Merge remote-tracking branch 'origin/5.6' into 5.7

Conflicts:
	tests/auto/corelib/io/qprocess/tst_qprocess.cpp

Change-Id: Ib6955eb874b516b185b45d6c38cec646fbaa95f4

37 files changed, 456 insertions, 170 deletions

diff --git a/mkspecs/win32-g++/qmake.conf b/mkspecs/win32-g++/qmake.conf
index abc6198bc7..c5f6353d39 100644
--- a/mkspecs/win32-g++/qmake.conf
+++ b/mkspecs/win32-g++/qmake.conf
@@ -105,7 +105,7 @@ QMAKE_LIBS_COMPAT       = -ladvapi32 -lshell32 -lcomdlg32 -luser32 -lgdi32 -lws2
 QMAKE_LIBS_QT_ENTRY     = -lmingw32 -lqtmain
 
 QMAKE_IDL               = midl
-QMAKE_LIB               = $${CROSS_COMPILE}ar -ru
+QMAKE_LIB               = $${CROSS_COMPILE}ar -rc
 QMAKE_RC                = $${CROSS_COMPILE}windres
 
 QMAKE_STRIP             = $${CROSS_COMPILE}strip
diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index 2441de16cd..5e340dbd27 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -252,10 +252,11 @@ static inline void convert_to_wchar_t_elided(wchar_t *d, size_t space, const cha
     if (len + 1 > space) {
         const size_t skip = len - space + 4; // 4 for "..." + '\0'
         s += skip;
+        len -= skip;
         for (int i = 0; i < 3; ++i)
           *d++ = L'.';
     }
-    while (*s)
+    while (len--)
         *d++ = *s++;
     *d++ = 0;
 }
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h
index b6d8e6fdc8..3cd3f52cff 100644
--- a/src/corelib/global/qnamespace.h
+++ b/src/corelib/global/qnamespace.h
@@ -1635,7 +1635,8 @@ public:
     };
 
     enum ScrollPhase {
-        ScrollBegin = 1,
+        NoScrollPhase = 0, // Make public in 5.7 or asap
+        ScrollBegin,
         ScrollUpdate,
         ScrollEnd
     };
diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc
index b17a1ab48b..aa3fc63833 100644
--- a/src/corelib/global/qnamespace.qdoc
+++ b/src/corelib/global/qnamespace.qdoc
@@ -3089,6 +3089,8 @@
 
     This enum describes the phase of scrolling.
 
+    \omitvalue NoScrollPhase The input device doesn't support scroll phase.
+
     \value ScrollBegin Scrolling is about to begin, but the scrolling
     distance did not yet change.
 
diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp
index cabcf656c3..09d23c0084 100644
--- a/src/gui/image/qpixmap.cpp
+++ b/src/gui/image/qpixmap.cpp
@@ -487,7 +487,7 @@ QMatrix QPixmap::trueMatrix(const QMatrix &m, int w, int h)
 
 bool QPixmap::isQBitmap() const
 {
-    return data->type == QPlatformPixmap::BitmapType;
+    return data && data->type == QPlatformPixmap::BitmapType;
 }
 
 /*!
diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index 0d34016dff..98499c11ac 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -733,7 +733,8 @@ QHoverEvent::~QHoverEvent()
 QWheelEvent::QWheelEvent(const QPointF &pos, int delta,
                          Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers,
                          Qt::Orientation orient)
-    : QInputEvent(Wheel, modifiers), p(pos), qt4D(delta), qt4O(orient), mouseState(buttons)
+    : QInputEvent(Wheel, modifiers), p(pos), qt4D(delta), qt4O(orient), mouseState(buttons),
+      ph(Qt::NoScrollPhase), src(Qt::MouseEventNotSynthesized)
 {
     g = QCursor::pos();
     if (orient == Qt::Vertical)
@@ -767,7 +768,8 @@ QWheelEvent::~QWheelEvent()
 QWheelEvent::QWheelEvent(const QPointF &pos, const QPointF& globalPos, int delta,
                          Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers,
                          Qt::Orientation orient)
-    : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), qt4D(delta), qt4O(orient), mouseState(buttons)
+    : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), qt4D(delta), qt4O(orient), mouseState(buttons),
+      ph(Qt::NoScrollPhase), src(Qt::MouseEventNotSynthesized)
 {
     if (orient == Qt::Vertical)
         angleD = QPoint(0, delta);
@@ -803,7 +805,8 @@ QWheelEvent::QWheelEvent(const QPointF &pos, const QPointF& globalPos,
             QPoint pixelDelta, QPoint angleDelta, int qt4Delta, Qt::Orientation qt4Orientation,
             Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers)
     : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), pixelD(pixelDelta),
-      angleD(angleDelta), qt4D(qt4Delta), qt4O(qt4Orientation), mouseState(buttons), ph(Qt::ScrollUpdate)
+      angleD(angleDelta), qt4D(qt4Delta), qt4O(qt4Orientation), mouseState(buttons), ph(Qt::NoScrollPhase),
+      src(Qt::MouseEventNotSynthesized)
 {}
 
 /*!
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index fadca9510b..029b76b2bd 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -224,6 +224,8 @@ protected:
     uint ph : 2;
     uint src: 2;
     int reserved : 28;
+
+    friend class QApplication;
 };
 #endif
 
diff --git a/src/gui/kernel/qhighdpiscaling_p.h b/src/gui/kernel/qhighdpiscaling_p.h
index fe71de6c27..364dfaeaee 100644
--- a/src/gui/kernel/qhighdpiscaling_p.h
+++ b/src/gui/kernel/qhighdpiscaling_p.h
@@ -168,7 +168,7 @@ inline QRect toNative(const QRect &rect, qreal scaleFactor, const QPoint &origin
 
 inline QRect fromNative(const QRect &rect, const QScreen *screen, const QPoint &screenOrigin)
 {
-    return toNative(rect, QHighDpiScaling::factor(screen), screenOrigin);
+    return fromNative(rect, QHighDpiScaling::factor(screen), screenOrigin);
 }
 
 inline QRect fromNativeScreenGeometry(const QRect &nativeScreenGeometry, const QScreen *screen)
diff --git a/src/gui/kernel/qplatformwindow.cpp b/src/gui/kernel/qplatformwindow.cpp
index 1d444f94c9..347d02d616 100644
--- a/src/gui/kernel/qplatformwindow.cpp
+++ b/src/gui/kernel/qplatformwindow.cpp
@@ -492,8 +492,9 @@ QPlatformScreen *QPlatformWindow::screenForGeometry(const QRect &newGeometry) co
     QPlatformScreen *fallback = currentScreen;
     // QRect::center can return a value outside the rectangle if it's empty.
     // Apply mapToGlobal() in case it is a foreign/embedded window.
-    const QPoint center =
-        mapToGlobal(newGeometry.isEmpty() ? newGeometry.topLeft() : newGeometry.center());
+    QPoint center = newGeometry.isEmpty() ? newGeometry.topLeft() : newGeometry.center();
+    if (window()->type() == Qt::ForeignWindow)
+        center = mapToGlobal(center - newGeometry.topLeft());
 
     if (!parent() && currentScreen && !currentScreen->geometry().contains(center)) {
         const auto screens = currentScreen->virtualSiblings();
diff --git a/src/gui/kernel/qscreen.cpp b/src/gui/kernel/qscreen.cpp
index 0e17b2d803..bc4a25a65f 100644
--- a/src/gui/kernel/qscreen.cpp
+++ b/src/gui/kernel/qscreen.cpp
@@ -46,6 +46,7 @@
 
 #include <QtCore/QDebug>
 #include <QtCore/private/qobject_p.h>
+#include "qhighdpiscaling_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -692,7 +693,19 @@ QPixmap QScreen::grabWindow(WId window, int x, int y, int width, int height)
         qWarning("invoked with handle==0");
         return QPixmap();
     }
-    return platformScreen->grabWindow(window, x, y, width, height);
+    const qreal factor = QHighDpiScaling::factor(this);
+    if (qFuzzyCompare(factor, 1))
+        return platformScreen->grabWindow(window, x, y, width, height);
+
+    const QPoint nativePos = QHighDpi::toNative(QPoint(x, y), factor);
+    QSize nativeSize(width, height);
+    if (nativeSize.isValid())
+        nativeSize = QHighDpi::toNative(nativeSize, factor);
+    QPixmap result =
+        platformScreen->grabWindow(window, nativePos.x(), nativePos.y(),
+                                   nativeSize.width(), nativeSize.height());
+    result.setDevicePixelRatio(factor);
+    return result;
 }
 
 #ifndef QT_NO_DEBUG_STREAM
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index c5c4f901e0..f43ef43c6c 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -2335,7 +2335,7 @@ QPoint QWindow::mapToGlobal(const QPoint &pos) const
     // QTBUG-43252, prefer platform implementation for foreign windows.
     if (d->platformWindow
         && (type() == Qt::ForeignWindow || d->platformWindow->isEmbedded())) {
-        return d->platformWindow->mapToGlobal(pos);
+        return QHighDpi::fromNativeLocalPosition(d->platformWindow->mapToGlobal(QHighDpi::toNativeLocalPosition(pos, this)), this);
     }
     return pos + d->globalPosition();
 }
@@ -2355,7 +2355,7 @@ QPoint QWindow::mapFromGlobal(const QPoint &pos) const
     // QTBUG-43252, prefer platform implementation for foreign windows.
     if (d->platformWindow
         && (type() == Qt::ForeignWindow || d->platformWindow->isEmbedded())) {
-        return d->platformWindow->mapFromGlobal(pos);
+        return QHighDpi::fromNativeLocalPosition(d->platformWindow->mapFromGlobal(QHighDpi::toNativeLocalPosition(pos, this)), this);
     }
     return pos - d->globalPosition();
 }
diff --git a/src/gui/kernel/qwindowsysteminterface.h b/src/gui/kernel/qwindowsysteminterface.h
index 0aec2cec07..66a4afb085 100644
--- a/src/gui/kernel/qwindowsysteminterface.h
+++ b/src/gui/kernel/qwindowsysteminterface.h
@@ -100,8 +100,16 @@ public:
                                        quint32 nativeModifiers,
                                        const QString& text = QString(), bool autorep = false,
                                        ushort count = 1, bool tryShortcutOverride = true);
-    static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
-    static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global, QPoint pixelDelta, QPoint angleDelta, Qt::KeyboardModifiers mods = Qt::NoModifier, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
+    static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global,
+                                 QPoint pixelDelta, QPoint angleDelta,
+                                 Qt::KeyboardModifiers mods = Qt::NoModifier,
+                                 Qt::ScrollPhase phase = Qt::NoScrollPhase,
+                                 Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
+    static void handleWheelEvent(QWindow *w, ulong timestamp, const QPointF & local, const QPointF & global,
+                                 QPoint pixelDelta, QPoint angleDelta,
+                                 Qt::KeyboardModifiers mods = Qt::NoModifier,
+                                 Qt::ScrollPhase phase = Qt::NoScrollPhase,
+                                 Qt::MouseEventSource source = Qt::MouseEventNotSynthesized);
 
     // Wheel event compatibility functions. Will be removed: do not use.
     static void handleWheelEvent(QWindow *w, const QPointF & local, const QPointF & global, int d, Qt::Orientation o, Qt::KeyboardModifiers mods = Qt::NoModifier);
diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h
index 35e036dc62..523aa984a9 100644
--- a/src/gui/kernel/qwindowsysteminterface_p.h
+++ b/src/gui/kernel/qwindowsysteminterface_p.h
@@ -242,7 +242,7 @@ public:
     class WheelEvent : public InputEvent {
     public:
         WheelEvent(QWindow *w, ulong time, const QPointF & local, const QPointF & global, QPoint pixelD, QPoint angleD, int qt4D, Qt::Orientation qt4O,
-                   Qt::KeyboardModifiers mods, Qt::ScrollPhase phase = Qt::ScrollUpdate, Qt::MouseEventSource src = Qt::MouseEventNotSynthesized)
+                   Qt::KeyboardModifiers mods, Qt::ScrollPhase phase = Qt::NoScrollPhase, Qt::MouseEventSource src = Qt::MouseEventNotSynthesized)
             : InputEvent(w, time, Wheel, mods), pixelDelta(pixelD), angleDelta(angleD), qt4Delta(qt4D), qt4Orientation(qt4O), localPos(local), globalPos(global), phase(phase), source(src) { }
         QPoint pixelDelta;
         QPoint angleDelta;
diff --git a/src/platformsupport/dbusmenu/qdbusplatformmenu.cpp b/src/platformsupport/dbusmenu/qdbusplatformmenu.cpp
index 5e4cf113e0..e2bde442af 100644
--- a/src/platformsupport/dbusmenu/qdbusplatformmenu.cpp
+++ b/src/platformsupport/dbusmenu/qdbusplatformmenu.cpp
@@ -274,7 +274,7 @@ void QDBusPlatformMenu::setContainingMenuItem(QDBusPlatformMenuItem *item)
 
 QPlatformMenuItem *QDBusPlatformMenu::menuItemAt(int position) const
 {
-    return m_items.at(position);
+    return m_items.value(position);
 }
 
 QPlatformMenuItem *QDBusPlatformMenu::menuItemForTag(quintptr tag) const
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 8733116c6f..fbcaf0b1d0 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -1410,6 +1410,8 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
                momentumPhase == NSEventPhaseEnded || momentumPhase == NSEventPhaseCancelled) {
         ph = Qt::ScrollEnd;
         m_scrolling = false;
+    } else if (phase == NSEventPhaseNone && momentumPhase == NSEventPhaseNone) {
+        ph = Qt::NoScrollPhase;
     }
 
     QWindowSystemInterface::handleWheelEvent(m_window, qt_timestamp, qt_windowPoint, qt_screenPoint, pixelDelta, angleDelta, currentWheelModifiers, ph, source);
diff --git a/src/plugins/platforms/cocoa/qprintengine_mac.mm b/src/plugins/platforms/cocoa/qprintengine_mac.mm
index 339b9b56ce..3d0c91c36c 100644
--- a/src/plugins/platforms/cocoa/qprintengine_mac.mm
+++ b/src/plugins/platforms/cocoa/qprintengine_mac.mm
@@ -476,7 +476,6 @@ void QMacPrintEngine::setProperty(PrintEnginePropertyKey key, const QVariant &va
         d->embedFonts = value.toBool();
         break;
     case PPK_Resolution:  {
-        // TODO It appears the old code didn't actually set the resolution???  Can we delete all this???
         int bestResolution = 0;
         int dpi = value.toInt();
         int bestDistance = INT_MAX;
@@ -492,7 +491,17 @@ void QMacPrintEngine::setProperty(PrintEnginePropertyKey key, const QVariant &va
                 }
             }
         }
-        PMSessionValidatePageFormat(d->session(), d->format(), kPMDontWantBoolean);
+        PMResolution resolution;
+        resolution.hRes = resolution.vRes = bestResolution;
+        if (PMPrinterSetOutputResolution(d->m_printDevice->macPrinter(), d->settings(), &resolution) == noErr) {
+            // Setting the resolution succeeded.
+            // Now try to read the actual resolution selected by the OS.
+            if (PMPrinterGetOutputResolution(d->m_printDevice->macPrinter(), d->settings(), &d->resolution) != noErr) {
+                // Reading the resolution somehow failed; d->resolution is in undefined state.
+                // So use the value which was acceptable to PMPrinterSetOutputResolution.
+                d->resolution = resolution;
+            }
+        }
         break;
     }
     case PPK_CollateCopies:
diff --git a/src/plugins/platforms/windows/accessible/comutils.cpp b/src/plugins/platforms/windows/accessible/comutils.cpp
index ac3683f4d5..7655bdf622 100644
--- a/src/plugins/platforms/windows/accessible/comutils.cpp
+++ b/src/plugins/platforms/windows/accessible/comutils.cpp
@@ -64,15 +64,15 @@ static DATE QDateTimeToDATE(const QDateTime &dt)
     QDate date = dt.date();
     QTime time = dt.time();
     if (date.isValid() && !date.isNull()) {
-        stime.wDay = date.day();
-        stime.wMonth = date.month();
-        stime.wYear = date.year();
+        stime.wDay = WORD(date.day());
+        stime.wMonth = WORD(date.month());
+        stime.wYear = WORD(date.year());
     }
     if (time.isValid() && !time.isNull()) {
-        stime.wMilliseconds = time.msec();
-        stime.wSecond = time.second();
-        stime.wMinute = time.minute();
-        stime.wHour = time.hour();
+        stime.wMilliseconds = WORD(time.msec());
+        stime.wSecond = WORD(time.second());
+        stime.wMinute = WORD(time.minute());
+        stime.wHour = WORD(time.hour());
     }
 
     double vtime;
@@ -98,8 +98,8 @@ bool QVariant2VARIANT(const QVariant &var, VARIANT &arg, const QByteArray &typeN
             proptype = QVariant::Double;
     }
     if (proptype != QVariant::Invalid && proptype != QVariant::UserType && proptype != qvar.type()) {
-        if (qvar.canConvert(proptype))
-            qvar.convert(proptype);
+        if (qvar.canConvert(int(proptype)))
+            qvar.convert(int(proptype));
         else
             qvar = QVariant(proptype);
     }
diff --git a/src/plugins/platforms/windows/accessible/comutils.h b/src/plugins/platforms/windows/accessible/comutils.h
index 468bc0e45c..b1e6183a0f 100644
--- a/src/plugins/platforms/windows/accessible/comutils.h
+++ b/src/plugins/platforms/windows/accessible/comutils.h
@@ -53,14 +53,9 @@ class QVariant;
 // Originally QVariantToVARIANT copied from ActiveQt - renamed to avoid conflicts in static builds.
 bool QVariant2VARIANT(const QVariant &var, VARIANT &arg, const QByteArray &typeName, bool out);
 
-inline QString BSTRToQString(const BSTR &bstr)
-{
-    return QString((QChar*)bstr);
-}
-
 inline BSTR QStringToBSTR(const QString &str)
 {
-    return SysAllocStringLen((OLECHAR*)str.unicode(), str.length());
+    return SysAllocStringLen(reinterpret_cast<const OLECHAR *>(str.unicode()), UINT(str.length()));
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/windows/accessible/iaccessible2.cpp b/src/plugins/platforms/windows/accessible/iaccessible2.cpp
index d81044cdda..f34649e327 100644
--- a/src/plugins/platforms/windows/accessible/iaccessible2.cpp
+++ b/src/plugins/platforms/windows/accessible/iaccessible2.cpp
@@ -47,8 +47,16 @@
 #include <QtGui/qguiapplication.h>
 #include <QtCore/qdebug.h>
 
+#include <algorithm>
+
 QT_BEGIN_NAMESPACE
 
+template <class T>
+static inline T *coTaskMemAllocArray(int size)
+{
+    return static_cast<T *>(::CoTaskMemAlloc(sizeof(T) * size_t(size)));
+}
+
 /**************************************************************\
  *                     AccessibleApplication                  *
  **************************************************************/
@@ -58,7 +66,7 @@ HRESULT STDMETHODCALLTYPE AccessibleApplication::QueryInterface(REFIID id, LPVOI
     *iface = 0;
     if (id == IID_IUnknown) {
         qCDebug(lcQpaAccessibility) << "AccessibleApplication::QI(): IID_IUnknown";
-        *iface = (IUnknown*)this;
+        *iface = static_cast<IUnknown *>(this);
     } else if (id == IID_IAccessibleApplication) {
         qCDebug(lcQpaAccessibility) << "AccessibleApplication::QI(): IID_IAccessibleApplication";
         *iface = static_cast<IAccessibleApplication*>(this);
@@ -128,7 +136,7 @@ HRESULT STDMETHODCALLTYPE AccessibleRelation::QueryInterface(REFIID id, LPVOID *
 {
     *iface = 0;
     if (id == IID_IUnknown || id == IID_IAccessibleRelation)
-        *iface = (IUnknown*)this;
+        *iface = static_cast<IUnknown *>(this);
 
     if (*iface) {
         AddRef();
@@ -206,7 +214,7 @@ HRESULT STDMETHODCALLTYPE AccessibleRelation::get_targets(
     /* [retval][out] */ long *nTargets)
 {
 
-    const int numTargets = qMin((int)maxTargets, m_targets.count());
+    const int numTargets = qMin(int(maxTargets), m_targets.count());
     for (int i = 0; i < numTargets; ++i) {
         QAccessibleInterface *iface = m_targets.at(i);
         IAccessible *iacc = QWindowsAccessibility::wrap(iface);
@@ -235,42 +243,40 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::QueryInterface(REFIID id, LPVOI
     HRESULT hr = QWindowsMsaaAccessible::QueryInterface(id, iface);
     if (!SUCCEEDED(hr)) {
         if (id == IID_IServiceProvider) {
-            *iface = (IServiceProvider*)this;
+            *iface = static_cast<IServiceProvider *>(this);
         } else if (id == IID_IAccessible2) {
-            *iface = (IAccessible2*)this;
+            *iface = static_cast<IAccessible2 *>(this);
         } else if (id == IID_IAccessibleAction) {
             if (accessible->actionInterface())
-                *iface = (IAccessibleAction*)this;
+                *iface = static_cast<IAccessibleAction *>(this);
         } else if (id == IID_IAccessibleComponent) {
-            *iface = (IAccessibleComponent*)this;
+            *iface = static_cast<IAccessibleComponent *>(this);
         } else if (id == IID_IAccessibleEditableText) {
             if (accessible->editableTextInterface() ||
                 accessible->role() == QAccessible::EditableText)
             {
-                *iface = (IAccessibleEditableText*)this;
+                *iface = static_cast<IAccessibleEditableText *>(this);
             }
         } else if (id == IID_IAccessibleHyperlink) {
-            //*iface = (IAccessibleHyperlink*)this;
+            //*iface = static_cast<IAccessibleHyperlink *>(this);
         } else if (id == IID_IAccessibleHypertext) {
-            //*iface = (IAccessibleHypertext*)this;
+            //*iface = static_cast<IAccessibleHypertext *>(this);
         } else if (id == IID_IAccessibleImage) {
-            //*iface = (IAccessibleImage*)this;
-        } else if (id == IID_IAccessibleRelation) {
-            *iface = (IAccessibleRelation*)this;
+            //*iface = static_cast<IAccessibleImage *>(this);
         } else if (id == IID_IAccessibleTable) {
-            //*iface = (IAccessibleTable*)this; // not supported
+            //*iface = static_cast<IAccessibleTable *>(this); // not supported
         } else if (id == IID_IAccessibleTable2) {
             if (accessible->tableInterface())
-                *iface = (IAccessibleTable2*)this;
+                *iface = static_cast<IAccessibleTable2 *>(this);
         } else if (id == IID_IAccessibleTableCell) {
             if (accessible->tableCellInterface())
-                *iface = (IAccessibleTableCell*)this;
+                *iface = static_cast<IAccessibleTableCell *>(this);
         } else if (id == IID_IAccessibleText) {
             if (accessible->textInterface())
-                *iface = (IAccessibleText*)this;
+                *iface = static_cast<IAccessibleText *>(this);
         } else if (id == IID_IAccessibleValue) {
             if (accessible->valueInterface())
-                *iface = (IAccessibleValue*)this;
+                *iface = static_cast<IAccessibleValue *>(this);
         }
         if (*iface) {
             AddRef();
@@ -599,9 +605,9 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_keyBinding(long actionIndex
         numBindings = keyBindings.count();
         if (numBindings > 0) {
             // The IDL documents that the client must free with CoTaskMemFree
-            arrayOfBindingsToReturn = (BSTR*)::CoTaskMemAlloc(sizeof(BSTR) * numBindings);
-            for (int i = 0; i < numBindings; ++i)
-                arrayOfBindingsToReturn[i] = QStringToBSTR(keyBindings.at(i));
+            arrayOfBindingsToReturn = coTaskMemAllocArray<BSTR>(numBindings);
+            std::transform(keyBindings.constBegin(), keyBindings.constEnd(),
+                           arrayOfBindingsToReturn, QStringToBSTR);
         }
     }
     *keyBindings = arrayOfBindingsToReturn;
@@ -674,7 +680,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_foreground(IA2Color *foregr
         return E_FAIL;
 
     // IA2Color is a typedef for long
-    *foreground = (IA2Color)accessible->foregroundColor().rgb();
+    *foreground = static_cast<IA2Color>(accessible->foregroundColor().rgb());
     return S_OK;
 }
 
@@ -686,7 +692,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_background(IA2Color *backgr
         return E_FAIL;
 
     // IA2Color is a typedef for long
-    *background = (IA2Color)accessible->backgroundColor().rgb();
+    *background = static_cast<IA2Color>(accessible->backgroundColor().rgb());
     return S_OK;
 }
 
@@ -760,7 +766,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::insertText(long offset, BSTR *t
 {
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
-    const QString txt(BSTRToQString(*text));
+    const QString txt = QString::fromWCharArray(*text);
     if (QAccessibleEditableTextInterface *editableTextIface = accessible->editableTextInterface())
         editableTextIface->insertText(offset, txt);
     else
@@ -805,7 +811,7 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::replaceText(long startOffset, l
 {
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
-    const QString txt(BSTRToQString(*text));
+    const QString txt = QString::fromWCharArray(*text);
     if (QAccessibleEditableTextInterface *editableTextIface = accessible->editableTextInterface())
         editableTextIface->replaceText(startOffset, endOffset, txt);
     else
@@ -978,12 +984,13 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_selectedColumns(long **sele
 
     if (QAccessibleTableInterface *tableIface = tableInterface()) {
         const QList<int> selectedIndices = tableIface->selectedColumns();
-        const int &count = selectedIndices.count();
-        long *selected = (count ? (long*)::CoTaskMemAlloc(sizeof(long) * count) : (long*)0);
-        for (int i = 0; i < count; ++i)
-            selected[i] = selectedIndices.at(i);
-        *selectedColumns = selected;
+        const int count = selectedIndices.count();
         *nColumns = count;
+        *selectedColumns = Q_NULLPTR;
+        if (count) {
+            *selectedColumns = coTaskMemAllocArray<long>(count);
+            std::copy(selectedIndices.constBegin(), selectedIndices.constEnd(), *selectedColumns);
+        }
         return count ? S_OK : S_FALSE;
     }
     return E_FAIL;
@@ -999,12 +1006,13 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_selectedRows(long **selecte
 
     if (QAccessibleTableInterface *tableIface = tableInterface()) {
         const QList<int> selectedIndices = tableIface->selectedRows();
-        const int &count = selectedIndices.count();
-        long *selected = (count ? (long*)::CoTaskMemAlloc(sizeof(long) * count) : (long*)0);
-        for (int i = 0; i < count; ++i)
-            selected[i] = selectedIndices.at(i);
-        *selectedRows = selected;
+        const int count = selectedIndices.count();
         *nRows = count;
+        *selectedRows = Q_NULLPTR;
+        if (count) {
+            *selectedRows = coTaskMemAllocArray<long>(count);
+            std::copy(selectedIndices.constBegin(), selectedIndices.constEnd(), *selectedRows);
+        }
         return count ? S_OK : S_FALSE;
     }
     return E_FAIL;
@@ -1204,10 +1212,10 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_rowColumnExtents(long *row,
     if (!accessible || !tableCellInterface())
         return E_FAIL;
 
-    *row = (long)tableCellInterface()->rowIndex();
-    *column = (long)tableCellInterface()->columnIndex();
-    *rowExtents = (long)tableCellInterface()->rowExtent();
-    *columnExtents = (long)tableCellInterface()->columnExtent();
+    *row = tableCellInterface()->rowIndex();
+    *column = tableCellInterface()->columnIndex();
+    *rowExtents = tableCellInterface()->rowExtent();
+    *columnExtents = tableCellInterface()->columnExtent();
     *isSelected = tableCellInterface()->isSelected();
     return S_OK;
 }
@@ -1248,7 +1256,8 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_attributes(long offset,
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
     if (QAccessibleTextInterface *text = textInterface()) {
-        const QString attrs = text->attributes(offset, (int*)startOffset, (int*)endOffset);
+        const QString attrs = text->attributes(offset, reinterpret_cast<int *>(startOffset),
+                                               reinterpret_cast<int *>(endOffset));
         *textAttributes = QStringToBSTR(attrs);
         return S_OK;
     }
@@ -1320,7 +1329,8 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_selection(long selectionInd
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
     if (QAccessibleTextInterface *text = textInterface()) {
-        text->selection(selectionIndex, (int*)startOffset, (int*)endOffset);
+        text->selection(selectionIndex, reinterpret_cast<int *>(startOffset),
+                        reinterpret_cast<int *>(endOffset));
         return S_OK;
     }
     return E_FAIL;
@@ -1352,7 +1362,10 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_textBeforeOffset(long offse
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
     if (QAccessibleTextInterface *textIface = textInterface()) {
-        const QString txt = textIface->textBeforeOffset(offset, (QAccessible::TextBoundaryType)boundaryType, (int*)startOffset, (int*)endOffset);
+        const QString txt =
+            textIface->textBeforeOffset(offset, static_cast<QAccessible::TextBoundaryType>(boundaryType),
+                                        reinterpret_cast<int *>(startOffset),
+                                        reinterpret_cast<int *>(endOffset));
         if (!txt.isEmpty()) {
             *text = QStringToBSTR(txt);
             return S_OK;
@@ -1372,7 +1385,10 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_textAfterOffset(
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
     if (QAccessibleTextInterface *textIface = textInterface()) {
-        const QString txt = textIface->textAfterOffset(offset, (QAccessible::TextBoundaryType)boundaryType, (int*)startOffset, (int*)endOffset);
+        const QString txt =
+                textIface->textAfterOffset(offset, static_cast<QAccessible::TextBoundaryType>(boundaryType),
+                                           reinterpret_cast<int *>(startOffset),
+                                           reinterpret_cast<int *>(endOffset));
         if (!txt.isEmpty()) {
             *text = QStringToBSTR(txt);
             return S_OK;
@@ -1391,7 +1407,10 @@ HRESULT STDMETHODCALLTYPE QWindowsIA2Accessible::get_textAtOffset(long offset,
     QAccessibleInterface *accessible = accessibleInterface();
     accessibleDebugClientCalls(accessible);
     if (QAccessibleTextInterface *textIface = textInterface()) {
-        const QString txt = textIface->textAtOffset(offset, (QAccessible::TextBoundaryType)boundaryType, (int*)startOffset, (int*)endOffset);
+        const QString txt =
+            textIface->textAtOffset(offset, static_cast<QAccessible::TextBoundaryType>(boundaryType),
+                                    reinterpret_cast<int *>(startOffset),
+                                    reinterpret_cast<int *>(endOffset));
         if (!txt.isEmpty()) {
             *text = QStringToBSTR(txt);
             return S_OK;
@@ -1630,7 +1649,7 @@ HRESULT QWindowsIA2Accessible::getRelationsHelper(IAccessibleRelation **relation
     QList<QAccessible::Relation> keys = relationMap.keys();
     const int numRelations = keys.count();
     if (relations) {
-        for (int i = startIndex; i < qMin(startIndex + (int)maxRelations, numRelations); ++i) {
+        for (int i = startIndex; i < qMin(startIndex + int(maxRelations), numRelations); ++i) {
             QAccessible::Relation relation = keys.at(i);
             QList<QAccessibleInterface*> targets = relationMap.values(relation);
             AccessibleRelation *rel = new AccessibleRelation(targets, relation);
@@ -1656,12 +1675,13 @@ HRESULT QWindowsIA2Accessible::wrapListOfCells(const QList<QAccessibleInterface*
 {
     const int count = inputCells.count();
     // Server allocates array
-    IUnknown **outputCells = count ? (IUnknown**)::CoTaskMemAlloc(sizeof(IUnknown*) * count ) : (IUnknown**)0;
-    for (int i = 0; i < count; ++i)
-        outputCells[i] = QWindowsAccessibility::wrap(inputCells.at(i));
-
-    *outputAccessibles = outputCells;
     *nCellCount = count;
+    *outputAccessibles = Q_NULLPTR;
+    if (count) {
+        *outputAccessibles = coTaskMemAllocArray<IUnknown *>(count);
+        std::transform(inputCells.constBegin(), inputCells.constEnd(),
+                       *outputAccessibles, QWindowsAccessibility::wrap);
+    }
     return count > 0 ? S_OK : S_FALSE;
 }
 
diff --git a/src/plugins/platforms/windows/accessible/qwindowsaccessibility.cpp b/src/plugins/platforms/windows/accessible/qwindowsaccessibility.cpp
index f91e57ae2f..4a3f0ccb2b 100644
--- a/src/plugins/platforms/windows/accessible/qwindowsaccessibility.cpp
+++ b/src/plugins/platforms/windows/accessible/qwindowsaccessibility.cpp
@@ -173,7 +173,7 @@ void QWindowsAccessibility::notifyAccessibilityUpdate(QAccessibleEvent *event)
     QPlatformNativeInterface *platform = QGuiApplication::platformNativeInterface();
     if (!window->handle()) // Called before show(), no native window yet.
         return;
-    HWND hWnd = (HWND)platform->nativeResourceForWindow("handle", window);
+    const HWND hWnd = reinterpret_cast<HWND>(platform->nativeResourceForWindow("handle", window));
 
     if (event->type() != QAccessible::MenuCommand && // MenuCommand is faked
         event->type() != QAccessible::ObjectDestroyed) {
@@ -220,7 +220,7 @@ IAccessible *QWindowsAccessibility::wrap(QAccessibleInterface *acc)
     QWindowsIA2Accessible *wacc = new QWindowsIA2Accessible(acc);
 # endif
     IAccessible *iacc = 0;
-    wacc->QueryInterface(IID_IAccessible, (void**)&iacc);
+    wacc->QueryInterface(IID_IAccessible, reinterpret_cast<void **>(&iacc));
     return iacc;
 #endif // defined(Q_OS_WINCE)
 }
@@ -230,7 +230,7 @@ bool QWindowsAccessibility::handleAccessibleObjectFromWindowRequest(HWND hwnd, W
 #if !defined(Q_OS_WINCE)
     if (static_cast<long>(lParam) == static_cast<long>(UiaRootObjectId)) {
         /* For UI Automation */
-    } else if ((DWORD)lParam == DWORD(OBJID_CLIENT)) {
+    } else if (DWORD(lParam) == DWORD(OBJID_CLIENT)) {
         // Start handling accessibility internally
         QGuiApplicationPrivate::platformIntegration()->accessibility()->setActive(true);
         // Ignoring all requests while starting up
@@ -244,7 +244,7 @@ bool QWindowsAccessibility::handleAccessibleObjectFromWindowRequest(HWND hwnd, W
 
         if (!oleaccChecked) {
             oleaccChecked = true;
-            ptrLresultFromObject = (PtrLresultFromObject)QSystemLibrary::resolve(QLatin1String("oleacc"), "LresultFromObject");
+            ptrLresultFromObject = reinterpret_cast<PtrLresultFromObject>(QSystemLibrary::resolve(QLatin1String("oleacc"), "LresultFromObject"));
         }
 
         if (ptrLresultFromObject) {
diff --git a/src/plugins/platforms/windows/accessible/qwindowsmsaaaccessible.cpp b/src/plugins/platforms/windows/accessible/qwindowsmsaaaccessible.cpp
index 0d3914d2ed..0fff804e29 100644
--- a/src/plugins/platforms/windows/accessible/qwindowsmsaaaccessible.cpp
+++ b/src/plugins/platforms/windows/accessible/qwindowsmsaaaccessible.cpp
@@ -100,9 +100,9 @@ HRESULT STDMETHODCALLTYPE QWindowsEnumerate::QueryInterface(REFIID id, LPVOID *i
 {
     *iface = 0;
     if (id == IID_IUnknown)
-        *iface = (IUnknown*)this;
+        *iface = static_cast<IUnknown *>(this);
     else if (id == IID_IEnumVARIANT)
-        *iface = (IEnumVARIANT*)this;
+        *iface = static_cast<IEnumVARIANT *>(this);
 
     if (*iface) {
         AddRef();
@@ -150,13 +150,13 @@ HRESULT STDMETHODCALLTYPE QWindowsEnumerate::Next(unsigned long  celt, VARIANT F
     ULONG l;
     for (l = 0; l < celt; l++) {
         VariantInit(&rgVar[l]);
-        if ((current+1) > (ULONG)array.size()) {
+        if (current + 1 > ULONG(array.size())) {
             *pCeltFetched = l;
             return S_FALSE;
         }
 
         rgVar[l].vt = VT_I4;
-        rgVar[l].lVal = array[(int)current];
+        rgVar[l].lVal = array[int(current)];
         ++current;
     }
     *pCeltFetched = l;
@@ -172,8 +172,8 @@ HRESULT STDMETHODCALLTYPE QWindowsEnumerate::Reset()
 HRESULT STDMETHODCALLTYPE QWindowsEnumerate::Skip(unsigned long celt)
 {
     current += celt;
-    if (current > (ULONG)array.size()) {
-        current = array.size();
+    if (current > ULONG(array.size())) {
+        current = ULONG(array.size());
         return S_FALSE;
     }
     return S_OK;
@@ -201,13 +201,13 @@ HRESULT STDMETHODCALLTYPE QWindowsMsaaAccessible::QueryInterface(REFIID id, LPVO
                                     << strIID << ", iface:" << accessibleInterface();
     }
     if (id == IID_IUnknown) {
-        *iface = (IUnknown*)(IDispatch*)this;
+        *iface =  static_cast<IUnknown *>(static_cast<IDispatch *>(this));
     } else if (id == IID_IDispatch) {
-        *iface = (IDispatch*)this;
+        *iface = static_cast<IDispatch *>(this);
     } else if (id == IID_IAccessible) {
-        *iface = (IAccessible*)this;
+        *iface = static_cast<IAccessible *>(this);
     } else if (id == IID_IOleWindow) {
-        *iface = (IOleWindow*)this;
+        *iface = static_cast<IOleWindow *>(this);
     }
 
     if (*iface) {
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 5ae5ae3129..78fff65d84 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -430,7 +430,7 @@ bool QWindowsMouseHandler::translateMouseWheelEvent(QWindow *window, HWND,
 
     int delta;
     if (msg.message == WM_MOUSEWHEEL || msg.message == WM_MOUSEHWHEEL)
-        delta = HIWORD (msg.wParam);
+        delta = GET_WHEEL_DELTA_WPARAM(msg.wParam);
     else
         delta = int(msg.wParam);
 
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index a7f00d5f6d..c64955be80 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -128,6 +128,41 @@ static inline QColor getSysColor(int index)
     return COLORREFToQColor(GetSysColor(index));
 }
 
+#ifndef QT_NO_WINCE_SHELLSDK
+// QTBUG-48823/Windows 10: SHGetFileInfo() (as called by item views on file system
+// models has been observed to trigger a WM_PAINT on the mainwindow. Suppress the
+// behavior by running it in a thread.
+class ShGetFileInfoFunction
+{
+public:
+    explicit ShGetFileInfoFunction(const wchar_t *fn, DWORD a, SHFILEINFO *i, UINT f, bool *r) :
+        m_fileName(fn), m_attributes(a), m_flags(f), m_info(i), m_result(r) {}
+
+    void operator()() const { *m_result = SHGetFileInfo(m_fileName, m_attributes, m_info, sizeof(SHFILEINFO), m_flags); }
+
+private:
+    const wchar_t *m_fileName;
+    const DWORD m_attributes;
+    const UINT m_flags;
+    SHFILEINFO *const m_info;
+    bool *m_result;
+};
+
+static bool shGetFileInfoBackground(QWindowsThreadPoolRunner &r,
+                                    const wchar_t *fileName, DWORD attributes,
+                                    SHFILEINFO *info, UINT flags,
+                                    unsigned long  timeOutMSecs = 5000)
+{
+    bool result = false;
+    if (!r.run(ShGetFileInfoFunction(fileName, attributes, info, flags, &result), timeOutMSecs)) {
+        qWarning().noquote() << "ShGetFileInfoBackground() timed out for "
+            << QString::fromWCharArray(fileName);
+        return false;
+    }
+    return result;
+}
+#endif // !QT_NO_WINCE_SHELLSDK
+
 // from QStyle::standardPalette
 static inline QPalette standardPalette()
 {
@@ -725,23 +760,22 @@ QPixmap QWindowsTheme::fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &s
     }
 
     SHFILEINFO info;
-    unsigned int flags =
+    const unsigned int flags =
 #ifndef Q_OS_WINCE
         SHGFI_ICON|iconSize|SHGFI_SYSICONINDEX|SHGFI_ADDOVERLAYS|SHGFI_OVERLAYINDEX;
 #else
         iconSize|SHGFI_SYSICONINDEX;
 #endif // Q_OS_WINCE
-    unsigned long val = 0;
+
+
 #if !defined(QT_NO_WINCE_SHELLSDK)
-    if (cacheableDirIcon && useDefaultFolderIcon) {
-        flags |= SHGFI_USEFILEATTRIBUTES;
-        val = SHGetFileInfo(L"dummy",
-                            FILE_ATTRIBUTE_DIRECTORY,
-                            &info, sizeof(SHFILEINFO), flags);
-    } else {
-        val = SHGetFileInfo(reinterpret_cast<const wchar_t *>(filePath.utf16()), 0,
-                            &info, sizeof(SHFILEINFO), flags);
-    }
+    const bool val = cacheableDirIcon && useDefaultFolderIcon
+        ? shGetFileInfoBackground(m_threadPoolRunner, L"dummy", FILE_ATTRIBUTE_DIRECTORY,
+                                  &info, flags | SHGFI_USEFILEATTRIBUTES)
+        : shGetFileInfoBackground(m_threadPoolRunner, reinterpret_cast<const wchar_t *>(filePath.utf16()), 0,
+                                  &info, flags);
+#else
+    const bool val = false;
 #endif // !QT_NO_WINCE_SHELLSDK
 
     // Even if GetFileInfo returns a valid result, hIcon can be empty in some cases
diff --git a/src/plugins/platforms/windows/qwindowstheme.h b/src/plugins/platforms/windows/qwindowstheme.h
index 45db934e47..acf89306c2 100644
--- a/src/plugins/platforms/windows/qwindowstheme.h
+++ b/src/plugins/platforms/windows/qwindowstheme.h
@@ -40,6 +40,7 @@
 #ifndef QWINDOWSTHEME_H
 #define QWINDOWSTHEME_H
 
+#include "qwindowsthreadpoolrunner.h"
 #include <qpa/qplatformtheme.h>
 
 QT_BEGIN_NAMESPACE
@@ -80,6 +81,7 @@ private:
     static QWindowsTheme *m_instance;
     QPalette *m_palettes[NPalettes];
     QFont *m_fonts[NFonts];
+    mutable QWindowsThreadPoolRunner m_threadPoolRunner;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/windows/qwindowsthreadpoolrunner.h b/src/plugins/platforms/windows/qwindowsthreadpoolrunner.h
new file mode 100644
index 0000000000..0361aa90f5
--- /dev/null
+++ b/src/plugins/platforms/windows/qwindowsthreadpoolrunner.h
@@ -0,0 +1,116 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWINDOWSTHREADPOOLRUNNER_H
+#define QWINDOWSTHREADPOOLRUNNER_H
+
+#include <QtCore/QMutex>
+#include <QtCore/QRunnable>
+#include <QtCore/QThreadPool>
+#include <QtCore/QWaitCondition>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QWindowsThreadPoolRunner
+    \brief Runs a task in the global instance of QThreadPool
+
+    QThreadPool does not provide a method to wait on a single task, so this needs
+    to be done by using QWaitCondition/QMutex.
+
+    \internal
+    \ingroup qt-lighthouse-win
+*/
+class QWindowsThreadPoolRunner
+{
+    Q_DISABLE_COPY(QWindowsThreadPoolRunner)
+
+#ifndef QT_NO_THREAD
+    template <class RunnableFunction> // nested class implementing QRunnable to execute a function.
+    class Runnable : public QRunnable
+    {
+    public:
+        explicit Runnable(QMutex *m, QWaitCondition *c, RunnableFunction f)
+            : m_mutex(m), m_condition(c), m_function(f) {}
+
+        void run() Q_DECL_OVERRIDE
+        {
+            m_function();
+            m_mutex->lock();
+            m_condition->wakeAll();
+            m_mutex->unlock();
+        }
+
+    private:
+        QMutex *m_mutex;
+        QWaitCondition *m_condition;
+        RunnableFunction m_function;
+    }; // class Runnable
+
+public:
+    QWindowsThreadPoolRunner() {}
+
+    template <class Function>
+    bool run(Function f, unsigned long timeOutMSecs = 5000)
+    {
+        QThreadPool *pool = QThreadPool::globalInstance();
+        Q_ASSERT(pool);
+        Runnable<Function> *runnable = new Runnable<Function>(&m_mutex, &m_condition, f);
+        m_mutex.lock();
+        pool->start(runnable);
+        const bool ok = m_condition.wait(&m_mutex, timeOutMSecs);
+        m_mutex.unlock();
+        if (!ok)
+            pool->cancel(runnable);
+        return ok;
+    }
+
+private:
+    QMutex m_mutex;
+    QWaitCondition m_condition;
+#else // !QT_NO_THREAD
+public:
+    QWindowsThreadPoolRunner() {}
+
+    template <class Function>
+    bool run(Function f, unsigned long /* timeOutMSecs */ = 5000)
+    {
+        f();
+        return true;
+    }
+#endif // QT_NO_THREAD
+};
+
+QT_END_NAMESPACE
+
+#endif // QWINDOWSTHREADPOOLRUNNER_H
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index c1a047e276..d9a7586096 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -2203,14 +2203,15 @@ void QWindowsWindow::getSizeHints(MINMAXINFO *mmi) const
 
         // Documentation of MINMAXINFO states that it will only work for the primary screen
         if (screen && screen == QGuiApplication::primaryScreen()) {
-            mmi->ptMaxSize.y = screen->availableGeometry().height();
+            const QRect availableGeometry = QHighDpi::toNativePixels(screen->availableGeometry(), screen);
+            mmi->ptMaxSize.y = availableGeometry.height();
 
             // Width, because you can have the taskbar on the sides too.
-            mmi->ptMaxSize.x = screen->availableGeometry().width();
+            mmi->ptMaxSize.x = availableGeometry.width();
 
             // If you have the taskbar on top, or on the left you don't want it at (0,0):
-            mmi->ptMaxPosition.x = screen->availableGeometry().x();
-            mmi->ptMaxPosition.y = screen->availableGeometry().y();
+            mmi->ptMaxPosition.x = availableGeometry.x();
+            mmi->ptMaxPosition.y = availableGeometry.y();
         } else if (!screen){
             qWarning() << "window()->screen() returned a null screen";
         }
diff --git a/src/plugins/platforms/windows/windows.pri b/src/plugins/platforms/windows/windows.pri
index 766168ccb8..d46cfbc43a 100644
--- a/src/plugins/platforms/windows/windows.pri
+++ b/src/plugins/platforms/windows/windows.pri
@@ -62,7 +62,8 @@ HEADERS += \
     $$PWD/qplatformfunctions_wince.h \
     $$PWD/qwindowsnativeimage.h \
     $$PWD/qwindowsnativeinterface.h \
-    $$PWD/qwindowsopengltester.h
+    $$PWD/qwindowsopengltester.h \
+    $$PWD/qwindowsthreadpoolrunner.h
 
 INCLUDEPATH += $$PWD
 
diff --git a/src/sql/kernel/qsqldriver.cpp b/src/sql/kernel/qsqldriver.cpp
index ac51941f43..ad5207cf6e 100644
--- a/src/sql/kernel/qsqldriver.cpp
+++ b/src/sql/kernel/qsqldriver.cpp
@@ -472,6 +472,17 @@ QString QSqlDriver::stripDelimiters(const QString &identifier, IdentifierType ty
     This method can be used to manipulate tables without having to worry
     about database-dependent SQL dialects. For non-prepared statements,
     the values will be properly escaped.
+
+    In the WHERE statement, each non-null field of \a rec specifies a
+    filter condition of equality to the field value, or if prepared, a
+    placeholder. However, prepared or not, a null field specifies the
+    condition IS NULL and never introduces a placeholder. The
+    application must not attempt to bind data for the null field during
+    execution. The field must be set to some non-null value if a
+    placeholder is desired. Furthermore, since non-null fields specify
+    equality conditions and SQL NULL is not equal to anything, even
+    itself, it is generally not useful to bind a null to a placeholder.
+
 */
 QString QSqlDriver::sqlStatement(StatementType type, const QString &tableName,
                                  const QSqlRecord &rec, bool preparedStatement) const
diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index a0a363ba2b..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;
@@ -3307,7 +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()) {
@@ -3315,27 +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
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/tests/auto/corelib/io/qprocess/tst_qprocess.cpp b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
index 0d690312e4..e5195000aa 100644
--- a/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
+++ b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
@@ -40,15 +40,7 @@
 #include <QtNetwork/QHostInfo>
 #include <stdlib.h>
 
-#ifndef QT_NO_PROCESS
 # include <private/qprocess_p.h>    // only so we get QPROCESS_USE_SPAWN
-# if defined(Q_OS_WIN)
-#  include <windows.h>
-# endif
-
-Q_DECLARE_METATYPE(QProcess::ExitStatus);
-Q_DECLARE_METATYPE(QProcess::ProcessState);
-#endif
 
 typedef void (QProcess::*QProcessFinishedSignal1)(int);
 typedef void (QProcess::*QProcessFinishedSignal2)(int, QProcess::ExitStatus);
@@ -1052,24 +1044,33 @@ private:
 void tst_QProcess::softExitInSlots_data()
 {
     QTest::addColumn<QString>("appName");
+    QTest::addColumn<int>("signalToConnect");
 
+    QByteArray dataTagPrefix("gui app ");
 #ifndef QT_NO_WIDGETS
-    QTest::newRow("gui app") << "testGuiProcess/testGuiProcess";
+    for (int i = 0; i < 6; ++i) {
+        QTest::newRow(dataTagPrefix + QByteArray::number(i))
+                << "testGuiProcess/testGuiProcess" << i;
+    }
 #endif
-    QTest::newRow("console app") << "testProcessEcho2/testProcessEcho2";
+
+    dataTagPrefix = "console app ";
+    for (int i = 0; i < 6; ++i) {
+        QTest::newRow(dataTagPrefix + QByteArray::number(i))
+                << "testProcessEcho2/testProcessEcho2" << i;
+    }
 }
 
 void tst_QProcess::softExitInSlots()
 {
     QFETCH(QString, appName);
+    QFETCH(int, signalToConnect);
 
-    for (int i = 0; i < 6; ++i) {
-        SoftExitProcess proc(i);
-        proc.writeAfterStart("OLEBOLE", 8); // include the \0
-        proc.start(appName);
-        QTRY_VERIFY_WITH_TIMEOUT(proc.waitedForFinished, 10000);
-        QCOMPARE(proc.state(), QProcess::NotRunning);
-    }
+    SoftExitProcess proc(signalToConnect);
+    proc.writeAfterStart("OLEBOLE", 8); // include the \0
+    proc.start(appName);
+    QTRY_VERIFY_WITH_TIMEOUT(proc.waitedForFinished, 10000);
+    QCOMPARE(proc.state(), QProcess::NotRunning);
 }
 #endif
 
diff --git a/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp b/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
index ff049b7600..cfec327319 100644
--- a/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/corelib/tools/qdatetime/tst_qdatetime.cpp
@@ -714,8 +714,6 @@ void tst_QDateTime::fromMSecsSinceEpoch()
         QCOMPARE(dtLocal.toLocalTime(), cet);
         QCOMPARE(dtUtc.toLocalTime(), cet);
         QCOMPARE(dtOffset.toLocalTime(), cet);
-    } else {
-        QSKIP("You must test using Central European (CET/CEST) time zone, e.g. TZ=Europe/Oslo");
     }
 
     // LocalTime will overflow for max
diff --git a/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp b/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
index 0219738a70..6adfe05fb0 100644
--- a/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
+++ b/tests/auto/gui/image/qpixmap/tst_qpixmap.cpp
@@ -96,6 +96,7 @@ private slots:
     void drawBitmap();
     void isNull();
     void task_246446();
+    void task_51271();
 
     void convertFromImageNoDetach();
     void convertFromImageDetach();
@@ -1425,6 +1426,14 @@ void tst_QPixmap::task_246446()
     QVERIFY(pm.mask().isNull());
 }
 
+void tst_QPixmap::task_51271()
+{
+    QPixmap pm;
+    QBitmap bm;
+    QVERIFY(!pm.isQBitmap()); // Should not crash !
+    QVERIFY(bm.isQBitmap());
+}
+
 void tst_QPixmap::preserveDepth()
 {
     QPixmap target(64, 64);
diff --git a/tests/auto/gui/kernel/qguimetatype/tst_qguimetatype.cpp b/tests/auto/gui/kernel/qguimetatype/tst_qguimetatype.cpp
index 0ffb0ea45f..8002303723 100644
--- a/tests/auto/gui/kernel/qguimetatype/tst_qguimetatype.cpp
+++ b/tests/auto/gui/kernel/qguimetatype/tst_qguimetatype.cpp
@@ -341,11 +341,11 @@ struct TypeAlignment
 void tst_QGuiMetaType::flags_data()
 {
     QTest::addColumn<int>("type");
-    QTest::addColumn<bool>("isMovable");
+    QTest::addColumn<bool>("isRelocatable");
     QTest::addColumn<bool>("isComplex");
 
 #define ADD_METATYPE_TEST_ROW(MetaTypeName, MetaTypeId, RealType) \
-    QTest::newRow(#RealType) << MetaTypeId << bool(!QTypeInfo<RealType>::isStatic) << bool(QTypeInfo<RealType>::isComplex);
+    QTest::newRow(#RealType) << MetaTypeId << bool(QTypeInfoQuery<RealType>::isRelocatable) << bool(QTypeInfoQuery<RealType>::isComplex);
 QT_FOR_EACH_STATIC_GUI_CLASS(ADD_METATYPE_TEST_ROW)
 #undef ADD_METATYPE_TEST_ROW
 }
@@ -353,12 +353,12 @@ QT_FOR_EACH_STATIC_GUI_CLASS(ADD_METATYPE_TEST_ROW)
 void tst_QGuiMetaType::flags()
 {
     QFETCH(int, type);
-    QFETCH(bool, isMovable);
+    QFETCH(bool, isRelocatable);
     QFETCH(bool, isComplex);
 
     QCOMPARE(bool(QMetaType::typeFlags(type) & QMetaType::NeedsConstruction), isComplex);
     QCOMPARE(bool(QMetaType::typeFlags(type) & QMetaType::NeedsDestruction), isComplex);
-    QCOMPARE(bool(QMetaType::typeFlags(type) & QMetaType::MovableType), isMovable);
+    QCOMPARE(bool(QMetaType::typeFlags(type) & QMetaType::MovableType), isRelocatable);
 }
 
 
diff --git a/tests/auto/printsupport/kernel/qprinter/tst_qprinter.cpp b/tests/auto/printsupport/kernel/qprinter/tst_qprinter.cpp
index 9d9ca6fb43..eb056475d1 100644
--- a/tests/auto/printsupport/kernel/qprinter/tst_qprinter.cpp
+++ b/tests/auto/printsupport/kernel/qprinter/tst_qprinter.cpp
@@ -1623,7 +1623,24 @@ void tst_QPrinter::resolution()
         // Test set/get
         int expected = 333;
 #ifdef Q_OS_MAC
-        // Set resolution does nothing on OSX, see QTBUG-7000
+        // QMacPrintEngine chooses the closest supported resolution.
+        const QList<int> all_supported = native.supportedResolutions();
+        foreach (int supported, all_supported) {
+            // Test setting a supported resolution
+            int requested = supported;
+            native.setResolution(requested);
+            QCOMPARE(native.resolution(), requested);
+
+            // Test setting an unsupported resolution
+            do {
+                requested += 5;
+            } while (all_supported.contains(requested));
+            native.setResolution(requested);
+            int result = native.resolution();
+            QVERIFY(all_supported.contains(result));
+            QVERIFY(qAbs(result - requested) <= qAbs(supported - requested));
+        }
+
         expected = native.resolution();
 #endif // Q_OS_MAC
         native.setResolution(expected);
diff --git a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
index 63be3de3ab..6528c24c1a 100644
--- a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
+++ b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
@@ -555,6 +555,11 @@ void tst_QDialog::reject()
     QCOMPARE(dialog.called, 4);
 }
 
+static QByteArray formatPoint(QPoint p)
+{
+    return QByteArray::number(p.x()) + ", " + QByteArray::number(p.y());
+}
+
 void tst_QDialog::snapToDefaultButton()
 {
 #ifdef QT_NO_CURSOR
@@ -563,9 +568,9 @@ void tst_QDialog::snapToDefaultButton()
     if (!QGuiApplication::platformName().compare(QLatin1String("wayland"), Qt::CaseInsensitive))
         QSKIP("Wayland: Wayland does not support setting the cursor position.");
 
-    QPoint topLeftPos = QApplication::desktop()->availableGeometry().topLeft();
-    topLeftPos = QPoint(topLeftPos.x() + 100, topLeftPos.y() + 100);
-    QPoint startingPos(topLeftPos.x() + 250, topLeftPos.y() + 250);
+    const QRect dialogGeometry(QApplication::desktop()->availableGeometry().topLeft()
+                               + QPoint(100, 100), QSize(200, 200));
+    const QPoint startingPos = dialogGeometry.bottomRight() + QPoint(100, 100);
     QCursor::setPos(startingPos);
 #ifdef Q_OS_OSX
     // On OS X we use CGEventPost to move the cursor, it needs at least
@@ -576,17 +581,14 @@ void tst_QDialog::snapToDefaultButton()
     QDialog dialog;
     QPushButton *button = new QPushButton(&dialog);
     button->setDefault(true);
-    dialog.setGeometry(QRect(topLeftPos, QSize(200, 200)));
+    dialog.setGeometry(dialogGeometry);
     dialog.show();
     QVERIFY(QTest::qWaitForWindowExposed(&dialog));
-    if (const QPlatformTheme *theme = QGuiApplicationPrivate::platformTheme()) {
-        if (theme->themeHint(QPlatformTheme::DialogSnapToDefaultButton).toBool()) {
-            QPoint localPos = button->mapFromGlobal(QCursor::pos());
-            QVERIFY(button->rect().contains(localPos));
-        } else {
-            QCOMPARE(startingPos, QCursor::pos());
-        }
-    }
+    const QPoint localPos = button->mapFromGlobal(QCursor::pos());
+    if (QGuiApplicationPrivate::platformTheme()->themeHint(QPlatformTheme::DialogSnapToDefaultButton).toBool())
+        QVERIFY2(button->rect().contains(localPos), formatPoint(localPos).constData());
+    else
+        QVERIFY2(!button->rect().contains(localPos), formatPoint(localPos).constData());
 #endif // !QT_NO_CURSOR
 }
 
diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index afee548c9b..515ddf480f 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -4974,7 +4974,9 @@ static inline QByteArray msgRgbMismatch(unsigned actual, unsigned expected)
 static QPixmap grabWindow(QWindow *window, int x, int y, int width, int height)
 {
     QScreen *screen = window->screen();
-    return screen ? screen->grabWindow(window->winId(), x, y, width, height) : QPixmap();
+    Q_ASSERT(screen);
+    QPixmap result = screen->grabWindow(window->winId(), x, y, width, height);
+    return result.devicePixelRatio() > 1 ? result.scaled(width, height) : result;
 }
 
 #define VERIFY_COLOR(child, region, color) verifyColor(child, region, color, __LINE__)
@@ -8500,7 +8502,7 @@ void tst_QWidget::translucentWidget()
 #ifdef Q_OS_WIN
     QWidget *desktopWidget = QApplication::desktop()->screen(0);
     if (QSysInfo::windowsVersion() >= QSysInfo::WV_VISTA)
-        widgetSnapshot = qApp->primaryScreen()->grabWindow(desktopWidget->winId(), labelPos.x(), labelPos.y(), label.width(), label.height());
+        widgetSnapshot = grabWindow(desktopWidget->windowHandle(), labelPos.x(), labelPos.y(), label.width(), label.height());
     else
 #endif
         widgetSnapshot = label.grab(QRect(QPoint(0, 0), label.size()));