_powerNotification)
+        return false;
+
+    d->m_powerDummyWindow = createDummyWindow(QStringLiteral("QtPowerDummyWindow"), L"QtPowerDummyWindow", qWindowsPowerWindowProc);
+    if (!d->m_powerDummyWindow)
+        return false;
+
+    d->m_powerNotification = RegisterPowerSettingNotification(d->m_powerDummyWindow, &GUID_MONITOR_POWER_ON, DEVICE_NOTIFY_WINDOW_HANDLE);
+    if (!d->m_powerNotification) {
+        DestroyWindow(d->m_powerDummyWindow);
+        d->m_powerDummyWindow = nullptr;
+        return false;
+    }
+    return true;
+}
+
 void QWindowsContext::setTabletAbsoluteRange(int a)
 {
 #if QT_CONFIG(tabletevent)
@@ -546,15 +604,12 @@ QString QWindowsContext::registerWindowClass(QString cname,
     // each one has to have window class names with a unique name
     // The first instance gets the unmodified name; if the class
     // has already been registered by another instance of Qt then
-    // add a UUID.
-    static int classExists = -1;
-
+    // add a UUID. The check needs to be performed for each name
+    // in case new message windows are added (QTBUG-81347).
     const auto appInstance = static_cast<HINSTANCE>(GetModuleHandle(nullptr));
-    if (classExists == -1) {
-        WNDCLASS wcinfo;
-        classExists = GetClassInfo(appInstance, reinterpret_cast<LPCWSTR>(cname.utf16()), &wcinfo);
-        classExists = classExists && wcinfo.lpfnWndProc != proc;
-    }
+    WNDCLASS wcinfo;
+    const bool classExists = GetClassInfo(appInstance, reinterpret_cast<LPCWSTR>(cname.utf16()), &wcinfo) == TRUE
+        && wcinfo.lpfnWndProc != proc;
 
     if (classExists)
         cname += QUuid::createUuid().toString();
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index d94ae3f73b..8027f09389 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -176,6 +176,8 @@ public:
     bool initTablet(unsigned integrationOptions);
     bool initPointer(unsigned integrationOptions);
 
+    bool initPowerNotificationHandler();
+
     int defaultDPI() const;
 
     QString registerWindowClass(const QWindow *w);
diff --git a/src/plugins/platforms/windows/qwindowscursor.cpp b/src/plugins/platforms/windows/qwindowscursor.cpp
index 17e8cffb76..59457f1720 100644
--- a/src/plugins/platforms/windows/qwindowscursor.cpp
+++ b/src/plugins/platforms/windows/qwindowscursor.cpp
@@ -50,6 +50,7 @@
 #include <QtGui/qscreen.h>
 #include <QtGui/private/qguiapplication_p.h> // getPixmapCursor()
 #include <QtGui/private/qhighdpiscaling_p.h>
+#include <QtCore/private/qwinregistry_p.h>
 
 #include <QtCore/qdebug.h>
 #include <QtCore/qscopedpointer.h>
@@ -686,6 +687,30 @@ void QWindowsCursor::setPos(const QPoint &pos)
     SetCursorPos(pos.x() , pos.y());
 }
 
+/*
+    The standard size is 32x32, even though the cursor is actually just
+    16 pixels large. If a large cursor is set in the accessibility settings,
+    then the cursor increases with 8 pixels for each step.
+*/
+QSize QWindowsCursor::size() const
+{
+    const QPair<DWORD,bool> cursorSizeSetting =
+        QWinRegistryKey(HKEY_CURRENT_USER, LR"(Control Panel\Cursors)")
+                       .dwordValue(L"CursorBaseSize");
+    const int baseSize = screenCursorSize(m_screen).width() / 2;
+    if (!cursorSizeSetting.second)
+        return QSize(baseSize / 2, baseSize / 2);
+
+    // The registry values are dpi-independent, so we need to scale the result.
+    int cursorSizeValue = cursorSizeSetting.first * m_screen->logicalDpi().first
+                                                  / m_screen->logicalBaseDpi().first;
+
+    // map from registry value 32-256 to 0-14, and from there to pixels
+    cursorSizeValue = (cursorSizeValue - 2 * baseSize) / baseSize;
+    const int cursorSize = baseSize + cursorSizeValue * (baseSize / 2);
+    return QSize(cursorSize, cursorSize);
+}
+
 QPixmap QWindowsCursor::dragDefaultCursor(Qt::DropAction action) const
 {
     switch (action) {
diff --git a/src/plugins/platforms/windows/qwindowscursor.h b/src/plugins/platforms/windows/qwindowscursor.h
index b896f4c7a9..cf3635bd6b 100644
--- a/src/plugins/platforms/windows/qwindowscursor.h
+++ b/src/plugins/platforms/windows/qwindowscursor.h
@@ -113,6 +113,8 @@ public:
     QPoint pos() const override;
     void setPos(const QPoint &pos) override;
 
+    QSize size() const override;
+
     static HCURSOR createPixmapCursor(QPixmap pixmap, const QPoint &hotSpot, qreal scaleFactor = 1);
     static HCURSOR createPixmapCursor(const PixmapCursor &pc, qreal scaleFactor = 1) { return createPixmapCursor(pc.pixmap, pc.hotSpot, scaleFactor); }
     static PixmapCursor customCursor(Qt::CursorShape cursorShape, const QPlatformScreen *screen = nullptr);
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index b7ab952a1d..b038e19689 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -91,7 +91,7 @@ static inline QString guidToString(const GUID &g)
     str << '{' << g.Data1 << ", " << g.Data2 << ", " << g.Data3;
     str.setFieldWidth(2);
     str.setFieldAlignment(QTextStream::AlignRight);
-    str.setPadChar(QLatin1Char('0'));
+    str.setPadChar(u'0');
     str << ",{" << g.Data4[0] << ", " << g.Data4[1]  << ", " << g.Data4[2]  << ", " << g.Data4[3]
         << ", " << g.Data4[4] << ", " << g.Data4[5]  << ", " << g.Data4[6]  << ", " << g.Data4[7]
         << "}};";
@@ -466,14 +466,14 @@ inline void QWindowsFileDialogSharedData::setSelectedNameFilter(const QString &f
 inline QList<QUrl> QWindowsFileDialogSharedData::selectedFiles() const
 {
     m_data->mutex.lock();
-    const QList<QUrl> result = m_data->selectedFiles;
+    const auto result = m_data->selectedFiles;
     m_data->mutex.unlock();
     return result;
 }
 
 inline QString QWindowsFileDialogSharedData::selectedFile() const
 {
-    const QList<QUrl> files = selectedFiles();
+    const auto files = selectedFiles();
     return files.isEmpty() ? QString() : files.front().toLocalFile();
 }
 
@@ -915,7 +915,7 @@ IShellItem *QWindowsNativeFileDialogBase::shellItem(const QUrl &url)
             return nullptr;
         }
         return result;
-    } else if (url.scheme() == QLatin1String("clsid")) {
+    } else if (url.scheme() == u"clsid") {
         // Support for virtual folders via GUID
         // (see https://msdn.microsoft.com/en-us/library/windows/desktop/dd378457(v=vs.85).aspx)
         // specified as "clsid:<GUID>" (without '{', '}').
@@ -1040,20 +1040,20 @@ static QList<FilterSpec> filterSpecs(const QStringList &filters,
     // Split filter specification as 'Texts (*.txt[;] *.doc)', '*.txt[;] *.doc'
     // into description and filters specification as '*.txt;*.doc'
     for (const QString &filterString : filters) {
-        const int openingParenPos = filterString.lastIndexOf(QLatin1Char('('));
+        const int openingParenPos = filterString.lastIndexOf(u'(');
         const int closingParenPos = openingParenPos != -1 ?
-            filterString.indexOf(QLatin1Char(')'), openingParenPos + 1) : -1;
+            filterString.indexOf(u')', openingParenPos + 1) : -1;
         FilterSpec filterSpec;
         filterSpec.filter = closingParenPos == -1 ?
             filterString :
             filterString.mid(openingParenPos + 1, closingParenPos - openingParenPos - 1).trimmed();
         if (filterSpec.filter.isEmpty())
-            filterSpec.filter += QLatin1Char('*');
+            filterSpec.filter += u'*';
         filterSpec.filter.replace(filterSeparatorRE, separator);
         filterSpec.description = filterString;
         if (hideFilterDetails && openingParenPos != -1) { // Do not show pattern in description
             filterSpec.description.truncate(openingParenPos);
-            while (filterSpec.description.endsWith(QLatin1Char(' ')))
+            while (filterSpec.description.endsWith(u' '))
                 filterSpec.description.truncate(filterSpec.description.size() - 1);
         }
         *totalStringLength += filterSpec.filter.size() + filterSpec.description.size();
@@ -1084,8 +1084,8 @@ void QWindowsNativeFileDialogBase::setNameFilters(const QStringList &filters)
         // 'AAA files (a.*) (a.*)'
         QString description = specs[i].description;
         const QString &filter = specs[i].filter;
-        if (!m_hideFiltersDetails && !filter.startsWith(QLatin1String("*."))) {
-            const int pos = description.lastIndexOf(QLatin1Char('('));
+        if (!m_hideFiltersDetails && !filter.startsWith(u"*.")) {
+            const int pos = description.lastIndexOf(u'(');
             if (pos > 0)
                 description.truncate(pos);
         }
@@ -1151,8 +1151,8 @@ static bool isHexRange(const QString& s, int start, int end)
     for (;start < end; ++start) {
         QChar ch = s.at(start);
         if (!(ch.isDigit()
-              || (ch >= QLatin1Char('a') && ch <= QLatin1Char('f'))
-              || (ch >= QLatin1Char('A') && ch <= QLatin1Char('F'))))
+              || (ch >= u'a' && ch <= u'f')
+              || (ch >= u'A' && ch <= u'F')))
             return false;
     }
     return true;
@@ -1161,7 +1161,7 @@ static bool isHexRange(const QString& s, int start, int end)
 static inline bool isClsid(const QString &s)
 {
     // detect "374DE290-123F-4565-9164-39C4925E467B".
-    const QChar dash(QLatin1Char('-'));
+    const QChar dash(u'-');
     return s.size() == 36
             && isHexRange(s, 0, 8)
             && s.at(8) == dash
@@ -1204,7 +1204,7 @@ void QWindowsNativeFileDialogBase::selectNameFilter(const QString &filter)
     if (index < 0) {
         qWarning("%s: Invalid parameter '%s' not found in '%s'.",
                  __FUNCTION__, qPrintable(filter),
-                 qPrintable(m_nameFilters.join(QLatin1String(", "))));
+                 qPrintable(m_nameFilters.join(u", ")));
         return;
     }
     m_fileDialog->SetFileTypeIndex(index + 1); // one-based.
@@ -1313,15 +1313,15 @@ public:
 // Also handles the simple name filter case "*.txt" -> "txt"
 static inline QString suffixFromFilter(const QString &filter)
 {
-    int suffixPos = filter.indexOf(QLatin1String("*."));
+    int suffixPos = filter.indexOf(u"*.");
     if (suffixPos < 0)
         return QString();
     suffixPos += 2;
-    int endPos = filter.indexOf(QLatin1Char(' '), suffixPos + 1);
+    int endPos = filter.indexOf(u' ', suffixPos + 1);
     if (endPos < 0)
-        endPos = filter.indexOf(QLatin1Char(';'), suffixPos + 1);
+        endPos = filter.indexOf(u';', suffixPos + 1);
     if (endPos < 0)
-        endPos = filter.indexOf(QLatin1Char(')'), suffixPos + 1);
+        endPos = filter.indexOf(u')', suffixPos + 1);
     if (endPos < 0)
         endPos = filter.size();
     return filter.mid(suffixPos, endPos - suffixPos);
@@ -1406,27 +1406,27 @@ static void cleanupTemporaryItemCopies()
 
 static bool validFileNameCharacter(QChar c)
 {
-    return c.isLetterOrNumber() || c == QLatin1Char('_') || c == QLatin1Char('-');
+    return c.isLetterOrNumber() || c == u'_' || c == u'-';
 }
 
 QString tempFilePattern(QString name)
 {
-    const int lastSlash = qMax(name.lastIndexOf(QLatin1Char('/')),
-                               name.lastIndexOf(QLatin1Char('\\')));
+    const int lastSlash = qMax(name.lastIndexOf(u'/'),
+                               name.lastIndexOf(u'\\'));
     if (lastSlash != -1)
         name.remove(0, lastSlash + 1);
 
-    int lastDot = name.lastIndexOf(QLatin1Char('.'));
+    int lastDot = name.lastIndexOf(u'.');
     if (lastDot < 0)
         lastDot = name.size();
     name.insert(lastDot, QStringLiteral("_XXXXXX"));
 
     for (int i = lastDot - 1; i >= 0; --i) {
         if (!validFileNameCharacter(name.at(i)))
-            name[i] = QLatin1Char('_');
+            name[i] = u'_';
     }
 
-    name.prepend(QDir::tempPath() + QLatin1Char('/'));
+    name.prepend(QDir::tempPath() + u'/');
     return name;
 }
 
@@ -1456,7 +1456,7 @@ static QString createTemporaryItemCopy(QWindowsShellItem &qItem, QString *errorM
 static QUrl itemToDialogUrl(QWindowsShellItem &qItem, QString *errorMessage)
 {
     QUrl url = qItem.url();
-    if (url.isLocalFile() || url.scheme().startsWith(QLatin1String("http")))
+    if (url.isLocalFile() || url.scheme().startsWith(u"http"))
         return url;
     const QString path = qItem.path();
     if (path.isEmpty() && !qItem.isDir() && qItem.canStream()) {
@@ -1859,10 +1859,12 @@ void QWindowsXpNativeFileDialog::populateOpenFileName(OPENFILENAME *ofn, HWND ow
     // for the target. If it contains any invalid character, the dialog
     // will not show.
     ofn->nMaxFile = 65535;
-    const QString initiallySelectedFile =
-        QDir::toNativeSeparators(m_data.selectedFile()).remove(QLatin1Char('<')).
-            remove(QLatin1Char('>')).remove(QLatin1Char('"')).remove(QLatin1Char('|'));
-    ofn->lpstrFile = qStringToWCharArray(initiallySelectedFile, ofn->nMaxFile);
+    QString initiallySelectedFile = m_data.selectedFile();
+    initiallySelectedFile.remove(u'<');
+    initiallySelectedFile.remove(u'>');
+    initiallySelectedFile.remove(u'"');
+    initiallySelectedFile.remove(u'|');
+    ofn->lpstrFile = qStringToWCharArray(QDir::toNativeSeparators(initiallySelectedFile), ofn->nMaxFile);
     ofn->lpstrInitialDir = qStringToWCharArray(QDir::toNativeSeparators(m_data.directory().toLocalFile()));
     ofn->lpstrTitle = (wchar_t*)m_title.utf16();
     // Determine lpstrDefExt. Note that the current MSDN docs document this
@@ -1872,7 +1874,7 @@ void QWindowsXpNativeFileDialog::populateOpenFileName(OPENFILENAME *ofn, HWND ow
     // the extension of the current filter".
     if (m_options->acceptMode() == QFileDialogOptions::AcceptSave) {
         QString defaultSuffix = m_options->defaultSuffix();
-        if (defaultSuffix.startsWith(QLatin1Char('.')))
+        if (defaultSuffix.startsWith(u'.'))
             defaultSuffix.remove(0, 1);
         // QTBUG-33156, also create empty strings to trigger the appending mechanism.
         ofn->lpstrDefExt = qStringToWCharArray(defaultSuffix);
@@ -1905,7 +1907,7 @@ QList<QUrl> QWindowsXpNativeFileDialog::execFileNames(HWND owner, int *selectedF
             wchar_t *ptr = ofn.lpstrFile + dir.size() + 1;
             if (*ptr) {
                 result.pop_front();
-                const QString path = dir + QLatin1Char('/');
+                const QString path = dir + u'/';
                 while (*ptr) {
                     const QString fileName = QString::fromWCharArray(ptr);
                     result.push_back(QUrl::fromLocalFile(path + fileName));
diff --git a/src/plugins/platforms/windows/qwindowsdropdataobject.cpp b/src/plugins/platforms/windows/qwindowsdropdataobject.cpp
index e1a41c0ede..c9dd1c7c17 100644
--- a/src/plugins/platforms/windows/qwindowsdropdataobject.cpp
+++ b/src/plugins/platforms/windows/qwindowsdropdataobject.cpp
@@ -95,7 +95,7 @@ bool QWindowsDropDataObject::shouldIgnore(LPFORMATETC pformatetc) const
                 || pformatetc->cfFormat == CF_TEXT
                 || formatName == QStringLiteral("UniformResourceLocator")
                 || formatName == QStringLiteral("UniformResourceLocatorW")) {
-            QList<QUrl> urls = dropData->urls();
+            const auto urls = dropData->urls();
             return std::all_of(urls.cbegin(), urls.cend(), [] (const QUrl &u) { return u.isLocalFile(); });
         }
     }
diff --git a/src/plugins/platforms/windows/qwindowseglcontext.cpp b/src/plugins/platforms/windows/qwindowseglcontext.cpp
index e9f3dc5189..76baa93d98 100644
--- a/src/plugins/platforms/windows/qwindowseglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowseglcontext.cpp
@@ -88,7 +88,7 @@ static void *resolveFunc(HMODULE lib, const char *name)
     while (!proc && argSize <= 64) {
         nameStr = baseNameStr;
         if (argSize >= 0)
-            nameStr += QLatin1Char('@') + QString::number(argSize);
+            nameStr += u'@' + QString::number(argSize);
         argSize = argSize < 0 ? 0 : argSize + 4;
         proc = (void *) ::GetProcAddress(lib, nameStr.toLatin1().constData());
     }
diff --git a/src/plugins/platforms/windows/qwindowsglcontext.h b/src/plugins/platforms/windows/qwindowsglcontext.h
index e5f6fefd5a..8794368fe4 100644
--- a/src/plugins/platforms/windows/qwindowsglcontext.h
+++ b/src/plugins/platforms/windows/qwindowsglcontext.h
@@ -89,7 +89,7 @@ struct QWindowsOpenGLContextFormat
 
     QSurfaceFormat::OpenGLContextProfile profile = QSurfaceFormat::NoProfile;
     int version = 0; //! majorVersion<<8 + minorVersion
-    QSurfaceFormat::FormatOptions options = nullptr;
+    QSurfaceFormat::FormatOptions options;
 };
 
 #ifndef QT_NO_DEBUG_STREAM
diff --git a/src/plugins/platforms/windows/qwindowsinputcontext.cpp b/src/plugins/platforms/windows/qwindowsinputcontext.cpp
index d5258ca6a3..f1f5d3a96e 100644
--- a/src/plugins/platforms/windows/qwindowsinputcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsinputcontext.cpp
@@ -280,13 +280,19 @@ void QWindowsInputContext::showInputPanel()
     // with Windows 10 if the Windows IME is (re)enabled _after_ the caret is shown.
     if (m_caretCreated) {
         cursorRectChanged();
-        // We only call ShowCaret() on Windows 10 as in earlier versions the caret
-        // would actually be visible (QTBUG-74492) and the workaround for the
-        // Surface seems unnecessary there anyway. But leave it hidden for IME.
-        if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows10)
+        // We only call ShowCaret() on Windows 10 after 1703 as in earlier versions
+        // the caret would actually be visible (QTBUG-74492) and the workaround for
+        // the Surface seems unnecessary there anyway. But leave it hidden for IME.
+        // Only trigger the native OSK if the Qt OSK is not in use.
+        static bool imModuleEmpty = qEnvironmentVariableIsEmpty("QT_IM_MODULE");
+        bool nativeVKDisabled = QCoreApplication::testAttribute(Qt::AA_MSWindowsDisableVirtualKeyboard);
+        if ((imModuleEmpty && !nativeVKDisabled)
+                && QOperatingSystemVersion::current()
+                    >= QOperatingSystemVersion(QOperatingSystemVersion::Windows, 10, 0, 16299)) {
             ShowCaret(platformWindow->handle());
-        else
+        } else {
             HideCaret(platformWindow->handle());
+        }
         setWindowsImeEnabled(platformWindow, false);
         setWindowsImeEnabled(platformWindow, true);
     }
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index eccf1c4928..32bd29a842 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -162,7 +162,7 @@ bool parseIntOption(const QString &parameter,const QLatin1String &option,
                     IntType minimumValue, IntType maximumValue, IntType *target)
 {
     const int valueLength = parameter.size() - option.size() - 1;
-    if (valueLength < 1 || !parameter.startsWith(option) || parameter.at(option.size()) != QLatin1Char('='))
+    if (valueLength < 1 || !parameter.startsWith(option) || parameter.at(option.size()) != u'=')
         return false;
     bool ok;
     const QStringRef valueRef = parameter.rightRef(valueLength);
@@ -186,38 +186,38 @@ static inline unsigned parseOptions(const QStringList &paramList,
 {
     unsigned options = 0;
     for (const QString &param : paramList) {
-        if (param.startsWith(QLatin1String("fontengine="))) {
-            if (param.endsWith(QLatin1String("freetype"))) {
+        if (param.startsWith(u"fontengine=")) {
+            if (param.endsWith(u"freetype")) {
                 options |= QWindowsIntegration::FontDatabaseFreeType;
-            } else if (param.endsWith(QLatin1String("native"))) {
+            } else if (param.endsWith(u"native")) {
                 options |= QWindowsIntegration::FontDatabaseNative;
             }
-        } else if (param.startsWith(QLatin1String("dialogs="))) {
-            if (param.endsWith(QLatin1String("xp"))) {
+        } else if (param.startsWith(u"dialogs=")) {
+            if (param.endsWith(u"xp")) {
                 options |= QWindowsIntegration::XpNativeDialogs;
-            } else if (param.endsWith(QLatin1String("none"))) {
+            } else if (param.endsWith(u"none")) {
                 options |= QWindowsIntegration::NoNativeDialogs;
             }
-        } else if (param == QLatin1String("altgr")) {
+        } else if (param == u"altgr") {
             options |= QWindowsIntegration::DetectAltGrModifier;
-        } else if (param == QLatin1String("gl=gdi")) {
+        } else if (param == u"gl=gdi") {
             options |= QWindowsIntegration::DisableArb;
-        } else if (param == QLatin1String("nodirectwrite")) {
+        } else if (param == u"nodirectwrite") {
             options |= QWindowsIntegration::DontUseDirectWriteFonts;
-        } else if (param == QLatin1String("nocolorfonts")) {
+        } else if (param == u"nocolorfonts") {
             options |= QWindowsIntegration::DontUseColorFonts;
-        } else if (param == QLatin1String("nomousefromtouch")) {
+        } else if (param == u"nomousefromtouch") {
             options |= QWindowsIntegration::DontPassOsMouseEventsSynthesizedFromTouch;
         } else if (parseIntOption(param, QLatin1String("verbose"), 0, INT_MAX, &QWindowsContext::verbose)
             || parseIntOption(param, QLatin1String("tabletabsoluterange"), 0, INT_MAX, tabletAbsoluteRange)
             || parseIntOption(param, QLatin1String("dpiawareness"), QtWindows::ProcessDpiUnaware, QtWindows::ProcessPerMonitorDpiAware, dpiAwareness)) {
-        } else if (param == QLatin1String("menus=native")) {
+        } else if (param == u"menus=native") {
             options |= QWindowsIntegration::AlwaysUseNativeMenus;
-        } else if (param == QLatin1String("menus=none")) {
+        } else if (param == u"menus=none") {
             options |= QWindowsIntegration::NoNativeMenus;
-        } else if (param == QLatin1String("nowmpointer")) {
+        } else if (param == u"nowmpointer") {
             options |= QWindowsIntegration::DontUseWMPointer;
-        } else if (param == QLatin1String("reverse")) {
+        } else if (param == u"reverse") {
             options |= QWindowsIntegration::RtlEnabled;
         } else {
             qWarning() << "Unknown option" << param;
@@ -258,6 +258,8 @@ QWindowsIntegrationPrivate::QWindowsIntegrationPrivate(const QStringList &paramL
 
     m_context.initTouch(m_options);
     QPlatformCursor::setCapability(QPlatformCursor::OverrideCursor);
+
+    m_context.initPowerNotificationHandler();
 }
 
 QWindowsIntegrationPrivate::~QWindowsIntegrationPrivate()
diff --git a/src/plugins/platforms/windows/qwindowskeymapper.cpp b/src/plugins/platforms/windows/qwindowskeymapper.cpp
index 4f0f846749..e3edf7e81e 100644
--- a/src/plugins/platforms/windows/qwindowskeymapper.cpp
+++ b/src/plugins/platforms/windows/qwindowskeymapper.cpp
@@ -1019,14 +1019,14 @@ bool QWindowsKeyMapper::translateKeyEventInternal(QWindow *window, MSG msg,
                 if (dirStatus == VK_LSHIFT
                         && ((msg.wParam == VK_SHIFT && GetKeyState(VK_LCONTROL))
                             || (msg.wParam == VK_CONTROL && GetKeyState(VK_LSHIFT)))) {
-                    sendExtendedPressRelease(receiver, Qt::Key_Direction_L, nullptr,
+                    sendExtendedPressRelease(receiver, Qt::Key_Direction_L, {},
                                              scancode, vk_key, nModifiers, QString(), false);
                     result = true;
                     dirStatus = 0;
                 } else if (dirStatus == VK_RSHIFT
                            && ( (msg.wParam == VK_SHIFT && GetKeyState(VK_RCONTROL))
                                 || (msg.wParam == VK_CONTROL && GetKeyState(VK_RSHIFT)))) {
-                    sendExtendedPressRelease(receiver, Qt::Key_Direction_R, nullptr,
+                    sendExtendedPressRelease(receiver, Qt::Key_Direction_R, {},
                                              scancode, vk_key, nModifiers, QString(), false);
                     result = true;
                     dirStatus = 0;
@@ -1388,7 +1388,7 @@ QList<int> QWindowsKeyMapper::possibleKeys(const QKeyEvent *e) const
         if (key && key != baseKey && ((keyMods & neededMods) == neededMods)) {
             const Qt::KeyboardModifiers missingMods = keyMods & ~neededMods;
             const int matchedKey = int(key) + missingMods;
-            const QList<int>::iterator it =
+            const auto it =
                 std::find_if(result.begin(), result.end(),
                              [key] (int k) { return (k & ~Qt::KeyboardModifierMask) == key; });
             // QTBUG-67200: Use the match with the least modifiers (prefer
diff --git a/src/plugins/platforms/windows/qwindowsmenu.cpp b/src/plugins/platforms/windows/qwindowsmenu.cpp
index d20edd685e..7c3e87eec1 100644
--- a/src/plugins/platforms/windows/qwindowsmenu.cpp
+++ b/src/plugins/platforms/windows/qwindowsmenu.cpp
@@ -445,7 +445,7 @@ QString QWindowsMenuItem::nativeText() const
     QString result = m_text;
 #if QT_CONFIG(shortcut)
     if (!m_shortcut.isEmpty()) {
-        result += QLatin1Char('\t');
+        result += u'\t';
         result += m_shortcut.toString(QKeySequence::NativeText);
     }
 #endif
diff --git a/src/plugins/platforms/windows/qwindowsmime.cpp b/src/plugins/platforms/windows/qwindowsmime.cpp
index b9d8b191f5..fe9e1fe31f 100644
--- a/src/plugins/platforms/windows/qwindowsmime.cpp
+++ b/src/plugins/platforms/windows/qwindowsmime.cpp
@@ -107,7 +107,7 @@ static inline QByteArray msgConversionError(const char *func, const char *format
     msg += ": Unable to convert DIB image. The image converter plugin for '";
     msg += format;
     msg += "' is not available. Available formats: ";
-    const QList<QByteArray> &formats = QImageReader::supportedImageFormats();
+    const auto &formats = QImageReader::supportedImageFormats();
     for (const QByteArray &af : formats) {
         msg += af;
         msg += ' ';
@@ -635,11 +635,11 @@ bool QWindowsMimeText::convertFromMime(const FORMATETC &formatetc, const QMimeDa
             int ri = 0;
             bool cr = false;
             for (int i=0; i < s; ++i) {
-                if (*u == QLatin1Char('\r'))
+                if (*u == u'\r')
                     cr = true;
                 else {
-                    if (*u == QLatin1Char('\n') && !cr)
-                        res[ri++] = QLatin1Char('\r');
+                    if (*u == u'\n' && !cr)
+                        res[ri++] = u'\r';
                     cr = false;
                 }
                 res[ri++] = *u;
@@ -663,7 +663,7 @@ bool QWindowsMimeText::convertFromMime(const FORMATETC &formatetc, const QMimeDa
 
 bool QWindowsMimeText::canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const
 {
-    return mimeType.startsWith(QLatin1String("text/plain"))
+    return mimeType.startsWith(u"text/plain")
            && (canGetData(CF_UNICODETEXT, pDataObj)
            || canGetData(CF_TEXT, pDataObj));
 }
@@ -680,7 +680,7 @@ QString QWindowsMimeText::mimeForFormat(const FORMATETC &formatetc) const
 QVector<FORMATETC> QWindowsMimeText::formatsForMime(const QString &mimeType, const QMimeData *mimeData) const
 {
     QVector<FORMATETC> formatics;
-    if (mimeType.startsWith(QLatin1String("text/plain")) && mimeData->hasText()) {
+    if (mimeType.startsWith(u"text/plain") && mimeData->hasText()) {
         formatics += setCf(CF_UNICODETEXT);
         formatics += setCf(CF_TEXT);
     }
@@ -747,7 +747,7 @@ QWindowsMimeURI::QWindowsMimeURI()
 bool QWindowsMimeURI::canConvertFromMime(const FORMATETC &formatetc, const QMimeData *mimeData) const
 {
     if (mimeData->hasUrls() && getCf(formatetc) == CF_HDROP) {
-        const QList<QUrl> urls = mimeData->urls();
+        const auto urls = mimeData->urls();
         for (const QUrl &url : urls) {
             if (url.isLocalFile())
                 return true;
@@ -760,7 +760,7 @@ bool QWindowsMimeURI::convertFromMime(const FORMATETC &formatetc, const QMimeDat
 {
     if (canConvertFromMime(formatetc, mimeData)) {
         if (getCf(formatetc) == CF_HDROP) {
-            const QList<QUrl> &urls = mimeData->urls();
+            const auto &urls = mimeData->urls();
             QStringList fileNames;
             int size = sizeof(DROPFILES)+2;
             for (const QUrl &url : urls) {
@@ -791,7 +791,7 @@ bool QWindowsMimeURI::convertFromMime(const FORMATETC &formatetc, const QMimeDat
             return setData(result, pmedium);
         }
         if (getCf(formatetc) == CF_INETURL_W) {
-            QList<QUrl> urls = mimeData->urls();
+            const auto urls = mimeData->urls();
             QByteArray result;
             if (!urls.isEmpty()) {
                 QString url = urls.at(0).toString();
@@ -803,7 +803,7 @@ bool QWindowsMimeURI::convertFromMime(const FORMATETC &formatetc, const QMimeDat
             return setData(result, pmedium);
         }
         if (getCf(formatetc) == CF_INETURL) {
-            QList<QUrl> urls = mimeData->urls();
+            const auto urls = mimeData->urls();
             QByteArray result;
             if (!urls.isEmpty())
                 result = urls.at(0).toString().toLocal8Bit();
@@ -816,7 +816,7 @@ bool QWindowsMimeURI::convertFromMime(const FORMATETC &formatetc, const QMimeDat
 
 bool QWindowsMimeURI::canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const
 {
-    return mimeType == QLatin1String("text/uri-list")
+    return mimeType == u"text/uri-list"
            && (canGetData(CF_HDROP, pDataObj) || canGetData(CF_INETURL_W, pDataObj) || canGetData(CF_INETURL, pDataObj));
 }
 
@@ -831,7 +831,7 @@ QString QWindowsMimeURI::mimeForFormat(const FORMATETC &formatetc) const
 QVector<FORMATETC> QWindowsMimeURI::formatsForMime(const QString &mimeType, const QMimeData *mimeData) const
 {
     QVector<FORMATETC> formatics;
-    if (mimeType == QLatin1String("text/uri-list")) {
+    if (mimeType == u"text/uri-list") {
         if (canConvertFromMime(setCf(CF_HDROP), mimeData))
             formatics += setCf(CF_HDROP);
         if (canConvertFromMime(setCf(CF_INETURL_W), mimeData))
@@ -844,7 +844,7 @@ QVector<FORMATETC> QWindowsMimeURI::formatsForMime(const QString &mimeType, cons
 
 QVariant QWindowsMimeURI::convertToMime(const QString &mimeType, LPDATAOBJECT pDataObj, QVariant::Type preferredType) const
 {
-    if (mimeType == QLatin1String("text/uri-list")) {
+    if (mimeType == u"text/uri-list") {
         if (canGetData(CF_HDROP, pDataObj)) {
             QList<QVariant> urls;
 
@@ -916,7 +916,7 @@ QWindowsMimeHtml::QWindowsMimeHtml()
 QVector<FORMATETC> QWindowsMimeHtml::formatsForMime(const QString &mimeType, const QMimeData *mimeData) const
 {
     QVector<FORMATETC> formatetcs;
-    if (mimeType == QLatin1String("text/html") && (!mimeData->html().isEmpty()))
+    if (mimeType == u"text/html" && (!mimeData->html().isEmpty()))
         formatetcs += setCf(CF_HTML);
     return formatetcs;
 }
@@ -930,7 +930,7 @@ QString QWindowsMimeHtml::mimeForFormat(const FORMATETC &formatetc) const
 
 bool QWindowsMimeHtml::canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const
 {
-    return mimeType == QLatin1String("text/html") && canGetData(CF_HTML, pDataObj);
+    return mimeType == u"text/html" && canGetData(CF_HTML, pDataObj);
 }
 
 
@@ -1053,7 +1053,7 @@ QWindowsMimeImage::QWindowsMimeImage()
 QVector<FORMATETC> QWindowsMimeImage::formatsForMime(const QString &mimeType, const QMimeData *mimeData) const
 {
     QVector<FORMATETC> formatetcs;
-    if (mimeData->hasImage() && mimeType == QLatin1String("application/x-qt-image")) {
+    if (mimeData->hasImage() && mimeType == u"application/x-qt-image") {
         //add DIBV5 if image has alpha channel. Do not add CF_PNG here as it will confuse MS Office (QTBUG47656).
         auto image = qvariant_cast<QImage>(mimeData->imageData());
         if (!image.isNull() && image.hasAlphaChannel())
@@ -1075,7 +1075,7 @@ QString QWindowsMimeImage::mimeForFormat(const FORMATETC &formatetc) const
 
 bool QWindowsMimeImage::canConvertToMime(const QString &mimeType, IDataObject *pDataObj) const
 {
-    return mimeType == QLatin1String("application/x-qt-image")
+    return mimeType == u"application/x-qt-image"
         && (canGetData(CF_DIB, pDataObj) || canGetData(CF_PNG, pDataObj));
 }
 
@@ -1149,7 +1149,7 @@ QVariant QWindowsMimeImage::convertToMime(const QString &mimeType, IDataObject *
 {
     Q_UNUSED(preferredType);
     QVariant result;
-    if (mimeType != QLatin1String("application/x-qt-image"))
+    if (mimeType != u"application/x-qt-image")
         return result;
     //Try to convert from a format which has more data
     //DIBV5, use only if its is not synthesized
@@ -1220,7 +1220,7 @@ bool QBuiltInMimes::convertFromMime(const FORMATETC &formatetc, const QMimeData
 {
     if (canConvertFromMime(formatetc, mimeData)) {
         QByteArray data;
-        if (outFormats.value(getCf(formatetc)) == QLatin1String("text/html")) {
+        if (outFormats.value(getCf(formatetc)) == u"text/html") {
             // text/html is in wide chars on windows (compatible with mozillia)
             QString html = mimeData->html();
             // same code as in the text converter up above
@@ -1232,11 +1232,11 @@ bool QBuiltInMimes::convertFromMime(const FORMATETC &formatetc, const QMimeData
             int ri = 0;
             bool cr = false;
             for (int i=0; i < s; ++i) {
-                if (*u == QLatin1Char('\r'))
+                if (*u == u'\r')
                     cr = true;
                 else {
-                    if (*u == QLatin1Char('\n') && !cr)
-                        res[ri++] = QLatin1Char('\r');
+                    if (*u == u'\n' && !cr)
+                        res[ri++] = u'\r';
                     cr = false;
                 }
                 res[ri++] = *u;
@@ -1285,7 +1285,7 @@ QVariant QBuiltInMimes::convertToMime(const QString &mimeType, IDataObject *pDat
         QByteArray data = getData(inFormats.key(mimeType), pDataObj);
         if (!data.isEmpty()) {
             qCDebug(lcQpaMime) << __FUNCTION__;
-            if (mimeType == QLatin1String("text/html") && preferredType == QVariant::String) {
+            if (mimeType == u"text/html" && preferredType == QVariant::String) {
                 // text/html is in wide chars on windows (compatible with Mozilla)
                 val = QString::fromWCharArray(reinterpret_cast<const wchar_t *>(data.constData()));
             } else {
@@ -1404,12 +1404,12 @@ static bool isCustomMimeType(const QString &mimeType)
 static QString customMimeType(const QString &mimeType, int *lindex = nullptr)
 {
     int len = sizeof(x_qt_windows_mime) - 1;
-    int n = mimeType.lastIndexOf(QLatin1Char('\"')) - len;
+    int n = mimeType.lastIndexOf(u'\"') - len;
     QString ret = mimeType.mid(len, n);
 
-    const int beginPos = mimeType.indexOf(QLatin1String(";index="));
+    const int beginPos = mimeType.indexOf(u";index=");
     if (beginPos > -1) {
-        const int endPos = mimeType.indexOf(QLatin1Char(';'), beginPos + 1);
+        const int endPos = mimeType.indexOf(u';', beginPos + 1);
         const int indexStartPos = beginPos + 7;
         if (lindex)
             *lindex = mimeType.midRef(indexStartPos, endPos == -1 ? endPos : endPos - indexStartPos).toInt();
@@ -1480,7 +1480,7 @@ QString QLastResortMimes::mimeForFormat(const FORMATETC &formatetc) const
                     }
                 }
                 if (!ianaType)
-                    format = QLatin1String(x_qt_windows_mime) + clipFormat + QLatin1Char('\"');
+                    format = QLatin1String(x_qt_windows_mime) + clipFormat + u'"';
                 else
                     format = clipFormat;
             }
diff --git a/src/plugins/platforms/windows/qwindowsmime.h b/src/plugins/platforms/windows/qwindowsmime.h
index 1c389e8800..f8708f1259 100644
--- a/src/plugins/platforms/windows/qwindowsmime.h
+++ b/src/plugins/platforms/windows/qwindowsmime.h
@@ -43,7 +43,6 @@
 #include <QtCore/qt_windows.h>
 
 #include <QtCore/qvector.h>
-#include <QtCore/qlist.h>
 #include <QtCore/qvariant.h>
 
 QT_BEGIN_NAMESPACE
@@ -95,7 +94,7 @@ public:
 private:
     void ensureInitialized() const;
 
-    mutable QList<QWindowsMime *> m_mimes;
+    mutable QVector<QWindowsMime *> m_mimes;
     mutable int m_internalMimeCount = 0;
 };
 
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 6df5e6aa27..b776efc942 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -165,7 +165,7 @@ void QWindowsMouseHandler::clearEvents()
 
 Qt::MouseButtons QWindowsMouseHandler::queryMouseButtons()
 {
-    Qt::MouseButtons result = nullptr;
+    Qt::MouseButtons result;
     const bool mouseSwapped = GetSystemMetrics(SM_SWAPBUTTON);
     if (GetAsyncKeyState(VK_LBUTTON) < 0)
         result |= mouseSwapped ? Qt::RightButton: Qt::LeftButton;
@@ -630,7 +630,7 @@ bool QWindowsMouseHandler::translateTouchEvent(QWindow *window, HWND,
 
     QTouchPointList touchPoints;
     touchPoints.reserve(winTouchPointCount);
-    Qt::TouchPointStates allStates = nullptr;
+    Qt::TouchPointStates allStates;
 
     GetTouchInputInfo(reinterpret_cast<HTOUCHINPUT>(msg.lParam),
                       UINT(msg.wParam), winTouchInputs.data(), sizeof(TOUCHINPUT));
diff --git a/src/plugins/platforms/windows/qwindowsopengltester.cpp b/src/plugins/platforms/windows/qwindowsopengltester.cpp
index afc1991e2c..72092a4481 100644
--- a/src/plugins/platforms/windows/qwindowsopengltester.cpp
+++ b/src/plugins/platforms/windows/qwindowsopengltester.cpp
@@ -206,7 +206,7 @@ QString GpuDescription::toString() const
     str <<   "         Card name         : " << description
         << "\n       Driver Name         : " << driverName
         << "\n    Driver Version         : " << driverVersion.toString()
-        << "\n         Vendor ID         : 0x" << qSetPadChar(QLatin1Char('0'))
+        << "\n         Vendor ID         : 0x" << qSetPadChar(u'0')
         << Qt::uppercasedigits << Qt::hex << qSetFieldWidth(4) << vendorId
         << "\n         Device ID         : 0x" << qSetFieldWidth(4) << deviceId
         << "\n         SubSys ID         : 0x" << qSetFieldWidth(8) << subSysId
@@ -285,7 +285,7 @@ static inline QString resolveBugListFile(const QString &fileName)
     // then resolve via QStandardPaths::ConfigLocation.
     const QString settingsPath = QLibraryInfo::location(QLibraryInfo::SettingsPath);
     if (!settingsPath.isEmpty()) { // SettingsPath is empty unless specified in qt.conf.
-        const QFileInfo fi(settingsPath + QLatin1Char('/') + fileName);
+        const QFileInfo fi(settingsPath + u'/' + fileName);
         if (fi.isFile())
             return fi.absoluteFilePath();
     }
diff --git a/src/plugins/platforms/windows/qwindowspointerhandler.cpp b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
index cffd8427a2..fba24d8696 100644
--- a/src/plugins/platforms/windows/qwindowspointerhandler.cpp
+++ b/src/plugins/platforms/windows/qwindowspointerhandler.cpp
@@ -482,7 +482,7 @@ bool QWindowsPointerHandler::translateTouchEvent(QWindow *window, HWND hwnd,
                 << " message=" << Qt::hex << msg.message
                 << " count=" << Qt::dec << count;
 
-    Qt::TouchPointStates allStates = nullptr;
+    Qt::TouchPointStates allStates;
 
     for (quint32 i = 0; i < count; ++i) {
         if (QWindowsContext::verbose > 1)
@@ -579,7 +579,9 @@ bool QWindowsPointerHandler::translatePenEvent(QWindow *window, HWND hwnd, QtWin
 
     const QTabletEvent::TabletDevice device = QTabletEvent::Stylus;
     QTabletEvent::PointerType type;
-    Qt::MouseButtons mouseButtons;
+    // Since it may be the middle button, so if the checks fail then it should
+    // be set to Middle if it was used.
+    Qt::MouseButtons mouseButtons = queryMouseButtons();
 
     const bool pointerInContact = IS_POINTER_INCONTACT_WPARAM(msg.wParam);
     if (pointerInContact)
diff --git a/src/plugins/platforms/windows/qwindowsscreen.cpp b/src/plugins/platforms/windows/qwindowsscreen.cpp
index df63adf558..c7a0c2e62e 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.cpp
+++ b/src/plugins/platforms/windows/qwindowsscreen.cpp
@@ -73,7 +73,7 @@ static inline QDpi monitorDPI(HMONITOR hMonitor)
     return {0, 0};
 }
 
-using WindowsScreenDataList = QList<QWindowsScreenData>;
+using WindowsScreenDataList = QVector<QWindowsScreenData>;
 
 static bool monitorData(HMONITOR hMonitor, QWindowsScreenData *data)
 {
@@ -87,7 +87,7 @@ static bool monitorData(HMONITOR hMonitor, QWindowsScreenData *data)
     data->geometry = QRect(QPoint(info.rcMonitor.left, info.rcMonitor.top), QPoint(info.rcMonitor.right - 1, info.rcMonitor.bottom - 1));
     data->availableGeometry = QRect(QPoint(info.rcWork.left, info.rcWork.top), QPoint(info.rcWork.right - 1, info.rcWork.bottom - 1));
     data->name = QString::fromWCharArray(info.szDevice);
-    if (data->name == QLatin1String("WinDisc")) {
+    if (data->name == u"WinDisc") {
         data->flags |= QWindowsScreenData::LockScreen;
     } else {
         if (const HDC hdc = CreateDC(info.szDevice, nullptr, nullptr, nullptr)) {
@@ -467,7 +467,7 @@ bool QWindowsScreenManager::handleDisplayChange(WPARAM wParam, LPARAM lParam)
     return false;
 }
 
-static inline int indexOfMonitor(const QList<QWindowsScreen *> &screens,
+static inline int indexOfMonitor(const QWindowsScreenManager::WindowsScreenList &screens,
                                  const QString &monitorName)
 {
     for (int i= 0; i < screens.size(); ++i)
@@ -476,7 +476,7 @@ static inline int indexOfMonitor(const QList<QWindowsScreen *> &screens,
     return -1;
 }
 
-static inline int indexOfMonitor(const QList<QWindowsScreenData> &screenData,
+static inline int indexOfMonitor(const WindowsScreenDataList &screenData,
                                  const QString &monitorName)
 {
     for (int i = 0; i < screenData.size(); ++i)
diff --git a/src/plugins/platforms/windows/qwindowsscreen.h b/src/plugins/platforms/windows/qwindowsscreen.h
index 2fd56f53cf..5c095808f2 100644
--- a/src/plugins/platforms/windows/qwindowsscreen.h
+++ b/src/plugins/platforms/windows/qwindowsscreen.h
@@ -127,7 +127,7 @@ private:
 class QWindowsScreenManager
 {
 public:
-    using WindowsScreenList = QList<QWindowsScreen *>;
+    using WindowsScreenList = QVector<QWindowsScreen *>;
 
     QWindowsScreenManager();
 
diff --git a/src/plugins/platforms/windows/qwindowsservices.cpp b/src/plugins/platforms/windows/qwindowsservices.cpp
index 83b052bb49..6a2708ee26 100644
--- a/src/plugins/platforms/windows/qwindowsservices.cpp
+++ b/src/plugins/platforms/windows/qwindowsservices.cpp
@@ -92,7 +92,7 @@ static inline QString mailCommand()
     // "rundll32.exe .. url.dll,MailToProtocolHandler %l" is returned. Launching it
     // silently fails or brings up a broken dialog after a long time, so exclude it and
     // fall back to ShellExecute() which brings up the URL assocation dialog.
-    if (command.isEmpty() || command.contains(QLatin1String(",MailToProtocolHandler")))
+    if (command.isEmpty() || command.contains(u",MailToProtocolHandler"))
         return QString();
     wchar_t expandedCommand[MAX_PATH] = {0};
     return ExpandEnvironmentStrings(reinterpret_cast<const wchar_t *>(command.utf16()),
@@ -108,7 +108,7 @@ static inline bool launchMail(const QUrl &url)
         return false;
     }
     //Make sure the path for the process is in quotes
-    const QChar doubleQuote = QLatin1Char('"');
+    const QChar doubleQuote = u'"';
     if (!command.startsWith(doubleQuote)) {
         const int exeIndex = command.indexOf(QStringLiteral(".exe "), 0, Qt::CaseInsensitive);
         if (exeIndex != -1) {
@@ -140,7 +140,7 @@ static inline bool launchMail(const QUrl &url)
 bool QWindowsServices::openUrl(const QUrl &url)
 {
     const QString scheme = url.scheme();
-    if (scheme == QLatin1String("mailto") && launchMail(url))
+    if (scheme == u"mailto" && launchMail(url))
         return true;
     return shellExecute(url);
 }
diff --git a/src/plugins/platforms/windows/qwindowssystemtrayicon.cpp b/src/plugins/platforms/windows/qwindowssystemtrayicon.cpp
index f2dba4d06b..66c558df1e 100644
--- a/src/plugins/platforms/windows/qwindowssystemtrayicon.cpp
+++ b/src/plugins/platforms/windows/qwindowssystemtrayicon.cpp
@@ -57,11 +57,13 @@
 #include "qwindowsmenu.h"
 #include "qwindowsscreen.h"
 
+#include <QtGui/qguiapplication.h>
 #include <QtGui/qpixmap.h>
 #include <QtCore/qdebug.h>
 #include <QtCore/qrect.h>
 #include <QtCore/qvector.h>
 #include <QtCore/qsettings.h>
+#include <qpa/qwindowsysteminterface.h>
 
 #include <qt_windows.h>
 #include <commctrl.h>
@@ -134,9 +136,12 @@ static int indexOfHwnd(HWND hwnd)
 extern "C" LRESULT QT_WIN_CALLBACK qWindowsTrayIconWndProc(HWND hwnd, UINT message,
                                                            WPARAM wParam, LPARAM lParam)
 {
+    // QTBUG-79248: Trigger screen update if there are no other windows.
+    if (message == WM_DPICHANGED && QGuiApplication::topLevelWindows().isEmpty())
+        QWindowsContext::instance()->screenManager().handleScreenChanges();
     if (message == MYWM_TASKBARCREATED || message == MYWM_NOTIFYICON
         || message == WM_INITMENU || message == WM_INITMENUPOPUP
-        || message == WM_COMMAND) {
+        || message == WM_CLOSE || message == WM_COMMAND) {
         const int index = indexOfHwnd(hwnd);
         if (index >= 0) {
             MSG msg;
@@ -256,7 +261,7 @@ void QWindowsSystemTrayIcon::showMessage(const QString &title, const QString &me
     // For empty messages, ensures that they show when only title is set
     QString message = messageIn;
     if (message.isEmpty() && !title.isEmpty())
-        message.append(QLatin1Char(' '));
+        message.append(u' ');
 
     NOTIFYICONDATA tnd;
     initNotifyIconData(tnd);
@@ -439,6 +444,9 @@ bool QWindowsSystemTrayIcon::winEvent(const MSG &message, long *result)
     case WM_INITMENUPOPUP:
         QWindowsPopupMenu::notifyAboutToShow(reinterpret_cast<HMENU>(message.wParam));
         break;
+    case WM_CLOSE:
+        QWindowSystemInterface::handleApplicationTermination<QWindowSystemInterface::SynchronousDelivery>();
+        break;
     case WM_COMMAND:
         QWindowsPopupMenu::notifyTriggered(LOWORD(message.wParam));
         break;
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index 40f9652cbd..010aea2068 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -96,7 +96,7 @@ static inline QTextStream& operator<<(QTextStream &str, const QColor &c)
 {
     str.setIntegerBase(16);
     str.setFieldWidth(2);
-    str.setPadChar(QLatin1Char('0'));
+    str.setPadChar(u'0');
     str << " rgb: #" << c.red()  << c.green() << c.blue();
     str.setIntegerBase(10);
     str.setFieldWidth(0);
@@ -164,7 +164,7 @@ public:
         QMutexLocker readyLocker(&m_readyMutex);
         while (!m_cancelled.loadRelaxed()) {
             if (!m_params && !m_cancelled.loadRelaxed()
-                && !m_readyCondition.wait(&m_readyMutex, 1000))
+                && !m_readyCondition.wait(&m_readyMutex, QDeadlineTimer(1000ll)))
                 continue;
 
             if (m_params) {
@@ -189,7 +189,7 @@ public:
             CoUninitialize();
     }
 
-    bool runWithParams(QShGetFileInfoParams *params, unsigned long timeOutMSecs)
+    bool runWithParams(QShGetFileInfoParams *params, qint64 timeOutMSecs)
     {
         QMutexLocker doneLocker(&m_doneMutex);
 
@@ -198,7 +198,7 @@ public:
         m_readyCondition.wakeAll();
         m_readyMutex.unlock();
 
-        return m_doneCondition.wait(&m_doneMutex, timeOutMSecs);
+        return m_doneCondition.wait(&m_doneMutex, QDeadlineTimer(timeOutMSecs));
     }
 
     void cancel()
@@ -220,7 +220,7 @@ private:
 
 static bool shGetFileInfoBackground(const QString &fileName, DWORD attributes,
                                     SHFILEINFO *info, UINT flags,
-                                    unsigned long  timeOutMSecs = 5000)
+                                    qint64 timeOutMSecs = 5000)
 {
     static QShGetFileInfoThread *getFileInfoThread = nullptr;
     if (!getFileInfoThread) {
@@ -731,13 +731,13 @@ static QString dirIconPixmapCacheKey(int iIcon, int iconSize, int imageListSize)
 {
     QString key = QLatin1String("qt_dir_") + QString::number(iIcon);
     if (iconSize == SHGFI_LARGEICON)
-        key += QLatin1Char('l');
+        key += u'l';
     switch (imageListSize) {
     case sHIL_EXTRALARGE:
-        key += QLatin1Char('e');
+        key += u'e';
         break;
     case sHIL_JUMBO:
-        key += QLatin1Char('j');
+        key += u'j';
         break;
     }
     return key;
@@ -815,9 +815,9 @@ QString QWindowsFileIconEngine::cacheKey() const
     // It is faster to just look at the file extensions;
     // avoiding slow QFileInfo::isExecutable() (QTBUG-13182)
     QString suffix = fileInfo().suffix();
-    if (!suffix.compare(QLatin1String("exe"), Qt::CaseInsensitive)
-        || !suffix.compare(QLatin1String("lnk"), Qt::CaseInsensitive)
-        || !suffix.compare(QLatin1String("ico"), Qt::CaseInsensitive)) {
+    if (!suffix.compare(u"exe", Qt::CaseInsensitive)
+        || !suffix.compare(u"lnk", Qt::CaseInsensitive)
+        || !suffix.compare(u"ico", Qt::CaseInsensitive)) {
         return QString();
     }
     return QLatin1String("qt_.")
diff --git a/src/plugins/platforms/windows/qwindowstheme.h b/src/plugins/platforms/windows/qwindowstheme.h
index 07120230ce..7a8c321da4 100644
--- a/src/plugins/platforms/windows/qwindowstheme.h
+++ b/src/plugins/platforms/windows/qwindowstheme.h
@@ -71,7 +71,7 @@ public:
 
     QPixmap standardPixmap(StandardPixmap sp, const QSizeF &size) const override;
 
-    QIcon fileIcon(const QFileInfo &fileInfo, QPlatformTheme::IconOptions iconOptions = nullptr) const override;
+    QIcon fileIcon(const QFileInfo &fileInfo, QPlatformTheme::IconOptions iconOptions = {}) const override;
 
     void windowsThemeChanged(QWindow *window);
     void displayChanged() { refreshIconPixmapSizes(); }
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 5c13bd9650..04596b2d4d 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -253,7 +253,7 @@ QDebug operator<<(QDebug d, const GUID &guid)
 {
     QDebugStateSaver saver(d);
     d.nospace();
-    d << '{' << Qt::hex << Qt::uppercasedigits << qSetPadChar(QLatin1Char('0'))
+    d << '{' << Qt::hex << Qt::uppercasedigits << qSetPadChar(u'0')
       << qSetFieldWidth(8) << guid.Data1
       << qSetFieldWidth(0) << '-' << qSetFieldWidth(4)
       << guid.Data2 << qSetFieldWidth(0) << '-' << qSetFieldWidth(4)
@@ -592,7 +592,7 @@ static QPoint calcPosition(const QWindow *w, const QWindowCreationContextPtr &co
         return posFrame;
 
     // Find the original screen containing the coordinates.
-    const QList<QScreen *> screens = screenForGL->virtualSiblings();
+    const auto screens = screenForGL->virtualSiblings();
     const QScreen *orgScreen = nullptr;
     for (QScreen *screen : screens) {
         if (screen->handle()->availableGeometry().contains(posFrame)) {
@@ -759,7 +759,10 @@ QWindowsWindowData
 
     const QString windowClassName = QWindowsContext::instance()->registerWindowClass(w);
 
-    const QRect rect = QPlatformWindow::initialGeometry(w, data.geometry, defaultWindowWidth, defaultWindowHeight);
+    const QScreen *screen{};
+    const QRect rect = QPlatformWindow::initialGeometry(w, data.geometry,
+                                                        defaultWindowWidth, defaultWindowHeight,
+                                                        &screen);
 
     if (title.isEmpty() && (result.flags & Qt::WindowTitleHint))
         title = topLevel ? qAppName() : w->objectName();
@@ -769,7 +772,9 @@ QWindowsWindowData
 
     // Capture events before CreateWindowEx() returns. The context is cleared in
     // the QWindowsWindow constructor.
-    const QWindowCreationContextPtr context(new QWindowCreationContext(w, data.geometry, rect, data.customMargins, style, exStyle));
+    const QWindowCreationContextPtr context(new QWindowCreationContext(w, screen, data.geometry,
+                                                                       rect, data.customMargins,
+                                                                       style, exStyle));
     QWindowsContext::instance()->setWindowCreationContext(context);
 
     const bool hasFrame = (style & (WS_DLGFRAME | WS_THICKFRAME));
@@ -879,10 +884,10 @@ void WindowCreationData::initialize(const QWindow *w, HWND hwnd, bool frameChang
 
 
 // Scaling helpers for size constraints.
-static QSize toNativeSizeConstrained(QSize dip, const QWindow *w)
+static QSize toNativeSizeConstrained(QSize dip, const QScreen *s)
 {
     if (QHighDpiScaling::isActive()) {
-        const qreal factor = QHighDpiScaling::factor(w);
+        const qreal factor = QHighDpiScaling::factor(s);
         if (!qFuzzyCompare(factor, qreal(1))) {
             if (dip.width() > 0 && dip.width() < QWINDOWSIZE_MAX)
                 dip.setWidth(qRound(qreal(dip.width()) * factor));
@@ -995,11 +1000,12 @@ bool QWindowsGeometryHint::handleCalculateSize(const QMargins &customMargins, co
     return true;
 }
 
-void QWindowsGeometryHint::frameSizeConstraints(const QWindow *w, const QMargins &margins,
+void QWindowsGeometryHint::frameSizeConstraints(const QWindow *w, const QScreen *screen,
+                                                const QMargins &margins,
                                                 QSize *minimumSize, QSize *maximumSize)
 {
-    *minimumSize = toNativeSizeConstrained(w->minimumSize(), w);
-    *maximumSize = toNativeSizeConstrained(w->maximumSize(), w);
+    *minimumSize = toNativeSizeConstrained(w->minimumSize(), screen);
+    *maximumSize = toNativeSizeConstrained(w->maximumSize(), screen);
 
     const int maximumWidth = qMax(maximumSize->width(), minimumSize->width());
     const int maximumHeight = qMax(maximumSize->height(), minimumSize->height());
@@ -1017,12 +1023,13 @@ void QWindowsGeometryHint::frameSizeConstraints(const QWindow *w, const QMargins
 }
 
 void QWindowsGeometryHint::applyToMinMaxInfo(const QWindow *w,
+                                             const QScreen *screen,
                                              const QMargins &margins,
                                              MINMAXINFO *mmi)
 {
     QSize minimumSize;
     QSize maximumSize;
-    frameSizeConstraints(w, margins, &minimumSize, &maximumSize);
+    frameSizeConstraints(w, screen, margins, &minimumSize, &maximumSize);
     qCDebug(lcQpaWindows).nospace() << '>' << __FUNCTION__ << '<' << " min="
         << minimumSize.width() << ',' << minimumSize.height()
         << " max=" << maximumSize.width() << ',' << maximumSize.height()
@@ -1041,6 +1048,13 @@ void QWindowsGeometryHint::applyToMinMaxInfo(const QWindow *w,
     qCDebug(lcQpaWindows).nospace() << '<' << __FUNCTION__ << " out " << *mmi;
 }
 
+void QWindowsGeometryHint::applyToMinMaxInfo(const QWindow *w,
+                                             const QMargins &margins,
+                                             MINMAXINFO *mmi)
+{
+    applyToMinMaxInfo(w, w->screen(), margins, mmi);
+}
+
 bool QWindowsGeometryHint::positionIncludesFrame(const QWindow *w)
 {
     return qt_window_private(const_cast<QWindow *>(w))->positionPolicy
@@ -1226,11 +1240,12 @@ void QWindowsForeignWindow::setVisible(bool visible)
     \ingroup qt-lighthouse-win
 */
 
-QWindowCreationContext::QWindowCreationContext(const QWindow *w,
+QWindowCreationContext::QWindowCreationContext(const QWindow *w, const QScreen *s,
                                                const QRect &geometryIn, const QRect &geometry,
                                                const QMargins &cm,
                                                DWORD style, DWORD exStyle) :
     window(w),
+    screen(s),
     requestedGeometryIn(geometryIn),
     requestedGeometry(geometry),
     obtainedPos(geometryIn.topLeft()),
@@ -1270,7 +1285,7 @@ QWindowCreationContext::QWindowCreationContext(const QWindow *w,
 
 void QWindowCreationContext::applyToMinMaxInfo(MINMAXINFO *mmi) const
 {
-    QWindowsGeometryHint::applyToMinMaxInfo(window, margins + customMargins, mmi);
+    QWindowsGeometryHint::applyToMinMaxInfo(window, screen, margins + customMargins, mmi);
 }
 
 /*!
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 7efbcf900c..1f8800272b 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -66,9 +66,12 @@ struct QWindowsGeometryHint
     static QMargins frame(const QWindow *w, const QRect &geometry,
                           DWORD style, DWORD exStyle);
     static bool handleCalculateSize(const QMargins &customMargins, const MSG &msg, LRESULT *result);
+    static void applyToMinMaxInfo(const QWindow *w, const QScreen *screen,
+                                  const QMargins &margins, MINMAXINFO *mmi);
     static void applyToMinMaxInfo(const QWindow *w, const QMargins &margins,
                                   MINMAXINFO *mmi);
-    static void frameSizeConstraints(const QWindow *w, const QMargins &margins,
+    static void frameSizeConstraints(const QWindow *w, const QScreen *screen,
+                                     const QMargins &margins,
                                      QSize *minimumSize, QSize *maximumSize);
     static inline QPoint mapToGlobal(HWND hwnd, const QPoint &);
     static inline QPoint mapToGlobal(const QWindow *w, const QPoint &);
@@ -80,13 +83,16 @@ struct QWindowsGeometryHint
 
 struct QWindowCreationContext
 {
-    explicit QWindowCreationContext(const QWindow *w,
+    explicit QWindowCreationContext(const QWindow *w, const QScreen *s,
                                     const QRect &geometryIn, const QRect &geometry,
                                     const QMargins &customMargins,
                                     DWORD style, DWORD exStyle);
     void applyToMinMaxInfo(MINMAXINFO *mmi) const;
 
     const QWindow *window;
+    // The screen to use to scale size constraints, etc. Might differ from the
+    // screen of the window after QPlatformWindow::initialGeometry() (QTBUG-77307).
+    const QScreen *screen;
     QRect requestedGeometryIn; // QWindow scaled
     QRect requestedGeometry; // after QPlatformWindow::initialGeometry()
     QPoint obtainedPos;
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaaccessibility.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiaaccessibility.cpp
index c7c0deab3f..32a57473ad 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaaccessibility.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaaccessibility.cpp
@@ -52,6 +52,8 @@
 #include <qpa/qplatformintegration.h>
 #include <QtWindowsUIAutomationSupport/private/qwindowsuiawrapper_p.h>
 
+#include <QtCore/private/qwinregistry_p.h>
+
 QT_BEGIN_NAMESPACE
 
 using namespace QWindowsUiAutomation;
@@ -85,12 +87,63 @@ bool QWindowsUiaAccessibility::handleWmGetObject(HWND hwnd, WPARAM wParam, LPARA
     return false;
 }
 
+// Retrieve sound name by checking the icon property of a message box
+// should it be the event object.
+static QString alertSound(const QObject *object)
+{
+    if (object->inherits("QMessageBox")) {
+        enum MessageBoxIcon { // Keep in sync with QMessageBox::Icon
+            Information = 1,
+            Warning = 2,
+            Critical = 3
+        };
+        switch (object->property("icon").toInt()) {
+        case Information:
+            return QStringLiteral("SystemAsterisk");
+        case Warning:
+            return QStringLiteral("SystemExclamation");
+        case Critical:
+            return QStringLiteral("SystemHand");
+        }
+    }
+    return QStringLiteral("SystemAsterisk");
+}
+
+static QString soundFileName(const QString &soundName)
+{
+    const QString key = QStringLiteral("AppEvents\\Schemes\\Apps\\.Default\\")
+        + soundName + QStringLiteral("\\.Current");
+    return QWinRegistryKey(HKEY_CURRENT_USER, key).stringValue(L"");
+}
+
+static void playSystemSound(const QString &soundName)
+{
+    if (!soundName.isEmpty() && !soundFileName(soundName).isEmpty()) {
+        PlaySound(reinterpret_cast<const wchar_t *>(soundName.utf16()), nullptr,
+                  SND_ALIAS | SND_ASYNC | SND_NODEFAULT | SND_NOWAIT);
+    }
+}
+
 // Handles accessibility update notifications.
 void QWindowsUiaAccessibility::notifyAccessibilityUpdate(QAccessibleEvent *event)
 {
     if (!event)
         return;
 
+    switch (event->type()) {
+        case QAccessible::PopupMenuStart:
+            playSystemSound(QStringLiteral("MenuPopup"));
+            break;
+        case QAccessible::MenuCommand:
+            playSystemSound(QStringLiteral("MenuCommand"));
+            break;
+        case QAccessible::Alert:
+            playSystemSound(alertSound(event->object()));
+            break;
+        default:
+            break;
+    }
+
     QAccessibleInterface *accessible = event->accessibleInterface();
     if (!isActive() || !accessible || !accessible->isValid())
         return;
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
index b2b401dd40..5f564f81c2 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
@@ -277,8 +277,9 @@ HRESULT QWindowsUiaMainProvider::GetPatternProvider(PATTERNID idPattern, IUnknow
         }
         break;
     case UIA_ValuePatternId:
-        // All accessible controls return text(QAccessible::Value) (which may be empty).
-        *pRetVal = new QWindowsUiaValueProvider(id());
+        // All non-static controls support the Value pattern.
+        if (accessible->role() != QAccessible::StaticText)
+            *pRetVal = new QWindowsUiaValueProvider(id());
         break;
     case UIA_RangeValuePatternId:
         // Controls providing a numeric value within a range (e.g., sliders, scroll bars, dials).
@@ -288,7 +289,8 @@ HRESULT QWindowsUiaMainProvider::GetPatternProvider(PATTERNID idPattern, IUnknow
         break;
     case UIA_TogglePatternId:
         // Checkbox controls.
-        if (accessible->role() == QAccessible::CheckBox) {
+        if (accessible->role() == QAccessible::CheckBox
+                || (accessible->role() == QAccessible::MenuItem && accessible->state().checkable)) {
             *pRetVal = new QWindowsUiaToggleProvider(id());
         }
         break;
@@ -389,7 +391,19 @@ HRESULT QWindowsUiaMainProvider::GetPropertyValue(PROPERTYID idProp, VARIANT *pR
             setVariantI4(UIA_WindowControlTypeId, pRetVal);
         } else {
             // Control type converted from role.
-            setVariantI4(roleToControlTypeId(accessible->role()), pRetVal);
+            auto controlType = roleToControlTypeId(accessible->role());
+
+            // The native OSK should be disbled if the Qt OSK is in use,
+            // or if disabled via application attribute.
+            static bool imModuleEmpty = qEnvironmentVariableIsEmpty("QT_IM_MODULE");
+            bool nativeVKDisabled = QCoreApplication::testAttribute(Qt::AA_MSWindowsDisableVirtualKeyboard);
+
+            // If we want to disable the native OSK auto-showing
+            // we have to report text fields as non-editable.
+            if (controlType == UIA_EditControlTypeId && (!imModuleEmpty || nativeVKDisabled))
+                controlType = UIA_TextControlTypeId;
+
+            setVariantI4(controlType, pRetVal);
         }
         break;
     case UIA_HelpTextPropertyId:
@@ -461,7 +475,7 @@ QString QWindowsUiaMainProvider::automationIdForAccessible(const QAccessibleInte
             if (name.isEmpty())
                 return QString();
             if (!result.isEmpty())
-                result.prepend(QLatin1Char('.'));
+                result.prepend(u'.');
             result.prepend(name);
             obj = obj->parent();
         }
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
index 3305e9c5c4..fb41012cf4 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.cpp
@@ -49,6 +49,7 @@
 #include <QtCore/qloggingcategory.h>
 #include <QtCore/qstring.h>
 #include <QtCore/qlist.h>
+#include <QtCore/qvector.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -78,7 +79,7 @@ HRESULT STDMETHODCALLTYPE QWindowsUiaSelectionProvider::GetSelection(SAFEARRAY *
         return UIA_E_ELEMENTNOTAVAILABLE;
 
     // First put selected items in a list, then build a safe array with the right size.
-    QList<QAccessibleInterface *> selectedList;
+    QVector<QAccessibleInterface *> selectedList;
     for (int i = 0; i < accessible->childCount(); ++i) {
         if (QAccessibleInterface *child = accessible->child(i)) {
             if (child->state().selected) {
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.cpp
index 2a94012590..1348ec7cc0 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.cpp
@@ -80,7 +80,7 @@ HRESULT STDMETHODCALLTYPE QWindowsUiaTableItemProvider::GetRowHeaderItems(SAFEAR
     if (!tableCellInterface)
         return UIA_E_ELEMENTNOTAVAILABLE;
 
-    QList<QAccessibleInterface *> headers = tableCellInterface->rowHeaderCells();
+    const auto headers = tableCellInterface->rowHeaderCells();
 
     if ((*pRetVal = SafeArrayCreateVector(VT_UNKNOWN, 0, headers.size()))) {
         for (LONG i = 0; i < headers.size(); ++i) {
@@ -110,7 +110,7 @@ HRESULT STDMETHODCALLTYPE QWindowsUiaTableItemProvider::GetColumnHeaderItems(SAF
     if (!tableCellInterface)
         return UIA_E_ELEMENTNOTAVAILABLE;
 
-    QList<QAccessibleInterface *> headers = tableCellInterface->columnHeaderCells();
+    const auto headers = tableCellInterface->columnHeaderCells();
 
     if ((*pRetVal = SafeArrayCreateVector(VT_UNKNOWN, 0, headers.size()))) {
         for (LONG i = 0; i < headers.size(); ++i) {
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglcontext.h b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglcontext.h
index c3ce8d8745..fda53f17a1 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglcontext.h
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglcontext.h
@@ -52,7 +52,7 @@ class QXcbEglContext : public QEGLPlatformContext
 public:
     QXcbEglContext(const QSurfaceFormat &glFormat, QPlatformOpenGLContext *share,
                            EGLDisplay display, const QVariant &nativeHandle)
-        : QEGLPlatformContext(glFormat, share, display, 0, nativeHandle)
+        : QEGLPlatformContext(glFormat, share, display, nullptr, nativeHandle)
     {
     }
 
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
index 65beac227c..30e3381993 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_egl/qxcbeglwindow.cpp
@@ -93,7 +93,7 @@ void QXcbEglWindow::create()
 {
     QXcbWindow::create();
 
-    m_surface = eglCreateWindowSurface(m_glIntegration->eglDisplay(), m_config, m_window, 0);
+    m_surface = eglCreateWindowSurface(m_glIntegration->eglDisplay(), m_config, m_window, nullptr);
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
index 2b77062b16..75189a9c80 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
@@ -223,13 +223,13 @@ QGLXContext::QGLXContext(QXcbScreen *screen, const QSurfaceFormat &format, QPlat
                          const QVariant &nativeHandle)
     : QPlatformOpenGLContext()
     , m_display(static_cast<Display *>(screen->connection()->xlib_display()))
-    , m_config(0)
-    , m_context(0)
-    , m_shareContext(0)
+    , m_config(nullptr)
+    , m_context(nullptr)
+    , m_shareContext(nullptr)
     , m_format(format)
     , m_isPBufferCurrent(false)
     , m_ownsContext(nativeHandle.isNull())
-    , m_getGraphicsResetStatus(0)
+    , m_getGraphicsResetStatus(nullptr)
     , m_lost(false)
 {
     if (nativeHandle.isNull())
@@ -254,14 +254,14 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
 
     GLXFBConfig config = qglx_findConfig(m_display, screen->screenNumber(), m_format);
     m_config = config;
-    XVisualInfo *visualInfo = 0;
+    XVisualInfo *visualInfo = nullptr;
     Window window = 0; // Temporary window used to query OpenGL context
 
     if (config) {
         const QByteArrayList glxExt = QByteArray(glXQueryExtensionsString(m_display, screen->screenNumber())).split(' ');
 
         // Resolve entry point for glXCreateContextAttribsARB
-        glXCreateContextAttribsARBProc glXCreateContextAttribsARB = 0;
+        glXCreateContextAttribsARBProc glXCreateContextAttribsARB = nullptr;
         if (glxExt.contains("GLX_ARB_create_context"))
             glXCreateContextAttribsARB = (glXCreateContextAttribsARBProc) glXGetProcAddress((const GLubyte*)"glXCreateContextAttribsARB");
 
@@ -271,7 +271,7 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
 
         // Use glXCreateContextAttribsARB if available
         // Also, GL ES context creation requires GLX_EXT_create_context_es2_profile
-        if (glXCreateContextAttribsARB != 0
+        if (glXCreateContextAttribsARB != nullptr
                 && (m_format.renderableType() != QSurfaceFormat::OpenGLES || (supportsProfiles && glxExt.contains("GLX_EXT_create_context_es2_profile")))) {
             // Try to create an OpenGL context for each known OpenGL version in descending
             // order from the requested version.
@@ -358,9 +358,9 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
                     m_context = glXCreateContextAttribsARB(m_display, config, m_shareContext, true, contextAttributes.data());
                     if (!m_context && m_shareContext) {
                         // re-try without a shared glx context
-                        m_context = glXCreateContextAttribsARB(m_display, config, 0, true, contextAttributes.data());
+                        m_context = glXCreateContextAttribsARB(m_display, config, nullptr, true, contextAttributes.data());
                         if (m_context)
-                            m_shareContext = 0;
+                            m_shareContext = nullptr;
                     }
                 }
             }
@@ -375,9 +375,9 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
             m_context = glXCreateNewContext(m_display, config, GLX_RGBA_TYPE, m_shareContext, true);
             if (!m_context && m_shareContext) {
                 // re-try without a shared glx context
-                m_context = glXCreateNewContext(m_display, config, GLX_RGBA_TYPE, 0, true);
+                m_context = glXCreateNewContext(m_display, config, GLX_RGBA_TYPE, nullptr, true);
                 if (m_context)
-                    m_shareContext = 0;
+                    m_shareContext = nullptr;
             }
         }
 
@@ -399,7 +399,7 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share)
         m_context = glXCreateContext(m_display, visualInfo, m_shareContext, true);
         if (!m_context && m_shareContext) {
             // re-try without a shared glx context
-            m_shareContext = 0;
+            m_shareContext = nullptr;
             m_context = glXCreateContext(m_display, visualInfo, nullptr, true);
         }
 
@@ -429,7 +429,7 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share, const
         qWarning("QGLXContext: Requires a QGLXNativeContext");
         return;
     }
-    QGLXNativeContext handle = nativeHandle.value<QGLXNativeContext>();
+    QGLXNativeContext handle = qvariant_cast<QGLXNativeContext>(nativeHandle);
     GLXContext context = handle.context();
     if (!context) {
         qWarning("QGLXContext: No GLXContext given");
@@ -444,7 +444,7 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share, const
     // Legacy contexts created using glXCreateContext are created using a visual
     // and the FBConfig cannot be queried. The only way to adapt these contexts
     // is to figure out the visual id.
-    XVisualInfo *vinfo = 0;
+    XVisualInfo *vinfo = nullptr;
     // If the VisualID is provided use it.
     VisualID vid = handle.visualId();
     if (!vid) {
@@ -464,13 +464,13 @@ void QGLXContext::init(QXcbScreen *screen, QPlatformOpenGLContext *share, const
         vinfo = XGetVisualInfo(dpy, VisualScreenMask | VisualIDMask, &v, &n);
         if (n < 1) {
             XFree(vinfo);
-            vinfo = 0;
+            vinfo = nullptr;
         }
     }
 
     // For contexts created with an FBConfig using the modern functions providing the
     // visual or window is not mandatory. Just query the config from the context.
-    GLXFBConfig config = 0;
+    GLXFBConfig config = nullptr;
     if (!vinfo) {
         int configId = 0;
         if (glXQueryContext(dpy, context, GLX_FBCONFIG_ID, &configId) != Success) {
@@ -595,8 +595,8 @@ bool QGLXContext::makeCurrent(QPlatformSurface *surface)
         if (interval >= 0 && interval != window->swapInterval() && screen) {
             typedef void (*qt_glXSwapIntervalEXT)(Display *, GLXDrawable, int);
             typedef void (*qt_glXSwapIntervalMESA)(unsigned int);
-            static qt_glXSwapIntervalEXT glXSwapIntervalEXT = 0;
-            static qt_glXSwapIntervalMESA glXSwapIntervalMESA = 0;
+            static qt_glXSwapIntervalEXT glXSwapIntervalEXT = nullptr;
+            static qt_glXSwapIntervalMESA glXSwapIntervalMESA = nullptr;
             static bool resolved = false;
             if (!resolved) {
                 resolved = true;
@@ -621,9 +621,9 @@ bool QGLXContext::makeCurrent(QPlatformSurface *surface)
 void QGLXContext::doneCurrent()
 {
     if (m_isPBufferCurrent)
-        glXMakeContextCurrent(m_display, 0, 0, 0);
+        glXMakeContextCurrent(m_display, 0, 0, nullptr);
     else
-        glXMakeCurrent(m_display, 0, 0);
+        glXMakeCurrent(m_display, 0, nullptr);
     m_isPBufferCurrent = false;
 }
 
@@ -658,12 +658,12 @@ QSurfaceFormat QGLXContext::format() const
 
 bool QGLXContext::isSharing() const
 {
-    return m_shareContext != 0;
+    return m_shareContext != nullptr;
 }
 
 bool QGLXContext::isValid() const
 {
-    return m_context != 0 && !m_lost;
+    return m_context != nullptr && !m_lost;
 }
 
 bool QGLXContext::m_queriedDummyContext = false;
@@ -675,7 +675,7 @@ bool QGLXContext::m_supportsThreading = true;
 // binary search.
 static const char *qglx_threadedgl_blacklist_renderer[] = {
     "Chromium",                             // QTBUG-32225 (initialization fails)
-    0
+    nullptr
 };
 
 static const char *qglx_threadedgl_blacklist_vendor[] = {
@@ -695,7 +695,7 @@ void QGLXContext::queryDummyContext()
         return;
 
     QOpenGLContext *oldContext = QOpenGLContext::currentContext();
-    QSurface *oldSurface = 0;
+    QSurface *oldSurface = nullptr;
     if (oldContext)
         oldSurface = oldContext->surface();
 
@@ -732,7 +732,7 @@ void QGLXContext::queryDummyContext()
 
     if (const char *renderer = (const char *) glGetString(GL_RENDERER)) {
         for (int i = 0; qglx_threadedgl_blacklist_renderer[i]; ++i) {
-            if (strstr(renderer, qglx_threadedgl_blacklist_renderer[i]) != 0) {
+            if (strstr(renderer, qglx_threadedgl_blacklist_renderer[i]) != nullptr) {
                 qCDebug(lcQpaGl).nospace() << "Multithreaded OpenGL disabled: "
                                              "blacklisted renderer \""
                                           << qglx_threadedgl_blacklist_renderer[i]
@@ -744,7 +744,7 @@ void QGLXContext::queryDummyContext()
     }
     if (const char *vendor = (const char *) glGetString(GL_VENDOR)) {
         for (int i = 0; qglx_threadedgl_blacklist_vendor[i]; ++i) {
-            if (strstr(vendor, qglx_threadedgl_blacklist_vendor[i]) != 0) {
+            if (strstr(vendor, qglx_threadedgl_blacklist_vendor[i]) != nullptr) {
                 qCDebug(lcQpaGl).nospace() << "Multithreaded OpenGL disabled: "
                                               "blacklisted vendor \""
                                            << qglx_threadedgl_blacklist_vendor[i]
@@ -759,7 +759,7 @@ void QGLXContext::queryDummyContext()
         // Blacklist Mesa drivers due to QTCREATORBUG-10875 (crash in creator),
         // QTBUG-34492 (flickering in fullscreen) and QTBUG-38221
         const char *mesaVersionStr = nullptr;
-        if (strstr(glxvendor, "Mesa Project") != 0) {
+        if (strstr(glxvendor, "Mesa Project") != nullptr) {
             mesaVersionStr = (const char *) glGetString(GL_VERSION);
             m_supportsThreading = false;
         }
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
index 34895caaa2..6814dbd844 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
@@ -133,7 +133,7 @@ bool QXcbGlxIntegration::handleXcbEvent(xcb_generic_event_t *event, uint respons
     Display *xdisplay = static_cast<Display *>(m_connection->xlib_display());
     XLockDisplay(xdisplay);
     bool locked = true;
-    Bool (*proc)(Display*, XEvent*, xEvent*) = XESetWireToEvent(xdisplay, responseType, 0);
+    Bool (*proc)(Display*, XEvent*, xEvent*) = XESetWireToEvent(xdisplay, responseType, nullptr);
     if (proc) {
         XESetWireToEvent(xdisplay, responseType, proc);
         XEvent dummy;
@@ -212,7 +212,7 @@ QPlatformOffscreenSurface *QXcbGlxIntegration::createPlatformOffscreenSurface(QO
     if (glxPbufferUsable)
         return new QGLXPbuffer(surface);
     else
-        return 0; // trigger fallback to hidden QWindow
+        return nullptr; // trigger fallback to hidden QWindow
 
 }
 
diff --git a/src/plugins/platforms/xcb/qxcbatom.cpp b/src/plugins/platforms/xcb/qxcbatom.cpp
index ecb73cb90b..79b5ba06e6 100644
--- a/src/plugins/platforms/xcb/qxcbatom.cpp
+++ b/src/plugins/platforms/xcb/qxcbatom.cpp
@@ -265,7 +265,7 @@ void QXcbAtom::initializeAllAtoms(xcb_connection_t *connection) {
         cookies[i] = xcb_intern_atom(connection, false, strlen(names[i]), names[i]);
 
     for (i = 0; i < QXcbAtom::NAtoms; ++i) {
-        xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(connection, cookies[i], 0);
+        xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(connection, cookies[i], nullptr);
         m_allAtoms[i] = reply->atom;
         free(reply);
     }
diff --git a/src/plugins/platforms/xcb/qxcbbackingstore.cpp b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
index 741317d766..8f55bc2e96 100644
--- a/src/plugins/platforms/xcb/qxcbbackingstore.cpp
+++ b/src/plugins/platforms/xcb/qxcbbackingstore.cpp
@@ -229,7 +229,7 @@ void QXcbBackingStoreImage::resize(const QSize &size)
                                    m_xcb_format->bits_per_pixel,
                                    0, byteOrder,
                                    XCB_IMAGE_ORDER_MSB_FIRST,
-                                   0, ~0, 0);
+                                   nullptr, ~0, nullptr);
 
     const size_t segmentSize = imageDataSize(m_xcb_image);
 
@@ -412,13 +412,13 @@ bool QXcbBackingStoreImage::createSystemVShmSegment(xcb_connection_t *c, size_t
         return false;
     }
 
-    void *addr = shmat(id, 0, 0);
+    void *addr = shmat(id, nullptr, 0);
     if (addr == (void *)-1) {
         qCWarning(lcQpaXcb, "shmat() failed (%d: %s) for id %d", errno, strerror(errno), id);
         return false;
     }
 
-    if (shmctl(id, IPC_RMID, 0) == -1)
+    if (shmctl(id, IPC_RMID, nullptr) == -1)
         qCWarning(lcQpaXcb, "Error while marking the shared memory segment to be destroyed");
 
     const auto seg = xcb_generate_id(c);
@@ -780,7 +780,7 @@ QXcbBackingStore::~QXcbBackingStore()
 QPaintDevice *QXcbBackingStore::paintDevice()
 {
     if (!m_image)
-        return 0;
+        return nullptr;
     return m_rgbImage.isNull() ? m_image->image() : &m_rgbImage;
 }
 
@@ -1036,7 +1036,7 @@ void QXcbSystemTrayBackingStore::recreateImage(QXcbWindow *win, const QSize &siz
     xcb_create_pixmap(xcb_connection(), 32, m_xrenderPixmap, screen->root(), size.width(), size.height());
 
     m_xrenderPicture = xcb_generate_id(xcb_connection());
-    xcb_render_create_picture(xcb_connection(), m_xrenderPicture, m_xrenderPixmap, m_xrenderPictFormat, 0, 0);
+    xcb_render_create_picture(xcb_connection(), m_xrenderPicture, m_xrenderPixmap, m_xrenderPictFormat, 0, nullptr);
 
     // XRender expects premultiplied alpha
     if (m_image)
@@ -1077,7 +1077,7 @@ void QXcbSystemTrayBackingStore::initXRenderMode()
 
     m_windowPicture = xcb_generate_id(conn);
     xcb_void_cookie_t cookie =
-            xcb_render_create_picture_checked(conn, m_windowPicture, platformWindow->xcb_window(), vfmt->format, 0, 0);
+            xcb_render_create_picture_checked(conn, m_windowPicture, platformWindow->xcb_window(), vfmt->format, 0, nullptr);
     xcb_generic_error_t *error = xcb_request_check(conn, cookie);
     if (error) {
         qWarning("QXcbSystemTrayBackingStore: Failed to create Picture with format %x for window %x, error code %d",
diff --git a/src/plugins/platforms/xcb/qxcbclipboard.cpp b/src/plugins/platforms/xcb/qxcbclipboard.cpp
index 2cb6720d40..c2d9d060fb 100644
--- a/src/plugins/platforms/xcb/qxcbclipboard.cpp
+++ b/src/plugins/platforms/xcb/qxcbclipboard.cpp
@@ -226,8 +226,8 @@ QXcbClipboard::QXcbClipboard(QXcbConnection *c)
 {
     Q_ASSERT(QClipboard::Clipboard == 0);
     Q_ASSERT(QClipboard::Selection == 1);
-    m_clientClipboard[QClipboard::Clipboard] = 0;
-    m_clientClipboard[QClipboard::Selection] = 0;
+    m_clientClipboard[QClipboard::Clipboard] = nullptr;
+    m_clientClipboard[QClipboard::Selection] = nullptr;
     m_timestamp[QClipboard::Clipboard] = XCB_CURRENT_TIME;
     m_timestamp[QClipboard::Selection] = XCB_CURRENT_TIME;
     m_owner = connection()->getQtSelectionOwner();
@@ -316,7 +316,7 @@ QClipboard::Mode QXcbClipboard::modeForAtom(xcb_atom_t a) const
 QMimeData * QXcbClipboard::mimeData(QClipboard::Mode mode)
 {
     if (mode > QClipboard::Selection)
-        return 0;
+        return nullptr;
 
     xcb_window_t clipboardOwner = getSelectionOwner(atomForMode(mode));
     if (clipboardOwner == owner()) {
@@ -334,7 +334,7 @@ void QXcbClipboard::setMimeData(QMimeData *data, QClipboard::Mode mode)
     if (mode > QClipboard::Selection)
         return;
 
-    QXcbClipboardMime *xClipboard = 0;
+    QXcbClipboardMime *xClipboard = nullptr;
     // verify if there is data to be cleared on global X Clipboard.
     if (!data) {
         xClipboard = qobject_cast<QXcbClipboardMime *>(mimeData(mode));
@@ -353,7 +353,7 @@ void QXcbClipboard::setMimeData(QMimeData *data, QClipboard::Mode mode)
     if (m_clientClipboard[mode]) {
         if (m_clientClipboard[QClipboard::Clipboard] != m_clientClipboard[QClipboard::Selection])
             delete m_clientClipboard[mode];
-        m_clientClipboard[mode] = 0;
+        m_clientClipboard[mode] = nullptr;
         m_timestamp[mode] = XCB_CURRENT_TIME;
     }
 
@@ -416,7 +416,7 @@ xcb_window_t QXcbClipboard::requestor() const
                           XCB_WINDOW_CLASS_INPUT_OUTPUT,         // window class
                           platformScreen->screen()->root_visual, // visual
                           0,                                     // value mask
-                          0);                                    // value list
+                          nullptr);                                    // value list
 
         QXcbWindow::setWindowTitle(connection(), window,
                                    QStringLiteral("Qt Clipboard Requestor Window"));
@@ -529,7 +529,7 @@ void QXcbClipboard::handleSelectionClearRequest(xcb_selection_clear_event_t *eve
     if (newOwner != XCB_NONE) {
         if (m_clientClipboard[QClipboard::Clipboard] != m_clientClipboard[QClipboard::Selection])
             delete m_clientClipboard[mode];
-        m_clientClipboard[mode] = 0;
+        m_clientClipboard[mode] = nullptr;
         m_timestamp[mode] = XCB_CURRENT_TIME;
     }
 }
@@ -576,7 +576,7 @@ void QXcbClipboard::handleSelectionRequest(xcb_selection_request_event_t *req)
     xcb_atom_t multipleAtom = atom(QXcbAtom::MULTIPLE);
     xcb_atom_t timestampAtom = atom(QXcbAtom::TIMESTAMP);
 
-    struct AtomPair { xcb_atom_t target; xcb_atom_t property; } *multi = 0;
+    struct AtomPair { xcb_atom_t target; xcb_atom_t property; } *multi = nullptr;
     xcb_atom_t multi_type = XCB_NONE;
     int multi_format = 0;
     int nmulti = 0;
@@ -587,7 +587,7 @@ void QXcbClipboard::handleSelectionRequest(xcb_selection_request_event_t *req)
         QByteArray multi_data;
         if (req->property == XCB_NONE
             || !clipboardReadProperty(req->requestor, req->property, false, &multi_data,
-                                           0, &multi_type, &multi_format)
+                                           nullptr, &multi_type, &multi_format)
             || multi_format != 32) {
             // MULTIPLE property not formatted correctly
             xcb_send_event(xcb_connection(), false, req->requestor, XCB_EVENT_MASK_NO_EVENT, (const char *)&event);
@@ -842,7 +842,7 @@ QByteArray QXcbClipboard::clipboardReadIncrementalProperty(xcb_window_t win, xcb
             continue;
         prev_time = event->time;
 
-        if (clipboardReadProperty(win, property, true, &tmp_buf, &length, 0, 0)) {
+        if (clipboardReadProperty(win, property, true, &tmp_buf, &length, nullptr, nullptr)) {
             if (length == 0) {                // no more data, we're done
                 if (nullterm) {
                     buf.resize(offset+1);
@@ -900,7 +900,7 @@ QByteArray QXcbClipboard::getSelection(xcb_atom_t selection, xcb_atom_t target,
         return buf;
 
     xcb_atom_t type;
-    if (clipboardReadProperty(win, property, true, &buf, 0, &type, 0)) {
+    if (clipboardReadProperty(win, property, true, &buf, nullptr, &type, nullptr)) {
         if (type == atom(QXcbAtom::INCR)) {
             int nbytes = buf.size() >= 4 ? *((int*)buf.data()) : 0;
             buf = clipboardReadIncrementalProperty(win, property, nbytes, false);
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index e51c3d0502..435c4aee93 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -184,7 +184,7 @@ QXcbWindow *QXcbConnection::platformWindowFromId(xcb_window_t id)
     QXcbWindowEventListener *listener = m_mapper.value(id, 0);
     if (listener)
         return listener->toWindow();
-    return 0;
+    return nullptr;
 }
 
 #define HANDLE_PLATFORM_WINDOW_EVENT(event_t, windowMember, handler) \
@@ -455,7 +455,7 @@ void QXcbConnection::printXcbError(const char *message, xcb_generic_error_t *err
 
 static Qt::MouseButtons translateMouseButtons(int s)
 {
-    Qt::MouseButtons ret = 0;
+    Qt::MouseButtons ret;
     if (s & XCB_BUTTON_MASK_1)
         ret |= Qt::LeftButton;
     if (s & XCB_BUTTON_MASK_2)
@@ -803,7 +803,7 @@ xcb_window_t QXcbConnection::getQtSelectionOwner()
                           XCB_WINDOW_CLASS_INPUT_OUTPUT,      // window class
                           xcbScreen->root_visual,             // visual
                           0,                                  // value mask
-                          0);                                 // value list
+                          nullptr);                                 // value list
 
         QXcbWindow::setWindowTitle(connection(), m_qtSelectionOwner,
                                    QLatin1String("Qt Selection Owner for ") + QCoreApplication::applicationName());
@@ -830,7 +830,7 @@ xcb_window_t QXcbConnection::clientLeader()
                           0,
                           XCB_WINDOW_CLASS_INPUT_OUTPUT,
                           screen->screen()->root_visual,
-                          0, 0);
+                          0, nullptr);
 
 
         QXcbWindow::setWindowTitle(connection(), m_clientLeader,
@@ -1031,7 +1031,7 @@ void QXcbConnection::sync()
 {
     // from xcb_aux_sync
     xcb_get_input_focus_cookie_t cookie = xcb_get_input_focus(xcb_connection());
-    free(xcb_get_input_focus_reply(xcb_connection(), cookie, 0));
+    free(xcb_get_input_focus_reply(xcb_connection(), cookie, nullptr));
 }
 
 QXcbSystemTrayTracker *QXcbConnection::systemTrayTracker() const
@@ -1049,14 +1049,14 @@ QXcbSystemTrayTracker *QXcbConnection::systemTrayTracker() const
 Qt::MouseButtons QXcbConnection::queryMouseButtons() const
 {
     int stateMask = 0;
-    QXcbCursor::queryPointer(connection(), 0, 0, &stateMask);
+    QXcbCursor::queryPointer(connection(), nullptr, nullptr, &stateMask);
     return translateMouseButtons(stateMask);
 }
 
 Qt::KeyboardModifiers QXcbConnection::queryKeyboardModifiers() const
 {
     int stateMask = 0;
-    QXcbCursor::queryPointer(connection(), 0, 0, &stateMask);
+    QXcbCursor::queryPointer(connection(), nullptr, nullptr, &stateMask);
     return keyboard()->translateModifiers(stateMask);
 }
 
@@ -1114,7 +1114,7 @@ void QXcbSyncWindowRequest::invalidate()
 {
     if (m_window) {
         m_window->clearSyncWindowRequest();
-        m_window = 0;
+        m_window = nullptr;
     }
 }
 
@@ -1134,7 +1134,7 @@ void QXcbConnectionGrabber::release()
 {
     if (m_connection) {
         m_connection->ungrabServer();
-        m_connection = 0;
+        m_connection = nullptr;
     }
 }
 
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index a894944096..2d89b971dc 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -127,7 +127,7 @@ class Q_XCB_EXPORT QXcbConnection : public QXcbBasicConnection
 {
     Q_OBJECT
 public:
-    QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGrabServer, xcb_visualid_t defaultVisualId, const char *displayName = 0);
+    QXcbConnection(QXcbNativeInterface *nativeInterface, bool canGrabServer, xcb_visualid_t defaultVisualId, const char *displayName = nullptr);
     ~QXcbConnection();
 
     QXcbConnection *connection() const { return const_cast<QXcbConnection *>(this); }
@@ -294,7 +294,7 @@ private:
         int deviceId = 0;
         QTabletEvent::PointerType pointerType = QTabletEvent::UnknownPointer;
         QTabletEvent::TabletDevice tool = QTabletEvent::Stylus;
-        Qt::MouseButtons buttons = 0;
+        Qt::MouseButtons buttons;
         qint64 serialId = 0;
         bool inProximity = false;
         struct ValuatorClassInfo {
@@ -318,8 +318,8 @@ private:
         int horizontalIndex = 0;
         double verticalIncrement = 0;
         double horizontalIncrement = 0;
-        Qt::Orientations orientations = 0;
-        Qt::Orientations legacyOrientations = 0;
+        Qt::Orientations orientations;
+        Qt::Orientations legacyOrientations;
         QPointF lastScrollPosition;
     };
     QHash<int, ScrollingDevice> m_scrollingDevices;
@@ -360,7 +360,7 @@ private:
 
     WindowMapper m_mapper;
 
-    Qt::MouseButtons m_buttonState = nullptr;
+    Qt::MouseButtons m_buttonState;
     Qt::MouseButton m_button = Qt::NoButton;
 
     QXcbWindow *m_focusWindow = nullptr;
diff --git a/src/plugins/platforms/xcb/qxcbconnection_basic.cpp b/src/plugins/platforms/xcb/qxcbconnection_basic.cpp
index 1ba4b4a1b9..18dee89adb 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_basic.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_basic.cpp
@@ -93,7 +93,7 @@ static int nullErrorHandler(Display *dpy, XErrorEvent *err)
 static int ioErrorHandler(Display *dpy)
 {
     xcb_connection_t *conn = XGetXCBConnection(dpy);
-    if (conn != NULL) {
+    if (conn != nullptr) {
         /* Print a message with a textual description of the error */
         int code = xcb_connection_has_error(conn);
         const char *str = "Unknown error";
@@ -134,7 +134,7 @@ QXcbBasicConnection::QXcbBasicConnection(const char *displayName)
 
     xcb_extension_t *extensions[] = {
         &xcb_shm_id, &xcb_xfixes_id, &xcb_randr_id, &xcb_shape_id, &xcb_sync_id,
-        &xcb_render_id, &xcb_xkb_id, &xcb_input_id, 0
+        &xcb_render_id, &xcb_xkb_id, &xcb_input_id, nullptr
     };
 
     for (xcb_extension_t **ext_it = extensions; *ext_it; ++ext_it)
diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index 4639185416..2d114c51b3 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -166,7 +166,7 @@ void QXcbConnection::xi2SetupDevice(void *info, bool removeExisting)
         }
         case XCB_INPUT_DEVICE_CLASS_TYPE_BUTTON: {
             auto *bci = reinterpret_cast<xcb_input_button_class_t *>(classinfo);
-            xcb_atom_t *labels = 0;
+            xcb_atom_t *labels = nullptr;
             if (bci->num_buttons >= 5) {
                 labels = xcb_input_button_class_labels(bci);
                 xcb_atom_t label4 = labels[3];
@@ -424,7 +424,7 @@ QXcbConnection::TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
 QXcbConnection::TouchDeviceData *QXcbConnection::populateTouchDevices(void *info)
 {
     auto *deviceinfo = reinterpret_cast<xcb_input_xi_device_info_t *>(info);
-    QTouchDevice::Capabilities caps = 0;
+    QTouchDevice::Capabilities caps;
     int type = -1;
     int maxTouchPoints = 1;
     bool isTouchDevice = false;
@@ -527,7 +527,7 @@ void QXcbConnection::xi2HandleEvent(xcb_ge_event_t *event)
     int sourceDeviceId = xiEvent->deviceid; // may be the master id
     qt_xcb_input_device_event_t *xiDeviceEvent = nullptr;
     xcb_input_enter_event_t *xiEnterEvent = nullptr;
-    QXcbWindowEventListener *eventListener = 0;
+    QXcbWindowEventListener *eventListener = nullptr;
 
     switch (xiEvent->event_type) {
     case XCB_INPUT_BUTTON_PRESS:
@@ -1252,14 +1252,16 @@ void QXcbConnection::xi2ReportTabletEvent(const void *event, TabletData *tabletD
             if (Q_LIKELY(useValuators)) {
                 const qreal value = scaleOneValuator(normalizedValue, physicalScreenArea.x(), physicalScreenArea.width());
                 global.setX(value);
-                local.setX(value - window->handle()->geometry().x());
+                // mapFromGlobal is ok for nested/embedded windows, but works only with whole-number QPoint;
+                // so map it first, then add back the sub-pixel position
+                local.setX(window->mapFromGlobal(QPoint(int(value), 0)).x() + (value - int(value)));
             }
             break;
         case QXcbAtom::AbsY:
             if (Q_LIKELY(useValuators)) {
                 qreal value = scaleOneValuator(normalizedValue, physicalScreenArea.y(), physicalScreenArea.height());
                 global.setY(value);
-                local.setY(value - window->handle()->geometry().y());
+                local.setY(window->mapFromGlobal(QPoint(0, int(value))).y() + (value - int(value)));
             }
             break;
         case QXcbAtom::AbsPressure:
diff --git a/src/plugins/platforms/xcb/qxcbcursor.cpp b/src/plugins/platforms/xcb/qxcbcursor.cpp
index fbadab4d50..639e4f039c 100644
--- a/src/plugins/platforms/xcb/qxcbcursor.cpp
+++ b/src/plugins/platforms/xcb/qxcbcursor.cpp
@@ -67,10 +67,10 @@ enum {
 };
 #undef CursorShape
 
-static PtrXcursorLibraryLoadCursor ptrXcursorLibraryLoadCursor = 0;
-static PtrXcursorLibraryGetTheme ptrXcursorLibraryGetTheme = 0;
-static PtrXcursorLibrarySetTheme ptrXcursorLibrarySetTheme = 0;
-static PtrXcursorLibraryGetDefaultSize ptrXcursorLibraryGetDefaultSize = 0;
+static PtrXcursorLibraryLoadCursor ptrXcursorLibraryLoadCursor = nullptr;
+static PtrXcursorLibraryGetTheme ptrXcursorLibraryGetTheme = nullptr;
+static PtrXcursorLibrarySetTheme ptrXcursorLibrarySetTheme = nullptr;
+static PtrXcursorLibraryGetDefaultSize ptrXcursorLibraryGetDefaultSize = nullptr;
 #endif
 
 static xcb_font_t cursorFont = 0;
@@ -118,7 +118,7 @@ static const uint8_t mcur_fdiag_bits[] = {
 static const uint8_t *cursor_bits16[] = {
     cur_ver_bits, mcur_ver_bits, cur_hor_bits, mcur_hor_bits,
     cur_bdiag_bits, mcur_bdiag_bits, cur_fdiag_bits, mcur_fdiag_bits,
-    0, 0, cur_blank_bits, cur_blank_bits };
+    nullptr, nullptr, cur_blank_bits, cur_blank_bits };
 
 static const uint8_t vsplit_bits[] = {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -219,7 +219,7 @@ static const uint8_t busym_bits[] = {
 
 static const uint8_t * const cursor_bits32[] = {
     vsplit_bits, vsplitm_bits, hsplit_bits, hsplitm_bits,
-    0, 0, 0, 0, whatsthis_bits, whatsthism_bits, busy_bits, busym_bits
+    nullptr, nullptr, nullptr, nullptr, whatsthis_bits, whatsthism_bits, busy_bits, busym_bits
 };
 
 static const uint8_t forbidden_bits[] = {
@@ -452,19 +452,19 @@ xcb_cursor_t QXcbCursor::createNonStandardCursor(int cshape)
 
     if (cshape == Qt::BlankCursor) {
         xcb_pixmap_t cp = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(), cur_blank_bits, 16, 16,
-                                                             1, 0, 0, 0);
+                                                             1, 0, 0, nullptr);
         xcb_pixmap_t mp = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(), cur_blank_bits, 16, 16,
-                                                             1, 0, 0, 0);
+                                                             1, 0, 0, nullptr);
         cursor = xcb_generate_id(conn);
         xcb_create_cursor(conn, cursor, cp, mp, 0, 0, 0, 0xFFFF, 0xFFFF, 0xFFFF, 8, 8);
     } else if (cshape >= Qt::SizeVerCursor && cshape < Qt::SizeAllCursor) {
         int i = (cshape - Qt::SizeVerCursor) * 2;
         xcb_pixmap_t pm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                              const_cast<uint8_t*>(cursor_bits16[i]),
-                                                             16, 16, 1, 0, 0, 0);
+                                                             16, 16, 1, 0, 0, nullptr);
         xcb_pixmap_t pmm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                               const_cast<uint8_t*>(cursor_bits16[i + 1]),
-                                                              16, 16, 1, 0, 0, 0);
+                                                              16, 16, 1, 0, 0, nullptr);
         cursor = xcb_generate_id(conn);
         xcb_create_cursor(conn, cursor, pm, pmm, 0, 0, 0, 0xFFFF, 0xFFFF, 0xFFFF, 8, 8);
     } else if ((cshape >= Qt::SplitVCursor && cshape <= Qt::SplitHCursor)
@@ -472,10 +472,10 @@ xcb_cursor_t QXcbCursor::createNonStandardCursor(int cshape)
         int i = (cshape - Qt::SplitVCursor) * 2;
         xcb_pixmap_t pm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                              const_cast<uint8_t*>(cursor_bits32[i]),
-                                                             32, 32, 1, 0, 0, 0);
+                                                             32, 32, 1, 0, 0, nullptr);
         xcb_pixmap_t pmm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                               const_cast<uint8_t*>(cursor_bits32[i + 1]),
-                                                              32, 32, 1, 0, 0, 0);
+                                                              32, 32, 1, 0, 0, nullptr);
         int hs = (cshape == Qt::PointingHandCursor || cshape == Qt::WhatsThisCursor
                   || cshape == Qt::BusyCursor) ? 0 : 16;
         cursor = xcb_generate_id(conn);
@@ -484,20 +484,20 @@ xcb_cursor_t QXcbCursor::createNonStandardCursor(int cshape)
         int i = (cshape - Qt::ForbiddenCursor) * 2;
         xcb_pixmap_t pm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                              const_cast<uint8_t*>(cursor_bits20[i]),
-                                                             20, 20, 1, 0, 0, 0);
+                                                             20, 20, 1, 0, 0, nullptr);
         xcb_pixmap_t pmm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                               const_cast<uint8_t*>(cursor_bits20[i + 1]),
-                                                              20, 20, 1, 0, 0, 0);
+                                                              20, 20, 1, 0, 0, nullptr);
         cursor = xcb_generate_id(conn);
         xcb_create_cursor(conn, cursor, pm, pmm, 0, 0, 0, 0xFFFF, 0xFFFF, 0xFFFF, 10, 10);
     } else if (cshape == Qt::OpenHandCursor || cshape == Qt::ClosedHandCursor) {
         bool open = cshape == Qt::OpenHandCursor;
         xcb_pixmap_t pm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                              const_cast<uint8_t*>(open ? openhand_bits : closedhand_bits),
-                                                             16, 16, 1, 0, 0, 0);
+                                                             16, 16, 1, 0, 0, nullptr);
         xcb_pixmap_t pmm = xcb_create_pixmap_from_bitmap_data(conn, m_screen->root(),
                                                              const_cast<uint8_t*>(open ? openhandm_bits : closedhandm_bits),
-                                                             16, 16, 1, 0, 0, 0);
+                                                             16, 16, 1, 0, 0, nullptr);
         cursor = xcb_generate_id(conn);
         xcb_create_cursor(conn, cursor, pm, pmm, 0, 0, 0, 0xFFFF, 0xFFFF, 0xFFFF, 8, 8);
     } else if (cshape == Qt::DragCopyCursor || cshape == Qt::DragMoveCursor
@@ -660,14 +660,14 @@ void QXcbCursor::queryPointer(QXcbConnection *c, QXcbVirtualDesktop **virtualDes
 QPoint QXcbCursor::pos() const
 {
     QPoint p;
-    queryPointer(connection(), 0, &p);
+    queryPointer(connection(), nullptr, &p);
     return p;
 }
 
 void QXcbCursor::setPos(const QPoint &pos)
 {
     QXcbVirtualDesktop *virtualDesktop = nullptr;
-    queryPointer(connection(), &virtualDesktop, 0);
+    queryPointer(connection(), &virtualDesktop, nullptr);
     xcb_warp_pointer(xcb_connection(), XCB_NONE, virtualDesktop->root(), 0, 0, 0, 0, pos.x(), pos.y());
     xcb_flush(xcb_connection());
 }
diff --git a/src/plugins/platforms/xcb/qxcbdrag.cpp b/src/plugins/platforms/xcb/qxcbdrag.cpp
index 3d525598ca..47d58fa880 100644
--- a/src/plugins/platforms/xcb/qxcbdrag.cpp
+++ b/src/plugins/platforms/xcb/qxcbdrag.cpp
@@ -148,7 +148,7 @@ void QXcbDrag::init()
     source_time = XCB_CURRENT_TIME;
     target_time = XCB_CURRENT_TIME;
 
-    QXcbCursor::queryPointer(connection(), &current_virtual_desktop, 0);
+    QXcbCursor::queryPointer(connection(), &current_virtual_desktop, nullptr);
     drag_types.clear();
 
     //current_embedding_widget = 0;
@@ -384,13 +384,13 @@ void QXcbDrag::move(const QPoint &globalPos, Qt::MouseButtons b, Qt::KeyboardMod
     if (!findXdndAwareTarget(globalPos, &target))
         return;
 
-    QXcbWindow *w = 0;
+    QXcbWindow *w = nullptr;
     if (target) {
         w = connection()->platformWindowFromId(target);
         if (w && (w->window()->type() == Qt::Desktop) /*&& !w->acceptDrops()*/)
-            w = 0;
+            w = nullptr;
     } else {
-        w = 0;
+        w = nullptr;
         target = current_virtual_desktop->root();
     }
 
@@ -522,7 +522,7 @@ void QXcbDrag::drop(const QPoint &globalPos, Qt::MouseButtons b, Qt::KeyboardMod
     QXcbWindow *w = connection()->platformWindowFromId(current_proxy_target);
 
     if (w && w->window()->type() == Qt::Desktop) // && !w->acceptDrops()
-        w = 0;
+        w = nullptr;
 
     Transaction t = {
         connection()->time(),
@@ -716,7 +716,7 @@ void QXcbDrag::handle_xdnd_position(QPlatformWindow *w, const xcb_client_message
         target_time = e->data.data32[3];
     }
 
-    QMimeData *dropData = 0;
+    QMimeData *dropData = nullptr;
     Qt::DropActions supported_actions = Qt::IgnoreAction;
     if (currentDrag()) {
         dropData = currentDrag()->mimeData();
@@ -883,7 +883,7 @@ void QXcbDrag::handleLeave(QPlatformWindow *w, const xcb_client_message_event_t
                 event->data.data32[0], xdnd_dragsource);
     }
 
-    QWindowSystemInterface::handleDrag(w->window(), nullptr, QPoint(), Qt::IgnoreAction, 0, 0);
+    QWindowSystemInterface::handleDrag(w->window(), nullptr, QPoint(), Qt::IgnoreAction, { }, { });
 }
 
 void QXcbDrag::send_leave()
@@ -911,7 +911,7 @@ void QXcbDrag::send_leave()
     QXcbWindow *w = connection()->platformWindowFromId(current_proxy_target);
 
     if (w && (w->window()->type() == Qt::Desktop) /*&& !w->acceptDrops()*/)
-        w = 0;
+        w = nullptr;
 
     qCDebug(lcQpaXDnd) << "sending XdndLeave to target:" << current_target;
 
@@ -945,7 +945,7 @@ void QXcbDrag::handleDrop(QPlatformWindow *, const xcb_client_message_event_t *e
         target_time = l[2];
 
     Qt::DropActions supported_drop_actions;
-    QMimeData *dropData = 0;
+    QMimeData *dropData = nullptr;
     if (currentDrag()) {
         dropData = currentDrag()->mimeData();
         supported_drop_actions = Qt::DropActions(l[4]);
@@ -1152,7 +1152,7 @@ void QXcbDrag::handleSelectionRequest(const xcb_selection_request_event_t *event
         }
     }
 
-    QDrag *transactionDrag = 0;
+    QDrag *transactionDrag = nullptr;
     if (at >= 0) {
         transactionDrag = transactions.at(at).drag;
     } else if (at == -2) {
@@ -1222,7 +1222,7 @@ bool QXcbDrag::dndEnable(QXcbWindow *w, bool on)
         if (w->window()->type() == Qt::Desktop) {
             xcb_delete_property(xcb_connection(), w->xcb_window(), atom(QXcbAtom::XdndProxy));
             delete desktop_proxy;
-            desktop_proxy = 0;
+            desktop_proxy = nullptr;
         } else {
             qCDebug(lcQpaXDnd) << "not deleting XDndAware";
         }
diff --git a/src/plugins/platforms/xcb/qxcbdrag.h b/src/plugins/platforms/xcb/qxcbdrag.h
index 1388e68acc..7bef7a818a 100644
--- a/src/plugins/platforms/xcb/qxcbdrag.h
+++ b/src/plugins/platforms/xcb/qxcbdrag.h
@@ -86,7 +86,7 @@ public:
     void handlePosition(QPlatformWindow *w, const xcb_client_message_event_t *event);
     void handleLeave(QPlatformWindow *w, const xcb_client_message_event_t *event);
     void handleDrop(QPlatformWindow *, const xcb_client_message_event_t *event,
-                    Qt::MouseButtons b = nullptr, Qt::KeyboardModifiers mods = nullptr);
+                    Qt::MouseButtons b = { }, Qt::KeyboardModifiers mods = { });
 
     void handleStatus(const xcb_client_message_event_t *event);
     void handleSelectionRequest(const xcb_selection_request_event_t *event);
@@ -109,7 +109,7 @@ private:
     void init();
 
     void handle_xdnd_position(QPlatformWindow *w, const xcb_client_message_event_t *event,
-                              Qt::MouseButtons b = nullptr, Qt::KeyboardModifiers mods = nullptr);
+                              Qt::MouseButtons b = { }, Qt::KeyboardModifiers mods = { });
     void handle_xdnd_status(const xcb_client_message_event_t *event);
     void send_leave();
 
diff --git a/src/plugins/platforms/xcb/qxcbeventqueue.h b/src/plugins/platforms/xcb/qxcbeventqueue.h
index 11d0b8e963..e7327b3fd6 100644
--- a/src/plugins/platforms/xcb/qxcbeventqueue.h
+++ b/src/plugins/platforms/xcb/qxcbeventqueue.h
@@ -49,6 +49,7 @@
 #include <xcb/xcb.h>
 
 #include <atomic>
+#include <limits>
 
 QT_BEGIN_NAMESPACE
 
@@ -106,7 +107,7 @@ public:
     bool peekEventQueue(PeekerCallback peeker, void *peekerData = nullptr,
                         PeekOptions option = PeekDefault, qint32 peekerId = -1);
 
-    void waitForNewEvents(unsigned long time = ULONG_MAX);
+    void waitForNewEvents(unsigned long time = std::numeric_limits<unsigned long>::max());
 
 private:
     QXcbEventNode *qXcbEventNodeFactory(xcb_generic_event_t *event);
diff --git a/src/plugins/platforms/xcb/qxcbimage.cpp b/src/plugins/platforms/xcb/qxcbimage.cpp
index 8f33e6ed31..b0e610dd51 100644
--- a/src/plugins/platforms/xcb/qxcbimage.cpp
+++ b/src/plugins/platforms/xcb/qxcbimage.cpp
@@ -221,7 +221,7 @@ xcb_pixmap_t qt_xcb_XPixmapFromBitmap(QXcbScreen *screen, const QImage &image)
     for (int i = 0; i < height; i++)
         memcpy(buf + (destLineSize * i), map + (bytesPerLine * i), destLineSize);
     xcb_pixmap_t pm = xcb_create_pixmap_from_bitmap_data(conn, screen->root(), buf,
-                                                         width, height, 1, 0, 0, 0);
+                                                         width, height, 1, 0, 0, nullptr);
     delete[] buf;
     return pm;
 }
@@ -249,7 +249,7 @@ xcb_cursor_t qt_xcb_createCursorXRender(QXcbScreen *screen, const QImage &image,
                                        32, 32, 32, 32,
                                        QSysInfo::ByteOrder == QSysInfo::BigEndian ? XCB_IMAGE_ORDER_MSB_FIRST : XCB_IMAGE_ORDER_LSB_FIRST,
                                        XCB_IMAGE_ORDER_MSB_FIRST,
-                                       0, 0, 0);
+                                       nullptr, 0, nullptr);
     if (!xi) {
         qWarning("qt_xcb_createCursorXRender: xcb_image_create failed");
         return XCB_NONE;
@@ -266,10 +266,10 @@ xcb_cursor_t qt_xcb_createCursorXRender(QXcbScreen *screen, const QImage &image,
     xcb_create_pixmap(conn, 32, pix, screen->root(), w, h);
 
     xcb_render_picture_t pic = xcb_generate_id(conn);
-    xcb_render_create_picture(conn, pic, pix, fmt->id, 0, 0);
+    xcb_render_create_picture(conn, pic, pix, fmt->id, 0, nullptr);
 
     xcb_gcontext_t gc = xcb_generate_id(conn);
-    xcb_create_gc(conn, gc, pix, 0, 0);
+    xcb_create_gc(conn, gc, pix, 0, nullptr);
     xcb_image_put(conn, pix, gc, xi, 0, 0, 0);
     xcb_free_gc(conn, gc);
 
diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index 95ca40fc95..3fd989e1f9 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -130,7 +130,7 @@ QXcbIntegration *QXcbIntegration::m_instance = nullptr;
 
 QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char **argv)
     : m_services(new QGenericUnixServices)
-    , m_instanceName(0)
+    , m_instanceName(nullptr)
     , m_canGrab(true)
     , m_defaultVisualId(UINT_MAX)
 {
@@ -146,7 +146,7 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char
     m_nativeInterface.reset(new QXcbNativeInterface);
 
     // Parse arguments
-    const char *displayName = 0;
+    const char *displayName = nullptr;
     bool noGrabArg = false;
     bool doGrabArg = false;
     if (argc) {
@@ -317,8 +317,7 @@ bool QXcbIntegration::hasCapability(QPlatformIntegration::Capability cap) const
     case OpenGL:
     case ThreadedOpenGL:
     {
-        const auto *connection = qAsConst(m_connections).first();
-        if (const auto *integration = connection->glIntegration())
+        if (const auto *integration = defaultConnection()->glIntegration())
             return cap != ThreadedOpenGL || integration->supportsThreadedOpenGL();
         return false;
     }
diff --git a/src/plugins/platforms/xcb/qxcbkeyboard.cpp b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
index 3caee3f409..e8286381a2 100644
--- a/src/plugins/platforms/xcb/qxcbkeyboard.cpp
+++ b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
@@ -579,7 +579,7 @@ void QXcbKeyboard::selectEvents()
                 required_events,
                 required_map_parts,
                 required_map_parts,
-                0);
+                nullptr);
 
     xcb_generic_error_t *error = xcb_request_check(xcb_connection(), select);
     if (error) {
@@ -620,7 +620,7 @@ void QXcbKeyboard::updateVModMapping()
     vmod_mask = name_reply->virtualMods;
     // find the virtual modifiers for which names are defined.
     for (bit = 1; vmod_mask; bit <<= 1) {
-        vmod_name = 0;
+        vmod_name = nullptr;
 
         if (!(vmod_mask & bit))
             continue;
diff --git a/src/plugins/platforms/xcb/qxcbnativeinterface.cpp b/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
index 81b889a80f..30fa6864ac 100644
--- a/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
+++ b/src/plugins/platforms/xcb/qxcbnativeinterface.cpp
@@ -268,7 +268,7 @@ QPlatformNativeInterface::NativeResourceForIntegrationFunction QXcbNativeInterfa
     if (lowerCaseResource == "peekeventqueue")
         return NativeResourceForIntegrationFunction(reinterpret_cast<void *>(peekEventQueue));
 
-    return 0;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForContextFunction QXcbNativeInterface::nativeResourceFunctionForContext(const QByteArray &resource)
@@ -291,7 +291,7 @@ QPlatformNativeInterface::NativeResourceForScreenFunction QXcbNativeInterface::n
         return NativeResourceForScreenFunction(reinterpret_cast<void *>(setAppTime));
     else if (lowerCaseResource == "setappusertime")
         return NativeResourceForScreenFunction(reinterpret_cast<void *>(setAppUserTime));
-    return 0;
+    return nullptr;
 }
 
 QPlatformNativeInterface::NativeResourceForWindowFunction QXcbNativeInterface::nativeResourceFunctionForWindow(const QByteArray &resource)
@@ -365,7 +365,7 @@ void *QXcbNativeInterface::startupId()
     QXcbConnection *defaultConnection = integration->defaultConnection();
     if (defaultConnection)
         return reinterpret_cast<void *>(const_cast<char *>(defaultConnection->startupId().constData()));
-    return 0;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::x11Screen()
@@ -374,7 +374,7 @@ void *QXcbNativeInterface::x11Screen()
     QXcbConnection *defaultConnection = integration->defaultConnection();
     if (defaultConnection)
         return reinterpret_cast<void *>(defaultConnection->primaryScreenNumber());
-    return 0;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::rootWindow()
@@ -383,7 +383,7 @@ void *QXcbNativeInterface::rootWindow()
     QXcbConnection *defaultConnection = integration->defaultConnection();
     if (defaultConnection)
         return reinterpret_cast<void *>(defaultConnection->rootWindow());
-    return 0;
+    return nullptr;
 }
 
 void *QXcbNativeInterface::display()
diff --git a/src/plugins/platforms/xcb/qxcbscreen.cpp b/src/plugins/platforms/xcb/qxcbscreen.cpp
index 8da299d491..2426b5243a 100644
--- a/src/plugins/platforms/xcb/qxcbscreen.cpp
+++ b/src/plugins/platforms/xcb/qxcbscreen.cpp
@@ -41,6 +41,7 @@
 #include "qxcbwindow.h"
 #include "qxcbcursor.h"
 #include "qxcbimage.h"
+#include "qxcbintegration.h"
 #include "qnamespace.h"
 #include "qxcbxsettings.h"
 
@@ -49,6 +50,7 @@
 #include <QDebug>
 #include <QtAlgorithms>
 
+#include <qpa/qplatformservices.h>
 #include <qpa/qwindowsysteminterface.h>
 #include <private/qmath_p.h>
 #include <QtGui/private/qhighdpiscaling_p.h>
@@ -318,12 +320,22 @@ bool QXcbVirtualDesktop::xResource(const QByteArray &identifier,
 
 static bool parseXftInt(const QByteArray& stringValue, int *value)
 {
-    Q_ASSERT(value != 0);
+    Q_ASSERT(value);
     bool ok;
     *value = stringValue.toInt(&ok);
     return ok;
 }
 
+static bool parseXftDpi(const QByteArray& stringValue, int *value)
+{
+    Q_ASSERT(value);
+    bool ok = parseXftInt(stringValue, value);
+    // Support GNOME 3 bug that wrote DPI with fraction:
+    if (!ok)
+        *value = qRound(stringValue.toDouble(&ok));
+    return ok;
+}
+
 static QFontEngine::HintStyle parseXftHintStyle(const QByteArray& stringValue)
 {
     if (stringValue == "hintfull")
@@ -356,6 +368,15 @@ static QFontEngine::SubpixelAntialiasingType parseXftRgba(const QByteArray& stri
 
 void QXcbVirtualDesktop::readXResources()
 {
+    const QPlatformServices *services = QXcbIntegration::instance()->services();
+    bool useXftConf = false;
+    if (services) {
+        const QList<QByteArray> desktopEnv = services->desktopEnvironment().split(':');
+        useXftConf = desktopEnv.contains("GNOME") || desktopEnv.contains("UNITY") || desktopEnv.contains("XFCE");
+    }
+    if (!useXftConf)
+        return;
+
     int offset = 0;
     QByteArray resources;
     while (true) {
@@ -380,7 +401,7 @@ void QXcbVirtualDesktop::readXResources()
         int value;
         QByteArray stringValue;
         if (xResource(r, "Xft.dpi:\t", stringValue)) {
-            if (parseXftInt(stringValue, &value))
+            if (parseXftDpi(stringValue, &value))
                 m_forcedDpi = value;
         } else if (xResource(r, "Xft.hintstyle:\t", stringValue)) {
             m_hintStyle = parseXftHintStyle(stringValue);
@@ -457,7 +478,7 @@ const xcb_visualtype_t *QXcbVirtualDesktop::visualForId(xcb_visualid_t visualid)
 {
     QMap<xcb_visualid_t, xcb_visualtype_t>::const_iterator it = m_visuals.find(visualid);
     if (it == m_visuals.constEnd())
-        return 0;
+        return nullptr;
     return &*it;
 }
 
@@ -577,7 +598,7 @@ QWindow *QXcbScreen::topLevelAt(const QPoint &p) const
     do {
         auto translate_reply = Q_XCB_REPLY_UNCHECKED(xcb_translate_coordinates, xcb_connection(), parent, child, x, y);
         if (!translate_reply) {
-            return 0;
+            return nullptr;
         }
 
         parent = child;
@@ -586,14 +607,14 @@ QWindow *QXcbScreen::topLevelAt(const QPoint &p) const
         y = translate_reply->dst_y;
 
         if (!child || child == root)
-            return 0;
+            return nullptr;
 
         QPlatformWindow *platformWindow = connection()->platformWindowFromId(child);
         if (platformWindow)
             return platformWindow->window();
     } while (parent != child);
 
-    return 0;
+    return nullptr;
 }
 
 void QXcbScreen::windowShown(QXcbWindow *window)
diff --git a/src/plugins/platforms/xcb/qxcbsessionmanager.cpp b/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
index f880d4d722..2eb32c069e 100644
--- a/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
+++ b/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
@@ -69,7 +69,7 @@ public Q_SLOTS:
 };
 
 
-static SmcConn smcConnection = 0;
+static SmcConn smcConnection = nullptr;
 static bool sm_interactionActive;
 static bool sm_smActive;
 static int sm_interactStyle;
@@ -81,7 +81,7 @@ static bool sm_phase2;
 static bool sm_in_phase2;
 bool qt_sm_blockUserInput = false;
 
-static QSmSocketReceiver* sm_receiver = 0;
+static QSmSocketReceiver* sm_receiver = nullptr;
 
 static void resetSmState();
 static void sm_setProperty(const char *name, const char *type,
@@ -191,7 +191,7 @@ static void sm_performSaveYourself(QXcbSessionManager *sm)
 
     // generate a new session key
     timeval tv;
-    gettimeofday(&tv, 0);
+    gettimeofday(&tv, nullptr);
     sm->setSessionKey(QString::number(qulonglong(tv.tv_sec)) +
                       QLatin1Char('_') +
                       QString::number(qulonglong(tv.tv_usec)));
@@ -203,7 +203,7 @@ static void sm_performSaveYourself(QXcbSessionManager *sm)
     // tell the session manager about our program in best POSIX style
     sm_setProperty(QString::fromLatin1(SmProgram), argument0);
     // tell the session manager about our user as well.
-    struct passwd *entryPtr = 0;
+    struct passwd *entryPtr = nullptr;
 #if defined(_POSIX_THREAD_SAFE_FUNCTIONS) && (_POSIX_THREAD_SAFE_FUNCTIONS - 0 > 0)
     QVarLengthArray<char, 1024> buf(qMax<long>(sysconf(_SC_GETPW_R_SIZE_MAX), 1024L));
     struct passwd entry;
@@ -329,7 +329,7 @@ static void sm_saveYourselfPhase2Callback(SmcConn smcConn, SmPointer clientData)
 
 void QSmSocketReceiver::socketActivated(int)
 {
-    IceProcessMessages(SmcGetIceConnection(smcConnection), 0, 0);
+    IceProcessMessages(SmcGetIceConnection(smcConnection), nullptr, nullptr);
 }
 
 
@@ -337,11 +337,11 @@ void QSmSocketReceiver::socketActivated(int)
 
 QXcbSessionManager::QXcbSessionManager(const QString &id, const QString &key)
     : QPlatformSessionManager(id, key)
-    , m_eventLoop(0)
+    , m_eventLoop(nullptr)
 {
     resetSmState();
     char cerror[256];
-    char* myId = 0;
+    char* myId = nullptr;
     QByteArray b_id = id.toLatin1();
     char* prevId = b_id.data();
 
@@ -359,7 +359,7 @@ QXcbSessionManager::QXcbSessionManager(const QString &id, const QString &key)
     if (!qEnvironmentVariableIsSet("SESSION_MANAGER"))
         return;
 
-    smcConnection = SmcOpenConnection(0, 0, 1, 0,
+    smcConnection = SmcOpenConnection(nullptr, nullptr, 1, 0,
                                       SmcSaveYourselfProcMask |
                                       SmcDieProcMask |
                                       SmcSaveCompleteProcMask |
@@ -382,8 +382,8 @@ QXcbSessionManager::QXcbSessionManager(const QString &id, const QString &key)
 QXcbSessionManager::~QXcbSessionManager()
 {
     if (smcConnection)
-        SmcCloseConnection(smcConnection, 0, 0);
-    smcConnection = 0;
+        SmcCloseConnection(smcConnection, 0, nullptr);
+    smcConnection = nullptr;
     delete sm_receiver;
 }
 
@@ -411,7 +411,7 @@ bool QXcbSessionManager::allowsInteraction()
         QEventLoop eventLoop;
         m_eventLoop = &eventLoop;
         eventLoop.exec();
-        m_eventLoop = 0;
+        m_eventLoop = nullptr;
 
         sm_waitingForInteraction = false;
         if (sm_smActive) { // not cancelled
@@ -441,7 +441,7 @@ bool QXcbSessionManager::allowsErrorInteraction()
         QEventLoop eventLoop;
         m_eventLoop = &eventLoop;
         eventLoop.exec();
-        m_eventLoop = 0;
+        m_eventLoop = nullptr;
 
         sm_waitingForInteraction = false;
         if (sm_smActive) { // not cancelled
diff --git a/src/plugins/platforms/xcb/qxcbsystemtraytracker.cpp b/src/plugins/platforms/xcb/qxcbsystemtraytracker.cpp
index 684e603fab..ff5ad98cd2 100644
--- a/src/plugins/platforms/xcb/qxcbsystemtraytracker.cpp
+++ b/src/plugins/platforms/xcb/qxcbsystemtraytracker.cpp
@@ -64,11 +64,11 @@ QXcbSystemTrayTracker *QXcbSystemTrayTracker::create(QXcbConnection *connection)
     // Selection, tray atoms for GNOME, NET WM Specification
     const xcb_atom_t trayAtom = connection->atom(QXcbAtom::_NET_SYSTEM_TRAY_OPCODE);
     if (!trayAtom)
-        return 0;
+        return nullptr;
     const QByteArray netSysTray = QByteArrayLiteral("_NET_SYSTEM_TRAY_S") + QByteArray::number(connection->primaryScreenNumber());
     const xcb_atom_t selection = connection->internAtom(netSysTray.constData());
     if (!selection)
-        return 0;
+        return nullptr;
 
     return new QXcbSystemTrayTracker(connection, trayAtom, selection);
 }
diff --git a/src/plugins/platforms/xcb/qxcbvulkaninstance.cpp b/src/plugins/platforms/xcb/qxcbvulkaninstance.cpp
index b3f8a5832d..bb82bcec39 100644
--- a/src/plugins/platforms/xcb/qxcbvulkaninstance.cpp
+++ b/src/plugins/platforms/xcb/qxcbvulkaninstance.cpp
@@ -93,7 +93,7 @@ bool QXcbVulkanInstance::supportsPresent(VkPhysicalDevice physicalDevice,
 
 VkSurfaceKHR QXcbVulkanInstance::createSurface(QXcbWindow *window)
 {
-    VkSurfaceKHR surface = 0;
+    VkSurfaceKHR surface = VK_NULL_HANDLE;
 
     if (!m_createSurface) {
         m_createSurface = reinterpret_cast<PFN_vkCreateXcbSurfaceKHR>(
diff --git a/src/plugins/platforms/xcb/qxcbvulkanwindow.cpp b/src/plugins/platforms/xcb/qxcbvulkanwindow.cpp
index 25bc340f97..a05ecab51d 100644
--- a/src/plugins/platforms/xcb/qxcbvulkanwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbvulkanwindow.cpp
@@ -43,7 +43,7 @@ QT_BEGIN_NAMESPACE
 
 QXcbVulkanWindow::QXcbVulkanWindow(QWindow *window)
     : QXcbWindow(window),
-      m_surface(0)
+      m_surface(VK_NULL_HANDLE)
 {
 }
 
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 76d3545d35..adca902c69 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -174,13 +174,13 @@ static inline XTextProperty* qstringToXTP(Display *dpy, const QString& s)
 {
     #include <X11/Xatom.h>
 
-    static XTextProperty tp = { 0, 0, 0, 0 };
+    static XTextProperty tp = { nullptr, 0, 0, 0 };
     static bool free_prop = true; // we can't free tp.value in case it references
                                   // the data of the static QByteArray below.
     if (tp.value) {
         if (free_prop)
             XFree(tp.value);
-        tp.value = 0;
+        tp.value = nullptr;
         free_prop = true;
     }
 
@@ -191,7 +191,7 @@ static inline XTextProperty* qstringToXTP(Display *dpy, const QString& s)
         QByteArray mapped = mapper->fromUnicode(s);
         char* tl[2];
         tl[0] = mapped.data();
-        tl[1] = 0;
+        tl[1] = nullptr;
         errCode = XmbTextListToTextProperty(dpy, tl, 1, XStdICCTextStyle, &tp);
         if (errCode < 0)
             qCDebug(lcQpaXcb, "XmbTextListToTextProperty result code %d", errCode);
@@ -280,7 +280,7 @@ void QXcbWindow::create()
         m_window = platformScreen->root();
         m_depth = platformScreen->screen()->root_depth;
         m_visualId = platformScreen->screen()->root_visual;
-        const xcb_visualtype_t *visual = 0;
+        const xcb_visualtype_t *visual = nullptr;
         if (connection()->hasDefaultVisualId()) {
             visual = platformScreen->visualForId(connection()->defaultVisualId());
             if (visual)
@@ -819,7 +819,7 @@ bool QXcbWindow::relayFocusToModalWindow() const
     while (w && w->parent())
         w = w->parent();
 
-    QWindow *modalWindow = 0;
+    QWindow *modalWindow = nullptr;
     const bool blocked = QGuiApplicationPrivate::instance()->isWindowBlocked(w, &modalWindow);
     if (blocked && modalWindow != w) {
         modalWindow->requestActivate();
@@ -876,7 +876,7 @@ enum {
 
 QXcbWindow::NetWmStates QXcbWindow::netWmStates()
 {
-    NetWmStates result(0);
+    NetWmStates result;
 
     auto reply = Q_XCB_REPLY_UNCHECKED(xcb_get_property, xcb_connection(),
                                        0, m_window, atom(QXcbAtom::_NET_WM_STATE),
@@ -927,10 +927,10 @@ void QXcbWindow::setWindowFlags(Qt::WindowFlags flags)
 
     xcb_change_window_attributes(xcb_connection(), xcb_window(), mask, values);
 
-    QXcbWindowFunctions::WmWindowTypes wmWindowTypes = 0;
+    QXcbWindowFunctions::WmWindowTypes wmWindowTypes;
     if (window()->dynamicPropertyNames().contains(wm_window_type_property_id)) {
         wmWindowTypes = static_cast<QXcbWindowFunctions::WmWindowTypes>(
-            window()->property(wm_window_type_property_id).value<int>());
+            qvariant_cast<int>(window()->property(wm_window_type_property_id)));
     }
 
     setWmWindowType(wmWindowTypes, flags);
@@ -1063,7 +1063,7 @@ void QXcbWindow::setNetWmStateOnUnmappedWindow()
     if (Q_UNLIKELY(m_mapped))
         qCWarning(lcQpaXcb()) << "internal error: " << Q_FUNC_INFO << "called on mapped window";
 
-    NetWmStates states(0);
+    NetWmStates states;
     const Qt::WindowFlags flags = window()->flags();
     if (flags & Qt::WindowStaysOnTopHint) {
         states |= NetWmStateAbove;
@@ -1193,7 +1193,7 @@ void QXcbWindow::updateNetWmUserTime(xcb_timestamp_t timestamp)
                               XCB_WINDOW_CLASS_INPUT_OUTPUT,   // window class
                               m_visualId,                      // visual
                               0,                               // value mask
-                              0);                              // value list
+                              nullptr);                              // value list
             wid = m_netWmUserTimeWindow;
             xcb_change_property(xcb_connection(), XCB_PROP_MODE_REPLACE, m_window, atom(QXcbAtom::_NET_WM_USER_TIME_WINDOW),
                                 XCB_ATOM_WINDOW, 32, 1, &m_netWmUserTimeWindow);
@@ -1223,7 +1223,7 @@ void QXcbWindow::setTransparentForMouseEvents(bool transparent)
 
     xcb_rectangle_t rectangle;
 
-    xcb_rectangle_t *rect = 0;
+    xcb_rectangle_t *rect = nullptr;
     int nrect = 0;
 
     if (!transparent) {
@@ -1394,6 +1394,8 @@ void QXcbWindow::propagateSizeHints()
     }
 
     xcb_icccm_set_wm_normal_hints(xcb_connection(), m_window, &hints);
+
+    m_sizeHintsScaleFactor = QHighDpiScaling::scaleAndOrigin(screen()).factor;
 }
 
 void QXcbWindow::requestActivateWindow()
@@ -1477,7 +1479,7 @@ uint QXcbWindow::visualIdStatic(QWindow *window)
 
 QXcbWindowFunctions::WmWindowTypes QXcbWindow::wmWindowTypes() const
 {
-    QXcbWindowFunctions::WmWindowTypes result(0);
+    QXcbWindowFunctions::WmWindowTypes result;
 
     auto reply = Q_XCB_REPLY_UNCHECKED(xcb_get_property, xcb_connection(),
                                        0, m_window, atom(QXcbAtom::_NET_WM_WINDOW_TYPE),
@@ -1785,6 +1787,9 @@ void QXcbWindow::handleConfigureNotifyEvent(const xcb_configure_notify_event_t *
     // will make the comparison later.
     QWindowSystemInterface::handleWindowScreenChanged(window(), newScreen->screen());
 
+    if (!qFuzzyCompare(QHighDpiScaling::scaleAndOrigin(newScreen).factor, m_sizeHintsScaleFactor))
+        propagateSizeHints();
+
     // Send the synthetic expose event on resize only when the window is shrinked,
     // because the "XCB_GRAVITY_NORTH_WEST" flag doesn't send it automatically.
     if (!m_oldWindowSize.isEmpty()
@@ -1882,7 +1887,7 @@ void QXcbWindow::handleButtonPressEvent(int event_x, int event_y, int root_x, in
     if (m_embedded && !m_trayIconWindow) {
         if (window() != QGuiApplication::focusWindow()) {
             const QXcbWindow *container = static_cast<const QXcbWindow *>(parent());
-            Q_ASSERT(container != 0);
+            Q_ASSERT(container != nullptr);
 
             sendXEmbedMessage(container->xcb_window(), XEMBED_REQUEST_FOCUS);
         }
@@ -2087,7 +2092,7 @@ void QXcbWindow::handleXIMouseEvent(xcb_ge_event_t *event, Qt::MouseEventSource
 
     const Qt::MouseButton button = conn->xiToQtMouseButton(ev->detail);
 
-    const char *sourceName = 0;
+    const char *sourceName = nullptr;
     if (Q_UNLIKELY(lcQpaXInputEvents().isDebugEnabled())) {
         const QMetaObject *metaObject = qt_getEnumMetaObject(source);
         const QMetaEnum me = metaObject->enumerator(metaObject->indexOfEnumerator(qt_getEnumName(source)));
diff --git a/src/plugins/platforms/xcb/qxcbwindow.h b/src/plugins/platforms/xcb/qxcbwindow.h
index 13b37db028..976a442b11 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.h
+++ b/src/plugins/platforms/xcb/qxcbwindow.h
@@ -278,6 +278,8 @@ protected:
 
     QXcbSyncWindowRequest *m_pendingSyncRequest = nullptr;
     int m_swapInterval = -1;
+
+    qreal m_sizeHintsScaleFactor = 1.0;
 };
 
 class QXcbForeignWindow : public QXcbWindow
diff --git a/src/plugins/platforms/xcb/qxcbxsettings.cpp b/src/plugins/platforms/xcb/qxcbxsettings.cpp
index 88f15e344f..902f196ba9 100644
--- a/src/plugins/platforms/xcb/qxcbxsettings.cpp
+++ b/src/plugins/platforms/xcb/qxcbxsettings.cpp
@@ -256,7 +256,7 @@ QXcbXSettings::QXcbXSettings(QXcbVirtualDesktop *screen)
 QXcbXSettings::~QXcbXSettings()
 {
     delete d_ptr;
-    d_ptr = 0;
+    d_ptr = nullptr;
 }
 
 bool QXcbXSettings::initialized() const