Merge remote-tracking branch 'origin/5.4' into 5.5

Conflicts:
	examples/xml/htmlinfo/simpleexample.html
	examples/xml/rsslisting/rsslisting.cpp
	qmake/generators/win32/msbuild_objectmodel.cpp
	src/3rdparty/harfbuzz-ng/src/hb-private.hh
	src/corelib/global/qlogging.cpp
	src/corelib/io/qstorageinfo_unix.cpp
	src/corelib/thread/qwaitcondition_unix.cpp
	src/gui/kernel/qguiapplication.cpp
	src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
	src/testlib/doc/src/qt-webpages.qdoc
	tests/auto/other/qaccessibility/tst_qaccessibility.cpp

Change-Id: Ib272ff0bc30a1a5d51275eb3cd2f201dc82c11ff

13 files changed, 240 insertions, 158 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
index 903da2498c..4ece1b5a22 100644
--- a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
+++ b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
@@ -438,7 +438,7 @@ static QString strippedText(QString s)
 - (void)panelSelectionDidChange:(id)sender
 {
     Q_UNUSED(sender);
-    if (mHelper) {
+    if (mHelper && [mSavePanel isVisible]) {
         QString selection = QCFString::toQString([[mSavePanel URL] path]);
         if (selection != mCurrentSelection) {
             *mCurrentSelection = selection;
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
index aedb8f7b88..36cfff43f5 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.cpp
@@ -68,8 +68,6 @@ enum {
     D2DDebugFillRectTag,
     D2DDebugDrawRectsTag,
     D2DDebugDrawRectFsTag,
-    D2DDebugDrawLinesTag,
-    D2DDebugDrawLineFsTag,
     D2DDebugDrawEllipseTag,
     D2DDebugDrawEllipseFTag,
     D2DDebugDrawImageTag,
@@ -102,22 +100,28 @@ static inline ID2D1Factory1 *factory()
     return QWindowsDirect2DContext::instance()->d2dFactory();
 }
 
-static inline D2D1_MATRIX_3X2_F transformFromLine(const QLineF &line, qreal penWidth)
+static inline D2D1_MATRIX_3X2_F transformFromLine(const QLineF &line, qreal penWidth, qreal dashOffset)
 {
     const qreal halfWidth = penWidth / 2;
     const qreal angle = -qDegreesToRadians(line.angle());
-    QTransform transform = QTransform::fromTranslate(line.p1().x() + qSin(angle) * halfWidth,
-                                                     line.p1().y() - qCos(angle) * halfWidth);
+    const qreal sinA = qSin(angle);
+    const qreal cosA = qCos(angle);
+    QTransform transform = QTransform::fromTranslate(line.p1().x() + dashOffset * cosA + sinA * halfWidth,
+                                                     line.p1().y() + dashOffset * sinA - cosA * halfWidth);
     transform.rotateRadians(angle);
     return to_d2d_matrix_3x2_f(transform);
 }
 
+static void adjustLine(QPointF *p1, QPointF *p2);
+static bool isLinePositivelySloped(const QPointF &p1, const QPointF &p2);
+
 class Direct2DPathGeometryWriter
 {
 public:
     Direct2DPathGeometryWriter()
         : m_inFigure(false)
         , m_roundCoordinates(false)
+        , m_adjustPositivelySlopedLines(false)
     {
 
     }
@@ -152,6 +156,11 @@ public:
         m_roundCoordinates = enable;
     }
 
+    void setPositiveSlopeAdjustmentEnabled(bool enable)
+    {
+        m_adjustPositivelySlopedLines = enable;
+    }
+
     bool isInFigure() const
     {
         return m_inFigure;
@@ -164,11 +173,20 @@ public:
 
         m_sink->BeginFigure(adjusted(point), D2D1_FIGURE_BEGIN_FILLED);
         m_inFigure = true;
+        m_previousPoint = point;
     }
 
     void lineTo(const QPointF &point)
     {
-        m_sink->AddLine(adjusted(point));
+        QPointF pt = point;
+        if (m_adjustPositivelySlopedLines && isLinePositivelySloped(m_previousPoint, point)) {
+            moveTo(m_previousPoint - QPointF(0, 1));
+            pt -= QPointF(0, 1);
+        }
+        m_sink->AddLine(adjusted(pt));
+        if (pt != point)
+            moveTo(point);
+        m_previousPoint = point;
     }
 
     void curveTo(const QPointF &p1, const QPointF &p2, const QPointF &p3)
@@ -180,6 +198,7 @@ public:
         };
 
         m_sink->AddBezier(segment);
+        m_previousPoint = p3;
     }
 
     void close()
@@ -212,6 +231,8 @@ private:
 
     bool m_inFigure;
     bool m_roundCoordinates;
+    bool m_adjustPositivelySlopedLines;
+    QPointF m_previousPoint;
 };
 
 struct D2DVectorPathCache {
@@ -257,6 +278,7 @@ public:
         ComPtr<ID2D1Brush> brush;
         ComPtr<ID2D1StrokeStyle1> strokeStyle;
         ComPtr<ID2D1BitmapBrush1> dashBrush;
+        int dashLength;
 
         inline void reset() {
             emulate = false;
@@ -264,6 +286,7 @@ public:
             brush.Reset();
             strokeStyle.Reset();
             dashBrush.Reset();
+            dashLength = 0;
         }
     } pen;
 
@@ -566,6 +589,7 @@ public:
             D2D1_BITMAP_BRUSH_PROPERTIES1 bitmapBrushProperties = D2D1::BitmapBrushProperties1(
                         D2D1_EXTEND_MODE_WRAP, D2D1_EXTEND_MODE_CLAMP, D2D1_INTERPOLATION_MODE_LINEAR);
             hr = dc()->CreateBitmapBrush(bitmap.bitmap(), bitmapBrushProperties, &pen.dashBrush);
+            pen.dashLength = bitmap.size().width();
         } else {
             hr = factory()->CreateStrokeStyle(props, NULL, 0, &pen.strokeStyle);
         }
@@ -795,6 +819,8 @@ public:
 
         writer.setWindingFillEnabled(path.hasWindingFill());
         writer.setAliasingEnabled(alias);
+        writer.setPositiveSlopeAdjustmentEnabled(path.shape() == QVectorPath::LinesHint
+                                                 || path.shape() == QVectorPath::PolygonHint);
 
         const QPainterPath::ElementType *types = path.elements();
         const int count = path.elementCount();
@@ -910,6 +936,90 @@ public:
                            DWRITE_MEASURING_MODE_GDI_CLASSIC);
     }
 
+    void stroke(const QVectorPath &path)
+    {
+        Q_Q(QWindowsDirect2DPaintEngine);
+
+        // Default path (no optimization)
+        if (!(path.shape() == QVectorPath::LinesHint || path.shape() == QVectorPath::PolygonHint)
+                || !pen.dashBrush || q->state()->renderHints.testFlag(QPainter::HighQualityAntialiasing)) {
+            ComPtr<ID2D1Geometry> geometry = vectorPathToID2D1PathGeometry(path);
+            if (!geometry) {
+                qWarning("%s: Could not convert path to d2d geometry", __FUNCTION__);
+                return;
+            }
+            dc()->DrawGeometry(geometry.Get(), pen.brush.Get(), pen.qpen.widthF(), pen.strokeStyle.Get());
+            return;
+        }
+
+        // Optimized dash line drawing
+        const bool isPolygon = path.shape() == QVectorPath::PolygonHint && path.elementCount() >= 3;
+        const bool implicitClose = isPolygon && (path.hints() & QVectorPath::ImplicitClose);
+        const bool skipJoin = !isPolygon // Non-polygons don't require joins
+                || (pen.qpen.joinStyle() == Qt::MiterJoin && qFuzzyIsNull(pen.qpen.miterLimit()));
+        const qreal *points = path.points();
+        const int lastElement = path.elementCount() - (implicitClose ? 1 : 2);
+        qreal dashOffset = 0;
+        QPointF jointStart;
+        ID2D1Brush *brush = pen.dashBrush ? pen.dashBrush.Get() : pen.brush.Get();
+        for (int i = 0; i <= lastElement; ++i) {
+            QPointF p1(points[i * 2], points[i * 2 + 1]);
+            QPointF p2 = implicitClose && i == lastElement ? QPointF(points[0], points[1])
+                                                           : QPointF(points[i * 2 + 2], points[i * 2 + 3]);
+            if (!isPolygon) // Advance the count for lines
+                ++i;
+
+            // Match raster engine output
+            if (p1 == p2 && pen.qpen.widthF() <= 1.0) {
+                q->fillRect(QRectF(p1, QSizeF(pen.qpen.widthF(), pen.qpen.widthF())), pen.qpen.brush());
+                continue;
+            }
+
+            if (!q->antiAliasingEnabled())
+                adjustLine(&p1, &p2);
+
+            q->adjustForAliasing(&p1);
+            q->adjustForAliasing(&p2);
+
+            const QLineF line(p1, p2);
+            const qreal lineLength = line.length();
+            if (pen.dashBrush) {
+                pen.dashBrush->SetTransform(transformFromLine(line, pen.qpen.widthF(), dashOffset));
+                dashOffset = pen.dashLength - fmod(lineLength - dashOffset, pen.dashLength);
+            }
+            dc()->DrawLine(to_d2d_point_2f(p1), to_d2d_point_2f(p2),
+                           brush, pen.qpen.widthF(), NULL);
+
+            if (skipJoin)
+                continue;
+
+            // Patch the join with the original brush
+            const qreal patchSegment = pen.dashBrush ? qBound(0.0, (pen.dashLength - dashOffset) / lineLength, 1.0)
+                                                     : pen.qpen.widthF();
+            if (i > 0) {
+                Direct2DPathGeometryWriter writer;
+                writer.begin();
+                writer.moveTo(jointStart);
+                writer.lineTo(p1);
+                writer.lineTo(line.pointAt(patchSegment));
+                writer.close();
+                dc()->DrawGeometry(writer.geometry().Get(), pen.brush.Get(), pen.qpen.widthF(), pen.strokeStyle.Get());
+            }
+            // Record the start position of the next joint
+            jointStart = line.pointAt(1 - patchSegment);
+
+            if (implicitClose && i == lastElement) { // Close the polygon
+                Direct2DPathGeometryWriter writer;
+                writer.begin();
+                writer.moveTo(jointStart);
+                writer.lineTo(p2);
+                writer.lineTo(QLineF(p2, QPointF(points[2], points[3])).pointAt(patchSegment));
+                writer.close();
+                dc()->DrawGeometry(writer.geometry().Get(), pen.brush.Get(), pen.qpen.widthF(), pen.strokeStyle.Get());
+            }
+        }
+    }
+
     ComPtr<IDWriteFontFace> fontFaceFromFontEngine(QFontEngine *fe)
     {
         const QFontDef fontDef = fe->fontDef;
@@ -1055,20 +1165,12 @@ void QWindowsDirect2DPaintEngine::setState(QPainterState *s)
 
 void QWindowsDirect2DPaintEngine::draw(const QVectorPath &path)
 {
-    Q_D(QWindowsDirect2DPaintEngine);
-
-    ComPtr<ID2D1Geometry> geometry = d->vectorPathToID2D1PathGeometry(path);
-    if (!geometry) {
-        qWarning("%s: Could not convert path to d2d geometry", __FUNCTION__);
-        return;
-    }
-
     const QBrush &brush = state()->brush;
     if (qbrush_style(brush) != Qt::NoBrush) {
         if (emulationRequired(BrushEmulation))
             rasterFill(path, brush);
         else
-            fill(geometry.Get(), brush);
+            fill(path, brush);
     }
 
     const QPen &pen = state()->pen;
@@ -1076,7 +1178,7 @@ void QWindowsDirect2DPaintEngine::draw(const QVectorPath &path)
         if (emulationRequired(PenEmulation))
             QPaintEngineEx::stroke(path, pen);
         else
-            stroke(geometry.Get(), pen);
+            stroke(path, pen);
     }
 }
 
@@ -1106,18 +1208,6 @@ void QWindowsDirect2DPaintEngine::fill(const QVectorPath &path, const QBrush &br
     d->dc()->FillGeometry(geometry.Get(), d->brush.brush.Get());
 }
 
-void QWindowsDirect2DPaintEngine::fill(ID2D1Geometry *geometry, const QBrush &brush)
-{
-    Q_D(QWindowsDirect2DPaintEngine);
-    D2D_TAG(D2DDebugFillTag);
-
-    ensureBrush(brush);
-    if (!d->brush.brush)
-        return;
-
-    d->dc()->FillGeometry(geometry, d->brush.brush.Get());
-}
-
 void QWindowsDirect2DPaintEngine::stroke(const QVectorPath &path, const QPen &pen)
 {
     Q_D(QWindowsDirect2DPaintEngine);
@@ -1135,25 +1225,7 @@ void QWindowsDirect2DPaintEngine::stroke(const QVectorPath &path, const QPen &pe
     if (!d->pen.brush)
         return;
 
-    ComPtr<ID2D1Geometry> geometry = d->vectorPathToID2D1PathGeometry(path);
-    if (!geometry) {
-        qWarning("%s: Could not convert path to d2d geometry", __FUNCTION__);
-        return;
-    }
-
-    d->dc()->DrawGeometry(geometry.Get(), d->pen.brush.Get(), d->pen.qpen.widthF(), d->pen.strokeStyle.Get());
-}
-
-void QWindowsDirect2DPaintEngine::stroke(ID2D1Geometry *geometry, const QPen &pen)
-{
-    Q_D(QWindowsDirect2DPaintEngine);
-    D2D_TAG(D2DDebugFillTag);
-
-    ensurePen(pen);
-    if (!d->pen.brush)
-        return;
-
-    d->dc()->DrawGeometry(geometry, d->pen.brush.Get(), d->pen.qpen.widthF(), d->pen.strokeStyle.Get());
+    d->stroke(path);
 }
 
 void QWindowsDirect2DPaintEngine::clip(const QVectorPath &path, Qt::ClipOperation op)
@@ -1301,88 +1373,6 @@ static void adjustLine(QPointF *p1, QPointF *p2)
     }
 }
 
-void QWindowsDirect2DPaintEngine::drawLines(const QLine *lines, int lineCount)
-{
-    Q_D(QWindowsDirect2DPaintEngine);
-    D2D_TAG(D2DDebugDrawLinesTag);
-
-    ensurePen();
-
-    if (emulationRequired(PenEmulation)) {
-        QPaintEngineEx::drawLines(lines, lineCount);
-    } else if (d->pen.brush) {
-        for (int i = 0; i < lineCount; i++) {
-            QPointF p1 = lines[i].p1();
-            QPointF p2 = lines[i].p2();
-
-            // Match raster engine output
-            if (p1 == p2 && d->pen.qpen.widthF() <= 1.0) {
-                fillRect(QRectF(p1, QSizeF(d->pen.qpen.widthF(), d->pen.qpen.widthF())),
-                         d->pen.qpen.brush());
-                continue;
-            }
-
-            // Match raster engine output
-            if (!antiAliasingEnabled())
-                adjustLine(&p1, &p2);
-
-            adjustForAliasing(&p1);
-            adjustForAliasing(&p2);
-
-            D2D1_POINT_2F d2d_p1 = to_d2d_point_2f(p1);
-            D2D1_POINT_2F d2d_p2 = to_d2d_point_2f(p2);
-
-            if (!d->pen.dashBrush || state()->renderHints.testFlag(QPainter::HighQualityAntialiasing)) {
-                d->dc()->DrawLine(d2d_p1, d2d_p2, d->pen.brush.Get(), d->pen.qpen.widthF(), d->pen.strokeStyle.Get());
-            } else {
-                d->pen.dashBrush->SetTransform(transformFromLine(lines[i], d->pen.qpen.widthF()));
-                d->dc()->DrawLine(d2d_p1, d2d_p2, d->pen.dashBrush.Get(), d->pen.qpen.widthF(), NULL);
-            }
-        }
-    }
-}
-
-void QWindowsDirect2DPaintEngine::drawLines(const QLineF *lines, int lineCount)
-{
-    Q_D(QWindowsDirect2DPaintEngine);
-    D2D_TAG(D2DDebugDrawLineFsTag);
-
-    ensurePen();
-
-    if (emulationRequired(PenEmulation)) {
-        QPaintEngineEx::drawLines(lines, lineCount);
-    } else if (d->pen.brush) {
-        for (int i = 0; i < lineCount; i++) {
-            QPointF p1 = lines[i].p1();
-            QPointF p2 = lines[i].p2();
-
-            // Match raster engine output
-            if (p1 == p2 && d->pen.qpen.widthF() <= 1.0) {
-                fillRect(QRectF(p1, QSizeF(d->pen.qpen.widthF(), d->pen.qpen.widthF())),
-                         d->pen.qpen.brush());
-                continue;
-            }
-
-            // Match raster engine output
-            if (!antiAliasingEnabled())
-                adjustLine(&p1, &p2);
-
-            adjustForAliasing(&p1);
-            adjustForAliasing(&p2);
-
-            D2D1_POINT_2F d2d_p1 = to_d2d_point_2f(p1);
-            D2D1_POINT_2F d2d_p2 = to_d2d_point_2f(p2);
-
-            if (!d->pen.dashBrush || state()->renderHints.testFlag(QPainter::HighQualityAntialiasing)) {
-                d->dc()->DrawLine(d2d_p1, d2d_p2, d->pen.brush.Get(), d->pen.qpen.widthF(), d->pen.strokeStyle.Get());
-            } else {
-                d->pen.dashBrush->SetTransform(transformFromLine(lines[i], d->pen.qpen.widthF()));
-                d->dc()->DrawLine(d2d_p1, d2d_p2, d->pen.dashBrush.Get(), d->pen.qpen.widthF(), NULL);
-            }
-        }
-    }
-}
-
 void QWindowsDirect2DPaintEngine::drawEllipse(const QRectF &r)
 {
     Q_D(QWindowsDirect2DPaintEngine);
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.h b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.h
index f9fd6eb591..a75c0b6cc7 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.h
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintengine.h
@@ -92,9 +92,6 @@ public:
     void drawRects(const QRect *rects, int rectCount) Q_DECL_OVERRIDE;
     void drawRects(const QRectF *rects, int rectCount) Q_DECL_OVERRIDE;
 
-    void drawLines(const QLine *lines, int lineCount) Q_DECL_OVERRIDE;
-    void drawLines(const QLineF *lines, int lineCount) Q_DECL_OVERRIDE;
-
     void drawEllipse(const QRectF &r) Q_DECL_OVERRIDE;
     void drawEllipse(const QRect &r) Q_DECL_OVERRIDE;
 
diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index 9470d1844e..f36cbaf685 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -138,8 +138,9 @@
     QRect previousGeometry = requestedGeometry != actualGeometry ?
             requestedGeometry : qt_window_private(m_qioswindow->window())->geometry;
 
-    QWindowSystemInterface::handleGeometryChange(m_qioswindow->window(), actualGeometry, previousGeometry);
-    QWindowSystemInterface::flushWindowSystemEvents();
+    QWindow *window = m_qioswindow->window();
+    QWindowSystemInterface::handleGeometryChange(window, actualGeometry, previousGeometry);
+    QWindowSystemInterface::flushWindowSystemEvents(window->inherits("QWidgetWindow") ? QEventLoop::ExcludeUserInputEvents : QEventLoop::AllEvents);
 
     if (actualGeometry.size() != previousGeometry.size()) {
         // Trigger expose event on resize
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
index 616e1af6b5..2c61f68e83 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
+++ b/src/plugins/platforms/linuxfb/qlinuxfbintegration.cpp
@@ -79,6 +79,8 @@ void QLinuxFbIntegration::initialize()
 
     m_inputContext = QPlatformInputContextFactory::create();
 
+    m_nativeInterface.reset(new QPlatformNativeInterface);
+
     m_vtHandler.reset(new QFbVtHandler);
 
     if (!qEnvironmentVariableIntValue("QT_QPA_FB_DISABLE_INPUT"))
@@ -141,4 +143,9 @@ void QLinuxFbIntegration::createInputHandlers()
 #endif
 }
 
+QPlatformNativeInterface *QLinuxFbIntegration::nativeInterface() const
+{
+    return m_nativeInterface.data();
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbintegration.h b/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
index f2fc95c4ce..0a3d5fd6ac 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
+++ b/src/plugins/platforms/linuxfb/qlinuxfbintegration.h
@@ -61,6 +61,8 @@ public:
     QPlatformServices *services() const Q_DECL_OVERRIDE;
     QPlatformInputContext *inputContext() const Q_DECL_OVERRIDE { return m_inputContext; }
 
+    QPlatformNativeInterface *nativeInterface() const Q_DECL_OVERRIDE;
+
     QList<QPlatformScreen *> screens() const;
 
 private:
@@ -71,6 +73,7 @@ private:
     QScopedPointer<QPlatformFontDatabase> m_fontDb;
     QScopedPointer<QPlatformServices> m_services;
     QScopedPointer<QFbVtHandler> m_vtHandler;
+    QScopedPointer<QPlatformNativeInterface> m_nativeInterface;
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 8f48efc7f9..b397b12311 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -675,6 +675,8 @@ static inline bool findPlatformWindowHelper(const POINT &screenPoint, unsigned c
 #ifndef Q_OS_WINCE
     const HWND child = ChildWindowFromPointEx(*hwnd, point, cwexFlags);
 #else
+//  Under Windows CE we don't use ChildWindowFromPointEx as it's not available
+//  and ChildWindowFromPoint does not work properly.
     Q_UNUSED(cwexFlags)
     const HWND child = WindowFromPoint(point);
 #endif
@@ -683,7 +685,13 @@ static inline bool findPlatformWindowHelper(const POINT &screenPoint, unsigned c
     if (QWindowsWindow *window = context->findPlatformWindow(child)) {
         *result = window;
         *hwnd = child;
+#ifndef Q_OS_WINCE
         return true;
+#else
+//      WindowFromPoint does not return same handle in two sequential calls, which leads
+//      to an endless loop, but calling WindowFromPoint once is good enough.
+        return false;
+#endif
     }
 #ifndef Q_OS_WINCE // Does not have  WS_EX_TRANSPARENT .
     // QTBUG-40555: despite CWP_SKIPINVISIBLE, it is possible to hit on invisible
diff --git a/src/plugins/platforms/windows/qwindowskeymapper.cpp b/src/plugins/platforms/windows/qwindowskeymapper.cpp
index db89402c05..0e26a17223 100644
--- a/src/plugins/platforms/windows/qwindowskeymapper.cpp
+++ b/src/plugins/platforms/windows/qwindowskeymapper.cpp
@@ -567,16 +567,15 @@ static inline int toKeyOrUnicode(int vk, int scancode, unsigned char *kbdBuffer,
     Q_ASSERT(vk > 0 && vk < 256);
     int code = 0;
     QChar unicodeBuffer[5];
-    // While key combinations containing alt and ctrl might trigger the third assignment of a key
-    // (for example "alt+ctrl+q" causes '@' on a German layout), ToUnicode often does not return the
-    // wanted character if only the ctrl modifier is used. Thus we unset this modifier temporarily
-    // if it is not used together with alt.
-    const unsigned char controlState = kbdBuffer[VK_MENU] ? 0 : kbdBuffer[VK_CONTROL];
-    if (controlState)
-        kbdBuffer[VK_CONTROL] = 0;
     int res = ToUnicode(vk, scancode, kbdBuffer, reinterpret_cast<LPWSTR>(unicodeBuffer), 5, 0);
-    if (controlState)
+    // When Ctrl modifier is used ToUnicode does not return correct values. In order to assign the
+    // right key the control modifier is removed for just that function if the previous call failed.
+    if (res == 0 && kbdBuffer[VK_CONTROL]) {
+        const unsigned char controlState = kbdBuffer[VK_CONTROL];
+        kbdBuffer[VK_CONTROL] = 0;
+        res = ToUnicode(vk, scancode, kbdBuffer, reinterpret_cast<LPWSTR>(unicodeBuffer), 5, 0);
         kbdBuffer[VK_CONTROL] = controlState;
+    }
     if (res)
         code = unicodeBuffer[0].toUpper().unicode();
 
diff --git a/src/plugins/platforms/winrt/qwinrttheme.cpp b/src/plugins/platforms/winrt/qwinrttheme.cpp
index ba8fcee829..f33e07901a 100644
--- a/src/plugins/platforms/winrt/qwinrttheme.cpp
+++ b/src/plugins/platforms/winrt/qwinrttheme.cpp
@@ -232,7 +232,7 @@ QVariant QWinRTTheme::styleHint(QPlatformIntegration::StyleHint hint)
         return false;
     case QPlatformIntegration::ShowIsMaximized:
         return false;
-    case MousePressAndHoldInterval:
+    case QPlatformIntegration::MousePressAndHoldInterval:
         return defaultThemeHint(MousePressAndHoldInterval);
     default:
         break;
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 250527e3ae..e1584999db 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -789,6 +789,15 @@ void QXcbConnection::handleButtonRelease(xcb_generic_event_t *ev)
     qCDebug(lcQpaXInput, "xcb: released mouse button %d, button state %X", event->detail, static_cast<unsigned int>(m_buttons));
 }
 
+void QXcbConnection::handleMotionNotify(xcb_generic_event_t *ev)
+{
+    xcb_motion_notify_event_t *event = (xcb_motion_notify_event_t *)ev;
+
+    m_buttons = (m_buttons & ~0x7) | translateMouseButtons(event->state);
+    if (Q_UNLIKELY(lcQpaXInput().isDebugEnabled()))
+        qDebug("xcb: moved mouse to %4d, %4d; button state %X", event->event_x, event->event_y, static_cast<unsigned int>(m_buttons));
+}
+
 #ifndef QT_NO_XKB
 namespace {
     typedef union {
@@ -839,11 +848,8 @@ void QXcbConnection::handleXcbEvent(xcb_generic_event_t *event)
             handleButtonRelease(event);
             HANDLE_PLATFORM_WINDOW_EVENT(xcb_button_release_event_t, event, handleButtonReleaseEvent);
         case XCB_MOTION_NOTIFY:
-            if (Q_UNLIKELY(lcQpaXInput().isDebugEnabled())) {
-                xcb_motion_notify_event_t *mev = (xcb_motion_notify_event_t *)event;
-                qDebug("xcb: moved mouse to %4d, %4d; button state %X", mev->event_x, mev->event_y, static_cast<unsigned int>(m_buttons));
-            }
             m_keyboard->updateXKBStateFromCore(((xcb_motion_notify_event_t *)event)->state);
+            handleMotionNotify(event);
             HANDLE_PLATFORM_WINDOW_EVENT(xcb_motion_notify_event_t, event, handleMotionNotifyEvent);
         case XCB_CONFIGURE_NOTIFY:
             HANDLE_PLATFORM_WINDOW_EVENT(xcb_configure_notify_event_t, event, handleConfigureNotifyEvent);
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index e3d9766a4b..90b859e612 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -497,6 +497,7 @@ private:
     void updateScreens();
     void handleButtonPress(xcb_generic_event_t *event);
     void handleButtonRelease(xcb_generic_event_t *event);
+    void handleMotionNotify(xcb_generic_event_t *event);
 
     bool m_xi2Enabled;
     int m_xi2Minor;
@@ -507,6 +508,7 @@ private:
     XInput2TouchDeviceData *touchDeviceForId(int id);
     void xi2HandleEvent(xcb_ge_event_t *event);
     void xi2HandleHierachyEvent(void *event);
+    void xi2HandleDeviceChangedEvent(void *event);
     int m_xiOpCode, m_xiEventBase, m_xiErrorBase;
 #ifndef QT_NO_TABLETEVENT
     struct TabletData {
@@ -540,6 +542,7 @@ private:
         Qt::Orientations legacyOrientations;
         QPointF lastScrollPosition;
     };
+    void updateScrollingDevice(ScrollingDevice& scrollingDevice, int num_classes, void *classes);
     void xi2HandleScrollEvent(void *event, ScrollingDevice &scrollingDevice);
     QHash<int, ScrollingDevice> m_scrollingDevices;
 #endif // XCB_USE_XINPUT2
diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index f225518cb9..e9fb47dabd 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -348,6 +348,7 @@ void QXcbConnection::xi2Select(xcb_window_t window)
         // Listen for hotplug events
         XIEventMask xiEventMask;
         bitMask = XI_HierarchyChangedMask;
+        bitMask |= XI_DeviceChangedMask;
         xiEventMask.deviceid = XIAllDevices;
         xiEventMask.mask_len = sizeof(bitMask);
         xiEventMask.mask = xiBitMask;
@@ -468,6 +469,11 @@ void QXcbConnection::xi2HandleEvent(xcb_ge_event_t *event)
             xi2HandleHierachyEvent(xiEvent);
             return;
         }
+        if (xiEvent->evtype == XI_DeviceChanged) {
+            xi2HandleDeviceChangedEvent(xiEvent);
+            return;
+        }
+
 #ifndef QT_NO_TABLETEVENT
         for (int i = 0; i < m_tabletData.count(); ++i) {
             if (m_tabletData.at(i).deviceId == xiEvent->deviceid) {
@@ -628,6 +634,64 @@ void QXcbConnection::xi2HandleHierachyEvent(void *event)
     }
 }
 
+void QXcbConnection::xi2HandleDeviceChangedEvent(void *event)
+{
+    xXIDeviceChangedEvent *xiEvent = reinterpret_cast<xXIDeviceChangedEvent *>(event);
+
+    // ### If a slave device changes (XIDeviceChange), we should probably run setup on it again.
+    if (xiEvent->reason != XISlaveSwitch)
+        return;
+
+#ifdef XCB_USE_XINPUT21
+    // This code handles broken scrolling device drivers that reset absolute positions
+    // when they are made active. Whenever a new slave device is made active the
+    // primary pointer sends a DeviceChanged event with XISlaveSwitch, and the new
+    // active slave in sourceid.
+
+    QHash<int, ScrollingDevice>::iterator device = m_scrollingDevices.find(xiEvent->sourceid);
+    if (device == m_scrollingDevices.end())
+        return;
+
+    int nrDevices = 0;
+    XIDeviceInfo* xiDeviceInfo = XIQueryDevice(static_cast<Display *>(m_xlib_display), xiEvent->sourceid, &nrDevices);
+    if (nrDevices <= 0) {
+        qCDebug(lcQpaXInputDevices, "scrolling device %d no longer present", xiEvent->sourceid);
+        return;
+    }
+    updateScrollingDevice(*device, xiDeviceInfo->num_classes, xiDeviceInfo->classes);
+    XIFreeDeviceInfo(xiDeviceInfo);
+#endif
+}
+
+void QXcbConnection::updateScrollingDevice(ScrollingDevice &scrollingDevice, int num_classes, void *classInfo)
+{
+#ifdef XCB_USE_XINPUT21
+    XIAnyClassInfo **classes = reinterpret_cast<XIAnyClassInfo**>(classInfo);
+    QPointF lastScrollPosition;
+    if (lcQpaXInput().isDebugEnabled())
+        lastScrollPosition = scrollingDevice.lastScrollPosition;
+    for (int c = 0; c < num_classes; ++c) {
+        if (classes[c]->type == XIValuatorClass) {
+            XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classes[c]);
+            const int valuatorAtom = qatom(vci->label);
+            if (valuatorAtom == QXcbAtom::RelHorizScroll || valuatorAtom == QXcbAtom::RelHorizWheel)
+                scrollingDevice.lastScrollPosition.setX(vci->value);
+            else if (valuatorAtom == QXcbAtom::RelVertScroll || valuatorAtom == QXcbAtom::RelVertWheel)
+                scrollingDevice.lastScrollPosition.setY(vci->value);
+        }
+    }
+    if (lcQpaXInput().isDebugEnabled() && lastScrollPosition != scrollingDevice.lastScrollPosition)
+        qCDebug(lcQpaXInput, "scrolling device %d moved from (%f, %f) to (%f, %f)", scrollingDevice.deviceId,
+                lastScrollPosition.x(), lastScrollPosition.y(),
+                scrollingDevice.lastScrollPosition.x(),
+                scrollingDevice.lastScrollPosition.y());
+#else
+    Q_UNUSED(scrollingDevice);
+    Q_UNUSED(num_classes);
+    Q_UNUSED(classInfo);
+#endif
+}
+
 void QXcbConnection::handleEnterEvent(const xcb_enter_notify_event_t *)
 {
 #ifdef XCB_USE_XINPUT21
@@ -638,19 +702,11 @@ void QXcbConnection::handleEnterEvent(const xcb_enter_notify_event_t *)
         int nrDevices = 0;
         XIDeviceInfo* xiDeviceInfo = XIQueryDevice(static_cast<Display *>(m_xlib_display), scrollingDevice.deviceId, &nrDevices);
         if (nrDevices <= 0) {
+            qCDebug(lcQpaXInputDevices, "scrolling device %d no longer present", scrollingDevice.deviceId);
             it = m_scrollingDevices.erase(it);
             continue;
         }
-        for (int c = 0; c < xiDeviceInfo->num_classes; ++c) {
-            if (xiDeviceInfo->classes[c]->type == XIValuatorClass) {
-                XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(xiDeviceInfo->classes[c]);
-                const int valuatorAtom = qatom(vci->label);
-                if (valuatorAtom == QXcbAtom::RelHorizScroll || valuatorAtom == QXcbAtom::RelHorizWheel)
-                    scrollingDevice.lastScrollPosition.setX(vci->value);
-                else if (valuatorAtom == QXcbAtom::RelVertScroll || valuatorAtom == QXcbAtom::RelVertWheel)
-                    scrollingDevice.lastScrollPosition.setY(vci->value);
-            }
-        }
+        updateScrollingDevice(scrollingDevice, xiDeviceInfo->num_classes, xiDeviceInfo->classes);
         XIFreeDeviceInfo(xiDeviceInfo);
         ++it;
     }
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 34289fb90e..54ebca0532 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -206,6 +206,18 @@ static inline QImage::Format imageFormatForVisual(int depth, quint32 red_mask, q
         break;
     }
     qWarning("Unsupported screen format: depth: %d, red_mask: %x, blue_mask: %x", depth, red_mask, blue_mask);
+
+    switch (depth) {
+    case 24:
+        qWarning("Using RGB32 fallback, if this works your X11 server is reporting a bad screen format.");
+        return QImage::Format_RGB32;
+    case 16:
+        qWarning("Using RGB16 fallback, if this works your X11 server is reporting a bad screen format.");
+        return QImage::Format_RGB16;
+    default:
+        break;
+    }
+
     return QImage::Format_Invalid;
 }