Merge "Merge remote-tracking branch 'origin/5.7' into dev" into refs/staging/dev

27 files changed, 153 insertions, 90 deletions

diff --git a/src/widgets/dialogs/qfiledialog.cpp b/src/widgets/dialogs/qfiledialog.cpp
index 3bcd6f7c4b..defc0539c9 100644
--- a/src/widgets/dialogs/qfiledialog.cpp
+++ b/src/widgets/dialogs/qfiledialog.cpp
@@ -2689,7 +2689,7 @@ void QFileDialogPrivate::saveSettings()
     settings.beginGroup(QLatin1String("FileDialog"));
 
     if (usingWidgets()) {
-        settings.setValue(QLatin1String("sidebarWidth"), qFileDialogUi->splitter->sizes().first());
+        settings.setValue(QLatin1String("sidebarWidth"), qFileDialogUi->splitter->sizes().constFirst());
         settings.setValue(QLatin1String("shortcuts"), QUrl::toStringList(qFileDialogUi->sidebar->urls()));
         settings.setValue(QLatin1String("treeViewHeader"), qFileDialogUi->treeView->header()->saveState());
     }
@@ -3001,9 +3001,9 @@ void QFileDialogPrivate::createWidgets()
     q->selectNameFilter(options->initiallySelectedNameFilter());
     q->setDefaultSuffix(options->defaultSuffix());
     q->setHistory(options->history());
-    if (options->initiallySelectedFiles().count() == 1)
-        q->selectFile(options->initiallySelectedFiles().first().fileName());
     const auto initiallySelectedFiles = options->initiallySelectedFiles();
+    if (initiallySelectedFiles.size() == 1)
+        q->selectFile(initiallySelectedFiles.first().fileName());
     for (const QUrl &url : initiallySelectedFiles)
         q->selectUrl(url);
     lineEdit()->selectAll();
@@ -4095,7 +4095,7 @@ QStringList QFSCompleter::splitPath(const QString &path) const
                 parts.removeFirst();
                 currentLocationList.removeLast();
             }
-            if (!currentLocationList.isEmpty() && currentLocationList.last().isEmpty())
+            if (!currentLocationList.isEmpty() && currentLocationList.constLast().isEmpty())
                 currentLocationList.removeLast();
             return currentLocationList + parts;
         }
diff --git a/src/widgets/dialogs/qfileinfogatherer.cpp b/src/widgets/dialogs/qfileinfogatherer.cpp
index 48ae5f1fc4..b20db8fc7c 100644
--- a/src/widgets/dialogs/qfileinfogatherer.cpp
+++ b/src/widgets/dialogs/qfileinfogatherer.cpp
@@ -217,9 +217,9 @@ void QFileInfoGatherer::run()
             condition.wait(&mutex);
         if (abort.load())
             return;
-        const QString thisPath = path.front();
+        const QString thisPath = qAsConst(path).front();
         path.pop_front();
-        const QStringList thisList = files.front();
+        const QStringList thisList = qAsConst(files).front();
         files.pop_front();
         locker.unlock();
 
diff --git a/src/widgets/dialogs/qfilesystemmodel.cpp b/src/widgets/dialogs/qfilesystemmodel.cpp
index bfa40317eb..c72761f2ae 100644
--- a/src/widgets/dialogs/qfilesystemmodel.cpp
+++ b/src/widgets/dialogs/qfilesystemmodel.cpp
@@ -374,7 +374,7 @@ QFileSystemModelPrivate::QFileSystemNode *QFileSystemModelPrivate::node(const QS
     QModelIndex index = QModelIndex(); // start with "My Computer"
 #if defined(Q_OS_WIN) && !defined(Q_OS_WINCE)
     if (absolutePath.startsWith(QLatin1String("//"))) { // UNC path
-        QString host = QLatin1String("\\\\") + pathElements.first();
+        QString host = QLatin1String("\\\\") + pathElements.constFirst();
         if (absolutePath == QDir::fromNativeSeparators(host))
             absolutePath.append(QLatin1Char('/'));
         if (longPath.endsWith(QLatin1Char('/')) && !absolutePath.endsWith(QLatin1Char('/')))
diff --git a/src/widgets/dialogs/qsidebar.cpp b/src/widgets/dialogs/qsidebar.cpp
index 2e884e238d..1b1eb6472e 100644
--- a/src/widgets/dialogs/qsidebar.cpp
+++ b/src/widgets/dialogs/qsidebar.cpp
@@ -127,7 +127,7 @@ QMimeData *QUrlModel::mimeData(const QModelIndexList &indexes) const
 */
 bool QUrlModel::canDrop(QDragEnterEvent *event)
 {
-    if (!event->mimeData()->formats().contains(mimeTypes().first()))
+    if (!event->mimeData()->formats().contains(mimeTypes().constFirst()))
         return false;
 
     const QList<QUrl> list = event->mimeData()->urls();
@@ -145,7 +145,7 @@ bool QUrlModel::canDrop(QDragEnterEvent *event)
 bool QUrlModel::dropMimeData(const QMimeData *data, Qt::DropAction action,
                                  int row, int column, const QModelIndex &parent)
 {
-    if (!data->formats().contains(mimeTypes().first()))
+    if (!data->formats().contains(mimeTypes().constFirst()))
         return false;
     Q_UNUSED(action);
     Q_UNUSED(column);
diff --git a/src/widgets/dialogs/qwizard.cpp b/src/widgets/dialogs/qwizard.cpp
index aa10f65389..53f947354c 100644
--- a/src/widgets/dialogs/qwizard.cpp
+++ b/src/widgets/dialogs/qwizard.cpp
@@ -850,9 +850,9 @@ void QWizardPrivate::switchToPage(int newId, Direction direction)
                 q->cleanupPage(oldId);
                 initialized.remove(oldId);
             }
-            Q_ASSERT(history.last() == oldId);
+            Q_ASSERT(history.constLast() == oldId);
             history.removeLast();
-            Q_ASSERT(history.last() == newId);
+            Q_ASSERT(history.constLast() == newId);
         }
     }
 
diff --git a/src/widgets/doc/qtwidgets.qdocconf b/src/widgets/doc/qtwidgets.qdocconf
index 8160396ca2..75bbb99579 100644
--- a/src/widgets/doc/qtwidgets.qdocconf
+++ b/src/widgets/doc/qtwidgets.qdocconf
@@ -26,7 +26,7 @@ qhp.QtWidgets.subprojects.classes.sortPages = true
 
 tagfile                 = ../../../doc/qtwidgets/qtwidgets.tags
 
-depends                 += qtcore qtgui qtdoc qtsql qtdesigner qtquick qmake qtsvg
+depends                 += qtcore qtgui qtdoc qtsql qtdesigner qtquick qmake qtplatformheaders qtsvg
 
 headerdirs  += ..
 
diff --git a/src/widgets/itemviews/qtableview.cpp b/src/widgets/itemviews/qtableview.cpp
index 714f09e893..e045d60fc8 100644
--- a/src/widgets/itemviews/qtableview.cpp
+++ b/src/widgets/itemviews/qtableview.cpp
@@ -2016,8 +2016,8 @@ QRegion QTableView::visualRegionForSelection(const QItemSelection &selection) co
             if (viewportRect.intersects(rangeRect))
                 selectionRegion += rangeRect;
             if (d->hasSpans()) {
-                foreach (QSpanCollection::Span *s,
-                         d->spans.spansInRect(range.left(), range.top(), range.width(), range.height())) {
+                const auto spansInRect = d->spans.spansInRect(range.left(), range.top(), range.width(), range.height());
+                for (QSpanCollection::Span *s : spansInRect) {
                     if (range.contains(s->top(), s->left(), range.parent())) {
                         const QRect &visualSpanRect = d->visualSpanRect(*s);
                         if (viewportRect.intersects(visualSpanRect))
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index ebdbdbd3e6..2d23bb61a2 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -424,6 +424,7 @@ QWidget *QApplicationPrivate::hidden_focus_widget = 0; // will get keyboard inpu
 QWidget *QApplicationPrivate::active_window = 0;        // toplevel with keyboard focus
 #ifndef QT_NO_WHEELEVENT
 int QApplicationPrivate::wheel_scroll_lines;   // number of lines to scroll
+QWidget *QApplicationPrivate::wheel_widget = Q_NULLPTR;
 #endif
 bool qt_in_tab_key_event = false;
 int qt_antialiasing_threshold = -1;
@@ -786,7 +787,7 @@ void QApplicationPrivate::initializeWidgetFontHash()
 QWidget *QApplication::activePopupWidget()
 {
     return QApplicationPrivate::popupWidgets && !QApplicationPrivate::popupWidgets->isEmpty() ?
-        QApplicationPrivate::popupWidgets->last() : 0;
+        QApplicationPrivate::popupWidgets->constLast() : nullptr;
 }
 
 
@@ -1718,9 +1719,11 @@ QString QApplicationPrivate::desktopStyleKey()
     // first valid one.
     if (const QPlatformTheme *theme = QGuiApplicationPrivate::platformTheme()) {
         const QStringList availableKeys = QStyleFactory::keys();
-        foreach (const QString &style, theme->themeHint(QPlatformTheme::StyleNames).toStringList())
+        const auto styles = theme->themeHint(QPlatformTheme::StyleNames).toStringList();
+        for (const QString &style : styles) {
             if (availableKeys.contains(style, Qt::CaseInsensitive))
                 return style;
+        }
     }
     return QString();
 }
@@ -2225,10 +2228,13 @@ QWidget *qt_tlw_for_window(QWindow *wnd)
         else
             break;
     }
-    if (wnd)
-        foreach (QWidget *tlw, qApp->topLevelWidgets())
+    if (wnd) {
+        const auto tlws = qApp->topLevelWidgets();
+        for (QWidget *tlw : tlws) {
             if (tlw->windowHandle() == wnd)
                 return tlw;
+        }
+    }
     return 0;
 }
 
@@ -2391,7 +2397,7 @@ void QApplicationPrivate::dispatchEnterLeave(QWidget* enter, QWidget* leave, con
         const QPoint globalPos = qIsInf(globalPosF.x())
             ? QPoint(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX)
             : globalPosF.toPoint();
-        const QPoint windowPos = enterList.back()->window()->mapFromGlobal(globalPos);
+        const QPoint windowPos = qAsConst(enterList).back()->window()->mapFromGlobal(globalPos);
         for (auto it = enterList.crbegin(), end = enterList.crend(); it != end; ++it) {
             auto *w = *it;
             if (!QApplication::activeModalWidget() || QApplicationPrivate::tryModalHelper(w, 0)) {
@@ -3302,7 +3308,6 @@ bool QApplication::notify(QObject *receiver, QEvent *e)
     case QEvent::Wheel:
         {
             QWidget* w = static_cast<QWidget *>(receiver);
-            QWheelEvent* wheel = static_cast<QWheelEvent*>(e);
 
             // QTBUG-40656, QTBUG-42731: ignore wheel events when a popup (QComboBox) is open.
             if (const QWidget *popup = QApplication::activePopupWidget()) {
@@ -3310,27 +3315,61 @@ bool QApplication::notify(QObject *receiver, QEvent *e)
                     return true;
             }
 
-            QPoint relpos = wheel->pos();
-            bool eventAccepted = wheel->isAccepted();
+            QWheelEvent* wheel = static_cast<QWheelEvent*>(e);
+            const bool spontaneous = wheel->spontaneous();
+            const Qt::ScrollPhase phase = wheel->phase();
 
-            if (e->spontaneous() && wheel->phase() == Qt::ScrollUpdate)
-                QApplicationPrivate::giveFocusAccordingToFocusPolicy(w, e, relpos);
+            if (phase == Qt::NoScrollPhase || phase == Qt::ScrollBegin
+                || (phase == Qt::ScrollUpdate && !QApplicationPrivate::wheel_widget)) {
+
+                if (spontaneous && phase == Qt::ScrollBegin)
+                    QApplicationPrivate::wheel_widget = Q_NULLPTR;
+
+                const QPoint &relpos = wheel->pos();
+
+                if (spontaneous && (phase == Qt::NoScrollPhase || phase == Qt::ScrollUpdate))
+                    QApplicationPrivate::giveFocusAccordingToFocusPolicy(w, e, relpos);
 
-            while (w) {
                 QWheelEvent we(relpos, wheel->globalPos(), wheel->pixelDelta(), wheel->angleDelta(), wheel->delta(), wheel->orientation(), wheel->buttons(),
-                               wheel->modifiers(), wheel->phase(), wheel->source());
-                we.spont = wheel->spontaneous();
-                res = d->notify_helper(w, w == receiver ? wheel : &we);
-                eventAccepted = ((w == receiver) ? wheel : &we)->isAccepted();
-                e->spont = false;
-                if ((res && eventAccepted)
-                    || w->isWindow() || w->testAttribute(Qt::WA_NoMousePropagation))
-                    break;
+                               wheel->modifiers(), phase, wheel->source());
+                bool eventAccepted;
+                while (w) {
+                    we.spont = spontaneous && w == receiver;
+                    we.ignore();
+                    res = d->notify_helper(w, &we);
+                    eventAccepted = we.isAccepted();
+                    if (res && eventAccepted) {
+                        if (spontaneous && phase != Qt::NoScrollPhase)
+                            QApplicationPrivate::wheel_widget = w;
+                        break;
+                    }
+                    if (w->isWindow() || w->testAttribute(Qt::WA_NoMousePropagation))
+                        break;
 
-                relpos += w->pos();
-                w = w->parentWidget();
+                    we.p += w->pos();
+                    w = w->parentWidget();
+                }
+                wheel->setAccepted(eventAccepted);
+            } else if (QApplicationPrivate::wheel_widget) {
+                if (!spontaneous) {
+                    // wheel_widget may forward the wheel event to a delegate widget,
+                    // either directly or indirectly (e.g. QAbstractScrollArea will
+                    // forward to its QScrollBars through viewportEvent()). In that
+                    // case, the event will not be spontaneous but synthesized, so
+                    // we can send it straigth to the receiver.
+                    d->notify_helper(w, wheel);
+                } else {
+                    const QPoint &relpos = QApplicationPrivate::wheel_widget->mapFromGlobal(wheel->globalPos());
+                    QWheelEvent we(relpos, wheel->globalPos(), wheel->pixelDelta(), wheel->angleDelta(), wheel->delta(), wheel->orientation(), wheel->buttons(),
+                                   wheel->modifiers(), wheel->phase(), wheel->source());
+                    we.spont = true;
+                    we.ignore();
+                    d->notify_helper(QApplicationPrivate::wheel_widget, &we);
+                    wheel->setAccepted(we.isAccepted());
+                    if (phase == Qt::ScrollEnd)
+                        QApplicationPrivate::wheel_widget = Q_NULLPTR;
+                }
             }
-            wheel->setAccepted(eventAccepted);
         }
         break;
 #endif
@@ -3795,7 +3834,7 @@ void QApplicationPrivate::closePopup(QWidget *popup)
 
     } else {
         // A popup was closed, so the previous popup gets the focus.
-        QWidget* aw = QApplicationPrivate::popupWidgets->last();
+        QWidget* aw = QApplicationPrivate::popupWidgets->constLast();
         if (QWidget *fw = aw->focusWidget())
             fw->setFocus(Qt::PopupFocusReason);
 
@@ -3942,7 +3981,8 @@ void QApplication::alert(QWidget *widget, int duration)
         if (QWindow *window= QApplicationPrivate::windowForWidget(widget))
             window->alert(duration);
     } else {
-        foreach (QWidget *topLevel, topLevelWidgets())
+        const auto topLevels = topLevelWidgets();
+        for (QWidget *topLevel : topLevels)
             QApplication::alert(topLevel, duration);
     }
 }
diff --git a/src/widgets/kernel/qapplication_p.h b/src/widgets/kernel/qapplication_p.h
index b884b32016..0482f83a8a 100644
--- a/src/widgets/kernel/qapplication_p.h
+++ b/src/widgets/kernel/qapplication_p.h
@@ -208,6 +208,7 @@ public:
     static QWidget *active_window;
 #ifndef QT_NO_WHEELEVENT
     static int  wheel_scroll_lines;
+    static QWidget *wheel_widget;
 #endif
 
     static int enabledAnimations; // Combination of QPlatformTheme::UiEffect
diff --git a/src/widgets/kernel/qgesturemanager.cpp b/src/widgets/kernel/qgesturemanager.cpp
index 4c85be33f5..9a3e9291bf 100644
--- a/src/widgets/kernel/qgesturemanager.cpp
+++ b/src/widgets/kernel/qgesturemanager.cpp
@@ -219,7 +219,8 @@ QGesture *QGestureManager::getState(QObject *object, QGestureRecognizer *recogni
     }
 
     // check if the QGesture for this recognizer has already been created
-    foreach (QGesture *state, m_objectGestures.value(QGestureManager::ObjectGesture(object, type))) {
+    const auto states = m_objectGestures.value(QGestureManager::ObjectGesture(object, type));
+    for (QGesture *state : states) {
         if (m_gestureToRecognizer.value(state) == recognizer)
             return state;
     }
@@ -684,7 +685,8 @@ void QGestureManager::deliverEvents(const QSet<QGesture *> &gestures,
 
         QApplication::sendEvent(receiver, &event);
         bool eventAccepted = event.isAccepted();
-        foreach(QGesture *gesture, event.gestures()) {
+        const auto eventGestures = event.gestures();
+        for (QGesture *gesture : eventGestures) {
             if (eventAccepted || event.isAccepted(gesture)) {
                 QWidget *w = event.m_targetWidgets.value(gesture->gestureType(), 0);
                 Q_ASSERT(w);
@@ -710,7 +712,8 @@ void QGestureManager::deliverEvents(const QSet<QGesture *> &gestures,
             QGestureEvent event(it.value());
             QApplication::sendEvent(it.key(), &event);
             bool eventAccepted = event.isAccepted();
-            foreach (QGesture *gesture, event.gestures()) {
+            const auto eventGestures = event.gestures();
+            for (QGesture *gesture : eventGestures) {
                 if (gesture->state() == Qt::GestureStarted &&
                     (eventAccepted || event.isAccepted(gesture))) {
                     QWidget *w = event.m_targetWidgets.value(gesture->gestureType(), 0);
diff --git a/src/widgets/kernel/qwhatsthis.cpp b/src/widgets/kernel/qwhatsthis.cpp
index b69ca54159..66b622911a 100644
--- a/src/widgets/kernel/qwhatsthis.cpp
+++ b/src/widgets/kernel/qwhatsthis.cpp
@@ -375,11 +375,9 @@ class QWhatsThisPrivate : public QObject
 
 void QWhatsThisPrivate::notifyToplevels(QEvent *e)
 {
-    QWidgetList toplevels = QApplication::topLevelWidgets();
-    for (int i = 0; i < toplevels.count(); ++i) {
-        QWidget *w = toplevels.at(i);
+    const QWidgetList toplevels = QApplication::topLevelWidgets();
+    for (auto *w : toplevels)
         QApplication::sendEvent(w, e);
-    }
 }
 
 QWhatsThisPrivate *QWhatsThisPrivate::instance = 0;
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 7e2e02b58e..ec5a68eeef 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -1417,7 +1417,8 @@ void QWidgetPrivate::create_sys(WId window, bool initializeWindow, bool destroyO
         win = topData()->window;
     }
 
-    foreach (const QByteArray &propertyName, q->dynamicPropertyNames()) {
+    const auto dynamicPropertyNames = q->dynamicPropertyNames();
+    for (const QByteArray &propertyName : dynamicPropertyNames) {
         if (!qstrncmp(propertyName, "_q_platform_", 12))
             win->setProperty(propertyName, q->property(propertyName));
     }
@@ -11984,7 +11985,9 @@ QWidget *QWidgetPrivate::widgetInNavigationDirection(Direction direction)
 
     QWidget *targetWidget = 0;
     int shortestDistance = INT_MAX;
-    foreach(QWidget *targetCandidate, QApplication::allWidgets()) {
+
+    const auto targetCandidates = QApplication::allWidgets();
+    for (QWidget *targetCandidate : targetCandidates) {
 
         const QRect targetCandidateRect = targetCandidate->rect().translated(targetCandidate->mapToGlobal(QPoint()));
 
@@ -12689,7 +12692,7 @@ QWidget *QWidget::keyboardGrabber()
     does not allow an application to interrupt what the user is currently
     doing in another application.
 
-    \sa isActiveWindow(), window(), show()
+    \sa isActiveWindow(), window(), show(), QWindowsWindowFunctions::setWindowActivationBehavior()
 */
 void QWidget::activateWindow()
 {
diff --git a/src/widgets/styles/qwindowsxpstyle.cpp b/src/widgets/styles/qwindowsxpstyle.cpp
index cda7dff509..c33e4167c1 100644
--- a/src/widgets/styles/qwindowsxpstyle.cpp
+++ b/src/widgets/styles/qwindowsxpstyle.cpp
@@ -406,10 +406,12 @@ HWND QWindowsXPStylePrivate::winId(const QWidget *widget)
             return hwnd;
 
     // Find top level with native window (there might be dialogs that do not have one).
-    foreach (const QWidget *toplevel, QApplication::topLevelWidgets())
+    const auto topLevels = QApplication::topLevelWidgets();
+    for (const QWidget *toplevel : topLevels) {
         if (toplevel->windowHandle() && toplevel->windowHandle()->handle())
             if (const HWND topLevelHwnd = QApplicationPrivate::getHWNDForWidget(toplevel))
                 return topLevelHwnd;
+    }
 
     if (QDesktopWidget *desktop = qApp->desktop())
         if (const HWND desktopHwnd = QApplicationPrivate::getHWNDForWidget(desktop))
diff --git a/src/widgets/util/qcompleter.cpp b/src/widgets/util/qcompleter.cpp
index 9c61a3a263..9f167f5924 100644
--- a/src/widgets/util/qcompleter.cpp
+++ b/src/widgets/util/qcompleter.cpp
@@ -755,9 +755,9 @@ void QUnsortedModelEngine::filterOnDemand(int n)
     const QAbstractItemModel *model = c->proxy->sourceModel();
     int lastRow = model->rowCount(curParent) - 1;
     QIndexMapper im(curMatch.indices.last() + 1, lastRow);
-    int lastIndex = buildIndices(curParts.last(), curParent, n, im, &curMatch);
+    int lastIndex = buildIndices(curParts.constLast(), curParent, n, im, &curMatch);
     curMatch.partial = (lastRow != lastIndex);
-    saveInCache(curParts.last(), curParent, curMatch);
+    saveInCache(curParts.constLast(), curParent, curMatch);
 }
 
 QMatchData QUnsortedModelEngine::filter(const QString& part, const QModelIndex& parent, int n)
diff --git a/src/widgets/util/qflickgesture.cpp b/src/widgets/util/qflickgesture.cpp
index 3d1971db8e..933db1711b 100644
--- a/src/widgets/util/qflickgesture.cpp
+++ b/src/widgets/util/qflickgesture.cpp
@@ -581,7 +581,8 @@ QGestureRecognizer::Result QFlickGestureRecognizer::recognize(QGesture *state,
 
     // Check for an active scroller at globalPos
     if (inputType == QScroller::InputPress) {
-        foreach (QScroller *as, QScroller::activeScrollers()) {
+        const auto activeScrollers = QScroller::activeScrollers();
+        for (QScroller *as : activeScrollers) {
             if (as != scroller) {
                 QRegion scrollerRegion;
 
@@ -589,11 +590,13 @@ QGestureRecognizer::Result QFlickGestureRecognizer::recognize(QGesture *state,
                     scrollerRegion = QRect(w->mapToGlobal(QPoint(0, 0)), w->size());
 #ifndef QT_NO_GRAPHICSVIEW
                 } else if (QGraphicsObject *go = qobject_cast<QGraphicsObject *>(as->target())) {
-                    if (go->scene()) {
+                    if (const auto *scene = go->scene()) {
                         const auto goBoundingRectMappedToScene = go->mapToScene(go->boundingRect());
-                        foreach (QGraphicsView *gv, go->scene()->views())
+                        const auto views = scene->views();
+                        for (QGraphicsView *gv : views) {
                             scrollerRegion |= gv->mapFromScene(goBoundingRectMappedToScene)
                                               .translated(gv->mapToGlobal(QPoint(0, 0)));
+                        }
                     }
 #endif
                 }
diff --git a/src/widgets/util/qscroller.cpp b/src/widgets/util/qscroller.cpp
index 2d6bcf72c6..02e3c2b82a 100644
--- a/src/widgets/util/qscroller.cpp
+++ b/src/widgets/util/qscroller.cpp
@@ -575,8 +575,11 @@ QPointF QScroller::pixelPerMeter() const
     if (QGraphicsObject *go = qobject_cast<QGraphicsObject *>(d->target)) {
         QTransform viewtr;
         //TODO: the first view isn't really correct - maybe use an additional field in the prepare event?
-        if (go->scene() && !go->scene()->views().isEmpty())
-            viewtr = go->scene()->views().first()->viewportTransform();
+        if (const auto *scene = go->scene()) {
+            const auto views = scene->views();
+            if (!views.isEmpty())
+                viewtr = views.first()->viewportTransform();
+        }
         QTransform tr = go->deviceTransform(viewtr);
         if (tr.isScaling()) {
             QPointF p0 = tr.map(QPointF(0, 0));
@@ -1121,12 +1124,15 @@ void QScrollerPrivate::pushSegment(ScrollType type, qreal deltaTime, qreal stopP
         return;
 
     ScrollSegment s;
-    if (orientation == Qt::Horizontal && !xSegments.isEmpty())
-        s.startTime = xSegments.last().startTime + xSegments.last().deltaTime * xSegments.last().stopProgress;
-    else if (orientation == Qt::Vertical && !ySegments.isEmpty())
-        s.startTime = ySegments.last().startTime + ySegments.last().deltaTime * ySegments.last().stopProgress;
-    else
+    if (orientation == Qt::Horizontal && !xSegments.isEmpty()) {
+        const auto &lastX = xSegments.constLast();
+        s.startTime = lastX.startTime + lastX.deltaTime * lastX.stopProgress;
+    } else if (orientation == Qt::Vertical && !ySegments.isEmpty()) {
+        const auto &lastY = ySegments.constLast();
+        s.startTime = lastY.startTime + lastY.deltaTime * lastY.stopProgress;
+    } else {
         s.startTime = monotonicTimer.elapsed();
+    }
 
     s.startPos = startPos;
     s.deltaPos = deltaPos;
@@ -1463,8 +1469,11 @@ bool QScrollerPrivate::prepareScrolling(const QPointF &position)
 #ifndef QT_NO_GRAPHICSVIEW
         if (QGraphicsObject *go = qobject_cast<QGraphicsObject *>(target)) {
             //TODO: the first view isn't really correct - maybe use an additional field in the prepare event?
-            if (go->scene() && !go->scene()->views().isEmpty())
-                setDpiFromWidget(go->scene()->views().first());
+            if (const auto *scene = go->scene()) {
+                const auto views = scene->views();
+                if (!views.isEmpty())
+                    setDpiFromWidget(views.first());
+            }
         }
 #endif
 
diff --git a/src/widgets/util/qundostack.cpp b/src/widgets/util/qundostack.cpp
index 6643b4429c..6f733f99d5 100644
--- a/src/widgets/util/qundostack.cpp
+++ b/src/widgets/util/qundostack.cpp
@@ -588,9 +588,9 @@ void QUndoStack::push(QUndoCommand *cmd)
 
     QUndoCommand *cur = 0;
     if (macro) {
-        QUndoCommand *macro_cmd = d->macro_stack.last();
+        QUndoCommand *macro_cmd = d->macro_stack.constLast();
         if (!macro_cmd->d->child_list.isEmpty())
-            cur = macro_cmd->d->child_list.last();
+            cur = macro_cmd->d->child_list.constLast();
     } else {
         if (d->index > 0)
             cur = d->command_list.at(d->index - 1);
@@ -616,7 +616,7 @@ void QUndoStack::push(QUndoCommand *cmd)
         }
     } else {
         if (macro) {
-            d->macro_stack.last()->d->child_list.append(cmd);
+            d->macro_stack.constLast()->d->child_list.append(cmd);
         } else {
             d->command_list.append(cmd);
             d->checkUndoLimit();
@@ -963,7 +963,7 @@ void QUndoStack::beginMacro(const QString &text)
             d->clean_index = -1; // we've deleted the clean state
         d->command_list.append(cmd);
     } else {
-        d->macro_stack.last()->d->child_list.append(cmd);
+        d->macro_stack.constLast()->d->child_list.append(cmd);
     }
     d->macro_stack.append(cmd);
 
diff --git a/src/widgets/widgets/qdialogbuttonbox.cpp b/src/widgets/widgets/qdialogbuttonbox.cpp
index 6fc8cb5e26..2b68c308ec 100644
--- a/src/widgets/widgets/qdialogbuttonbox.cpp
+++ b/src/widgets/widgets/qdialogbuttonbox.cpp
@@ -964,7 +964,8 @@ bool QDialogButtonBox::event(QEvent *event)
                 break;
         }
 
-        foreach (QPushButton *pb, (dialog ? dialog : this)->findChildren<QPushButton *>()) {
+        const auto pbs = (dialog ? dialog : this)->findChildren<QPushButton *>();
+        for (QPushButton *pb : pbs) {
             if (pb->isDefault() && pb != firstAcceptButton) {
                 hasDefault = true;
                 break;
diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index 29089311c6..c14fd5a942 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -3096,7 +3096,7 @@ void QDockAreaLayout::addDockWidget(QInternal::DockPosition pos, QDockWidget *do
 
 void QDockAreaLayout::tabifyDockWidget(QDockWidget *first, QDockWidget *second)
 {
-    QList<int> path = indexOf(first);
+    const QList<int> path = indexOf(first);
     if (path.isEmpty())
         return;
 
@@ -3133,7 +3133,7 @@ void QDockAreaLayout::resizeDocks(const QList<QDockWidget *> &docks,
         while (path.size() > 1) {
             QDockAreaLayoutInfo *info = this->info(path);
             if (!info->tabbed && info->o == o) {
-                info->item_list[path.last()].size = size;
+                info->item_list[path.constLast()].size = size;
                 int totalSize = 0;
                 foreach (const QDockAreaLayoutItem &item, info->item_list) {
                     if (!item.skip()) {
@@ -3147,7 +3147,7 @@ void QDockAreaLayout::resizeDocks(const QList<QDockWidget *> &docks,
             path.removeLast();
         }
 
-        const int dockNum = path.first();
+        const int dockNum = path.constFirst();
         Q_ASSERT(dockNum < QInternal::DockCount);
         QRect &r = this->docks[dockNum].rect;
         QSize s = r.size();
diff --git a/src/widgets/widgets/qlineedit_p.cpp b/src/widgets/widgets/qlineedit_p.cpp
index 8410568cc1..b646e82209 100644
--- a/src/widgets/widgets/qlineedit_p.cpp
+++ b/src/widgets/widgets/qlineedit_p.cpp
@@ -427,7 +427,7 @@ QIcon QLineEditPrivate::clearButtonIcon() const
 
 void QLineEditPrivate::setClearButtonEnabled(bool enabled)
 {
-    foreach (const SideWidgetEntry &e, trailingSideWidgets) {
+    for (const SideWidgetEntry &e : trailingSideWidgets) {
         if (e.flags & SideWidgetClearButton) {
             e.action->setEnabled(enabled);
             break;
@@ -443,13 +443,13 @@ void QLineEditPrivate::positionSideWidgets()
         const QSize iconSize = QLineEditPrivate::iconSize();
         const int delta = QLineEditIconButton::IconMargin + iconSize.width();
         QRect widgetGeometry(QPoint(QLineEditIconButton::IconMargin, (contentRect.height() - iconSize.height()) / 2), iconSize);
-        foreach (const SideWidgetEntry &e, leftSideWidgetList()) {
+        for (const SideWidgetEntry &e : leftSideWidgetList()) {
             e.widget->setGeometry(widgetGeometry);
             if (e.action->isVisible())
                 widgetGeometry.moveLeft(widgetGeometry.left() + delta);
         }
         widgetGeometry.moveLeft(contentRect.width() - iconSize.width() - QLineEditIconButton::IconMargin);
-        foreach (const SideWidgetEntry &e, rightSideWidgetList()) {
+        for (const SideWidgetEntry &e : rightSideWidgetList()) {
             e.widget->setGeometry(widgetGeometry);
             if (e.action->isVisible())
                 widgetGeometry.moveLeft(widgetGeometry.left() - delta);
diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index ae87ea526d..63a6c718bc 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -1163,7 +1163,7 @@ void QMainWindowLayout::insertToolBar(QToolBar *before, QToolBar *toolbar)
             // copy the toolbar also in the saved state
             savedState.toolBarAreaLayout.insertItem(before, item);
         }
-        if (!currentGapPos.isEmpty() && currentGapPos.first() == 0) {
+        if (!currentGapPos.isEmpty() && currentGapPos.constFirst() == 0) {
             currentGapPos = layoutState.toolBarAreaLayout.currentGapIndex();
             if (!currentGapPos.isEmpty()) {
                 currentGapPos.prepend(0);
@@ -1501,7 +1501,7 @@ void QMainWindowLayout::splitDockWidget(QDockWidget *after,
 
 Qt::DockWidgetArea QMainWindowLayout::dockWidgetArea(QWidget *widget) const
 {
-    QList<int> pathToWidget = layoutState.dockAreaLayout.indexOf(widget);
+    const QList<int> pathToWidget = layoutState.dockAreaLayout.indexOf(widget);
     if (pathToWidget.isEmpty())
         return Qt::NoDockWidgetArea;
     return toDockWidgetArea(pathToWidget.first());
@@ -1783,7 +1783,7 @@ QLayoutItem *QMainWindowLayout::takeAt(int index)
         }
 
 #ifndef QT_NO_TOOLBAR
-        if (!currentGapPos.isEmpty() && currentGapPos.first() == 0) {
+        if (!currentGapPos.isEmpty() && currentGapPos.constFirst() == 0) {
             currentGapPos = layoutState.toolBarAreaLayout.currentGapIndex();
             if (!currentGapPos.isEmpty()) {
                 currentGapPos.prepend(0);
@@ -2057,7 +2057,7 @@ void QMainWindowLayout::animationFinished(QWidget *widget)
 
             if (parentInfo->tabbed) {
                 // merge the two tab widgets
-                int idx = path.last();
+                int idx = path.constLast();
                 Q_ASSERT(parentInfo->item_list[idx].widgetItem->widget() == dwgw);
                 delete parentInfo->item_list[idx].widgetItem;
                 parentInfo->item_list.removeAt(idx);
@@ -2283,7 +2283,7 @@ QLayoutItem *QMainWindowLayout::unplug(QWidget *widget, bool group)
 
 #ifndef QT_NO_DOCKWIDGET
     if (QDockWidget *dw = qobject_cast<QDockWidget*>(widget)) {
-        Q_ASSERT(path.first() == 1);
+        Q_ASSERT(path.constFirst() == 1);
         bool actualGroup = false;
 #ifndef QT_NO_TABBAR
         if (group && (dockOptions & QMainWindow::GroupedDragging) && path.size() > 3) {
@@ -2386,7 +2386,7 @@ void QMainWindowLayout::hover(QLayoutItem *widgetItem, const QPoint &mousePos)
                 }
             }
         }
-        foreach (QWidget *w, candidates) {
+        for (QWidget *w : candidates) {
             QWindow *handle1 = widget->windowHandle();
             QWindow *handle2 = w->windowHandle();
             if (handle1 && handle2 && handle1->screen() != handle2->screen())
diff --git a/src/widgets/widgets/qmdiarea.cpp b/src/widgets/widgets/qmdiarea.cpp
index 2b734b603f..b42ebe7e48 100644
--- a/src/widgets/widgets/qmdiarea.cpp
+++ b/src/widgets/widgets/qmdiarea.cpp
@@ -516,7 +516,7 @@ QVector<QRect> MinOverlapPlacer::findMaxOverlappers(const QRect &domain, const Q
         if (overlap >= maxOverlap || maxOverlap == -1) {
             if (overlap > maxOverlap) {
                 maxOverlap = overlap;
-                result.resize(0);
+                result.clear();
             }
             result << srcRect;
         }
diff --git a/src/widgets/widgets/qmenu.cpp b/src/widgets/widgets/qmenu.cpp
index 514cb1a8c9..1b9e31968a 100644
--- a/src/widgets/widgets/qmenu.cpp
+++ b/src/widgets/widgets/qmenu.cpp
@@ -117,7 +117,7 @@ public:
     {
         Q_D(QTornOffMenu);
         // make the torn-off menu a sibling of p (instead of a child)
-        QWidget *parentWidget = d->causedStack.isEmpty() ? p : d->causedStack.last();
+        QWidget *parentWidget = d->causedStack.isEmpty() ? p : d->causedStack.constLast();
         if (parentWidget->parentWidget())
             parentWidget = parentWidget->parentWidget();
         setParent(parentWidget, Qt::Window | Qt::Tool);
@@ -1270,14 +1270,17 @@ void QMenuPrivate::_q_platformMenuAboutToShow()
     Q_Q(QMenu);
 
 #ifdef Q_OS_OSX
-    if (platformMenu)
-        Q_FOREACH (QAction *action, q->actions())
+    if (platformMenu) {
+        const auto actions = q->actions();
+        for (QAction *action : actions) {
             if (QWidget *widget = widgetItems.value(action))
                 if (widget->parent() == q) {
                     QPlatformMenuItem *menuItem = platformMenu->menuItemForTag(reinterpret_cast<quintptr>(action));
                     moveWidgetToPlatformItem(widget, menuItem);
                     platformMenu->syncMenuItem(menuItem);
                 }
+        }
+    }
 #endif
 
     emit q->aboutToShow();
diff --git a/src/widgets/widgets/qmenubar.cpp b/src/widgets/widgets/qmenubar.cpp
index f15ce06e23..261ff0bca3 100644
--- a/src/widgets/widgets/qmenubar.cpp
+++ b/src/widgets/widgets/qmenubar.cpp
@@ -200,7 +200,7 @@ void QMenuBarPrivate::updateGeometries()
     if(itemsDirty) {
         for(int j = 0; j < shortcutIndexMap.size(); ++j)
             q->releaseShortcut(shortcutIndexMap.value(j));
-        shortcutIndexMap.resize(0); // faster than clear
+        shortcutIndexMap.clear();
         const int actionsCount = actions.count();
         shortcutIndexMap.reserve(actionsCount);
         for (int i = 0; i < actionsCount; i++)
diff --git a/src/widgets/widgets/qtabbar.cpp b/src/widgets/widgets/qtabbar.cpp
index cf485974f6..ba3fc2fcd7 100644
--- a/src/widgets/widgets/qtabbar.cpp
+++ b/src/widgets/widgets/qtabbar.cpp
@@ -590,7 +590,7 @@ QRect QTabBarPrivate::normalizedScrollRect(int index)
         }
 
         bool tearTopVisible = index != 0 && topEdge != -scrollOffset;
-        bool tearBottomVisible = index != tabList.size() - 1 && bottomEdge != tabList.last().rect.bottom() + 1 - scrollOffset;
+        bool tearBottomVisible = index != tabList.size() - 1 && bottomEdge != tabList.constLast().rect.bottom() + 1 - scrollOffset;
         if (tearTopVisible && !tearLeftRect.isNull())
             topEdge = tearLeftRect.bottom() + 1;
         if (tearBottomVisible && !tearRightRect.isNull())
@@ -621,7 +621,7 @@ QRect QTabBarPrivate::normalizedScrollRect(int index)
         }
 
         bool tearLeftVisible = index != 0 && leftEdge != -scrollOffset;
-        bool tearRightVisible = index != tabList.size() - 1 && rightEdge != tabList.last().rect.right() + 1 - scrollOffset;
+        bool tearRightVisible = index != tabList.size() - 1 && rightEdge != tabList.constLast().rect.right() + 1 - scrollOffset;
         if (tearLeftVisible && !tearLeftRect.isNull())
             leftEdge = tearLeftRect.right() + 1;
         if (tearRightVisible && !tearRightRect.isNull())
@@ -642,7 +642,7 @@ void QTabBarPrivate::makeVisible(int index)
     const bool horiz = !verticalTabs(shape);
     const int tabStart = horiz ? tabRect.left() : tabRect.top();
     const int tabEnd = horiz ? tabRect.right() : tabRect.bottom();
-    const int lastTabEnd = horiz ? tabList.last().rect.right() : tabList.last().rect.bottom();
+    const int lastTabEnd = horiz ? tabList.constLast().rect.right() : tabList.constLast().rect.bottom();
     const QRect scrollRect = normalizedScrollRect(index);
     const int scrolledTabBarStart = qMax(1, scrollRect.left() + scrollOffset);
     const int scrolledTabBarEnd = qMin(lastTabEnd - 1, scrollRect.right() + scrollOffset);
diff --git a/src/widgets/widgets/qtextbrowser.cpp b/src/widgets/widgets/qtextbrowser.cpp
index d8a7b27d60..db66d39089 100644
--- a/src/widgets/widgets/qtextbrowser.cpp
+++ b/src/widgets/widgets/qtextbrowser.cpp
@@ -1141,7 +1141,7 @@ void QTextBrowser::clearHistory()
     d->forwardStack.clear();
     if (!d->stack.isEmpty()) {
         QTextBrowserPrivate::HistoryEntry historyEntry = d->stack.top();
-        d->stack.resize(0);
+        d->stack.clear();
         d->stack.push(historyEntry);
         d->home = historyEntry.url;
     }
diff --git a/src/widgets/widgets/qtoolbararealayout.cpp b/src/widgets/widgets/qtoolbararealayout.cpp
index 2e79b502ea..05564bb6b1 100644
--- a/src/widgets/widgets/qtoolbararealayout.cpp
+++ b/src/widgets/widgets/qtoolbararealayout.cpp
@@ -347,7 +347,7 @@ void QToolBarAreaLayoutInfo::removeToolBar(QToolBar *toolBar)
 void QToolBarAreaLayoutInfo::insertToolBarBreak(QToolBar *before)
 {
     if (before == 0) {
-        if (!lines.isEmpty() && lines.last().toolBarItems.isEmpty())
+        if (!lines.isEmpty() && lines.constLast().toolBarItems.isEmpty())
             return;
         lines.append(QToolBarAreaLayoutLine(o));
         return;