Merge remote-tracking branch 'origin/5.7' into dev

Conflicts:
	config_help.txt
	configure
	mkspecs/features/uikit/sdk.prf
	src/corelib/global/qhooks.cpp
	src/corelib/io/qfilesystemwatcher.cpp
	src/corelib/io/qlockfile_unix.cpp
	src/corelib/tools/qalgorithms.h
	src/gui/kernel/qwindowsysteminterface.h
	src/gui/text/qtextdocument_p.cpp
	src/network/access/access.pri
	src/network/access/qnetworkaccessmanager.cpp
	src/network/access/qnetworkreplynsurlconnectionimpl.mm
	src/src.pro
	src/testlib/qtestcase.cpp
	src/widgets/kernel/qwidgetbackingstore_p.h
	src/widgets/styles/qwindowscestyle.cpp
	src/widgets/styles/qwindowsmobilestyle.cpp
	tests/auto/corelib/io/qdiriterator/qdiriterator.pro
	tests/auto/corelib/io/qfileinfo/qfileinfo.pro
	tests/auto/gui/kernel/qwindow/BLACKLIST
	tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp
	tools/configure/configureapp.cpp

Change-Id: Ibf7fb9c8cf263a810ade82f821345d0725c57c67

40 files changed, 224 insertions, 219 deletions

diff --git a/src/gui/doc/snippets/code/src_gui_kernel_qclipboard.cpp b/src/gui/doc/snippets/code/src_gui_kernel_qclipboard.cpp
index d5f610cf28..8581510133 100644
--- a/src/gui/doc/snippets/code/src_gui_kernel_qclipboard.cpp
+++ b/src/gui/doc/snippets/code/src_gui_kernel_qclipboard.cpp
@@ -49,7 +49,7 @@
 ****************************************************************************/
 
 //! [0]
-QClipboard *clipboard = QApplication::clipboard();
+QClipboard *clipboard = QGuiApplication::clipboard();
 QString originalText = clipboard->text();
 ...
 clipboard->setText(newText);
diff --git a/src/gui/image/qbmphandler.cpp b/src/gui/image/qbmphandler.cpp
index b8290861af..9545abfd21 100644
--- a/src/gui/image/qbmphandler.cpp
+++ b/src/gui/image/qbmphandler.cpp
@@ -289,6 +289,12 @@ static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, int offset, int
             format = QImage::Format_Mono;
     }
 
+    if (depth != 32) {
+        ncols = bi.biClrUsed ? bi.biClrUsed : 1 << nbits;
+        if (ncols < 1 || ncols > 256) // sanity check - don't run out of mem if color table is broken
+            return false;
+    }
+
     if (bi.biHeight < 0)
         h = -h;                  // support images with negative height
 
@@ -296,19 +302,15 @@ static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, int offset, int
         image = QImage(w, h, format);
         if (image.isNull())                        // could not create image
             return false;
-    }
-
-    if (depth != 32) {
-        ncols = bi.biClrUsed ? bi.biClrUsed : 1 << nbits;
-        if (ncols < 1 || ncols > 256) // sanity check - don't run out of mem if color table is broken
-            return false;
-        image.setColorCount(ncols);
+        if (ncols)
+            image.setColorCount(ncols);            // Ensure valid QImage
     }
 
     image.setDotsPerMeterX(bi.biXPelsPerMeter);
     image.setDotsPerMeterY(bi.biYPelsPerMeter);
 
     if (ncols > 0) {                                // read color table
+        image.setColorCount(ncols);
         uchar rgb[4];
         int   rgb_len = t == BMP_OLD ? 3 : 4;
         for (int i=0; i<ncols; i++) {
diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index 620cbde25d..0dec4b512d 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -284,7 +284,7 @@ QPixmap QPixmapIconEngine::pixmap(const QSize &size, QIcon::Mode mode, QIcon::St
     if (pm.isNull()) {
         int idx = pixmaps.count();
         while (--idx >= 0) {
-            if (pe == &pixmaps[idx]) {
+            if (pe == &pixmaps.at(idx)) {
                 pixmaps.remove(idx);
                 break;
             }
diff --git a/src/gui/image/qiconloader.cpp b/src/gui/image/qiconloader.cpp
index cc8337fcb9..38782ac0a0 100644
--- a/src/gui/image/qiconloader.cpp
+++ b/src/gui/image/qiconloader.cpp
@@ -296,7 +296,7 @@ QIconTheme::QIconTheme(const QString &themeName)
 {
     QFile themeIndex;
 
-    QStringList iconDirs = QIcon::themeSearchPaths();
+    const QStringList iconDirs = QIcon::themeSearchPaths();
     for ( int i = 0 ; i < iconDirs.size() ; ++i) {
         QDir iconDir(iconDirs[i]);
         QString themeDir = iconDir.path() + QLatin1Char('/') + themeName;
diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 3238d83729..3a31af8645 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -176,6 +176,9 @@ QImageData::~QImageData()
     data = 0;
 }
 
+#if defined(_M_ARM)
+#pragma optimize("", off)
+#endif
 
 bool QImageData::checkForAlphaPixels() const
 {
@@ -193,74 +196,81 @@ bool QImageData::checkForAlphaPixels() const
         break;
     case QImage::Format_ARGB32:
     case QImage::Format_ARGB32_Premultiplied: {
-        uchar *bits = data;
+        const uchar *bits = data;
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
+            uint alphaAnd = 0xff000000;
             for (int x=0; x<width; ++x)
-                has_alpha_pixels |= (((uint *)bits)[x] & 0xff000000) != 0xff000000;
+                alphaAnd &= reinterpret_cast<const uint*>(bits)[x];
+            has_alpha_pixels = (alphaAnd != 0xff000000);
             bits += bytes_per_line;
         }
     } break;
 
     case QImage::Format_RGBA8888:
     case QImage::Format_RGBA8888_Premultiplied: {
-        uchar *bits = data;
+        const uchar *bits = data;
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
+            uchar alphaAnd = 0xff;
             for (int x=0; x<width; ++x)
-                has_alpha_pixels |= bits[x*4+3] != 0xff;
+                alphaAnd &= bits[x * 4+ 3];
+            has_alpha_pixels = (alphaAnd != 0xff);
             bits += bytes_per_line;
         }
     } break;
 
     case QImage::Format_A2BGR30_Premultiplied:
     case QImage::Format_A2RGB30_Premultiplied: {
-        uchar *bits = data;
+        const uchar *bits = data;
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
+            uint alphaAnd = 0xc0000000;
             for (int x=0; x<width; ++x)
-                has_alpha_pixels |= (((uint *)bits)[x] & 0xc0000000) != 0xc0000000;
+                alphaAnd &= reinterpret_cast<const uint*>(bits)[x];
+            has_alpha_pixels = (alphaAnd != 0xc0000000);
             bits += bytes_per_line;
         }
     } break;
 
     case QImage::Format_ARGB8555_Premultiplied:
     case QImage::Format_ARGB8565_Premultiplied: {
-        uchar *bits = data;
-        uchar *end_bits = data + bytes_per_line;
+        const uchar *bits = data;
+        const uchar *end_bits = data + bytes_per_line;
 
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
+            uchar alphaAnd = 0xff;
             while (bits < end_bits) {
-                has_alpha_pixels |= bits[0] != 0;
+                alphaAnd &= bits[0];
                 bits += 3;
             }
+            has_alpha_pixels = (alphaAnd != 0xff);
             bits = end_bits;
             end_bits += bytes_per_line;
         }
     } break;
 
     case QImage::Format_ARGB6666_Premultiplied: {
-        uchar *bits = data;
-        uchar *end_bits = data + bytes_per_line;
+        const uchar *bits = data;
+        const uchar *end_bits = data + bytes_per_line;
 
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
+            uchar alphaAnd = 0xfc;
             while (bits < end_bits) {
-                has_alpha_pixels |= (bits[0] & 0xfc) != 0;
+                alphaAnd &= bits[0];
                 bits += 3;
             }
+            has_alpha_pixels = (alphaAnd != 0xfc);
             bits = end_bits;
             end_bits += bytes_per_line;
         }
     } break;
 
     case QImage::Format_ARGB4444_Premultiplied: {
-        uchar *bits = data;
-        uchar *end_bits = data + bytes_per_line;
-
+        const uchar *bits = data;
         for (int y=0; y<height && !has_alpha_pixels; ++y) {
-            while (bits < end_bits) {
-                has_alpha_pixels |= (bits[0] & 0xf0) != 0;
-                bits += 2;
-            }
-            bits = end_bits;
-            end_bits += bytes_per_line;
+            ushort alphaAnd = 0xf000;
+            for (int x=0; x<width; ++x)
+                alphaAnd &= reinterpret_cast<const ushort*>(bits)[x];
+            has_alpha_pixels = (alphaAnd != 0xf000);
+            bits += bytes_per_line;
         }
     } break;
 
@@ -283,6 +293,9 @@ bool QImageData::checkForAlphaPixels() const
 
     return has_alpha_pixels;
 }
+#if defined(_M_ARM)
+#pragma optimize("", on)
+#endif
 
 /*!
     \class QImage
diff --git a/src/gui/image/qimagepixmapcleanuphooks.cpp b/src/gui/image/qimagepixmapcleanuphooks.cpp
index 10fa4303b2..f383e7a60e 100644
--- a/src/gui/image/qimagepixmapcleanuphooks.cpp
+++ b/src/gui/image/qimagepixmapcleanuphooks.cpp
@@ -84,38 +84,38 @@ void QImagePixmapCleanupHooks::removeImageHook(_qt_image_cleanup_hook_64 hook)
 
 void QImagePixmapCleanupHooks::executePlatformPixmapModificationHooks(QPlatformPixmap* pmd)
 {
-    QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
+    const QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
     // the global destructor for the pixmap and image hooks might have
     // been called already if the app is "leaking" global
     // pixmaps/images
     if (!h)
         return;
-    for (int i = 0; i < h->pixmapModificationHooks.count(); ++i)
-        h->pixmapModificationHooks[i](pmd);
+    for (auto hook : h->pixmapModificationHooks)
+        hook(pmd);
 }
 
 void QImagePixmapCleanupHooks::executePlatformPixmapDestructionHooks(QPlatformPixmap* pmd)
 {
-    QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
+    const QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
     // the global destructor for the pixmap and image hooks might have
     // been called already if the app is "leaking" global
     // pixmaps/images
     if (!h)
         return;
-    for (int i = 0; i < h->pixmapDestructionHooks.count(); ++i)
-        h->pixmapDestructionHooks[i](pmd);
+    for (auto hook : h->pixmapDestructionHooks)
+        hook(pmd);
 }
 
 void QImagePixmapCleanupHooks::executeImageHooks(qint64 key)
 {
-    QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
+    const QImagePixmapCleanupHooks *h = qt_image_and_pixmap_cleanup_hooks();
     // the global destructor for the pixmap and image hooks might have
     // been called already if the app is "leaking" global
     // pixmaps/images
     if (!h)
         return;
-    for (int i = 0; i < h->imageHooks.count(); ++i)
-        h->imageHooks[i](key);
+    for (auto hook : h->imageHooks)
+        hook(key);
 }
 
 
diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index 7fbb498bbb..96d6be502d 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -749,7 +749,7 @@ static void set_text(const QImage &image, png_structp png_ptr, png_infop info_pt
     QMap<QString, QString>::ConstIterator it = text.constBegin();
     int i = 0;
     while (it != text.constEnd()) {
-        text_ptr[i].key = qstrdup(it.key().left(79).toLatin1().constData());
+        text_ptr[i].key = qstrdup(it.key().leftRef(79).toLatin1().constData());
         bool noCompress = (it.value().length() < 40);
 
 #ifdef PNG_iTXt_SUPPORTED
diff --git a/src/gui/image/qxpmhandler.cpp b/src/gui/image/qxpmhandler.cpp
index 5c8ff84929..756e31318f 100644
--- a/src/gui/image/qxpmhandler.cpp
+++ b/src/gui/image/qxpmhandler.cpp
@@ -1154,7 +1154,7 @@ static bool write_xpm_image(const QImage &sourceImage, QIODevice *device, const
         int cc = 0;
         for(x=0; x<w; x++) {
             int color = (int)(*(yp + x));
-            QByteArray chars(xpm_color_name(cpp, colorMap[color]));
+            const QByteArray chars(xpm_color_name(cpp, colorMap[color]));
             line[cc++] = QLatin1Char(chars[0]);
             if (cpp > 1) {
                 line[cc++] = QLatin1Char(chars[1]);
diff --git a/src/gui/itemmodels/qstandarditemmodel.cpp b/src/gui/itemmodels/qstandarditemmodel.cpp
index ff54602a5d..973e5c4333 100644
--- a/src/gui/itemmodels/qstandarditemmodel.cpp
+++ b/src/gui/itemmodels/qstandarditemmodel.cpp
@@ -3018,10 +3018,7 @@ QMimeData *QStandardItemModel::mimeData(const QModelIndexList &indexes) const
             for (int i = 0; i < childList.count(); ++i) {
                 QStandardItem *chi = childList.at(i);
                 if (chi) {
-                    QSet<QStandardItem *>::iterator it = itemsSet.find(chi);
-                    if (it != itemsSet.end()) {
-                        itemsSet.erase(it);
-                    }
+                    itemsSet.erase(itemsSet.constFind(chi));
                     stack.push(chi);
                 }
             }
@@ -3130,13 +3127,13 @@ bool QStandardItemModel::dropMimeData(const QMimeData *data, Qt::DropAction acti
     for (int i = 0; i < rows.count(); ++i)
         rowsToInsert[rows.at(i)] = 1;
     for (int i = 0; i < rowsToInsert.count(); ++i) {
-        if (rowsToInsert[i] == 1){
+        if (rowsToInsert.at(i) == 1){
             rowsToInsert[i] = dragRowCount;
             ++dragRowCount;
         }
     }
     for (int i = 0; i < rows.count(); ++i)
-        rows[i] = top + rowsToInsert[rows[i]];
+        rows[i] = top + rowsToInsert.at(rows.at(i));
 
     QBitArray isWrittenTo(dragRowCount * dragColumnCount);
 
diff --git a/src/gui/kernel/qclipboard.cpp b/src/gui/kernel/qclipboard.cpp
index 7932b9a2dc..e9da36a42a 100644
--- a/src/gui/kernel/qclipboard.cpp
+++ b/src/gui/kernel/qclipboard.cpp
@@ -67,7 +67,7 @@ QT_BEGIN_NAMESPACE
     Drop}.
 
     There is a single QClipboard object in an application, accessible
-    as QApplication::clipboard().
+    as QGuiApplication::clipboard().
 
     Example:
     \snippet code/src_gui_kernel_qclipboard.cpp 0
@@ -137,7 +137,7 @@ QT_BEGIN_NAMESPACE
 
     \endlist
 
-    \sa QApplication
+    \sa QGuiApplication
 */
 
 /*!
@@ -147,7 +147,7 @@ QT_BEGIN_NAMESPACE
 
     Do not call this function.
 
-    Call QApplication::clipboard() instead to get a pointer to the
+    Call QGuiApplication::clipboard() instead to get a pointer to the
     application's global clipboard object.
 
     There is only one clipboard in the window system, and creating
@@ -165,7 +165,7 @@ QClipboard::QClipboard(QObject *parent)
 
     Destroys the clipboard.
 
-    You should never delete the clipboard. QApplication will do this
+    You should never delete the clipboard. QGuiApplication will do this
     when the application terminates.
 */
 QClipboard::~QClipboard()
diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index 305ce5c82e..6adbea6da6 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -3904,6 +3904,9 @@ QDebug operator<<(QDebug dbg, const QEvent *e)
     case QEvent::Expose:
         dbg << "QExposeEvent(" << static_cast<const QExposeEvent *>(e)->region() << ')';
         break;
+    case QEvent::Paint:
+        dbg << "QPaintEvent(" << static_cast<const QPaintEvent *>(e)->region() << ')';
+        break;
     case QEvent::MouseButtonPress:
     case QEvent::MouseMove:
     case QEvent::MouseButtonRelease:
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index d0bfc7ff5f..7afeadcced 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1035,7 +1035,7 @@ QWindow *QGuiApplication::topLevelAt(const QPoint &pos)
         // may repeat. Find only when there is more than one virtual desktop.
         if (!windowScreen && screens.count() != primaryScreens.count()) {
             for (int i = 1; i < screens.size(); ++i) {
-                QScreen *screen = screens[i];
+                QScreen *screen = screens.at(i);
                 if (screen->geometry().contains(pos)) {
                     windowScreen = screen;
                     break;
@@ -2641,7 +2641,7 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
                 if (b == Qt::NoButton)
                     self->synthesizedMousePoints.clear();
 
-                QList<QTouchEvent::TouchPoint> touchPoints = touchEvent.touchPoints();
+                const QList<QTouchEvent::TouchPoint> &touchPoints = touchEvent.touchPoints();
                 if (eventType == QEvent::TouchBegin)
                     m_fakeMouseSourcePointId = touchPoints.first().id();
 
diff --git a/src/gui/kernel/qkeysequence.cpp b/src/gui/kernel/qkeysequence.cpp
index 8ccd85795b..e7b1f9e073 100644
--- a/src/gui/kernel/qkeysequence.cpp
+++ b/src/gui/kernel/qkeysequence.cpp
@@ -1154,21 +1154,22 @@ int QKeySequencePrivate::decodeString(const QString &str, QKeySequence::Sequence
     }
 
     int p = accel.lastIndexOf(QLatin1Char('+'), str.length() - 2); // -2 so that Ctrl++ works
+    QStringRef accelRef(&accel);
     if(p > 0)
-        accel = accel.mid(p + 1);
+        accelRef = accelRef.mid(p + 1);
 
     int fnum = 0;
-    if (accel.length() == 1) {
+    if (accelRef.length() == 1) {
 #if defined(Q_OS_MACX)
-        int qtKey = qtkeyForMacSymbol(accel[0]);
+        int qtKey = qtkeyForMacSymbol(accelRef.at(0));
         if (qtKey != -1) {
             ret |= qtKey;
         } else
 #endif
         {
-            ret |= accel[0].toUpper().unicode();
+            ret |= accelRef.at(0).toUpper().unicode();
         }
-    } else if (accel[0] == QLatin1Char('f') && (fnum = accel.mid(1).toInt()) && (fnum >= 1) && (fnum <= 35)) {
+    } else if (accelRef.at(0) == QLatin1Char('f') && (fnum = accelRef.mid(1).toInt()) >= 1 && fnum <= 35) {
         ret |= Qt::Key_F1 + fnum - 1;
     } else {
         // For NativeText, check the traslation table first,
@@ -1182,7 +1183,7 @@ int QKeySequencePrivate::decodeString(const QString &str, QKeySequence::Sequence
                 QString keyName(tran == 0
                                 ? QCoreApplication::translate("QShortcut", keyname[i].name)
                                 : QString::fromLatin1(keyname[i].name));
-                if (accel == keyName.toLower()) {
+                if (accelRef == keyName.toLower()) {
                     ret |= keyname[i].key;
                     found = true;
                     break;
diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp
index 19464eeca3..7e5697e5d8 100644
--- a/src/gui/kernel/qopenglcontext.cpp
+++ b/src/gui/kernel/qopenglcontext.cpp
@@ -1418,7 +1418,7 @@ void QOpenGLContextGroupPrivate::removeContext(QOpenGLContext *ctx)
         m_shares.removeOne(ctx);
 
         if (ctx == m_context && !m_shares.isEmpty())
-            m_context = m_shares.first();
+            m_context = m_shares.constFirst();
 
         if (!m_refs.deref()) {
             cleanup();
@@ -1582,7 +1582,7 @@ QOpenGLMultiGroupSharedResource::~QOpenGLMultiGroupSharedResource()
 #endif
     for (int i = 0; i < m_groups.size(); ++i) {
         if (!m_groups.at(i)->shares().isEmpty()) {
-            QOpenGLContext *context = m_groups.at(i)->shares().first();
+            QOpenGLContext *context = m_groups.at(i)->shares().constFirst();
             QOpenGLSharedResource *resource = value(context);
             if (resource)
                 resource->free();
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index a0e65654a6..3490e786a8 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -474,11 +474,11 @@ void QPlatformIntegration::screenAdded(QPlatformScreen *ps, bool isPrimary)
 
 void QPlatformIntegration::removeScreen(QScreen *screen)
 {
-    const bool wasPrimary = (!QGuiApplicationPrivate::screen_list.isEmpty() && QGuiApplicationPrivate::screen_list[0] == screen);
+    const bool wasPrimary = (!QGuiApplicationPrivate::screen_list.isEmpty() && QGuiApplicationPrivate::screen_list.at(0) == screen);
     QGuiApplicationPrivate::screen_list.removeOne(screen);
 
     if (wasPrimary && qGuiApp && !QGuiApplicationPrivate::screen_list.isEmpty())
-        emit qGuiApp->primaryScreenChanged(QGuiApplicationPrivate::screen_list[0]);
+        emit qGuiApp->primaryScreenChanged(QGuiApplicationPrivate::screen_list.at(0));
 }
 
 /*!
diff --git a/src/gui/kernel/qplatformscreen.cpp b/src/gui/kernel/qplatformscreen.cpp
index 8450c6a083..3c1552c31e 100644
--- a/src/gui/kernel/qplatformscreen.cpp
+++ b/src/gui/kernel/qplatformscreen.cpp
@@ -93,7 +93,7 @@ QPixmap QPlatformScreen::grabWindow(WId window, int x, int y, int width, int hei
 */
 QWindow *QPlatformScreen::topLevelAt(const QPoint & pos) const
 {
-    QWindowList list = QGuiApplication::topLevelWindows();
+    const QWindowList list = QGuiApplication::topLevelWindows();
     for (int i = list.size()-1; i >= 0; --i) {
         QWindow *w = list[i];
         if (w->isVisible() && QHighDpi::toNativePixels(w->geometry(), w).contains(pos))
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 81310ae2a2..fa26fd77a3 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -1688,11 +1688,9 @@ void QWindow::destroy()
     if (QGuiApplicationPrivate::currentMousePressWindow == this)
         QGuiApplicationPrivate::currentMousePressWindow = parent();
 
-    for (int i = 0; i < QGuiApplicationPrivate::tabletDevicePoints.size(); ++i) {
-        QGuiApplicationPrivate::TabletPointData &pointData = QGuiApplicationPrivate::tabletDevicePoints[i];
-        if (pointData.target == this)
-            pointData.target = parent();
-    }
+    for (int i = 0; i < QGuiApplicationPrivate::tabletDevicePoints.size(); ++i)
+        if (QGuiApplicationPrivate::tabletDevicePoints.at(i).target == this)
+            QGuiApplicationPrivate::tabletDevicePoints[i].target = parent();
 
     bool wasVisible = isVisible();
     d->visibilityOnDestroy = wasVisible && d->platformWindow;
diff --git a/src/gui/kernel/qwindowsysteminterface.h b/src/gui/kernel/qwindowsysteminterface.h
index cde70a1102..5e42f5ba90 100644
--- a/src/gui/kernel/qwindowsysteminterface.h
+++ b/src/gui/kernel/qwindowsysteminterface.h
@@ -117,7 +117,7 @@ public:
     static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, int d, Qt::Orientation o, Qt::KeyboardModifiers mods = Qt::NoModifier);
 
     struct TouchPoint {
-        TouchPoint() : id(0), uniqueId(-1), pressure(0), rotation(0), state(Qt::TouchPointStationary), flags(0) { }
+        TouchPoint() : id(0), uniqueId(-1), pressure(0), rotation(0), state(Qt::TouchPointStationary) { }
         int id;                 // for application use
         qint64 uniqueId;        // for TUIO: object/token ID; otherwise empty
                                 // TODO for TUIO 2.0: add registerPointerUniqueID(QPointerUniqueId)
@@ -142,7 +142,7 @@ public:
 
     // rect is relative to parent
     static void handleGeometryChange(QWindow *w, const QRect &newRect, const QRect &oldRect = QRect());
-    static void handleCloseEvent(QWindow *w, bool *accepted = 0);
+    static void handleCloseEvent(QWindow *w, bool *accepted = Q_NULLPTR);
     static void handleEnterEvent(QWindow *w, const QPointF &local = QPointF(), const QPointF& global = QPointF());
     static void handleLeaveEvent(QWindow *w);
     static void handleEnterLeaveEvent(QWindow *enter, QWindow *leave, const QPointF &local = QPointF(), const QPointF& global = QPointF());
diff --git a/src/gui/opengl/qopenglframebufferobject.cpp b/src/gui/opengl/qopenglframebufferobject.cpp
index b932ee60c9..303d4d4eb1 100644
--- a/src/gui/opengl/qopenglframebufferobject.cpp
+++ b/src/gui/opengl/qopenglframebufferobject.cpp
@@ -1073,7 +1073,7 @@ bool QOpenGLFramebufferObject::bind()
     if (d->format.samples() == 0) {
         // Create new textures to replace the ones stolen via takeTexture().
         for (int i = 0; i < d->colorAttachments.count(); ++i) {
-            if (!d->colorAttachments[i].guard)
+            if (!d->colorAttachments.at(i).guard)
                 d->initTexture(i);
         }
     }
@@ -1206,10 +1206,11 @@ GLuint QOpenGLFramebufferObject::takeTexture(int colorAttachmentIndex)
         QOpenGLContext *current = QOpenGLContext::currentContext();
         if (current && current->shareGroup() == d->fbo_guard->group() && isBound())
             release();
-        id = d->colorAttachments[colorAttachmentIndex].guard ? d->colorAttachments[colorAttachmentIndex].guard->id() : 0;
+        auto &guard = d->colorAttachments[colorAttachmentIndex].guard;
+        id = guard ? guard->id() : 0;
         // Do not call free() on texture_guard, just null it out.
         // This way the texture will not be deleted when the guard is destroyed.
-        d->colorAttachments[colorAttachmentIndex].guard = 0;
+        guard = 0;
     }
     return id;
 }
diff --git a/src/gui/opengl/qopenglgradientcache.cpp b/src/gui/opengl/qopenglgradientcache.cpp
index c135489379..58dcbed50a 100644
--- a/src/gui/opengl/qopenglgradientcache.cpp
+++ b/src/gui/opengl/qopenglgradientcache.cpp
@@ -108,7 +108,7 @@ GLuint QOpenGL2GradientCache::getBuffer(const QGradient &gradient, qreal opacity
 {
     quint64 hash_val = 0;
 
-    QGradientStops stops = gradient.stops();
+    const QGradientStops stops = gradient.stops();
     for (int i = 0; i < stops.size() && i <= 2; i++)
         hash_val += stops[i].second.rgba();
 
@@ -170,16 +170,12 @@ GLuint QOpenGL2GradientCache::addCacheElement(quint64 hash_val, const QGradient
 void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient, QRgba64 *colorTable, int size, qreal opacity) const
 {
     int pos = 0;
-    QGradientStops s = gradient.stops();
-    QVector<QRgba64> colors(s.size());
-
-    for (int i = 0; i < s.size(); ++i)
-        colors[i] = s[i].second.rgba64();
+    const QGradientStops s = gradient.stops();
 
     bool colorInterpolation = (gradient.interpolationMode() == QGradient::ColorInterpolation);
 
     uint alpha = qRound(opacity * 256);
-    QRgba64 current_color = combineAlpha256(colors[0], alpha);
+    QRgba64 current_color = combineAlpha256(s[0].second.rgba64(), alpha);
     qreal incr = 1.0 / qreal(size);
     qreal fpos = 1.5 * incr;
     colorTable[pos++] = qPremultiply(current_color);
@@ -193,9 +189,10 @@ void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient
     if (colorInterpolation)
         current_color = qPremultiply(current_color);
 
-    for (int i = 0; i < s.size() - 1; ++i) {
+    const int sLast = s.size() - 1;
+    for (int i = 0; i < sLast; ++i) {
         qreal delta = 1/(s[i+1].first - s[i].first);
-        QRgba64 next_color = combineAlpha256(colors[i+1], alpha);
+        QRgba64 next_color = combineAlpha256(s[i + 1].second.rgba64(), alpha);
         if (colorInterpolation)
             next_color = qPremultiply(next_color);
 
@@ -214,7 +211,7 @@ void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient
 
     Q_ASSERT(s.size() > 0);
 
-    QRgba64 last_color = qPremultiply(combineAlpha256(colors[s.size() - 1], alpha));
+    QRgba64 last_color = qPremultiply(combineAlpha256(s[sLast].second.rgba64(), alpha));
     for (;pos < size; ++pos)
         colorTable[pos] = last_color;
 
@@ -225,16 +222,13 @@ void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient
 void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient, uint *colorTable, int size, qreal opacity) const
 {
     int pos = 0;
-    QGradientStops s = gradient.stops();
-    QVector<uint> colors(s.size());
-
-    for (int i = 0; i < s.size(); ++i)
-        colors[i] = s[i].second.rgba(); // Qt LIES! It returns ARGB (on little-endian AND on big-endian)
+    const QGradientStops s = gradient.stops();
 
     bool colorInterpolation = (gradient.interpolationMode() == QGradient::ColorInterpolation);
 
     uint alpha = qRound(opacity * 256);
-    uint current_color = ARGB_COMBINE_ALPHA(colors[0], alpha);
+    // Qt LIES! It returns ARGB (on little-endian AND on big-endian)
+    uint current_color = ARGB_COMBINE_ALPHA(s[0].second.rgba(), alpha);
     qreal incr = 1.0 / qreal(size);
     qreal fpos = 1.5 * incr;
     colorTable[pos++] = ARGB2RGBA(qPremultiply(current_color));
@@ -248,9 +242,10 @@ void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient
     if (colorInterpolation)
         current_color = qPremultiply(current_color);
 
-    for (int i = 0; i < s.size() - 1; ++i) {
+    const int sLast = s.size() - 1;
+    for (int i = 0; i < sLast; ++i) {
         qreal delta = 1/(s[i+1].first - s[i].first);
-        uint next_color = ARGB_COMBINE_ALPHA(colors[i+1], alpha);
+        uint next_color = ARGB_COMBINE_ALPHA(s[i + 1].second.rgba(), alpha);
         if (colorInterpolation)
             next_color = qPremultiply(next_color);
 
@@ -269,7 +264,7 @@ void QOpenGL2GradientCache::generateGradientColorTable(const QGradient& gradient
 
     Q_ASSERT(s.size() > 0);
 
-    uint last_color = ARGB2RGBA(qPremultiply(ARGB_COMBINE_ALPHA(colors[s.size() - 1], alpha)));
+    uint last_color = ARGB2RGBA(qPremultiply(ARGB_COMBINE_ALPHA(s[sLast].second.rgba(), alpha)));
     for (;pos < size; ++pos)
         colorTable[pos] = last_color;
 
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 8defcfb28d..6472481e7a 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -2186,11 +2186,10 @@ void QPainter::setBrushOrigin(const QPointF &p)
     destination pixel in such a way that the alpha component of the
     source defines the translucency of the pixel.
 
-    When the paint device is a QImage, the image format must be set to
-    \l {QImage::Format}{Format_ARGB32_Premultiplied} or
-    \l {QImage::Format}{Format_ARGB32} for the composition modes to have
-    any effect. For performance the premultiplied version is the preferred
-    format.
+    Several composition modes require an alpha channel in the source or
+    target images to have an effect. For optimal performance the
+    image format \l {QImage::Format}{Format_ARGB32_Premultiplied} is
+    preferred.
 
     When a composition mode is set it applies to all painting
     operator, pens, brushes, gradients and pixmap/image drawing.
@@ -2469,7 +2468,7 @@ void QPainter::setClipping(bool enable)
 
     // we can't enable clipping if we don't have a clip
     if (enable
-        && (d->state->clipInfo.isEmpty() || d->state->clipInfo.last().operation == Qt::NoClip))
+        && (d->state->clipInfo.isEmpty() || d->state->clipInfo.constLast().operation == Qt::NoClip))
         return;
     d->state->clipEnabled = enable;
 
diff --git a/src/gui/painting/qpainterpath.cpp b/src/gui/painting/qpainterpath.cpp
index 7072a2d79c..7dbc83b338 100644
--- a/src/gui/painting/qpainterpath.cpp
+++ b/src/gui/painting/qpainterpath.cpp
@@ -690,7 +690,7 @@ void QPainterPath::moveTo(const QPointF &p)
 
     d->require_moveTo = false;
 
-    if (d->elements.last().type == MoveToElement) {
+    if (d->elements.constLast().type == MoveToElement) {
         d->elements.last().x = p.x();
         d->elements.last().y = p.y();
     } else {
@@ -738,7 +738,7 @@ void QPainterPath::lineTo(const QPointF &p)
     QPainterPathData *d = d_func();
     Q_ASSERT(!d->elements.isEmpty());
     d->maybeMoveTo();
-    if (p == QPointF(d->elements.last()))
+    if (p == QPointF(d->elements.constLast()))
         return;
     Element elm = { p.x(), p.y(), LineToElement };
     d->elements.append(elm);
@@ -801,7 +801,7 @@ void QPainterPath::cubicTo(const QPointF &c1, const QPointF &c2, const QPointF &
 
     // Abort on empty curve as a stroker cannot handle this and the
     // curve is irrelevant anyway.
-    if (d->elements.last() == c1 && c1 == c2 && c2 == e)
+    if (d->elements.constLast() == c1 && c1 == c2 && c2 == e)
         return;
 
     d->maybeMoveTo();
@@ -984,7 +984,7 @@ QPointF QPainterPath::currentPosition() const
 {
     return !d_ptr || d_func()->elements.isEmpty()
         ? QPointF()
-        : QPointF(d_func()->elements.last().x, d_func()->elements.last().y);
+        : QPointF(d_func()->elements.constLast().x, d_func()->elements.constLast().y);
 }
 
 
@@ -1073,7 +1073,7 @@ void QPainterPath::addPolygon(const QPolygonF &polygon)
 
     d_func()->elements.reserve(d_func()->elements.size() + polygon.size());
 
-    moveTo(polygon.first());
+    moveTo(polygon.constFirst());
     for (int i=1; i<polygon.size(); ++i) {
         Element elm = { polygon.at(i).x(), polygon.at(i).y(), LineToElement };
         d_func()->elements << elm;
@@ -1178,12 +1178,12 @@ void QPainterPath::addText(const QPointF &point, const QFont &f, const QString &
     QVarLengthArray<int> visualOrder(nItems);
     QVarLengthArray<uchar> levels(nItems);
     for (int i = 0; i < nItems; ++i)
-        levels[i] = eng->layoutData->items[i].analysis.bidiLevel;
+        levels[i] = eng->layoutData->items.at(i).analysis.bidiLevel;
     QTextEngine::bidiReorder(nItems, levels.data(), visualOrder.data());
 
     for (int i = 0; i < nItems; ++i) {
         int item = visualOrder[i];
-        QScriptItem &si = eng->layoutData->items[item];
+        const QScriptItem &si = eng->layoutData->items.at(item);
 
         if (si.analysis.flags < QScriptAnalysis::TabOrObject) {
             QGlyphLayout glyphs = eng->shapedGlyphs(&si);
@@ -1230,7 +1230,7 @@ void QPainterPath::addPath(const QPainterPath &other)
 
     QPainterPathData *d = reinterpret_cast<QPainterPathData *>(d_func());
     // Remove last moveto so we don't get multiple moveto's
-    if (d->elements.last().type == MoveToElement)
+    if (d->elements.constLast().type == MoveToElement)
         d->elements.remove(d->elements.size()-1);
 
     // Locate where our own current subpath will start after the other path is added.
@@ -1261,7 +1261,7 @@ void QPainterPath::connectPath(const QPainterPath &other)
 
     QPainterPathData *d = reinterpret_cast<QPainterPathData *>(d_func());
     // Remove last moveto so we don't get multiple moveto's
-    if (d->elements.last().type == MoveToElement)
+    if (d->elements.constLast().type == MoveToElement)
         d->elements.remove(d->elements.size()-1);
 
     // Locate where our own current subpath will start after the other path is added.
@@ -1273,7 +1273,7 @@ void QPainterPath::connectPath(const QPainterPath &other)
         d->elements[first].type = LineToElement;
 
     // avoid duplicate points
-    if (first > 0 && QPointF(d->elements[first]) == QPointF(d->elements[first - 1])) {
+    if (first > 0 && QPointF(d->elements.at(first)) == QPointF(d->elements.at(first - 1))) {
         d->elements.remove(first--);
         --cStart;
     }
@@ -1685,8 +1685,9 @@ QList<QPolygonF> QPainterPath::toFillPolygons(const QTransform &matrix) const
             int isect_j = current_isects.at(j);
             if (isect_j == i)
                 continue;
-            for (int k=0; k<isects[isect_j].size(); ++k) {
-                int isect_k = isects[isect_j][k];
+            const QVector<int> &isects_j = isects.at(isect_j);
+            for (int k = 0, size = isects_j.size(); k < size; ++k) {
+                int isect_k = isects_j.at(k);
                 if (isect_k != i && !isects.at(i).contains(isect_k)) {
                     isects[i] += isect_k;
                 }
@@ -1708,7 +1709,7 @@ QList<QPolygonF> QPainterPath::toFillPolygons(const QTransform &matrix) const
 
     // Join the intersected subpaths as rewinded polygons
     for (int i=0; i<count; ++i) {
-        const QVector<int> &subpath_list = isects[i];
+        const QVector<int> &subpath_list = isects.at(i);
         if (!subpath_list.isEmpty()) {
             QPolygonF buildUp;
             for (int j=0; j<subpath_list.size(); ++j) {
@@ -1717,7 +1718,7 @@ QList<QPolygonF> QPainterPath::toFillPolygons(const QTransform &matrix) const
                 if (!subpath.isClosed())
                     buildUp += subpath.first();
                 if (!buildUp.isClosed())
-                    buildUp += buildUp.first();
+                    buildUp += buildUp.constFirst();
             }
             polys += buildUp;
         }
@@ -2789,7 +2790,7 @@ void QPainterPathStroker::setDashOffset(qreal offset)
 QPolygonF QPainterPath::toFillPolygon(const QTransform &matrix) const
 {
 
-    QList<QPolygonF> flats = toSubpathPolygons(matrix);
+    const QList<QPolygonF> flats = toSubpathPolygons(matrix);
     QPolygonF polygon;
     if (flats.isEmpty())
         return polygon;
diff --git a/src/gui/painting/qpathclipper.cpp b/src/gui/painting/qpathclipper.cpp
index 48ae3cfc80..4f2b59c775 100644
--- a/src/gui/painting/qpathclipper.cpp
+++ b/src/gui/painting/qpathclipper.cpp
@@ -1648,7 +1648,7 @@ bool QPathClipper::doClip(QWingedEdge &list, ClipperMode mode)
 #ifdef QDEBUG_CLIPPER
     printf("sorted y coords:\n");
     for (int i = 0; i < y_coords.size(); ++i) {
-        printf("%.9f\n", y_coords[i]);
+        printf("%.9f\n", y_coords.at(i));
     }
 #endif
 
@@ -1686,23 +1686,23 @@ bool QPathClipper::doClip(QWingedEdge &list, ClipperMode mode)
             QPathVertex *b = list.vertex(edge->second);
 
             // FIXME: this can be optimized by using binary search
-            const int first = qFuzzyFind(y_coords.begin(), y_coords.end(), qMin(a->y, b->y)) - y_coords.begin();
-            const int last = qFuzzyFind(y_coords.begin() + first, y_coords.end(), qMax(a->y, b->y)) - y_coords.begin();
+            const int first = qFuzzyFind(y_coords.cbegin(), y_coords.cend(), qMin(a->y, b->y)) - y_coords.cbegin();
+            const int last = qFuzzyFind(y_coords.cbegin() + first, y_coords.cend(), qMax(a->y, b->y)) - y_coords.cbegin();
 
             Q_ASSERT(first < y_coords.size() - 1);
             Q_ASSERT(last < y_coords.size());
 
-            qreal bestY = 0.5 * (y_coords[first] + y_coords[first+1]);
-            qreal biggestGap = y_coords[first+1] - y_coords[first];
-
+            qreal biggestGap = y_coords.at(first + 1) - y_coords.at(first);
+            int bestIdx = first;
             for (int i = first + 1; i < last; ++i) {
-                qreal gap = y_coords[i+1] - y_coords[i];
+                qreal gap = y_coords.at(i + 1) - y_coords.at(i);
 
                 if (gap > biggestGap) {
-                    bestY = 0.5 * (y_coords[i] + y_coords[i+1]);
+                    bestIdx = i;
                     biggestGap = gap;
                 }
             }
+            const qreal bestY = 0.5 * (y_coords.at(bestIdx) + y_coords.at(bestIdx + 1));
 
 #ifdef QDEBUG_CLIPPER
             printf("y: %.9f, gap: %.9f\n", bestY, biggestGap);
diff --git a/src/gui/painting/qpdf.cpp b/src/gui/painting/qpdf.cpp
index b014305796..34f1c51f6d 100644
--- a/src/gui/painting/qpdf.cpp
+++ b/src/gui/painting/qpdf.cpp
@@ -1674,7 +1674,7 @@ void QPdfEnginePrivate::writePage()
     uint resources = requestObject();
     uint annots = requestObject();
 
-    addXrefEntry(pages.last());
+    addXrefEntry(pages.constLast());
     xprintf("<<\n"
             "/Type /Page\n"
             "/Parent %d 0 R\n"
@@ -1767,7 +1767,7 @@ void QPdfEnginePrivate::writeTail()
             ">>\n"
             "startxref\n%d\n"
             "%%%%EOF\n",
-            xrefPositions.size()-1, info, catalog, xrefPositions.last());
+            xrefPositions.size()-1, info, catalog, xrefPositions.constLast());
 }
 
 int QPdfEnginePrivate::addXrefEntry(int object, bool printostr)
diff --git a/src/gui/text/qcssparser.cpp b/src/gui/text/qcssparser.cpp
index bb92e6bfba..940de87eee 100644
--- a/src/gui/text/qcssparser.cpp
+++ b/src/gui/text/qcssparser.cpp
@@ -1507,10 +1507,10 @@ QRect Declaration::rectValue() const
     const QCss::Value &v = d->values.at(0);
     if (v.type != Value::Function)
         return QRect();
-    QStringList func = v.variant.toStringList();
+    const QStringList func = v.variant.toStringList();
     if (func.count() != 2 || func.at(0).compare(QLatin1String("rect")) != 0)
         return QRect();
-    QStringList args = func[1].split(QLatin1Char(' '), QString::SkipEmptyParts);
+    const auto args = func[1].splitRef(QLatin1Char(' '), QString::SkipEmptyParts);
     if (args.count() != 4)
         return QRect();
     QRect rect(args[0].toInt(), args[1].toInt(), args[2].toInt(), args[3].toInt());
@@ -1653,6 +1653,7 @@ Qt::Alignment Declaration::alignmentValue() const
 void Declaration::borderImageValue(QString *image, int *cuts,
                                    TileMode *h, TileMode *v) const
 {
+    const DeclarationData *d = this->d.data(); // make it const and shadow d
     *image = uriValue();
     for (int i = 0; i < 4; i++)
         cuts[i] = -1;
@@ -1914,9 +1915,8 @@ bool StyleSelector::basicSelectorMatches(const BasicSelector &sel, NodePtr node)
                 return false;
 
             if (a.valueMatchCriterium == QCss::AttributeSelector::MatchContains) {
-
-                QStringList lst = attrValue.split(QLatin1Char(' '));
-                if (!lst.contains(a.value))
+                const auto lst = attrValue.splitRef(QLatin1Char(' '));
+                if (!lst.contains(QStringRef(&a.value)))
                     return false;
             } else if (
                 (a.valueMatchCriterium == QCss::AttributeSelector::MatchEqual
diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp
index f92e4ab457..828dbc318c 100644
--- a/src/gui/text/qfont.cpp
+++ b/src/gui/text/qfont.cpp
@@ -2033,7 +2033,7 @@ uint qHash(const QFont &font, uint seed) Q_DECL_NOTHROW
  */
 bool QFont::fromString(const QString &descrip)
 {
-    QStringList l(descrip.split(QLatin1Char(',')));
+    const auto l = descrip.splitRef(QLatin1Char(','));
 
     int count = l.count();
     if (!count || (count > 2 && count < 9) || count > 11) {
@@ -2042,7 +2042,7 @@ bool QFont::fromString(const QString &descrip)
         return false;
     }
 
-    setFamily(l[0]);
+    setFamily(l[0].toString());
     if (count > 1 && l[1].toDouble() > 0.0)
         setPointSizeF(l[1].toDouble());
     if (count == 9) {
diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
index e4c9b45dc2..cdfcdec80c 100644
--- a/src/gui/text/qfontdatabase.cpp
+++ b/src/gui/text/qfontdatabase.cpp
@@ -697,25 +697,20 @@ static QStringList familyList(const QFontDef &req)
     if (req.family.isEmpty())
         return family_list;
 
-    QStringList list = req.family.split(QLatin1Char(','));
+    const auto list = req.family.splitRef(QLatin1Char(','));
     const int numFamilies = list.size();
     family_list.reserve(numFamilies);
     for (int i = 0; i < numFamilies; ++i) {
-        QString str = list.at(i).trimmed();
+        QStringRef str = list.at(i).trimmed();
         if ((str.startsWith(QLatin1Char('"')) && str.endsWith(QLatin1Char('"')))
             || (str.startsWith(QLatin1Char('\'')) && str.endsWith(QLatin1Char('\''))))
             str = str.mid(1, str.length() - 2);
-        family_list << str;
+        family_list << str.toString();
     }
 
     // append the substitute list for each family in family_list
-    QStringList subs_list;
-    QStringList::ConstIterator it = family_list.constBegin(), end = family_list.constEnd();
-    for (; it != end; ++it)
-        subs_list += QFont::substitutes(*it);
-//         qDebug() << "adding substs: " << subs_list;
-
-    family_list += subs_list;
+    for (int i = 0, size = family_list.size(); i < size; ++i)
+        family_list += QFont::substitutes(family_list.at(i));
 
     return family_list;
 }
@@ -2737,8 +2732,6 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
     }
     if (req.pointSize < 0)
         req.pointSize = req.pixelSize*72.0/d->dpi;
-    if (req.weight == 0)
-        req.weight = QFont::Normal;
     if (req.stretch == 0)
         req.stretch = 100;
 
diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index 16c654dcb7..adc8f634dc 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -1833,8 +1833,7 @@ QFontEngine *QFontEngineMulti::loadEngine(int at)
     request.family = fallbackFamilyAt(at - 1);
 
     if (QFontEngine *engine = QFontDatabase::findFont(request, m_script)) {
-        if (request.weight > QFont::Normal)
-            engine->fontDef.weight = request.weight;
+        engine->fontDef.weight = request.weight;
         if (request.style > QFont::StyleNormal)
             engine->fontDef.style = request.style;
         return engine;
diff --git a/src/gui/text/qfragmentmap_p.h b/src/gui/text/qfragmentmap_p.h
index 4cf17aadc7..b54d7261d0 100644
--- a/src/gui/text/qfragmentmap_p.h
+++ b/src/gui/text/qfragmentmap_p.h
@@ -255,14 +255,11 @@ uint QFragmentMapData<Fragment>::createFragment()
     uint freePos = head->freelist;
     if (freePos == head->allocated) {
         // need to create some free space
-        if (freePos >= uint(MaxAllocSize) / fragmentSize)
-            qBadAlloc();
-        uint needed = qAllocMore((freePos+1)*fragmentSize, 0);
-        Q_ASSERT(needed/fragmentSize > head->allocated);
-        Fragment *newFragments = (Fragment *)realloc(fragments, needed);
+        auto blockInfo = qCalculateGrowingBlockSize(freePos + 1, fragmentSize);
+        Fragment *newFragments = (Fragment *)realloc(fragments, blockInfo.size);
         Q_CHECK_PTR(newFragments);
         fragments = newFragments;
-        head->allocated = needed/fragmentSize;
+        head->allocated = quint32(blockInfo.elementCount);
         F(freePos).right = 0;
     }
 
diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index 8e4fa8a730..a3dbf455cf 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -2430,7 +2430,7 @@ bool QTextHtmlExporter::emitCharFormatStyle(const QTextCharFormat &format)
         html += QLatin1Char(';');
         attributesEmitted = true;
     } else {
-        html.chop(qstrlen(decorationTag.latin1()));
+        html.chop(decorationTag.size());
     }
 
     if (format.foreground() != defaultCharFormat.foreground()
@@ -2665,7 +2665,7 @@ void QTextHtmlExporter::emitFragment(const QTextFragment &fragment)
     if (attributesEmitted)
         html += QLatin1String("\">");
     else
-        html.chop(qstrlen(styleTag.latin1()));
+        html.chop(styleTag.size());
 
     if (isObject) {
         for (int i = 0; isImage && i < txt.length(); ++i) {
@@ -2700,13 +2700,8 @@ void QTextHtmlExporter::emitFragment(const QTextFragment &fragment)
         // split for [\n{LineSeparator}]
         QString forcedLineBreakRegExp = QString::fromLatin1("[\\na]");
         forcedLineBreakRegExp[3] = QChar::LineSeparator;
-
-        const QStringList lines = txt.split(QRegExp(forcedLineBreakRegExp));
-        for (int i = 0; i < lines.count(); ++i) {
-            if (i > 0)
-                html += QLatin1String("<br />"); // space on purpose for compatibility with Netscape, Lynx & Co.
-            html += lines.at(i);
-        }
+        // space in BR on purpose for compatibility with old-fashioned browsers
+        html += txt.replace(QRegExp(forcedLineBreakRegExp), QLatin1String("<br />"));
     }
 
     if (attributesEmitted)
@@ -3227,7 +3222,7 @@ void QTextHtmlExporter::emitFrameStyle(const QTextFrameFormat &format, FrameType
                     QString::number(format.rightMargin()));
 
     if (html.length() == originalHtmlLength) // nothing emitted?
-        html.chop(qstrlen(styleAttribute.latin1()));
+        html.chop(styleAttribute.size());
     else
         html += QLatin1Char('\"');
 }
diff --git a/src/gui/text/qtextdocument_p.cpp b/src/gui/text/qtextdocument_p.cpp
index df0d52d8e9..3537adba9e 100644
--- a/src/gui/text/qtextdocument_p.cpp
+++ b/src/gui/text/qtextdocument_p.cpp
@@ -1006,9 +1006,9 @@ int QTextDocumentPrivate::undoRedo(bool undo)
         bool inBlock = (
                 undoState > 0
                 && undoState < undoStack.size()
-                && undoStack[undoState].block_part
-                && undoStack[undoState-1].block_part
-                && !undoStack[undoState-1].block_end
+                && undoStack.at(undoState).block_part
+                && undoStack.at(undoState - 1).block_part
+                && !undoStack.at(undoState - 1).block_end
                 );
         if (!inBlock)
             break;
@@ -1074,13 +1074,14 @@ void QTextDocumentPrivate::appendUndoItem(const QTextUndoCommand &c)
 
 
     if (!undoStack.isEmpty() && modified) {
-        QTextUndoCommand &last = undoStack[undoState - 1];
+        const int lastIdx = undoState - 1;
+        const QTextUndoCommand &last = undoStack.at(lastIdx);
 
         if ( (last.block_part && c.block_part && !last.block_end) // part of the same block => can merge
             || (!c.block_part && !last.block_part) // two single undo items => can merge
             || (c.command == QTextUndoCommand::Inserted && last.command == c.command && (last.block_part && !c.block_part))) {
             // two sequential inserts that are not part of the same block => can merge
-            if (last.tryMerge(c))
+            if (undoStack[lastIdx].tryMerge(c))
                 return;
         }
     }
@@ -1102,7 +1103,7 @@ void QTextDocumentPrivate::clearUndoRedoStacks(QTextDocument::Stacks stacksToCle
     bool redoCommandsAvailable = undoState != undoStack.size();
     if (stacksToClear == QTextDocument::UndoStack && undoCommandsAvailable) {
         for (int i = 0; i < undoState; ++i) {
-            QTextUndoCommand c = undoStack[undoState];
+            QTextUndoCommand c = undoStack.at(undoState);
             if (c.command & QTextUndoCommand::Custom)
                 delete c.custom;
         }
@@ -1114,7 +1115,7 @@ void QTextDocumentPrivate::clearUndoRedoStacks(QTextDocument::Stacks stacksToCle
     } else if (stacksToClear == QTextDocument::RedoStack
                && redoCommandsAvailable) {
         for (int i = undoState; i < undoStack.size(); ++i) {
-            QTextUndoCommand c = undoStack[i];
+            QTextUndoCommand c = undoStack.at(i);
             if (c.command & QTextUndoCommand::Custom)
                 delete c.custom;
         }
@@ -1124,7 +1125,7 @@ void QTextDocumentPrivate::clearUndoRedoStacks(QTextDocument::Stacks stacksToCle
     } else if (stacksToClear == QTextDocument::UndoAndRedoStacks
                && !undoStack.isEmpty()) {
         for (int i = 0; i < undoStack.size(); ++i) {
-            QTextUndoCommand c = undoStack[i];
+            QTextUndoCommand c = undoStack.at(i);
             if (c.command & QTextUndoCommand::Custom)
                 delete c.custom;
         }
@@ -1187,8 +1188,8 @@ void QTextDocumentPrivate::endEditBlock()
         return;
 
     if (undoEnabled && undoState > 0) {
-        const bool wasBlocking = !undoStack[undoState - 1].block_end;
-        if (undoStack[undoState - 1].block_part) {
+        const bool wasBlocking = !undoStack.at(undoState - 1).block_end;
+        if (undoStack.at(undoState - 1).block_part) {
             undoStack[undoState - 1].block_end = true;
             if (wasBlocking)
                 emit document()->undoCommandAdded();
diff --git a/src/gui/text/qtextdocumentfragment.cpp b/src/gui/text/qtextdocumentfragment.cpp
index f8f4e454e0..a1a562c839 100644
--- a/src/gui/text/qtextdocumentfragment.cpp
+++ b/src/gui/text/qtextdocumentfragment.cpp
@@ -882,7 +882,7 @@ QTextHtmlImporter::Table QTextHtmlImporter::scanTable(int tableNodeIdx)
             if (at(cell).isTableCell()) {
                 // skip all columns with spans from previous rows
                 while (colsInRow < rowColSpanForColumn.size()) {
-                    const RowColSpanInfo &spanInfo = rowColSpanForColumn[colsInRow];
+                    const RowColSpanInfo &spanInfo = rowColSpanForColumn.at(colsInRow);
 
                     if (spanInfo.row + spanInfo.rowSpan > effectiveRow) {
                         Q_ASSERT(spanInfo.col == colsInRow);
@@ -1081,8 +1081,8 @@ QTextHtmlImporter::ProcessNodeResult QTextHtmlImporter::processBlockNode()
         && indent != 0
         && (lists.isEmpty()
             || !hasBlock
-            || !lists.last().list
-            || lists.last().list->itemNumber(cursor.block()) == -1
+            || !lists.constLast().list
+            || lists.constLast().list->itemNumber(cursor.block()) == -1
            )
        ) {
         block.setIndent(indent);
diff --git a/src/gui/text/qtextdocumentlayout.cpp b/src/gui/text/qtextdocumentlayout.cpp
index 1b2113d281..0c8904b4c5 100644
--- a/src/gui/text/qtextdocumentlayout.cpp
+++ b/src/gui/text/qtextdocumentlayout.cpp
@@ -265,7 +265,7 @@ void QTextTableData::updateTableSize()
     const QFixed effectiveLeftMargin = this->leftMargin + border + padding;
     const QFixed effectiveRightMargin = this->rightMargin + border + padding;
     size.height = contentsHeight == -1
-                   ? rowPositions.last() + heights.last() + padding + border + cellSpacing + effectiveBottomMargin
+                   ? rowPositions.constLast() + heights.constLast() + padding + border + cellSpacing + effectiveBottomMargin
                    : effectiveTopMargin + contentsHeight + effectiveBottomMargin;
     size.width = effectiveLeftMargin + contentsWidth + effectiveRightMargin;
 }
@@ -1238,7 +1238,7 @@ void QTextDocumentLayoutPrivate::drawFlow(const QPointF &offset, QPainter *paint
 
             // if we're past what is already laid out then we're better off
             // not trying to draw things that may not be positioned correctly yet
-            if (currentPosInDoc >= checkPoints.last().positionInFrame)
+            if (currentPosInDoc >= checkPoints.constLast().positionInFrame)
                 break;
 
             if (lastVisibleCheckPoint != checkPoints.end()
@@ -1798,7 +1798,7 @@ recalc_minmax_widths:
         td->columnPositions[i] = td->columnPositions.at(i-1) + td->widths.at(i-1) + 2 * td->border + cellSpacing;
 
     // - margin to compensate the + margin in columnPositions[0]
-    const QFixed contentsWidth = td->columnPositions.last() + td->widths.last() + td->padding + td->border + cellSpacing - leftMargin;
+    const QFixed contentsWidth = td->columnPositions.constLast() + td->widths.constLast() + td->padding + td->border + cellSpacing - leftMargin;
 
     // if the table is too big and causes an overflow re-do the layout with WrapAnywhere as wrap
     // mode
@@ -1845,14 +1845,14 @@ recalc_minmax_widths:
         td->calcRowPosition(r);
 
         const int tableStartPage = (absoluteTableY / pageHeight).truncate();
-        const int currentPage = ((td->rowPositions[r] + absoluteTableY) / pageHeight).truncate();
+        const int currentPage = ((td->rowPositions.at(r) + absoluteTableY) / pageHeight).truncate();
         const QFixed pageBottom = (currentPage + 1) * pageHeight - td->effectiveBottomMargin - absoluteTableY - cellSpacing - td->border;
         const QFixed pageTop = currentPage * pageHeight + td->effectiveTopMargin - absoluteTableY + cellSpacing + td->border;
         const QFixed nextPageTop = pageTop + pageHeight;
 
-        if (td->rowPositions[r] > pageBottom)
+        if (td->rowPositions.at(r) > pageBottom)
             td->rowPositions[r] = nextPageTop;
-        else if (td->rowPositions[r] < pageTop)
+        else if (td->rowPositions.at(r) < pageTop)
             td->rowPositions[r] = pageTop;
 
         bool dropRowToNextPage = true;
@@ -1863,7 +1863,7 @@ recalc_minmax_widths:
         QFixed dropDistance = 0;
 
 relayout:
-        const int rowStartPage = ((td->rowPositions[r] + absoluteTableY) / pageHeight).truncate();
+        const int rowStartPage = ((td->rowPositions.at(r) + absoluteTableY) / pageHeight).truncate();
         // if any of the header rows or the first non-header row start on the next page
         // then the entire header should be dropped
         if (r <= headerRowCount && rowStartPage > tableStartPage && !hasDroppedTable) {
@@ -1927,13 +1927,13 @@ relayout:
         }
 
         if (rowCellCount > 0 && dropRowToNextPage) {
-            dropDistance = nextPageTop - td->rowPositions[r];
+            dropDistance = nextPageTop - td->rowPositions.at(r);
             td->rowPositions[r] = nextPageTop;
             td->heights[r] = 0;
             dropRowToNextPage = false;
             cellHeights.resize(cellCountBeforeRow);
             if (r > headerRowCount)
-                td->heights[r-1] = pageBottom - td->rowPositions[r-1];
+                td->heights[r - 1] = pageBottom - td->rowPositions.at(r - 1);
             goto relayout;
         }
 
@@ -1944,7 +1944,7 @@ relayout:
         }
 
         if (r == headerRowCount - 1) {
-            td->headerHeight = td->rowPositions[r] + td->heights[r] - td->rowPositions[0] + td->cellSpacing + 2 * td->border;
+            td->headerHeight = td->rowPositions.at(r) + td->heights.at(r) - td->rowPositions.at(0) + td->cellSpacing + 2 * td->border;
             td->headerHeight -= td->headerHeight * (td->headerHeight / pageHeight).truncate();
             td->effectiveTopMargin += td->headerHeight;
         }
@@ -2304,7 +2304,7 @@ void QTextDocumentLayoutPrivate::layoutFlow(QTextFrame::Iterator it, QTextLayout
             docPos = it.currentBlock().position();
 
         if (inRootFrame) {
-            if (qAbs(layoutStruct->y - checkPoints.last().y) > 2000) {
+            if (qAbs(layoutStruct->y - checkPoints.constLast().y) > 2000) {
                 QFixed left, right;
                 floatMargins(layoutStruct->y, layoutStruct, &left, &right);
                 if (left == layoutStruct->x_left && right == layoutStruct->x_right) {
@@ -2554,7 +2554,7 @@ void QTextDocumentLayoutPrivate::layoutFlow(QTextFrame::Iterator it, QTextLayout
             checkPoints.append(cp);
             checkPoints.reserve(checkPoints.size());
         } else {
-            currentLazyLayoutPosition = checkPoints.last().positionInFrame;
+            currentLazyLayoutPosition = checkPoints.constLast().positionInFrame;
             // #######
             //checkPoints.last().positionInFrame = q->document()->docHandle()->length();
         }
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 6be84c0186..d11f8c34b1 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -1643,8 +1643,14 @@ void QTextEngine::itemize() const
             if (analysis->bidiLevel % 2)
                 --analysis->bidiLevel;
             analysis->flags = QScriptAnalysis::LineOrParagraphSeparator;
-            if (option.flags() & QTextOption::ShowLineAndParagraphSeparators)
+            if (option.flags() & QTextOption::ShowLineAndParagraphSeparators) {
+                const int offset = uc - string;
+                layoutData->string.detach();
+                string = reinterpret_cast<const ushort *>(layoutData->string.unicode());
+                uc = string + offset;
+                e = uc + length;
                 *const_cast<ushort*>(uc) = 0x21B5; // visual line separator
+            }
             break;
         case QChar::Tabulation:
             analysis->flags = QScriptAnalysis::Tab;
@@ -3272,7 +3278,7 @@ int QTextEngine::endOfLine(int lineNum)
     insertionPointsForLine(lineNum, insertionPoints);
 
     if (insertionPoints.size() > 0)
-        return insertionPoints.last();
+        return insertionPoints.constLast();
     return 0;
 }
 
@@ -3282,7 +3288,7 @@ int QTextEngine::beginningOfLine(int lineNum)
     insertionPointsForLine(lineNum, insertionPoints);
 
     if (insertionPoints.size() > 0)
-        return insertionPoints.first();
+        return insertionPoints.constFirst();
     return 0;
 }
 
diff --git a/src/gui/text/qtextformat.cpp b/src/gui/text/qtextformat.cpp
index 49ec9ca768..2109b15a85 100644
--- a/src/gui/text/qtextformat.cpp
+++ b/src/gui/text/qtextformat.cpp
@@ -364,9 +364,10 @@ void QTextFormatPrivate::recalcFont() const
                 f.setPixelSize(props.at(i).value.toInt());
                 break;
             case QTextFormat::FontWeight: {
-                int weight = props.at(i).value.toInt();
-                if (weight == 0) weight = QFont::Normal;
-                f.setWeight(weight);
+                const QVariant weightValue = props.at(i).value;
+                int weight = weightValue.toInt();
+                if (weight >= 0 && weightValue.isValid())
+                    f.setWeight(weight);
                 break; }
             case QTextFormat::FontItalic:
                 f.setItalic(props.at(i).value.toBool());
@@ -3462,7 +3463,7 @@ void QTextFormatCollection::setDefaultFont(const QFont &f)
 {
     defaultFnt = f;
     for (int i = 0; i < formats.count(); ++i)
-        if (formats[i].d)
+        if (formats.at(i).d)
             formats[i].d->resolveFont(defaultFnt);
 }
 
diff --git a/src/gui/text/qtextformat.h b/src/gui/text/qtextformat.h
index bc627521ff..805affd87c 100644
--- a/src/gui/text/qtextformat.h
+++ b/src/gui/text/qtextformat.h
@@ -431,9 +431,9 @@ public:
     { return doubleProperty(FontPointSize); }
 
     inline void setFontWeight(int weight)
-    { if (weight == QFont::Normal) weight = 0; setProperty(FontWeight, weight); }
+    { setProperty(FontWeight, weight); }
     inline int fontWeight() const
-    { int weight = intProperty(FontWeight); if (weight == 0) weight = QFont::Normal; return weight; }
+    { return hasProperty(FontWeight) ? intProperty(FontWeight) : QFont::Normal; }
     inline void setFontItalic(bool italic)
     { setProperty(FontItalic, italic); }
     inline bool fontItalic() const
diff --git a/src/gui/text/qtexthtmlparser.cpp b/src/gui/text/qtexthtmlparser.cpp
index 576ff7d935..103a208c26 100644
--- a/src/gui/text/qtexthtmlparser.cpp
+++ b/src/gui/text/qtexthtmlparser.cpp
@@ -665,7 +665,7 @@ void QTextHtmlParser::parseTag()
     if (hasPrefix(QLatin1Char('/'))) {
         if (nodes.last().id == Html_style) {
 #ifndef QT_NO_CSSPARSER
-            QCss::Parser parser(nodes.last().text);
+            QCss::Parser parser(nodes.constLast().text);
             QCss::StyleSheet sheet;
             sheet.origin = QCss::StyleSheetOrigin_Author;
             parser.parse(&sheet, Qt::CaseInsensitive);
diff --git a/src/gui/text/qtextodfwriter.cpp b/src/gui/text/qtextodfwriter.cpp
index f7741bad2c..73d2e545ba 100644
--- a/src/gui/text/qtextodfwriter.cpp
+++ b/src/gui/text/qtextodfwriter.cpp
@@ -812,10 +812,10 @@ bool QTextOdfWriter::writeAll()
     }
 
     // add objects for lists, frames and tables
-    QVector<QTextFormat> allFormats = m_document->allFormats();
-    QList<int> copy = formats.toList();
-    for (QList<int>::Iterator iter = copy.begin(); iter != copy.end(); ++iter) {
-        QTextObject *object = m_document->objectForFormat(allFormats[*iter]);
+    const QVector<QTextFormat> allFormats = m_document->allFormats();
+    const QList<int> copy = formats.toList();
+    for (auto index : copy) {
+        QTextObject *object = m_document->objectForFormat(allFormats[index]);
         if (object)
             formats << object->formatIndex();
     }
diff --git a/src/gui/text/qtexttable.cpp b/src/gui/text/qtexttable.cpp
index 2d5636e1d9..e4a3c2b915 100644
--- a/src/gui/text/qtexttable.cpp
+++ b/src/gui/text/qtexttable.cpp
@@ -824,7 +824,7 @@ void QTextTable::insertColumns(int pos, int num)
     QVector<QTextLength> columnWidths = tfmt.columnWidthConstraints();
     if (! columnWidths.isEmpty()) {
         for (int i = num; i > 0; --i)
-            columnWidths.insert(pos, columnWidths[qMax(0, pos-1)]);
+            columnWidths.insert(pos, columnWidths.at(qMax(0, pos - 1)));
     }
     tfmt.setColumnWidthConstraints (columnWidths);
     QTextObject::setFormat(tfmt);
@@ -1046,11 +1046,12 @@ void QTextTable::mergeCells(int row, int column, int numRows, int numCols)
 
     // find the position at which to insert the contents of the merged cells
     QFragmentFindHelper helper(origCellPosition, p->fragmentMap());
-    const auto it = std::lower_bound(d->cells.begin(), d->cells.end(), helper);
+    const auto begin = d->cells.cbegin();
+    const auto it = std::lower_bound(begin, d->cells.cend(), helper);
     Q_ASSERT(it != d->cells.end());
     Q_ASSERT(!(helper < *it));
     Q_ASSERT(*it == cellFragment);
-    const int insertCellIndex = it - d->cells.begin();
+    const int insertCellIndex = it - begin;
     int insertFragment = d->cells.value(insertCellIndex + 1, d->fragment_end);
     uint insertPos = p->fragmentMap().position(insertFragment);
 
@@ -1079,11 +1080,12 @@ void QTextTable::mergeCells(int row, int column, int numRows, int numCols)
 
             if (firstCellIndex == -1) {
                 QFragmentFindHelper helper(pos, p->fragmentMap());
-                const auto it = std::lower_bound(d->cells.begin(), d->cells.end(), helper);
+                const auto begin = d->cells.cbegin();
+                const auto it = std::lower_bound(begin, d->cells.cend(), helper);
                 Q_ASSERT(it != d->cells.end());
                 Q_ASSERT(!(helper < *it));
                 Q_ASSERT(*it == fragment);
-                firstCellIndex = cellIndex = it - d->cells.begin();
+                firstCellIndex = cellIndex = it - begin;
             }
 
             ++cellIndex;
@@ -1136,7 +1138,7 @@ void QTextTable::mergeCells(int row, int column, int numRows, int numCols)
         }
     }
 
-    d->fragment_start = d->cells.first();
+    d->fragment_start = d->cells.constFirst();
 
     fmt.setTableCellRowSpan(numRows);
     fmt.setTableCellColumnSpan(numCols);
@@ -1212,9 +1214,9 @@ void QTextTable::splitCell(int row, int column, int numRows, int numCols)
     for (int r = row + 1; r < row + rowSpan; ++r) {
         // find the cell before which to insert the new cell markers
         int gridIndex = r * d->nCols + column;
-        QVector<int>::iterator it = std::upper_bound(d->cellIndices.begin(), d->cellIndices.end(), gridIndex);
-        int cellIndex = it - d->cellIndices.begin();
-        int fragment = d->cells.value(cellIndex, d->fragment_end);
+        const auto begin = d->cellIndices.cbegin();
+        const auto it = std::upper_bound(begin, d->cellIndices.cend(), gridIndex);
+        int fragment = d->cells.value(it - begin, d->fragment_end);
         rowPositions[r - row] = p->fragmentMap().position(fragment);
     }
 
diff --git a/src/gui/util/qgridlayoutengine.cpp b/src/gui/util/qgridlayoutengine.cpp
index 20bc7166ab..8ff2a3eeec 100644
--- a/src/gui/util/qgridlayoutengine.cpp
+++ b/src/gui/util/qgridlayoutengine.cpp
@@ -218,8 +218,9 @@ void QGridLayoutRowData::calculateGeometries(int start, int end, qreal targetSiz
     qreal sumAvailable;
 
     for (int i = 0; i < n; ++i) {
-        if (stretches[start + i] > 0)
-            sumStretches += stretches[start + i];
+        const int stretch = stretches.at(start + i);
+        if (stretch > 0)
+            sumStretches += stretch;
     }
 
     if (targetSize < totalBox.q_preferredSize) {
@@ -1034,19 +1035,19 @@ void QGridLayoutEngine::setGeometries(const QRectF &contentsGeometry, const QAbs
     for (int i = q_items.count() - 1; i >= 0; --i) {
         QGridLayoutItem *item = q_items.at(i);
 
-        qreal x = q_xx[item->firstColumn()];
-        qreal y = q_yy[item->firstRow()];
-        qreal width = q_widths[item->lastColumn()];
-        qreal height = q_heights[item->lastRow()];
+        qreal x = q_xx.at(item->firstColumn());
+        qreal y = q_yy.at(item->firstRow());
+        qreal width = q_widths.at(item->lastColumn());
+        qreal height = q_heights.at(item->lastRow());
 
         if (item->columnSpan() != 1)
-            width += q_xx[item->lastColumn()] - x;
+            width += q_xx.at(item->lastColumn()) - x;
         if (item->rowSpan() != 1)
-            height += q_yy[item->lastRow()] - y;
+            height += q_yy.at(item->lastRow()) - y;
 
         const Qt::Alignment align = effectiveAlignment(item);
         QRectF geom = item->geometryWithin(contentsGeometry.x() + x, contentsGeometry.y() + y,
-                                               width, height, q_descents[item->lastRow()], align, m_snapToPixelGrid);
+                                               width, height, q_descents.at(item->lastRow()), align, m_snapToPixelGrid);
         if (m_snapToPixelGrid) {
             // x and y should already be rounded, but the call to geometryWithin() above might
             // result in a geom with x,y at half-pixels (due to centering within the cell)