diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index 1e6b328c757..58ca8279ea6 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -194,7 +194,7 @@ QT_BEGIN_NAMESPACE
     \omitvalue Pointer
     \value Polish                           The widget is polished.
     \value PolishRequest                    The widget should be polished.
-    \value QueryWhatsThis                   The widget should accept the event if it has "What's This?" help.
+    \value QueryWhatsThis                   The widget should accept the event if it has "What's This?" help (QHelpEvent).
     \value ReadOnlyChange                   Widget's read-only state has changed (since Qt 5.4).
     \value RequestSoftwareInputPanel        A widget wants to open a software input panel (SIP).
     \value Resize                           Widget's size changed (QResizeEvent).
diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index 0e3163eefbc..f7578a3c575 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -641,6 +641,7 @@ QRasterPaintEngineState::QRasterPaintEngineState()
     txscale = 1.;
 
     flags.fast_pen = true;
+    flags.non_complex_pen = false;
     flags.antialiased = false;
     flags.bilinear = false;
     flags.legacy_rounding = false;
diff --git a/src/network/kernel/qnetworkinterface.cpp b/src/network/kernel/qnetworkinterface.cpp
index 70674e9adf5..75a26848a68 100644
--- a/src/network/kernel/qnetworkinterface.cpp
+++ b/src/network/kernel/qnetworkinterface.cpp
@@ -706,7 +706,7 @@ int QNetworkInterface::index() const
 
     \sa QUdpSocket
 */
-int QNetworkInterface::maxTransmissionUnit() const
+int QNetworkInterface::maximumTransmissionUnit() const
 {
     return d ? d->mtu : 0;
 }
diff --git a/src/network/kernel/qnetworkinterface.h b/src/network/kernel/qnetworkinterface.h
index f7ef192dc04..148fd5e10d6 100644
--- a/src/network/kernel/qnetworkinterface.h
+++ b/src/network/kernel/qnetworkinterface.h
@@ -153,7 +153,7 @@ public:
     bool isValid() const;
 
     int index() const;
-    int maxTransmissionUnit() const;
+    int maximumTransmissionUnit() const;
     QString name() const;
     QString humanReadableName() const;
     InterfaceFlags flags() const;
diff --git a/src/plugins/platforms/windows/qwindowsglcontext.cpp b/src/plugins/platforms/windows/qwindowsglcontext.cpp
index 4bdf3167e42..e9c52e2c02b 100644
--- a/src/plugins/platforms/windows/qwindowsglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsglcontext.cpp
@@ -391,6 +391,15 @@ static PIXELFORMATDESCRIPTOR
         pfd.dwFlags |= PFD_DOUBLEBUFFER;
     pfd.cDepthBits =
         format.depthBufferSize() >= 0 ? format.depthBufferSize() : 32;
+    const int redBufferSize = format.redBufferSize();
+    if (redBufferSize != -1)
+        pfd.cRedBits = BYTE(redBufferSize);
+    const int greenBufferSize = format.greenBufferSize();
+    if (greenBufferSize != -1)
+        pfd.cGreenBits = BYTE(greenBufferSize);
+    const int blueBufferSize = format.blueBufferSize();
+    if (blueBufferSize != -1)
+        pfd.cBlueBits = BYTE(blueBufferSize);
     pfd.cAlphaBits = format.alphaBufferSize() > 0 ? format.alphaBufferSize() : 8;
     pfd.cStencilBits = format.stencilBufferSize() > 0 ? format.stencilBufferSize() : 8;
     if (additional.formatFlags & QWindowsGLAccumBuffer)
diff --git a/src/plugins/platforms/windows/qwindowstabletsupport.cpp b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
index 78e33e57ab4..dcad23e4463 100644
--- a/src/plugins/platforms/windows/qwindowstabletsupport.cpp
+++ b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
@@ -111,6 +111,61 @@ inline QPointF QWindowsTabletDeviceData::scaleCoordinates(int coordX, int coordY
     return QPointF(x, y);
 }
 
+template <class Stream>
+static void formatOptions(Stream &str, unsigned options)
+{
+    if (options & CXO_SYSTEM)
+        str << " CXO_SYSTEM";
+    if (options & CXO_PEN)
+        str << " CXO_PEN";
+    if (options & CXO_MESSAGES)
+        str << " CXO_MESSAGES";
+    if (options & CXO_MARGIN)
+        str << " CXO_MARGIN";
+    if (options & CXO_MGNINSIDE)
+        str << " CXO_MGNINSIDE";
+    if (options & CXO_CSRMESSAGES)
+        str << " CXO_CSRMESSAGES";
+}
+
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug d, const QWindowsTabletDeviceData &t)
+{
+    QDebugStateSaver saver(d);
+    d.nospace();
+    d << "TabletDevice id:" << t.uniqueId << " pressure: " << t.minPressure
+      << ".." << t.maxPressure << " tan pressure: " << t.minTanPressure << ".."
+      << t.maxTanPressure << " area:" << t.minX << t.minY <<t.minZ
+      << ".." << t.maxX << t.maxY << t.maxZ << " device " << t.currentDevice
+      << " pointer " << t.currentPointerType;
+    return d;
+}
+
+QDebug operator<<(QDebug d, const LOGCONTEXT &lc)
+{
+    QDebugStateSaver saver(d);
+    d.nospace();
+    d << "LOGCONTEXT(\"" << QString::fromWCharArray(lc.lcName) << "\", options=0x"
+        << hex << lc.lcOptions << dec;
+    formatOptions(d, lc.lcOptions);
+    d << ", status=0x" << hex << lc.lcStatus << ", device=0x" << lc.lcDevice
+        << dec << ", PktRate=" << lc.lcPktRate
+        << ", PktData=" << lc.lcPktData << ", PktMode=" << lc.lcPktMode
+        << ", MoveMask=0x" << hex << lc.lcMoveMask << ", BtnDnMask=0x" << lc.lcBtnDnMask
+        << ", BtnUpMask=0x" << lc.lcBtnUpMask << dec << ", SysMode=" << lc.lcSysMode
+        << ", InOrg=(" << lc.lcInOrgX << ", " << lc.lcInOrgY << ", " << lc.lcInOrgZ
+        <<  "), InExt=(" << lc.lcInExtX << ", " << lc.lcInExtY << ", " << lc.lcInExtZ
+        << ") OutOrg=(" << lc.lcOutOrgX << ", " << lc.lcOutOrgY << ", "
+        << lc.lcOutOrgZ <<  "), OutExt=(" << lc.lcOutExtX << ", " << lc.lcOutExtY
+        << ", " << lc.lcOutExtZ
+        << "), Sens=(" << lc.lcSensX << ", " << lc.lcSensX << ", " << lc.lcSensZ
+        << ") SysOrg=(" << lc.lcSysOrgX << ", " << lc.lcSysOrgY
+        << "), SysExt=(" << lc.lcSysExtX << ", " << lc.lcSysExtY
+        << "), SysSens=(" << lc.lcSysSensX << ", " << lc.lcSysSensY << "))";
+    return d;
+}
+#endif // !QT_NO_DEBUG_STREAM
+
 QWindowsWinTab32DLL QWindowsTabletSupport::m_winTab32DLL;
 
 /*!
@@ -186,6 +241,7 @@ QWindowsTabletSupport *QWindowsTabletSupport::create()
     LOGCONTEXT lcMine;
     // build our context from the default context
     QWindowsTabletSupport::m_winTab32DLL.wTInfo(WTI_DEFSYSCTX, 0, &lcMine);
+    qCDebug(lcQpaTablet) << "Default: " << lcMine;
     // Go for the raw coordinates, the tablet event will return good stuff
     lcMine.lcOptions |= CXO_MESSAGES | CXO_CSRMESSAGES;
     lcMine.lcPktData = lcMine.lcMoveMask = PACKETDATA;
@@ -194,6 +250,7 @@ QWindowsTabletSupport *QWindowsTabletSupport::create()
     lcMine.lcOutExtX = lcMine.lcInExtX;
     lcMine.lcOutOrgY = 0;
     lcMine.lcOutExtY = -lcMine.lcInExtY;
+    qCDebug(lcQpaTablet) << "Requesting: " << lcMine;
     const HCTX context = QWindowsTabletSupport::m_winTab32DLL.wTOpen(window, &lcMine, true);
     if (!context) {
         qCDebug(lcQpaTablet) << __FUNCTION__ << "Unable to open tablet.";
@@ -215,7 +272,7 @@ QWindowsTabletSupport *QWindowsTabletSupport::create()
     } // mismatch
     qCDebug(lcQpaTablet) << "Opened tablet context " << context << " on window "
         <<  window << "changed packet queue size " << currentQueueSize
-        << "->" <<  TabletPacketQSize;
+        << "->" <<  TabletPacketQSize << "\nobtained: " << lcMine;
     return new QWindowsTabletSupport(window, context);
 }
 
@@ -238,17 +295,23 @@ QString QWindowsTabletSupport::description() const
     WORD specificationVersion = 0;
     m_winTab32DLL.wTInfo(WTI_INTERFACE, IFC_SPECVERSION, &specificationVersion);
     const unsigned opts = options();
-    QString result = QString::fromLatin1("%1 specification: v%2.%3 implementation: v%4.%5 options: 0x%6")
-        .arg(QString::fromWCharArray(winTabId.data()))
-        .arg(specificationVersion >> 8).arg(specificationVersion & 0xFF)
-        .arg(implementationVersion >> 8).arg(implementationVersion & 0xFF)
-        .arg(opts, 0, 16);
-    if (opts & CXO_MESSAGES)
-        result += QLatin1String(" CXO_MESSAGES");
-    if (opts & CXO_CSRMESSAGES)
-        result += QLatin1String(" CXO_CSRMESSAGES");
+    WORD devices = 0;
+    m_winTab32DLL.wTInfo(WTI_INTERFACE, IFC_NDEVICES, &devices);
+    WORD cursors = 0;
+    m_winTab32DLL.wTInfo(WTI_INTERFACE, IFC_NCURSORS, &cursors);
+    WORD extensions = 0;
+    m_winTab32DLL.wTInfo(WTI_INTERFACE, IFC_NEXTENSIONS, &extensions);
+    QString result;
+    QTextStream str(&result);
+    str << '"' << QString::fromWCharArray(winTabId.data())
+        << "\" specification: v" << (specificationVersion >> 8)
+        << '.' << (specificationVersion & 0xFF) << " implementation: v"
+        << (implementationVersion >> 8) << '.' << (implementationVersion & 0xFF)
+        << ' ' << devices << " device(s), " << cursors << " cursor(s), "
+        << extensions << " extensions" << ", options: 0x" << hex << opts << dec;
+    formatOptions(str, opts);
     if (m_tiltSupport)
-        result += QLatin1String(" tilt");
+        str << " tilt";
     return result;
 }
 
@@ -306,20 +369,6 @@ static inline QTabletEvent::PointerType pointerType(unsigned currentCursor)
     return QTabletEvent::UnknownPointer;
 }
 
-#ifndef QT_NO_DEBUG_STREAM
-QDebug operator<<(QDebug d, const QWindowsTabletDeviceData &t)
-{
-    QDebugStateSaver saver(d);
-    d.nospace();
-    d << "TabletDevice id:" << t.uniqueId << " pressure: " << t.minPressure
-      << ".." << t.maxPressure << " tan pressure: " << t.minTanPressure << ".."
-      << t.maxTanPressure << " area:" << t.minX << t.minY <<t.minZ
-      << ".." << t.maxX << t.maxY << t.maxZ << " device " << t.currentDevice
-      << " pointer " << t.currentPointerType;
-    return d;
-}
-#endif // !QT_NO_DEBUG_STREAM
-
 QWindowsTabletDeviceData QWindowsTabletSupport::tabletInit(qint64 uniqueId, UINT cursorType) const
 {
     QWindowsTabletDeviceData result;
diff --git a/src/widgets/kernel/qaction.cpp b/src/widgets/kernel/qaction.cpp
index 8c8217bb75f..0ef4ed06348 100644
--- a/src/widgets/kernel/qaction.cpp
+++ b/src/widgets/kernel/qaction.cpp
@@ -1088,7 +1088,7 @@ QAction::event(QEvent *e)
                    "QAction::event",
                    "Received shortcut event from incorrect shortcut");
         if (se->isAmbiguous())
-            qWarning("QAction::eventFilter: Ambiguous shortcut overload: %s", se->key().toString(QKeySequence::NativeText).toLatin1().constData());
+            qWarning("QAction::event: Ambiguous shortcut overload: %s", se->key().toString(QKeySequence::NativeText).toLatin1().constData());
         else
             activate(Trigger);
         return true;
diff --git a/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp b/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
index 0b4ed4870dc..b73ed8eaec4 100644
--- a/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
+++ b/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
@@ -143,7 +143,7 @@ void tst_QNetworkInterface::dump()
         qDebug() << "    flags:     " << qPrintable(flags);
         qDebug() << "    type:      " << i.type();
         qDebug() << "    hw address:" << qPrintable(i.hardwareAddress());
-        qDebug() << "    MTU:       " << i.maxTransmissionUnit();
+        qDebug() << "    MTU:       " << i.maximumTransmissionUnit();
 
         int count = 0;
         foreach (const QNetworkAddressEntry &e, i.addressEntries()) {
@@ -187,7 +187,7 @@ void tst_QNetworkInterface::consistencyCheck()
         if (iface.index())
             interfaceIndexes << iface.index();
 
-        QVERIFY(iface.maxTransmissionUnit() >= 0);
+        QVERIFY(iface.maximumTransmissionUnit() >= 0);
 
         const QList<QNetworkAddressEntry> addresses = iface.addressEntries();
         for (auto entry : addresses) {
@@ -275,7 +275,7 @@ void tst_QNetworkInterface::localAddress()
              << "pmtu" << pmtu;
 
     // check that the Path MTU is less than or equal the interface's MTU
-    QVERIFY(pmtu <= outgoingIface->maxTransmissionUnit());
+    QVERIFY(pmtu <= outgoingIface->maximumTransmissionUnit());
 }
 
 void tst_QNetworkInterface::interfaceFromXXX_data()