Merge "Merge dev into 5.7" into refs/staging/5.7

62 files changed, 479 insertions, 257 deletions

diff --git a/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp b/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp
index ccf8399e0d..ba02f75963 100644
--- a/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp
+++ b/src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp
@@ -568,6 +568,29 @@ struct A : public B {
 template<> class QTypeInfo<A> : public QTypeInfoMerger<A, B, C, D> {};
 //! [51]
 
+//! [52]
+    struct Foo {
+        void overloadedFunction();
+        void overloadedFunction(int, QString);
+    };
+    ... qOverload<>(&Foo:overloadedFunction)
+    ... qOverload<int, QString>(&Foo:overloadedFunction)
+//! [52]
+
+//! [53]
+    ... QOverload<>::of(&Foo:overloadedFunction)
+    ... QOverload<int, QString>::of(&Foo:overloadedFunction)
+//! [53]
+
+//! [54]
+    struct Foo {
+        void overloadedFunction(int, QString);
+        void overloadedFunction(int, QString) const;
+    };
+    ... qConstOverload<>(&Foo:overloadedFunction)
+    ... qNonConstOverload<int, QString>(&Foo:overloadedFunction)
+//! [54]
+
 //! [qlikely]
     // the condition inside the "if" will be successful most of the times
     for (int i = 1; i <= 365; i++) {
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index a7ed29d859..e4fa0f7391 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -921,6 +921,49 @@ Q_STATIC_ASSERT_X(QT_POINTER_SIZE == sizeof(void *), "QT_POINTER_SIZE defined in
     \sa qMin(), qMax()
 */
 
+/*! \fn auto qOverload(T functionPointer)
+    \relates <QtGlobal>
+    \since 5.7
+
+    qOverload() returns a pointer to an overloaded function. The template
+    parameter is the list of the argument types of the function.
+    \a functionPointer is the pointer to the (member) function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 52
+
+    If a member function is also const-overladed \l qConstOverload and
+    \l qNonConstOverload needs to be used.
+
+    qOverload() needs C++14 enabled. In C++11 only code the helper
+    classes QOverload, QConstOverload, and QNonConstOverload could be used directly:
+
+    \snippet code/src_corelib_global_qglobal.cpp 53
+
+    \sa qConstOverload(), qNonConstOverload()
+*/
+
+/*! \fn auto qConstOverload(T memberFunctionPointer)
+    \relates <QtGlobal>
+    \since 5.7
+
+    qConstOverload() returns a pointer to an constant member function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 54
+
+    \sa qOverload, qNonConstOverload
+*/
+
+/*! \fn auto qNonConstOverload(T memberFunctionPointer)
+    \relates <QtGlobal>
+    \since 5.7
+
+    qNonConstOverload() eturns a pointer to an non constant member function:
+
+    \snippet code/src_corelib_global_qglobal.cpp 54
+
+    \sa qOverload, qNonConstOverload
+*/
+
 /*!
     \macro QT_VERSION_CHECK
     \relates <QtGlobal>
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index 69840996dc..d607b04192 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -1018,6 +1018,66 @@ Q_CORE_EXPORT QString qtTrId(const char *id, int n = -1);
   { return T::dynamic_cast_will_always_fail_because_rtti_is_disabled; }
 #endif
 
+
+#ifdef Q_QDOC
+
+// Just for documentation generation
+auto qOverload(T functionPointer);
+auto qConstOverload(T memberFunctionPointer);
+auto qNonConstOverload(T memberFunctionPointer);
+
+#elif defined(Q_COMPILER_VARIADIC_TEMPLATES)
+
+template <typename... Args>
+struct QNonConstOverload
+{
+    template <typename R, typename T>
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R, typename T>
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+};
+
+template <typename... Args>
+struct QConstOverload
+{
+    template <typename R, typename T>
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R, typename T>
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+};
+
+template <typename... Args>
+struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
+{
+    using QConstOverload<Args...>::of;
+    using QConstOverload<Args...>::operator();
+    using QNonConstOverload<Args...>::of;
+    using QNonConstOverload<Args...>::operator();
+
+    template <typename R>
+    Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+
+    template <typename R>
+    static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    { return ptr; }
+};
+
+#if defined(__cpp_variable_templates) && __cpp_variable_templates >= 201304 // C++14
+template <typename... Args> Q_CONSTEXPR QOverload<Args...> qOverload Q_DECL_UNUSED = {};
+template <typename... Args> Q_CONSTEXPR QConstOverload<Args...> qConstOverload Q_DECL_UNUSED = {};
+template <typename... Args> Q_CONSTEXPR QNonConstOverload<Args...> qNonConstOverload Q_DECL_UNUSED = {};
+#endif
+
+#endif
+
+
 class QByteArray;
 Q_CORE_EXPORT QByteArray qgetenv(const char *varName);
 Q_CORE_EXPORT bool qputenv(const char *varName, const QByteArray& value);
diff --git a/src/corelib/io/qfileselector.cpp b/src/corelib/io/qfileselector.cpp
index 7a9a4b581c..4ac12fc9ea 100644
--- a/src/corelib/io/qfileselector.cpp
+++ b/src/corelib/io/qfileselector.cpp
@@ -396,6 +396,7 @@ void QFileSelectorPrivate::addStatics(const QStringList &statics)
 {
     QMutexLocker locker(&sharedDataMutex);
     sharedData->preloadedStatics << statics;
+    sharedData->staticSelectors.clear();
 }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/io/qtextstream.cpp b/src/corelib/io/qtextstream.cpp
index 9d3689736c..bc4a5fa538 100644
--- a/src/corelib/io/qtextstream.cpp
+++ b/src/corelib/io/qtextstream.cpp
@@ -3130,10 +3130,7 @@ void QTextStream::setGenerateByteOrderMark(bool generate)
 {
     Q_D(QTextStream);
     if (d->writeBuffer.isEmpty()) {
-        if (generate)
-            d->writeConverterState.flags &= ~QTextCodec::IgnoreHeader;
-        else
-            d->writeConverterState.flags |= QTextCodec::IgnoreHeader;
+        d->writeConverterState.flags.setFlag(QTextCodec::IgnoreHeader, !generate);
     }
 }
 
diff --git a/src/corelib/itemmodels/qstringlistmodel.cpp b/src/corelib/itemmodels/qstringlistmodel.cpp
index 61323ad9c7..1a1b2b9fb6 100644
--- a/src/corelib/itemmodels/qstringlistmodel.cpp
+++ b/src/corelib/itemmodels/qstringlistmodel.cpp
@@ -237,8 +237,8 @@ bool QStringListModel::removeRows(int row, int count, const QModelIndex &parent)
 
     beginRemoveRows(QModelIndex(), row, row + count - 1);
 
-    for (int r = 0; r < count; ++r)
-        lst.removeAt(row);
+    const auto it = lst.begin() + row;
+    lst.erase(it, it + count);
 
     endRemoveRows();
 
@@ -274,8 +274,8 @@ void QStringListModel::sort(int, Qt::SortOrder order)
         std::sort(list.begin(), list.end(), decendingLessThan);
 
     lst.clear();
-    QVector<int> forwarding(list.count());
-    for (int i = 0; i < list.count(); ++i) {
+    QVector<int> forwarding(lstCount);
+    for (int i = 0; i < lstCount; ++i) {
         lst.append(list.at(i).first);
         forwarding[list.at(i).second] = i;
     }
diff --git a/src/corelib/kernel/qabstracteventdispatcher.cpp b/src/corelib/kernel/qabstracteventdispatcher.cpp
index 31369f9a09..907b3ccf1f 100644
--- a/src/corelib/kernel/qabstracteventdispatcher.cpp
+++ b/src/corelib/kernel/qabstracteventdispatcher.cpp
@@ -458,7 +458,7 @@ bool QAbstractEventDispatcher::filterNativeEvent(const QByteArray &eventType, vo
     if (!d->eventFilters.isEmpty()) {
         // Raise the loopLevel so that deleteLater() calls in or triggered
         // by event_filter() will be processed from the main event loop.
-        QScopedLoopLevelCounter loopLevelCounter(d->threadData);
+        QScopedScopeLevelCounter scopeLevelCounter(d->threadData);
         for (int i = 0; i < d->eventFilters.size(); ++i) {
             QAbstractNativeEventFilter *filter = d->eventFilters.at(i);
             if (!filter)
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 60f3dc0db0..42bda25be5 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -980,7 +980,7 @@ bool QCoreApplication::notifyInternal2(QObject *receiver, QEvent *event)
     // call overhead.
     QObjectPrivate *d = receiver->d_func();
     QThreadData *threadData = d->threadData;
-    QScopedLoopLevelCounter loopLevelCounter(threadData);
+    QScopedScopeLevelCounter scopeLevelCounter(threadData);
     if (!selfRequired)
         return doNotify(receiver, event);
     return self->notify(receiver, event);
@@ -1193,6 +1193,9 @@ void QCoreApplication::processEvents(QEventLoop::ProcessEventsFlags flags)
 */
 void QCoreApplication::processEvents(QEventLoop::ProcessEventsFlags flags, int maxtime)
 {
+    // ### Qt 6: consider splitting this method into a public and a private
+    //           one, so that a user-invoked processEvents can be detected
+    //           and handled properly.
     QThreadData *data = QThreadData::current();
     if (!data->hasEventDispatcher())
         return;
@@ -1396,8 +1399,24 @@ void QCoreApplication::postEvent(QObject *receiver, QEvent *event, int priority)
 
     if (event->type() == QEvent::DeferredDelete && data == QThreadData::current()) {
         // remember the current running eventloop for DeferredDelete
-        // events posted in the receiver's thread
-        static_cast<QDeferredDeleteEvent *>(event)->level = data->loopLevel;
+        // events posted in the receiver's thread.
+
+        // Events sent by non-Qt event handlers (such as glib) may not
+        // have the scopeLevel set correctly. The scope level makes sure that
+        // code like this:
+        //     foo->deleteLater();
+        //     qApp->processEvents(); // without passing QEvent::DeferredDelete
+        // will not cause "foo" to be deleted before returning to the event loop.
+
+        // If the scope level is 0 while loopLevel != 0, we are called from a
+        // non-conformant code path, and our best guess is that the scope level
+        // should be 1. (Loop level 0 is special: it means that no event loops
+        // are running.)
+        int loopLevel = data->loopLevel;
+        int scopeLevel = data->scopeLevel;
+        if (scopeLevel == 0 && loopLevel != 0)
+            scopeLevel = 1;
+        static_cast<QDeferredDeleteEvent *>(event)->level = loopLevel + scopeLevel;
     }
 
     // delete the event on exceptions to protect against memory leaks till the event is
@@ -1474,6 +1493,9 @@ bool QCoreApplication::compressEvent(QEvent *event, QObject *receiver, QPostEven
 */
 void QCoreApplication::sendPostedEvents(QObject *receiver, int event_type)
 {
+    // ### Qt 6: consider splitting this method into a public and a private
+    //           one, so that a user-invoked sendPostedEvents can be detected
+    //           and handled properly.
     QThreadData *data = QThreadData::current();
 
     QCoreApplicationPrivate::sendPostedEvents(receiver, event_type, data);
@@ -1565,15 +1587,19 @@ void QCoreApplicationPrivate::sendPostedEvents(QObject *receiver, int event_type
         }
 
         if (pe.event->type() == QEvent::DeferredDelete) {
-            // DeferredDelete events are only sent when we are explicitly asked to
-            // (s.a. QEvent::DeferredDelete), and then only if the event loop that
-            // posted the event has returned.
-            int loopLevel = static_cast<QDeferredDeleteEvent *>(pe.event)->loopLevel();
+            // DeferredDelete events are sent either
+            // 1) when the event loop that posted the event has returned; or
+            // 2) if explicitly requested (with QEvent::DeferredDelete) for
+            //    events posted by the current event loop; or
+            // 3) if the event was posted before the outermost event loop.
+
+            int eventLevel = static_cast<QDeferredDeleteEvent *>(pe.event)->loopLevel();
+            int loopLevel = data->loopLevel + data->scopeLevel;
             const bool allowDeferredDelete =
-                (loopLevel > data->loopLevel
-                 || (!loopLevel && data->loopLevel > 0)
+                (eventLevel > loopLevel
+                 || (!eventLevel && loopLevel > 0)
                  || (event_type == QEvent::DeferredDelete
-                     && loopLevel == data->loopLevel));
+                     && eventLevel == loopLevel));
             if (!allowDeferredDelete) {
                 // cannot send deferred delete
                 if (!event_type && !receiver) {
diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index c5a6875a77..1c426225a5 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -333,14 +333,8 @@ const char *QMetaObject::className() const
 */
 QObject *QMetaObject::cast(QObject *obj) const
 {
-    if (obj) {
-        const QMetaObject *m = obj->metaObject();
-        do {
-            if (m == this)
-                return obj;
-        } while ((m = m->d.superdata));
-    }
-    return 0;
+    // ### Qt 6: inline
+    return const_cast<QObject*>(cast(const_cast<const QObject*>(obj)));
 }
 
 /*!
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index dea8c200ef..e3e536d7e1 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -3713,8 +3713,6 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i
             if (receiverInSameThread) {
                 sw.switchSender(receiver, sender, signal_index);
             }
-            const QObjectPrivate::StaticMetaCallFunction callFunction = c->callFunction;
-            const int method_relative = c->method_relative;
             if (c->isSlotObject) {
                 c->slotObj->ref();
                 QScopedPointer<QtPrivate::QSlotObjectBase, QSlotObjectBaseDeleter> obj(c->slotObj);
@@ -3727,10 +3725,12 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i
                 obj.reset();
 
                 locker.relock();
-            } else if (callFunction && c->method_offset <= receiver->metaObject()->methodOffset()) {
+            } else if (c->callFunction && c->method_offset <= receiver->metaObject()->methodOffset()) {
                 //we compare the vtable to make sure we are not in the destructor of the object.
-                locker.unlock();
                 const int methodIndex = c->method();
+                const int method_relative = c->method_relative;
+                const auto callFunction = c->callFunction;
+                locker.unlock();
                 if (qt_signal_spy_callback_set.slot_begin_callback != 0)
                     qt_signal_spy_callback_set.slot_begin_callback(receiver, methodIndex, argv ? argv : empty_argv);
 
@@ -3740,7 +3740,7 @@ void QMetaObject::activate(QObject *sender, int signalOffset, int local_signal_i
                     qt_signal_spy_callback_set.slot_end_callback(receiver, methodIndex);
                 locker.relock();
             } else {
-                const int method = method_relative + c->method_offset;
+                const int method = c->method_relative + c->method_offset;
                 locker.unlock();
 
                 if (qt_signal_spy_callback_set.slot_begin_callback != 0) {
@@ -4538,6 +4538,8 @@ void qDeleteInEventHandler(QObject *o)
 
     make sure to declare the argument type with Q_DECLARE_METATYPE
 
+    Overloaded functions can be resolved with help of \l qOverload.
+
     \note The number of arguments in the signal or slot are limited to 6 if
     the compiler does not support C++11 variadic templates.
  */
@@ -4573,6 +4575,8 @@ void qDeleteInEventHandler(QObject *o)
     However, you should take care that any objects used within the functor
     are still alive when the signal is emitted.
 
+    Overloaded functions can be resolved with help of \l qOverload.
+
     \note If the compiler does not support C++11 variadic templates, the number
     of arguments in the signal or slot are limited to 6, and the functor object
     must not have an overloaded or templated operator().
@@ -4612,6 +4616,8 @@ void qDeleteInEventHandler(QObject *o)
     However, you should take care that any objects used within the functor
     are still alive when the signal is emitted.
 
+    Overloaded functions can be resolved with help of \l qOverload.
+
     \note If the compiler does not support C++11 variadic templates, the number
     of arguments in the signal or slot are limited to 6, and the functor object
     must not have an overloaded or templated operator().
diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index f689ad4d21..48b94abae5 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -56,7 +56,7 @@ QT_BEGIN_NAMESPACE
 */
 
 QThreadData::QThreadData(int initialRefCount)
-    : _ref(initialRefCount), loopLevel(0), thread(0), threadId(0),
+    : _ref(initialRefCount), loopLevel(0), scopeLevel(0), thread(0), threadId(0),
       eventDispatcher(0),
       quitNow(false), canWait(true), isAdopted(false), requiresCoreApplication(true)
 {
diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index 39a41f1ef4..5f7d01f50f 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -280,6 +280,7 @@ private:
 
 public:
     int loopLevel;
+    int scopeLevel;
 
     QStack<QEventLoop *> eventLoops;
     QPostEventList postEventList;
@@ -295,15 +296,15 @@ public:
     bool requiresCoreApplication;
 };
 
-class QScopedLoopLevelCounter
+class QScopedScopeLevelCounter
 {
     QThreadData *threadData;
 public:
-    inline QScopedLoopLevelCounter(QThreadData *threadData)
+    inline QScopedScopeLevelCounter(QThreadData *threadData)
         : threadData(threadData)
-    { ++threadData->loopLevel; }
-    inline ~QScopedLoopLevelCounter()
-    { --threadData->loopLevel; }
+    { ++threadData->scopeLevel; }
+    inline ~QScopedScopeLevelCounter()
+    { --threadData->scopeLevel; }
 };
 
 // thread wrapper for the main() thread
diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index c1a1b9715f..b49c9d683a 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -1803,6 +1803,19 @@ uint qHash(long double key, uint seed) Q_DECL_NOTHROW
     returns \c false.
 */
 
+/*! \fn QPair<iterator, iterator> QHash::equal_range(const Key &key)
+    \since 5.7
+
+    Returns a pair of iterators delimiting the range of values \c{[first, second)}, that
+    are stored under \a key. If the range is empty then both iterators will be equal to end().
+*/
+
+/*!
+    \fn QPair<const_iterator, const_iterator> QHash::equal_range(const Key &key) const
+    \overload
+    \since 5.7
+*/
+
 /*! \typedef QHash::ConstIterator
 
     Qt-style synonym for QHash::const_iterator.
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 819631932b..5e3016d313 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -458,6 +458,8 @@ public:
     inline key_iterator keyBegin() const { return key_iterator(begin()); }
     inline key_iterator keyEnd() const { return key_iterator(end()); }
 
+    QPair<iterator, iterator> equal_range(const Key &key);
+    QPair<const_iterator, const_iterator> equal_range(const Key &key) const Q_DECL_NOTHROW;
     iterator erase(iterator it) { return erase(const_iterator(it.i)); }
     iterator erase(const_iterator it);
 
@@ -945,6 +947,39 @@ Q_OUTOFLINE_TEMPLATE bool QHash<Key, T>::operator==(const QHash &other) const
 }
 
 template <class Key, class T>
+QPair<typename QHash<Key, T>::iterator, typename QHash<Key, T>::iterator> QHash<Key, T>::equal_range(const Key &akey)
+{
+    detach();
+    auto pair = qAsConst(*this).equal_range(akey);
+    return qMakePair(iterator(pair.first.i), iterator(pair.second.i));
+}
+
+template <class Key, class T>
+QPair<typename QHash<Key, T>::const_iterator, typename QHash<Key, T>::const_iterator> QHash<Key, T>::equal_range(const Key &akey) const Q_DECL_NOTHROW
+{
+    uint h;
+    Node *node = *findNode(akey, &h);
+    const_iterator firstIt = const_iterator(node);
+
+    if (node != e) {
+        // equal keys must hash to the same value and so they all
+        // end up in the same bucket. So we can use node->next,
+        // which only works within a bucket, instead of (out-of-line)
+        // QHashData::nextNode()
+        while (node->next != e && node->next->key == akey)
+            node = node->next;
+
+        // 'node' may be the last node in the bucket. To produce the end iterator, we'd
+        // need to enter the next bucket in this case, so we need to use
+        // QHashData::nextNode() here, which, unlike node->next above, can move between
+        // buckets.
+        node = concrete(QHashData::nextNode(reinterpret_cast<QHashData::Node *>(node)));
+    }
+
+    return qMakePair(firstIt, const_iterator(node));
+}
+
+template <class Key, class T>
 class QMultiHash : public QHash<Key, T>
 {
 public:
diff --git a/src/corelib/tools/qrect.cpp b/src/corelib/tools/qrect.cpp
index 6215c534f8..4b6183646b 100644
--- a/src/corelib/tools/qrect.cpp
+++ b/src/corelib/tools/qrect.cpp
@@ -706,6 +706,20 @@ QRect QRect::normalized() const Q_DECL_NOTHROW
     current position.
 */
 
+/*!
+    \fn QRect QRect::transposed() const
+    \since 5.7
+
+    Returns a copy of the rectangle that has its width and height
+    exchanged:
+
+    \code
+    QRect r = {15, 51, 42, 24};
+    r = r.transposed(); // r == {15, 51, 24, 42}
+    \endcode
+
+    \sa QSize::transposed()
+*/
 
 /*!
     \fn void QRect::setRect(int x, int y, int width, int height)
@@ -1842,6 +1856,20 @@ QRectF QRectF::normalized() const Q_DECL_NOTHROW
     current position.
 */
 
+/*!
+    \fn QRectF QRectF::transposed() const
+    \since 5.7
+
+    Returns a copy of the rectangle that has its width and height
+    exchanged:
+
+    \code
+    QRectF r = {1.5, 5.1, 4.2, 2.4};
+    r = r.transposed(); // r == {1.5, 5.1, 2.4, 4.2}
+    \endcode
+
+    \sa QSizeF::transposed()
+*/
 
 /*!
     \fn void QRectF::setRect(qreal x, qreal y, qreal width, qreal height)
diff --git a/src/corelib/tools/qrect.h b/src/corelib/tools/qrect.h
index e90bb8a21e..31fdc8ce6b 100644
--- a/src/corelib/tools/qrect.h
+++ b/src/corelib/tools/qrect.h
@@ -102,6 +102,7 @@ public:
     Q_DECL_RELAXED_CONSTEXPR inline void translate(const QPoint &p) Q_DECL_NOTHROW;
     Q_DECL_CONSTEXPR inline QRect translated(int dx, int dy) const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
     Q_DECL_CONSTEXPR inline QRect translated(const QPoint &p) const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
+    Q_DECL_CONSTEXPR inline QRect transposed() const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
 
     Q_DECL_RELAXED_CONSTEXPR inline void moveTo(int x, int t) Q_DECL_NOTHROW;
     Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPoint &p) Q_DECL_NOTHROW;
@@ -284,6 +285,9 @@ Q_DECL_CONSTEXPR inline QRect QRect::translated(int dx, int dy) const Q_DECL_NOT
 Q_DECL_CONSTEXPR inline QRect QRect::translated(const QPoint &p) const Q_DECL_NOTHROW
 { return QRect(QPoint(x1 + p.x(), y1 + p.y()), QPoint(x2 + p.x(), y2 + p.y())); }
 
+Q_DECL_CONSTEXPR inline QRect QRect::transposed() const Q_DECL_NOTHROW
+{ return QRect(topLeft(), size().transposed()); }
+
 Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(int ax, int ay) Q_DECL_NOTHROW
 {
     x2 += ax - x1;
@@ -551,6 +555,8 @@ public:
     Q_DECL_CONSTEXPR inline QRectF translated(qreal dx, qreal dy) const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
     Q_DECL_CONSTEXPR inline QRectF translated(const QPointF &p) const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
 
+    Q_DECL_CONSTEXPR inline QRectF transposed() const Q_DECL_NOTHROW Q_REQUIRED_RESULT;
+
     Q_DECL_RELAXED_CONSTEXPR inline void moveTo(qreal x, qreal y) Q_DECL_NOTHROW;
     Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPointF &p) Q_DECL_NOTHROW;
 
@@ -751,6 +757,9 @@ Q_DECL_CONSTEXPR inline QRectF QRectF::translated(qreal dx, qreal dy) const Q_DE
 Q_DECL_CONSTEXPR inline QRectF QRectF::translated(const QPointF &p) const Q_DECL_NOTHROW
 { return QRectF(xp + p.x(), yp + p.y(), w, h); }
 
+Q_DECL_CONSTEXPR inline QRectF QRectF::transposed() const Q_DECL_NOTHROW
+{ return QRectF(topLeft(), size().transposed()); }
+
 Q_DECL_RELAXED_CONSTEXPR inline void QRectF::getRect(qreal *ax, qreal *ay, qreal *aaw, qreal *aah) const
 {
     *ax = this->xp;
diff --git a/src/corelib/xml/qxmlstream.h b/src/corelib/xml/qxmlstream.h
index 765b3eeaca..bf6ddefcdd 100644
--- a/src/corelib/xml/qxmlstream.h
+++ b/src/corelib/xml/qxmlstream.h
@@ -99,13 +99,16 @@ class QXmlStreamReaderPrivate;
 class QXmlStreamAttributes;
 class Q_CORE_EXPORT QXmlStreamAttribute {
     QXmlStreamStringRef m_name, m_namespaceUri, m_qualifiedName, m_value;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     void *reserved;
+#endif
     uint m_isDefault : 1;
     friend class QXmlStreamReaderPrivate;
     friend class QXmlStreamAttributes;
 public:
     QXmlStreamAttribute();
     QXmlStreamAttribute(const QString &qualifiedName, const QString &value);
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     QXmlStreamAttribute(const QString &namespaceUri, const QString &name, const QString &value);
     QXmlStreamAttribute(const QXmlStreamAttribute &);
 #ifdef Q_COMPILER_RVALUE_REFS
@@ -132,6 +135,8 @@ public:
 #endif
     QXmlStreamAttribute& operator=(const QXmlStreamAttribute &);
     ~QXmlStreamAttribute();
+#endif // < Qt 6
+
     inline QStringRef namespaceUri() const { return m_namespaceUri; }
     inline QStringRef name() const { return m_name; }
     inline QStringRef qualifiedName() const { return m_qualifiedName; }
@@ -185,15 +190,34 @@ public:
 
 class Q_CORE_EXPORT QXmlStreamNamespaceDeclaration {
     QXmlStreamStringRef m_prefix, m_namespaceUri;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     void *reserved;
+#endif
 
     friend class QXmlStreamReaderPrivate;
 public:
     QXmlStreamNamespaceDeclaration();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     QXmlStreamNamespaceDeclaration(const QXmlStreamNamespaceDeclaration &);
+    QXmlStreamNamespaceDeclaration(QXmlStreamNamespaceDeclaration &&other) Q_DECL_NOTHROW // = default
+        : m_prefix(std::move(other.m_prefix)),
+          m_namespaceUri(std::move(other.m_namespaceUri)),
+          reserved(other.reserved)
+    {
+        other.reserved = nullptr;
+    }
+    QXmlStreamNamespaceDeclaration &operator=(QXmlStreamNamespaceDeclaration &&other) Q_DECL_NOTHROW // = default
+    {
+        m_prefix = std::move(other.m_prefix);
+        m_namespaceUri = std::move(other.m_namespaceUri);
+        qSwap(reserved, other.reserved);
+        return *this;
+    }
     QXmlStreamNamespaceDeclaration(const QString &prefix, const QString &namespaceUri);
     ~QXmlStreamNamespaceDeclaration();
     QXmlStreamNamespaceDeclaration& operator=(const QXmlStreamNamespaceDeclaration &);
+#endif // < Qt 6
+
     inline QStringRef prefix() const { return m_prefix; }
     inline QStringRef namespaceUri() const { return m_namespaceUri; }
     inline bool operator==(const QXmlStreamNamespaceDeclaration &other) const {
@@ -208,14 +232,35 @@ typedef QVector<QXmlStreamNamespaceDeclaration> QXmlStreamNamespaceDeclarations;
 
 class Q_CORE_EXPORT QXmlStreamNotationDeclaration {
     QXmlStreamStringRef m_name, m_systemId, m_publicId;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     void *reserved;
+#endif
 
     friend class QXmlStreamReaderPrivate;
 public:
     QXmlStreamNotationDeclaration();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     ~QXmlStreamNotationDeclaration();
     QXmlStreamNotationDeclaration(const QXmlStreamNotationDeclaration &);
+    QXmlStreamNotationDeclaration(QXmlStreamNotationDeclaration &&other) Q_DECL_NOTHROW // = default
+        : m_name(std::move(other.m_name)),
+          m_systemId(std::move(other.m_systemId)),
+          m_publicId(std::move(other.m_publicId)),
+          reserved(other.reserved)
+    {
+        other.reserved = nullptr;
+    }
     QXmlStreamNotationDeclaration& operator=(const QXmlStreamNotationDeclaration &);
+    QXmlStreamNotationDeclaration &operator=(QXmlStreamNotationDeclaration &&other) Q_DECL_NOTHROW // = default
+    {
+        m_name = std::move(other.m_name);
+        m_systemId = std::move(other.m_systemId);
+        m_publicId = std::move(other.m_publicId);
+        qSwap(reserved, other.reserved);
+        return *this;
+    }
+#endif // < Qt 6
+
     inline QStringRef name() const { return m_name; }
     inline QStringRef systemId() const { return m_systemId; }
     inline QStringRef publicId() const { return m_publicId; }
@@ -232,14 +277,39 @@ typedef QVector<QXmlStreamNotationDeclaration> QXmlStreamNotationDeclarations;
 
 class Q_CORE_EXPORT QXmlStreamEntityDeclaration {
     QXmlStreamStringRef m_name, m_notationName, m_systemId, m_publicId, m_value;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     void *reserved;
+#endif
 
     friend class QXmlStreamReaderPrivate;
 public:
     QXmlStreamEntityDeclaration();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     ~QXmlStreamEntityDeclaration();
     QXmlStreamEntityDeclaration(const QXmlStreamEntityDeclaration &);
+    QXmlStreamEntityDeclaration(QXmlStreamEntityDeclaration &&other) Q_DECL_NOTHROW // = default
+        : m_name(std::move(other.m_name)),
+          m_notationName(std::move(other.m_notationName)),
+          m_systemId(std::move(other.m_systemId)),
+          m_publicId(std::move(other.m_publicId)),
+          m_value(std::move(other.m_value)),
+          reserved(other.reserved)
+    {
+        other.reserved = nullptr;
+    }
     QXmlStreamEntityDeclaration& operator=(const QXmlStreamEntityDeclaration &);
+    QXmlStreamEntityDeclaration &operator=(QXmlStreamEntityDeclaration &&other) Q_DECL_NOTHROW // = default
+    {
+        m_name = std::move(other.m_name);
+        m_notationName = std::move(other.m_notationName);
+        m_systemId = std::move(other.m_systemId);
+        m_publicId = std::move(other.m_publicId);
+        m_value = std::move(other.m_value);
+        qSwap(reserved, other.reserved);
+        return *this;
+    }
+#endif // < Qt 6
+
     inline QStringRef name() const { return m_name; }
     inline QStringRef notationName() const { return m_notationName; }
     inline QStringRef systemId() const { return m_systemId; }
diff --git a/src/gui/image/qbitmap.cpp b/src/gui/image/qbitmap.cpp
index 54a4dc646b..e8405a6d11 100644
--- a/src/gui/image/qbitmap.cpp
+++ b/src/gui/image/qbitmap.cpp
@@ -196,6 +196,8 @@ QBitmap &QBitmap::operator=(const QPixmap &pixmap)
     return *this;
 }
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+
 /*!
   Destroys the bitmap.
 */
@@ -203,6 +205,8 @@ QBitmap::~QBitmap()
 {
 }
 
+#endif
+
 /*!
     \fn void QBitmap::swap(QBitmap &other)
     \since 4.8
diff --git a/src/gui/image/qbitmap.h b/src/gui/image/qbitmap.h
index 878aeaafa3..68727e74b5 100644
--- a/src/gui/image/qbitmap.h
+++ b/src/gui/image/qbitmap.h
@@ -55,7 +55,14 @@ public:
     QBitmap(int w, int h);
     explicit QBitmap(const QSize &);
     explicit QBitmap(const QString &fileName, const char *format = Q_NULLPTR);
+    // ### Qt 6: don't inherit QPixmap
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    QBitmap(const QBitmap &other) : QPixmap(other) {}
+    // QBitmap(QBitmap &&other) : QPixmap(std::move(other)) {} // QPixmap doesn't, yet, have a move ctor
+    QBitmap &operator=(const QBitmap &other) { QPixmap::operator=(other); return *this; }
+    QBitmap &operator=(QBitmap &&other) Q_DECL_NOTHROW { QPixmap::operator=(std::move(other)); return *this; }
     ~QBitmap();
+#endif
 
     QBitmap &operator=(const QPixmap &);
     inline void swap(QBitmap &other) { QPixmap::swap(other); } // prevent QBitmap<->QPixmap swaps
diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index 2b148383b0..620cbde25d 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -51,6 +51,7 @@
 #include "qvariant.h"
 #include "qcache.h"
 #include "qdebug.h"
+#include "qdir.h"
 #include "qpalette.h"
 #include "qmath.h"
 
@@ -1171,6 +1172,8 @@ QIcon QIcon::fromTheme(const QString &name)
 
     if (qtIconCache()->contains(name)) {
         icon = *qtIconCache()->object(name);
+    } else if (QDir::isAbsolutePath(name)) {
+        return QIcon(name);
     } else {
         QPlatformTheme * const platformTheme = QGuiApplicationPrivate::platformTheme();
         bool hasUserTheme = QIconLoader::instance()->hasUserTheme();
diff --git a/src/gui/kernel/qsurfaceformat.cpp b/src/gui/kernel/qsurfaceformat.cpp
index 83481692ff..d7dc0faceb 100644
--- a/src/gui/kernel/qsurfaceformat.cpp
+++ b/src/gui/kernel/qsurfaceformat.cpp
@@ -282,11 +282,8 @@ QSurfaceFormat::~QSurfaceFormat()
 void QSurfaceFormat::setStereo(bool enable)
 {
     QSurfaceFormat::FormatOptions newOptions = d->opts;
-    if (enable) {
-        newOptions |= QSurfaceFormat::StereoBuffers;
-    } else {
-        newOptions &= ~QSurfaceFormat::StereoBuffers;
-    }
+    newOptions.setFlag(QSurfaceFormat::StereoBuffers, enable);
+
     if (int(newOptions) != int(d->opts)) {
         detach();
         d->opts = newOptions;
diff --git a/src/gui/painting/qregion.cpp b/src/gui/painting/qregion.cpp
index 5bfe681e73..d104f9ff5a 100644
--- a/src/gui/painting/qregion.cpp
+++ b/src/gui/painting/qregion.cpp
@@ -210,6 +210,16 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn QRegion::QRegion(QRegion &&other)
+    \since 5.7
+
+    Move-constructs a new region from region \a other.
+    After the call, \a other is null.
+
+    \sa isNull()
+*/
+
+/*!
     \fn QRegion::QRegion(const QBitmap &bm)
 
     Constructs a region from the bitmap \a bm.
diff --git a/src/gui/painting/qregion.h b/src/gui/painting/qregion.h
index 94e2db2648..d66f80fcde 100644
--- a/src/gui/painting/qregion.h
+++ b/src/gui/painting/qregion.h
@@ -68,6 +68,8 @@ public:
     QRegion(const QRect &r, RegionType t = Rectangle);
     QRegion(const QPolygon &pa, Qt::FillRule fillRule = Qt::OddEvenFill);
     QRegion(const QRegion &region);
+    QRegion(QRegion &&other) Q_DECL_NOTHROW
+        : d(other.d) { other.d = const_cast<QRegionData*>(&shared_empty); }
     QRegion(const QBitmap &bitmap);
     ~QRegion();
     QRegion &operator=(const QRegion &);
diff --git a/src/gui/text/qglyphrun.cpp b/src/gui/text/qglyphrun.cpp
index 0988454410..bd44e11dce 100644
--- a/src/gui/text/qglyphrun.cpp
+++ b/src/gui/text/qglyphrun.cpp
@@ -414,10 +414,7 @@ void QGlyphRun::setFlag(GlyphRunFlag flag, bool enabled)
         return;
 
     detach();
-    if (enabled)
-        d->flags |= flag;
-    else
-        d->flags &= ~flag;
+    d->flags.setFlag(flag, enabled);
 }
 
 /*!
diff --git a/src/gui/text/qtextobject.cpp b/src/gui/text/qtextobject.cpp
index 49cf35ecc0..a756549f3e 100644
--- a/src/gui/text/qtextobject.cpp
+++ b/src/gui/text/qtextobject.cpp
@@ -675,7 +675,7 @@ QTextFrame::iterator::iterator(QTextFrame *frame, int block, int begin, int end)
 /*!
     Copy constructor. Constructs a copy of the \a other iterator.
 */
-QTextFrame::iterator::iterator(const iterator &other)
+QTextFrame::iterator::iterator(const iterator &other) Q_DECL_NOTHROW
 {
     f = other.f;
     b = other.b;
@@ -688,7 +688,7 @@ QTextFrame::iterator::iterator(const iterator &other)
     Assigns \a other to this iterator and returns a reference to
     this iterator.
 */
-QTextFrame::iterator &QTextFrame::iterator::operator=(const iterator &other)
+QTextFrame::iterator &QTextFrame::iterator::operator=(const iterator &other) Q_DECL_NOTHROW
 {
     f = other.f;
     b = other.b;
diff --git a/src/gui/text/qtextobject.h b/src/gui/text/qtextobject.h
index 18df53945c..d3f6b3d0ac 100644
--- a/src/gui/text/qtextobject.h
+++ b/src/gui/text/qtextobject.h
@@ -148,10 +148,14 @@ public:
         friend class QTextDocumentLayoutPrivate;
         iterator(QTextFrame *frame, int block, int begin, int end);
     public:
-        iterator();
+        iterator(); // ### Qt 6: inline
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
-        iterator(const iterator &o);
-        iterator &operator=(const iterator &o);
+        iterator(const iterator &o) Q_DECL_NOTHROW; // = default
+        iterator &operator=(const iterator &o) Q_DECL_NOTHROW; // = default
+        iterator(iterator &&other) Q_DECL_NOTHROW // = default
+        { memcpy(this, &other, sizeof(iterator)); }
+        iterator &operator=(iterator &&other) Q_DECL_NOTHROW // = default
+        { memcpy(this, &other, sizeof(iterator)); return *this; }
 #endif
 
         QTextFrame *parentFrame() const { return f; }
diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index 072c5c9ff5..15a886c21d 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -261,15 +261,17 @@ void QHttpNetworkConnectionPrivate::prepareRequest(HttpMessagePair &messagePair)
     // check if Content-Length is provided
     QNonContiguousByteDevice* uploadByteDevice = request.uploadByteDevice();
     if (uploadByteDevice) {
-        if (request.contentLength() != -1 && uploadByteDevice->size() != -1) {
+        const qint64 contentLength = request.contentLength();
+        const qint64 uploadDeviceSize = uploadByteDevice->size();
+        if (contentLength != -1 && uploadDeviceSize != -1) {
             // both values known, take the smaller one.
-            request.setContentLength(qMin(uploadByteDevice->size(), request.contentLength()));
-        } else if (request.contentLength() == -1 && uploadByteDevice->size() != -1) {
+            request.setContentLength(qMin(uploadDeviceSize, contentLength));
+        } else if (contentLength == -1 && uploadDeviceSize != -1) {
             // content length not supplied by user, but the upload device knows it
-            request.setContentLength(uploadByteDevice->size());
-        } else if (request.contentLength() != -1 && uploadByteDevice->size() == -1) {
+            request.setContentLength(uploadDeviceSize);
+        } else if (contentLength != -1 && uploadDeviceSize == -1) {
             // everything OK, the user supplied us the contentLength
-        } else if (Q_UNLIKELY(request.contentLength() == -1 && uploadByteDevice->size() == -1)) {
+        } else if (Q_UNLIKELY(contentLength == -1 && uploadDeviceSize == -1)) {
             qFatal("QHttpNetworkConnectionPrivate: Neither content-length nor upload device size were given");
         }
     }
@@ -1113,11 +1115,12 @@ void QHttpNetworkConnectionPrivate::startHostInfoLookup()
 #endif
     QHostAddress temp;
     if (temp.setAddress(lookupHost)) {
-        if (temp.protocol() == QAbstractSocket::IPv4Protocol) {
+        const QAbstractSocket::NetworkLayerProtocol protocol = temp.protocol();
+        if (protocol == QAbstractSocket::IPv4Protocol) {
             networkLayerState = QHttpNetworkConnectionPrivate::IPv4;
             QMetaObject::invokeMethod(this->q_func(), "_q_startNextRequest", Qt::QueuedConnection);
             return;
-        } else if (temp.protocol() == QAbstractSocket::IPv6Protocol) {
+        } else if (protocol == QAbstractSocket::IPv6Protocol) {
             networkLayerState = QHttpNetworkConnectionPrivate::IPv6;
             QMetaObject::invokeMethod(this->q_func(), "_q_startNextRequest", Qt::QueuedConnection);
             return;
@@ -1146,13 +1149,14 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(const QHostInfo &info)
         return;
 
     foreach (const QHostAddress &address, info.addresses()) {
-        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+        const QAbstractSocket::NetworkLayerProtocol protocol = address.protocol();
+        if (protocol == QAbstractSocket::IPv4Protocol) {
             if (!foundAddress) {
                 foundAddress = true;
                 delayIpv4 = false;
             }
             bIpv4 = true;
-        } else if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+        } else if (protocol == QAbstractSocket::IPv6Protocol) {
             if (!foundAddress) {
                 foundAddress = true;
                 delayIpv4 = true;
@@ -1213,13 +1217,14 @@ void QHttpNetworkConnectionPrivate::startNetworkLayerStateLookup()
         int timeout = 300;
 #ifndef QT_NO_BEARERMANAGEMENT
         if (networkSession) {
-            if (networkSession->configuration().bearerType() == QNetworkConfiguration::Bearer2G)
+            const QNetworkConfiguration::BearerType bearerType = networkSession->configuration().bearerType();
+            if (bearerType == QNetworkConfiguration::Bearer2G)
                 timeout = 800;
-            else if (networkSession->configuration().bearerType() == QNetworkConfiguration::BearerCDMA2000)
+            else if (bearerType == QNetworkConfiguration::BearerCDMA2000)
                 timeout = 500;
-            else if (networkSession->configuration().bearerType() == QNetworkConfiguration::BearerWCDMA)
+            else if (bearerType == QNetworkConfiguration::BearerWCDMA)
                 timeout = 500;
-            else if (networkSession->configuration().bearerType() == QNetworkConfiguration::BearerHSPA)
+            else if (bearerType == QNetworkConfiguration::BearerHSPA)
                 timeout = 400;
         }
 #endif
diff --git a/src/network/access/qspdyprotocolhandler.cpp b/src/network/access/qspdyprotocolhandler.cpp
index d7ca49aa52..f3073dcd3c 100644
--- a/src/network/access/qspdyprotocolhandler.cpp
+++ b/src/network/access/qspdyprotocolhandler.cpp
@@ -476,7 +476,7 @@ QByteArray QSpdyProtocolHandler::composeHeader(const QHttpNetworkRequest &reques
     // calculate additional headers first, because we need to know the size
     // ### do not partially copy the list, but restrict the set header fields
     // in QHttpNetworkConnection
-    QList<QPair<QByteArray, QByteArray> > additionalHeaders;
+    QVector<QPair<QByteArray, QByteArray> > additionalHeaders;
     for (int a = 0; a < request.header().count(); ++a) {
         QByteArray key = request.header().at(a).first;
         if (key == "Connection" || key == "Host" || key == "Keep-Alive"
diff --git a/src/network/ssl/qsslconfiguration.cpp b/src/network/ssl/qsslconfiguration.cpp
index 0cc08b9fcc..f9bb28e033 100644
--- a/src/network/ssl/qsslconfiguration.cpp
+++ b/src/network/ssl/qsslconfiguration.cpp
@@ -664,10 +664,7 @@ QList<QSslCertificate> QSslConfiguration::systemCaCertificates()
 */
 void QSslConfiguration::setSslOption(QSsl::SslOption option, bool on)
 {
-    if (on)
-        d->sslOptions |= option;
-    else
-        d->sslOptions &= ~option;
+    d->sslOptions.setFlag(option, on);
 }
 
 /*!
diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index bf0a2f8dd7..a8409346ba 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -5553,10 +5553,7 @@ QSize QGLTexture::bindCompressedTexturePVR(const char *buf, int len)
 
     // Set the invert flag for the texture.  The "vertical flip"
     // flag in PVR is the opposite sense to our sense of inversion.
-    if ((pvrHeader->flags & PVR_VERTICAL_FLIP) != 0)
-        options &= ~QGLContext::InvertedYBindOption;
-    else
-        options |= QGLContext::InvertedYBindOption;
+    options.setFlag(QGLContext::InvertedYBindOption, !(pvrHeader->flags & PVR_VERTICAL_FLIP));
 
     return QSize(pvrHeader->width, pvrHeader->height);
 }
diff --git a/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp b/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
index ce9043c098..7f73a7ef94 100644
--- a/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
+++ b/src/platformsupport/input/evdevmouse/qevdevmousehandler.cpp
@@ -266,10 +266,7 @@ void QEvdevMouseHandler::readMouseData()
             case 0x11e: button = Qt::ExtraButton12; break;
             case 0x11f: button = Qt::ExtraButton13; break;
             }
-            if (data->value)
-                m_buttons |= button;
-            else
-                m_buttons &= ~button;
+            m_buttons.setFlag(button, data->value);
             btnChanged = true;
         } else if (data->type == EV_SYN && data->code == SYN_REPORT) {
             if (btnChanged) {
diff --git a/src/platformsupport/input/libinput/qlibinputpointer.cpp b/src/platformsupport/input/libinput/qlibinputpointer.cpp
index 3476235d6b..d5a3a8b437 100644
--- a/src/platformsupport/input/libinput/qlibinputpointer.cpp
+++ b/src/platformsupport/input/libinput/qlibinputpointer.cpp
@@ -76,10 +76,7 @@ void QLibInputPointer::processButton(libinput_event_pointer *e)
     case 0x11f: button = Qt::ExtraButton13; break;
     }
 
-    if (pressed)
-        m_buttons |= button;
-    else
-        m_buttons &= ~button;
+    m_buttons.setFlag(button, pressed);
 
     QWindowSystemInterface::handleMouseEvent(Q_NULLPTR, m_pos, m_pos, m_buttons, QGuiApplication::keyboardModifiers());
 }
diff --git a/src/plugins/platforms/cocoa/qcocoamenu.mm b/src/plugins/platforms/cocoa/qcocoamenu.mm
index 8091ba8465..8c576c7cbe 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenu.mm
@@ -128,7 +128,7 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaMenuDelegate);
 - (void) itemFired:(NSMenuItem*) item
 {
     QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
-    QScopedLoopLevelCounter loopLevelCounter(QGuiApplicationPrivate::instance()->threadData);
+    QScopedScopeLevelCounter scopeLevelCounter(QGuiApplicationPrivate::instance()->threadData);
     QGuiApplicationPrivate::modifier_buttons = [QNSView convertKeyModifiers:[NSEvent modifierFlags]];
     static QMetaMethod activatedSignal = QMetaMethod::fromSignal(&QCocoaMenuItem::activated);
     activatedSignal.invoke(cocoaItem, Qt::QueuedConnection);
diff --git a/src/plugins/platforms/cocoa/qcocoamenuloader.mm b/src/plugins/platforms/cocoa/qcocoamenuloader.mm
index d73b9a8b7b..e440a9080c 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuloader.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenuloader.mm
@@ -308,7 +308,7 @@ QT_END_NAMESPACE
 
     if ([item tag]) {
         QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
-        QScopedLoopLevelCounter loopLevelCounter(QGuiApplicationPrivate::instance()->threadData);
+        QScopedScopeLevelCounter scopeLevelCounter(QGuiApplicationPrivate::instance()->threadData);
         cocoaItem->activated();
     }
 }
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index e707010979..8733116c6f 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -1898,6 +1898,18 @@ static QPoint mapWindowCoordinates(QWindow *source, QWindow *target, QPoint poin
     return NO;
 }
 
+
+- (BOOL)wantsPeriodicDraggingUpdates:(void *)dummy
+{
+    // This method never gets called. It's a workaround for Apple's
+    // bug: they first respondsToSelector : @selector(wantsPeriodicDraggingUpdates:)
+    // (note ':') and then call -wantsPeriodicDraggingUpdate (without colon).
+    // So, let's make them happy.
+    Q_UNUSED(dummy);
+
+    return NO;
+}
+
 - (void)updateCursorFromDragResponse:(QPlatformDragQtResponse)response drag:(QCocoaDrag *)drag
 {
     const QPixmap pixmapCursor = drag->currentDrag()->dragCursor(response.acceptedAction());
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index 6a2ecacd77..02dc95e852 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -472,7 +472,7 @@ public:
     xcb_window_t getSelectionOwner(xcb_atom_t atom) const;
     xcb_window_t getQtSelectionOwner();
 
-    void setButton(Qt::MouseButton button, bool down) { if (down) m_buttons |= button; else m_buttons &= ~button; }
+    void setButton(Qt::MouseButton button, bool down) { m_buttons.setFlag(button, down); }
     Qt::MouseButtons buttons() const { return m_buttons; }
     Qt::MouseButton translateMouseButton(xcb_button_t s);
 
diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index ca2b0c0889..07422f8811 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -787,10 +787,8 @@ void QFileDialog::setOptions(Options options)
 
         if (changed & DontUseCustomDirectoryIcons) {
             QFileIconProvider::Options providerOptions = iconProvider()->options();
-            if (options & DontUseCustomDirectoryIcons)
-                providerOptions |= QFileIconProvider::DontUseCustomDirectoryIcons;
-            else
-                providerOptions &= ~QFileIconProvider::DontUseCustomDirectoryIcons;
+            providerOptions.setFlag(QFileIconProvider::DontUseCustomDirectoryIcons,
+                                    options & DontUseCustomDirectoryIcons);
             iconProvider()->setOptions(providerOptions);
         }
     }
@@ -3455,7 +3453,7 @@ void QFileDialogPrivate::_q_autoCompleteFileName(const QString &text)
     const QStringList multipleFiles = typedFiles();
     if (multipleFiles.count() > 0) {
         QModelIndexList oldFiles = qFileDialogUi->listView->selectionModel()->selectedRows();
-        QModelIndexList newFiles;
+        QVector<QModelIndex> newFiles;
         for (const auto &file : multipleFiles) {
             QModelIndex idx = model->index(file);
             if (oldFiles.removeAll(idx) == 0)
@@ -3718,10 +3716,7 @@ void QFileDialogPrivate::_q_showHidden()
 {
     Q_Q(QFileDialog);
     QDir::Filters dirFilters = q->filter();
-    if (showHiddenAction->isChecked())
-        dirFilters |= QDir::Hidden;
-    else
-        dirFilters &= ~QDir::Hidden;
+    dirFilters.setFlag(QDir::Hidden, showHiddenAction->isChecked());
     q->setFilter(dirFilters);
 }
 
diff --git a/src/widgets/doc/snippets/javastyle.cpp b/src/widgets/doc/snippets/javastyle.cpp
index 4997e25ada..cf62c2155e 100644
--- a/src/widgets/doc/snippets/javastyle.cpp
+++ b/src/widgets/doc/snippets/javastyle.cpp
@@ -242,8 +242,7 @@ void JavaStyle::drawControl(ControlElement control, const QStyleOption *option,
             QRect rect = docker->rect;
             QRect titleRect = rect;
             if (docker->verticalTitleBar) {
-                QRect r = rect;
-                r.setSize(r.size().transposed());
+                QRect r = rect.transposed();
 
                 titleRect = QRect(r.left() + rect.bottom()
                                 - titleRect.bottom(),
diff --git a/src/widgets/graphicsview/qgraphicsview.cpp b/src/widgets/graphicsview/qgraphicsview.cpp
index e1b835e727..450d5a7d9c 100644
--- a/src/widgets/graphicsview/qgraphicsview.cpp
+++ b/src/widgets/graphicsview/qgraphicsview.cpp
@@ -1297,10 +1297,7 @@ void QGraphicsView::setRenderHint(QPainter::RenderHint hint, bool enabled)
 {
     Q_D(QGraphicsView);
     QPainter::RenderHints oldHints = d->renderHints;
-    if (enabled)
-        d->renderHints |= hint;
-    else
-        d->renderHints &= ~hint;
+    d->renderHints.setFlag(hint, enabled);
     if (oldHints != d->renderHints)
         d->updateAll();
 }
@@ -1463,10 +1460,7 @@ void QGraphicsView::setOptimizationFlags(OptimizationFlags flags)
 void QGraphicsView::setOptimizationFlag(OptimizationFlag flag, bool enabled)
 {
     Q_D(QGraphicsView);
-    if (enabled)
-        d->optimizationFlags |= flag;
-    else
-        d->optimizationFlags &= ~flag;
+    d->optimizationFlags.setFlag(flag, enabled);
 }
 
 /*!
diff --git a/src/widgets/graphicsview/qgraphicswidget.cpp b/src/widgets/graphicsview/qgraphicswidget.cpp
index bb6d867280..e7fca55550 100644
--- a/src/widgets/graphicsview/qgraphicswidget.cpp
+++ b/src/widgets/graphicsview/qgraphicswidget.cpp
@@ -2272,15 +2272,8 @@ void QGraphicsWidget::paintWindowFrame(QPainter *painter, const QStyleOptionGrap
     bar.QStyleOption::operator=(*option);
     d->initStyleOptionTitleBar(&bar);   // this clear flags in bar.state
     d->ensureWindowData();
-    if (d->windowData->buttonMouseOver)
-        bar.state |= QStyle::State_MouseOver;
-    else
-        bar.state &= ~QStyle::State_MouseOver;
-    if (d->windowData->buttonSunken)
-        bar.state |= QStyle::State_Sunken;
-    else
-        bar.state &= ~QStyle::State_Sunken;
-
+    bar.state.setFlag(QStyle::State_MouseOver, d->windowData->buttonMouseOver);
+    bar.state.setFlag(QStyle::State_Sunken, d->windowData->buttonSunken);
     bar.rect = windowFrameRect;
 
     // translate painter to make the style happy
@@ -2337,17 +2330,9 @@ void QGraphicsWidget::paintWindowFrame(QPainter *painter, const QStyleOptionGrap
     initStyleOption(&frameOptions);
     if (!hasBorder)
         painter->setClipRect(windowFrameRect.adjusted(0, +height, 0, 0), Qt::IntersectClip);
-    if (hasFocus()) {
-        frameOptions.state |= QStyle::State_HasFocus;
-    } else {
-        frameOptions.state &= ~QStyle::State_HasFocus;
-    }
+    frameOptions.state.setFlag(QStyle::State_HasFocus, hasFocus());
     bool isActive = isActiveWindow();
-    if (isActive) {
-        frameOptions.state |= QStyle::State_Active;
-    } else {
-        frameOptions.state &= ~QStyle::State_Active;
-    }
+    frameOptions.state.setFlag(QStyle::State_Active, isActive);
 
     frameOptions.palette.setCurrentColorGroup(isActive ? QPalette::Active : QPalette::Normal);
     frameOptions.rect = windowFrameRect;
diff --git a/src/widgets/graphicsview/qgraphicswidget_p.cpp b/src/widgets/graphicsview/qgraphicswidget_p.cpp
index 0c40583659..faf1a4c49a 100644
--- a/src/widgets/graphicsview/qgraphicswidget_p.cpp
+++ b/src/widgets/graphicsview/qgraphicswidget_p.cpp
@@ -327,12 +327,11 @@ void QGraphicsWidgetPrivate::initStyleOptionTitleBar(QStyleOptionTitleBar *optio
     option->subControls = QStyle::SC_TitleBarCloseButton | QStyle::SC_TitleBarLabel | QStyle::SC_TitleBarSysMenu;
     option->activeSubControls = windowData->hoveredSubControl;
     bool isActive = q->isActiveWindow();
+    option->state.setFlag(QStyle::State_Active, isActive);
     if (isActive) {
-        option->state |= QStyle::State_Active;
         option->titleBarState = Qt::WindowActive;
         option->titleBarState |= QStyle::State_Active;
     } else {
-        option->state &= ~QStyle::State_Active;
         option->titleBarState = Qt::WindowNoState;
     }
     QFont windowTitleFont = QApplication::font("QMdiSubWindowTitleBar");
diff --git a/src/widgets/itemviews/qcolumnview.cpp b/src/widgets/itemviews/qcolumnview.cpp
index cba7e8aacc..26173b5e92 100644
--- a/src/widgets/itemviews/qcolumnview.cpp
+++ b/src/widgets/itemviews/qcolumnview.cpp
@@ -568,7 +568,7 @@ void QColumnViewPrivate::closeColumns(const QModelIndex &parent, bool build)
     bool clearAll = !parent.isValid();
     bool passThroughRoot = false;
 
-    QList<QModelIndex> dirsToAppend;
+    QVector<QModelIndex> dirsToAppend;
 
     // Find the last column that matches the parent's tree
     int currentColumn = -1;
diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp
index bf6d26dbfe..53a5dcba9c 100644
--- a/src/widgets/itemviews/qlistview.cpp
+++ b/src/widgets/itemviews/qlistview.cpp
@@ -1015,10 +1015,7 @@ void QListView::paintEvent(QPaintEvent *e)
             if (viewState == EditingState)
                 option.state |= QStyle::State_Editing;
         }
-        if (*it == hover)
-            option.state |= QStyle::State_MouseOver;
-        else
-            option.state &= ~QStyle::State_MouseOver;
+        option.state.setFlag(QStyle::State_MouseOver, *it == hover);
 
         if (alternate) {
             int row = (*it).row();
@@ -1033,11 +1030,7 @@ void QListView::paintEvent(QPaintEvent *e)
                     alternateBase = (row & 1) != 0;
                 }
             }
-            if (alternateBase) {
-                option.features |= QStyleOptionViewItem::Alternate;
-            } else {
-                option.features &= ~QStyleOptionViewItem::Alternate;
-            }
+            option.features.setFlag(QStyleOptionViewItem::Alternate, alternateBase);
 
             // draw background of the item (only alternate row). rest of the background
             // is provided by the delegate
diff --git a/src/widgets/itemviews/qtableview.cpp b/src/widgets/itemviews/qtableview.cpp
index 6a669d4a1f..714f09e893 100644
--- a/src/widgets/itemviews/qtableview.cpp
+++ b/src/widgets/itemviews/qtableview.cpp
@@ -824,10 +824,7 @@ void QTableViewPrivate::drawAndClipSpans(const QRegion &area, QPainter *painter,
         QStyleOptionViewItem opt = option;
         opt.rect = rect;
         alternateBase = alternatingColors && (span->top() & 1);
-        if (alternateBase)
-            opt.features |= QStyleOptionViewItem::Alternate;
-        else
-            opt.features &= ~QStyleOptionViewItem::Alternate;
+        opt.features.setFlag(QStyleOptionViewItem::Alternate, alternateBase);
         drawCell(painter, opt, index);
         region -= rect;
         for (int r = span->top(); r <= span->bottom(); ++r) {
diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index ccc7c34602..95f14bec78 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1359,11 +1359,7 @@ void QTreeViewPrivate::paintAlternatingRowColors(QPainter *painter, QStyleOption
     }
     while (y <= bottom) {
         option->rect.setRect(0, y, viewport->width(), rowHeight);
-        if (current & 1) {
-            option->features |= QStyleOptionViewItem::Alternate;
-        } else {
-            option->features &= ~QStyleOptionViewItem::Alternate;
-        }
+        option->features.setFlag(QStyleOptionViewItem::Alternate, current & 1);
         ++current;
         q->style()->drawPrimitive(QStyle::PE_PanelItemViewRow, option, painter, q);
         y += rowHeight;
@@ -1709,11 +1705,9 @@ void QTreeView::drawRow(QPainter *painter, const QStyleOptionViewItem &option,
             else
                 opt.state |= QStyle::State_HasFocus;
         }
-        if ((hoverRow || modelIndex == hover)
-            && (option.showDecorationSelected || (d->hoverBranch == -1)))
-            opt.state |= QStyle::State_MouseOver;
-        else
-            opt.state &= ~QStyle::State_MouseOver;
+        opt.state.setFlag(QStyle::State_MouseOver,
+                          (hoverRow || modelIndex == hover)
+                          && (option.showDecorationSelected || d->hoverBranch == -1));
 
         if (enabled) {
             QPalette::ColorGroup cg;
@@ -1729,11 +1723,7 @@ void QTreeView::drawRow(QPainter *painter, const QStyleOptionViewItem &option,
         }
 
         if (alternate) {
-            if (d->current & 1) {
-                opt.features |= QStyleOptionViewItem::Alternate;
-            } else {
-                opt.features &= ~QStyleOptionViewItem::Alternate;
-            }
+            opt.features.setFlag(QStyleOptionViewItem::Alternate, d->current & 1);
         }
 
         /* Prior to Qt 4.3, the background of the branch (in selected state and
@@ -1832,11 +1822,7 @@ void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
         painter->setBrushOrigin(QPoint(0, verticalOffset()));
 
     if (d->alternatingColors) {
-        if (d->current & 1) {
-            opt.features |= QStyleOptionViewItem::Alternate;
-        } else {
-            opt.features &= ~QStyleOptionViewItem::Alternate;
-        }
+        opt.features.setFlag(QStyleOptionViewItem::Alternate, d->current & 1);
     }
 
     // When hovering over a row, pass State_Hover for painting the branch
@@ -1862,10 +1848,8 @@ void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
                     | (moreSiblings ? QStyle::State_Sibling : QStyle::State_None)
                     | (children ? QStyle::State_Children : QStyle::State_None)
                     | (expanded ? QStyle::State_Open : QStyle::State_None);
-        if (hoverRow || item == d->hoverBranch)
-            opt.state |= QStyle::State_MouseOver;
-        else
-            opt.state &= ~QStyle::State_MouseOver;
+        opt.state.setFlag(QStyle::State_MouseOver, hoverRow || item == d->hoverBranch);
+
         style()->drawPrimitive(QStyle::PE_IndicatorBranch, &opt, painter, this);
     }
     // then go out level by level
@@ -1890,10 +1874,8 @@ void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
         }
         if (moreSiblings)
             opt.state |= QStyle::State_Sibling;
-        if (hoverRow || item == d->hoverBranch)
-            opt.state |= QStyle::State_MouseOver;
-        else
-            opt.state &= ~QStyle::State_MouseOver;
+        opt.state.setFlag(QStyle::State_MouseOver, hoverRow || item == d->hoverBranch);
+
         style()->drawPrimitive(QStyle::PE_IndicatorBranch, &opt, painter, this);
         current = ancestor;
         ancestor = current.parent();
diff --git a/src/widgets/styles/qandroidstyle.cpp b/src/widgets/styles/qandroidstyle.cpp
index d97201c601..e59c35ed68 100644
--- a/src/widgets/styles/qandroidstyle.cpp
+++ b/src/widgets/styles/qandroidstyle.cpp
@@ -1233,30 +1233,21 @@ const QAndroidStyle::AndroidDrawable * QAndroidStyle::AndroidStateDrawable::best
 
 int QAndroidStyle::AndroidStateDrawable::extractState(const QVariantMap &value)
 {
-    int state = QStyle::State_Enabled | QStyle::State_Active;;
+    QStyle::State state = QStyle::State_Enabled | QStyle::State_Active;;
     foreach (const QString &key, value.keys()) {
         bool val = value.value(key).toString() == QLatin1String("true");
         if (key == QLatin1String("enabled")) {
-            if (val)
-                state |= QStyle::State_Enabled;
-            else
-                state &= ~QStyle::State_Enabled;
+            state.setFlag(QStyle::State_Enabled, val);
             continue;
         }
 
         if (key == QLatin1String("window_focused")) {
-            if (val)
-                state |= QStyle::State_Active;
-            else
-                state &= ~QStyle::State_Active;
+            state.setFlag(QStyle::State_Active, val);
             continue;
         }
 
         if (key == QLatin1String("focused")) {
-            if (val)
-                state |= QStyle::State_HasFocus;
-            else
-                state &= ~QStyle::State_HasFocus;
+            state.setFlag(QStyle::State_HasFocus, val);
             continue;
         }
 
@@ -1271,18 +1262,12 @@ int QAndroidStyle::AndroidStateDrawable::extractState(const QVariantMap &value)
         }
 
         if (key == QLatin1String("selected")) {
-            if (val)
-                state |= QStyle::State_Selected;
-            else
-                state &= ~QStyle::State_Selected;
+            state.setFlag(QStyle::State_Selected, val);
             continue;
         }
 
         if (key == QLatin1String("active")) {
-            if (val)
-                state |= QStyle::State_Active;
-            else
-                state &= ~QStyle::State_Active;
+            state.setFlag(QStyle::State_Active, val);
             continue;
         }
 
@@ -1292,7 +1277,7 @@ int QAndroidStyle::AndroidStateDrawable::extractState(const QVariantMap &value)
         if (key == QLatin1String("background") && val)
             return -1;
     }
-    return state;
+    return static_cast<int>(state);
 }
 
 void QAndroidStyle::AndroidStateDrawable::setPaddingLeftToSizeWidth()
diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index c28a70e3f9..c26da68ac9 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -2036,7 +2036,7 @@ void QCommonStyle::drawControl(ControlElement element, const QStyleOption *opt,
                 const bool verticalTitleBar = dwOpt->verticalTitleBar;
 
                 if (verticalTitleBar) {
-                    r.setSize(r.size().transposed());
+                    r = r.transposed();
 
                     p->save();
                     p->translate(r.left(), r.top() + r.width());
@@ -2924,7 +2924,7 @@ QRect QCommonStyle::subElementRect(SubElement sr, const QStyleOption *opt,
         // horizontal, then transpose again.
 
         if (verticalTitleBar)
-            rect.setSize(rect.size().transposed());
+            rect = rect.transposed();
 
         do {
 
diff --git a/src/widgets/styles/qfusionstyle.cpp b/src/widgets/styles/qfusionstyle.cpp
index 92c065e138..1cd91a26ee 100644
--- a/src/widgets/styles/qfusionstyle.cpp
+++ b/src/widgets/styles/qfusionstyle.cpp
@@ -684,10 +684,7 @@ void QFusionStyle::drawPrimitive(PrimitiveElement elem,
     {
         QStyleOption dockWidgetHandle = *option;
         bool horizontal = option->state & State_Horizontal;
-        if (horizontal)
-            dockWidgetHandle.state &= ~State_Horizontal;
-        else
-            dockWidgetHandle.state |= State_Horizontal;
+        dockWidgetHandle.state.setFlag(State_Horizontal, !horizontal);
         proxy()->drawControl(CE_Splitter, &dockWidgetHandle, painter, widget);
     }
         break;
@@ -1228,8 +1225,7 @@ void QFusionStyle::drawControl(ControlElement element, const QStyleOption *optio
             QRect titleRect = subElementRect(SE_DockWidgetTitleBarText, option, widget);
             if (verticalTitleBar) {
                 QRect rect = dwOpt->rect;
-                QRect r = rect;
-                r.setSize(r.size().transposed());
+                QRect r = rect.transposed();
                 titleRect = QRect(r.left() + rect.bottom()
                                   - titleRect.bottom(),
                                   r.top() + titleRect.left() - rect.left(),
diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 74554f6d3d..3490d09fdf 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -4342,8 +4342,7 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
                 QRect titleRect = subElementRect(SE_DockWidgetTitleBarText, opt, w);
                 if (verticalTitleBar) {
                     QRect rect = dwOpt->rect;
-                    QRect r = rect;
-                    r.setSize(r.size().transposed());
+                    QRect r = rect.transposed();
 
                     titleRect = QRect(r.left() + rect.bottom()
                                         - titleRect.bottom(),
@@ -5167,7 +5166,7 @@ QRect QMacStyle::subElementRect(SubElement sr, const QStyleOption *opt,
             // If this is a vertical titlebar, we transpose and work as if it was
             // horizontal, then transpose again.
             if (verticalTitleBar)
-                srect.setSize(srect.size().transposed());
+                srect = srect.transposed();
 
             do {
                 int right = srect.right();
diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index 55b91714cf..053820e459 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -4130,7 +4130,7 @@ void QStyleSheetStyle::drawControl(ControlElement ce, const QStyleOption *opt, Q
            if (!dwOpt->title.isEmpty()) {
                QRect r = subElementRect(SE_DockWidgetTitleBarText, opt, w);
                if (dwOpt->verticalTitleBar) {
-                   r.setSize(r.size().transposed());
+                   r = r.transposed();
                    p->save();
                    p->translate(r.left(), r.top() + r.width());
                    p->rotate(-90);
diff --git a/src/widgets/styles/qwindowsmobilestyle.cpp b/src/widgets/styles/qwindowsmobilestyle.cpp
index 93da8d42f0..45323d1d15 100644
--- a/src/widgets/styles/qwindowsmobilestyle.cpp
+++ b/src/widgets/styles/qwindowsmobilestyle.cpp
@@ -5690,7 +5690,7 @@ void QWindowsMobileStyle::drawControl(ControlElement element, const QStyleOption
             QRect r = rect;
 
             if (verticalTitleBar) {
-                r.setSize(r.size().transposed());
+                r = r.transposed();
 
                 painter->save();
                 painter->translate(r.left(), r.top() + r.width());
diff --git a/src/widgets/styles/qwindowsstyle.cpp b/src/widgets/styles/qwindowsstyle.cpp
index 34b281a36f..d8af8c5de8 100644
--- a/src/widgets/styles/qwindowsstyle.cpp
+++ b/src/widgets/styles/qwindowsstyle.cpp
@@ -1779,7 +1779,7 @@ void QWindowsStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPai
             QRect r = rect;
 
             if (verticalTitleBar) {
-                r.setSize(r.size().transposed());
+                r = r.transposed();
 
                 p->save();
                 p->translate(r.left(), r.top() + r.width());
diff --git a/src/widgets/styles/qwindowsvistastyle.cpp b/src/widgets/styles/qwindowsvistastyle.cpp
index c8ecc3f192..a48417677a 100644
--- a/src/widgets/styles/qwindowsvistastyle.cpp
+++ b/src/widgets/styles/qwindowsvistastyle.cpp
@@ -1383,7 +1383,7 @@ void QWindowsVistaStyle::drawControl(ControlElement element, const QStyleOption
             const bool verticalTitleBar = dwOpt->verticalTitleBar;
 
             if (verticalTitleBar) {
-                rect.setSize(rect.size().transposed());
+                rect = rect.transposed();
 
                 painter->translate(rect.left() - 1, rect.top() + rect.width());
                 painter->rotate(-90);
diff --git a/src/widgets/styles/qwindowsxpstyle.cpp b/src/widgets/styles/qwindowsxpstyle.cpp
index fecfb02782..cda7dff509 100644
--- a/src/widgets/styles/qwindowsxpstyle.cpp
+++ b/src/widgets/styles/qwindowsxpstyle.cpp
@@ -2383,7 +2383,7 @@ void QWindowsXPStyle::drawControl(ControlElement element, const QStyleOption *op
             const bool verticalTitleBar = dwOpt->verticalTitleBar;
 
             if (verticalTitleBar) {
-                rect.setSize(rect.size().transposed());
+                rect = rect.transposed();
 
                 p->translate(rect.left() - 1, rect.top() + rect.width());
                 p->rotate(-90);
diff --git a/src/widgets/widgets/qcheckbox.cpp b/src/widgets/widgets/qcheckbox.cpp
index 6ce6d288ff..ad2d019c4a 100644
--- a/src/widgets/widgets/qcheckbox.cpp
+++ b/src/widgets/widgets/qcheckbox.cpp
@@ -177,10 +177,7 @@ void QCheckBox::initStyleOption(QStyleOptionButton *option) const
     else
         option->state |= d->checked ? QStyle::State_On : QStyle::State_Off;
     if (testAttribute(Qt::WA_Hover) && underMouse()) {
-        if (d->hovering)
-            option->state |= QStyle::State_MouseOver;
-        else
-            option->state &= ~QStyle::State_MouseOver;
+        option->state.setFlag(QStyle::State_MouseOver, d->hovering);
     }
     option->text = d->text;
     option->icon = d->icon;
diff --git a/src/widgets/widgets/qgroupbox.cpp b/src/widgets/widgets/qgroupbox.cpp
index 0b4add4eb3..5bdd6f20e6 100644
--- a/src/widgets/widgets/qgroupbox.cpp
+++ b/src/widgets/widgets/qgroupbox.cpp
@@ -103,11 +103,7 @@ void QGroupBox::initStyleOption(QStyleOptionGroupBox *option) const
     option->activeSubControls |= d->pressedControl;
     option->subControls = QStyle::SC_GroupBoxFrame;
 
-    if (d->hover)
-        option->state |= QStyle::State_MouseOver;
-    else
-        option->state &= ~QStyle::State_MouseOver;
-
+    option->state.setFlag(QStyle::State_MouseOver, d->hover);
     if (d->flat)
         option->features |= QStyleOptionFrame::Flat;
 
diff --git a/src/widgets/widgets/qlineedit.cpp b/src/widgets/widgets/qlineedit.cpp
index fb2818de83..3cdd7dc0f0 100644
--- a/src/widgets/widgets/qlineedit.cpp
+++ b/src/widgets/widgets/qlineedit.cpp
@@ -568,16 +568,10 @@ void QLineEdit::setEchoMode(EchoMode mode)
     if (mode == (EchoMode)d->control->echoMode())
         return;
     Qt::InputMethodHints imHints = inputMethodHints();
-    if (mode == Password || mode == NoEcho) {
-        imHints |= Qt::ImhHiddenText;
-    } else {
-        imHints &= ~Qt::ImhHiddenText;
-    }
-    if (mode != Normal) {
-        imHints |= (Qt::ImhNoAutoUppercase | Qt::ImhNoPredictiveText | Qt::ImhSensitiveData);
-    } else {
-        imHints &= ~(Qt::ImhNoAutoUppercase | Qt::ImhNoPredictiveText | Qt::ImhSensitiveData);
-    }
+    imHints.setFlag(Qt::ImhHiddenText, mode == Password || mode == NoEcho);
+    imHints.setFlag(Qt::ImhNoAutoUppercase, mode != Normal);
+    imHints.setFlag(Qt::ImhNoPredictiveText, mode != Normal);
+    imHints.setFlag(Qt::ImhSensitiveData, mode != Normal);
     setInputMethodHints(imHints);
     d->control->setEchoMode(mode);
     update();
diff --git a/src/widgets/widgets/qmainwindow.cpp b/src/widgets/widgets/qmainwindow.cpp
index a448f2fe72..4ee22dc235 100644
--- a/src/widgets/widgets/qmainwindow.cpp
+++ b/src/widgets/widgets/qmainwindow.cpp
@@ -922,10 +922,7 @@ void QMainWindow::setAnimated(bool enabled)
     Q_D(QMainWindow);
 
     DockOptions opts = d->layout->dockOptions;
-    if (enabled)
-        opts |= AnimatedDocks;
-    else
-        opts &= ~AnimatedDocks;
+    opts.setFlag(AnimatedDocks, enabled);
 
     d->layout->setDockOptions(opts);
 }
@@ -961,10 +958,7 @@ void QMainWindow::setDockNestingEnabled(bool enabled)
     Q_D(QMainWindow);
 
     DockOptions opts = d->layout->dockOptions;
-    if (enabled)
-        opts |= AllowNestedDocks;
-    else
-        opts &= ~AllowNestedDocks;
+    opts.setFlag(AllowNestedDocks, enabled);
 
     d->layout->setDockOptions(opts);
 }
diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index b695918406..ae87ea526d 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -375,10 +375,7 @@ void QDockWidgetGroupWindow::adjustFlags()
     Qt::WindowFlags flags = oldFlags;
     if (nativeDeco) {
         flags |= Qt::CustomizeWindowHint | Qt::WindowTitleHint;
-        if (top->features() & QDockWidget::DockWidgetClosable)
-            flags |= Qt::WindowCloseButtonHint;
-        else
-            flags &= ~Qt::WindowCloseButtonHint;
+        flags.setFlag(Qt::WindowCloseButtonHint, top->features() & QDockWidget::DockWidgetClosable);
         flags &= ~Qt::FramelessWindowHint;
     } else {
         flags |= Qt::FramelessWindowHint;
diff --git a/src/widgets/widgets/qmdiarea.cpp b/src/widgets/widgets/qmdiarea.cpp
index bb43abf34c..2b734b603f 100644
--- a/src/widgets/widgets/qmdiarea.cpp
+++ b/src/widgets/widgets/qmdiarea.cpp
@@ -2104,10 +2104,7 @@ void QMdiArea::setActivationOrder(WindowOrder order)
 void QMdiArea::setOption(AreaOption option, bool on)
 {
     Q_D(QMdiArea);
-    if (on && !(d->options & option))
-        d->options |= option;
-    else if (!on && (d->options & option))
-        d->options &= ~option;
+    d->options.setFlag(option, on);
 }
 
 /*!
diff --git a/src/widgets/widgets/qmdisubwindow.cpp b/src/widgets/widgets/qmdisubwindow.cpp
index cda61e8181..610cb1201f 100644
--- a/src/widgets/widgets/qmdisubwindow.cpp
+++ b/src/widgets/widgets/qmdisubwindow.cpp
@@ -575,10 +575,7 @@ void ControllerWidget::setControlVisible(QMdiSubWindowPrivate::WindowStateAction
     if (subControl == QStyle::SC_None)
         return;
 
-    if (visible && !(visibleControls & subControl))
-        visibleControls |= subControl;
-    else if (!visible && (visibleControls & subControl))
-        visibleControls &= ~subControl;
+    visibleControls.setFlag(subControl, visible && !(visibleControls & subControl));
 }
 
 /*
@@ -2417,10 +2414,7 @@ bool QMdiSubWindow::isShaded() const
 void QMdiSubWindow::setOption(SubWindowOption option, bool on)
 {
     Q_D(QMdiSubWindow);
-    if (on && !(d->options & option))
-        d->options |= option;
-    else if (!on && (d->options & option))
-        d->options &= ~option;
+    d->options.setFlag(option, on);
 
 #ifndef QT_NO_RUBBERBAND
     if ((option & (RubberBandResize | RubberBandMove)) && !on && d->isInRubberBandMode)
@@ -3172,10 +3166,7 @@ void QMdiSubWindow::paintEvent(QPaintEvent *paintEvent)
     QStyleOptionFrame frameOptions;
     frameOptions.initFrom(this);
     frameOptions.lineWidth = style()->pixelMetric(QStyle::PM_MdiSubWindowFrameWidth, 0, this);
-    if (d->isActive)
-        frameOptions.state |= QStyle::State_Active;
-    else
-        frameOptions.state &= ~QStyle::State_Active;
+    frameOptions.state.setFlag(QStyle::State_Active, d->isActive);
 
     // ### Ensure that we do not require setting the cliprect for 4.4
     if (!isMinimized() && !d->hasBorder(d->cachedStyleOptions))
diff --git a/src/widgets/widgets/qradiobutton.cpp b/src/widgets/widgets/qradiobutton.cpp
index 37f8c2eef2..125182f79f 100644
--- a/src/widgets/widgets/qradiobutton.cpp
+++ b/src/widgets/widgets/qradiobutton.cpp
@@ -182,10 +182,7 @@ void QRadioButton::initStyleOption(QStyleOptionButton *option) const
         option->state |= QStyle::State_Sunken;
     option->state |= (d->checked) ? QStyle::State_On : QStyle::State_Off;
     if (testAttribute(Qt::WA_Hover) && underMouse()) {
-        if (d->hovering)
-            option->state |= QStyle::State_MouseOver;
-        else
-            option->state &= ~QStyle::State_MouseOver;
+        option->state.setFlag(QStyle::State_MouseOver, d->hovering);
     }
 }