Updated WebKit to 807157e42add842605ec67d9363dd3f1861748ca

* Changes integrated:

|| <https://webkit.org/b/24289> || [Qt] lacks clipToImageBuffer() ||
|| <https://webkit.org/b/38641> || [Qt] Nested overflow div does not scroll ||
|| <https://webkit.org/b/37322> || [Qt] tst_QWebHistory::serialize_2() fails ||
|| <https://webkit.org/b/35340> || [Qt] Enable alternate HTML/JavaScript front-ends for Web Inspector ||
|| <https://webkit.org/b/39314> || [Qt] Skipping popup focus test for maemo ||
|| <https://webkit.org/b/39150> || Canvas's getContext() must return null when called with an invalid/unsupported parameter ||
|| <https://webkit.org/b/39153> || Canvas's toDataURL() should be case insensitive wrt the mimeType argument ||
|| <https://webkit.org/b/39218> || [Qt] Tiled backing store tiles sometimes flicker when exiting a zoom animation ||
|| <https://webkit.org/b/38456> || [Qt] QtTestBrowser does not support websites which requires HTTP Authentication via dialogs ||
|| <https://webkit.org/b/37273> || [Qt] Weekly binary builds on Mac OS X don't work when launched in the Finder ||
|| <https://webkit.org/b/38779> || [Qt] QWebPage::inputMethodQuery() returns wrong values for Qt::ImCursorPosition, Qt::ImAnchorPosition ||
|| <https://webkit.org/b/38526> || [Qt] REGRESSION: CoolClock isn't rendered properly ||

Plus def file fixes.

13 files changed, 226 insertions, 34 deletions

diff --git a/src/3rdparty/webkit/WebCore/ChangeLog b/src/3rdparty/webkit/WebCore/ChangeLog
index 481b416..625faa6 100644
--- a/src/3rdparty/webkit/WebCore/ChangeLog
+++ b/src/3rdparty/webkit/WebCore/ChangeLog
@@ -1,3 +1,124 @@
+2010-05-19  Kenneth Rohde Christiansen  <kenneth@webkit.org>
+
+        Reviewed by Simon Hausmann.
+
+        Fix painting when using clipToImageBuffer()
+
+        When we apply the transform of the parent painter to the painter of
+        the transparency layer, we adopt its coordinate system, thus offset
+        should not be in page coordinates, but in the coordinate system of
+        the parent painter.
+
+        * platform/graphics/qt/GraphicsContextQt.cpp:
+        (WebCore::TransparencyLayer::TransparencyLayer):
+
+2010-05-19  Andreas Kling  <andreas.kling@nokia.com>
+
+        Reviewed by Simon Hausmann.
+
+        [Qt] REGRESSION: CoolClock isn't rendered properly
+
+        https://bugs.webkit.org/show_bug.cgi?id=38526
+
+        CanvasRenderingContext2D's arc() should connect to the previous point
+        with a straight line (HTML5 spec 4.8.11.1.8), but if the path is empty
+        to begin with, we don't want a line back to (0,0)
+        This also fixes the rendering artifact discussed in bug 36226.
+
+        Spec link:
+        http://www.whatwg.org/specs/web-apps/current-work/#dom-context-2d-arc
+
+        Test: fast/canvas/canvas-arc-connecting-line.html
+
+        * platform/graphics/qt/PathQt.cpp:
+        (WebCore::Path::addArc):
+
+2010-05-18  Kenneth Rohde Christiansen  <kenneth@webkit.org>
+
+        Rubberstamped by Simon Hausmann.
+
+        Return null when creating an ImageBuffer failed, due to for
+        instance a nulled pixmap.
+
+        * platform/graphics/qt/ImageBufferQt.cpp:
+        (WebCore::ImageBufferData::ImageBufferData):
+        (WebCore::ImageBuffer::ImageBuffer):
+
+2010-05-17  Antti Koivisto  <koivisto@iki.fi>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        https://bugs.webkit.org/show_bug.cgi?id=39218
+        [Qt] Tiled backing store tiles sometimes flicker when exiting a zoom animation
+        
+        Tiles sometimes flicker when exiting a zoom animation. This happens as a result
+        of the visible rectangle being momentarily out of sync.
+        
+        Instead of updating the visible rect by explicitly setting it, pull it through
+        the client and recompute in the WebKit level.
+
+        * page/ChromeClient.h:
+        (WebCore::ChromeClient::visibleRectForTiledBackingStore):
+        * page/Frame.cpp:
+        (WebCore::Frame::tiledBackingStoreVisibleRect):
+        * page/Frame.h:
+        * platform/graphics/TiledBackingStore.cpp:
+        (WebCore::TiledBackingStore::checkVisibleRectChanged):
+        (WebCore::TiledBackingStore::createTiles):
+        * platform/graphics/TiledBackingStore.h:
+        * platform/graphics/TiledBackingStoreClient.h:
+
+2010-05-18  Zoltan Herczeg  <zherczeg@webkit.org>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        [Qt] Implementing clipToImageBuffer for Qt port.
+        https://bugs.webkit.org/show_bug.cgi?id=24289
+
+        The implementation combines pixmap layers and destinationIn
+        composition mode.
+
+        * platform/graphics/qt/GraphicsContextQt.cpp:
+        (WebCore::TransparencyLayer::TransparencyLayer):
+        (WebCore::GraphicsContextPlatformPrivate::GraphicsContextPlatformPrivate):
+        (WebCore::GraphicsContext::savePlatformState):
+        (WebCore::GraphicsContext::restorePlatformState):
+        (WebCore::GraphicsContext::inTransparencyLayer):
+        (WebCore::GraphicsContext::beginTransparencyLayer):
+        (WebCore::GraphicsContext::endTransparencyLayer):
+        (WebCore::GraphicsContext::clipToImageBuffer):
+
+2010-05-16  Andreas Kling  <andreas.kling@nokia.com>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        Canvas's toDataURL() should be case insensitive wrt the mimeType argument.
+        https://bugs.webkit.org/show_bug.cgi?id=39153
+
+        Spec link:
+        http://www.whatwg.org/specs/web-apps/current-work/#dom-canvas-todataurl
+
+        Test: fast/canvas/canvas-toDataURL-case-insensitive-mimetype.html
+
+        * dom/CanvasSurface.cpp:
+        (WebCore::CanvasSurface::toDataURL):
+
+2010-05-16  Andreas Kling  <andreas.kling@nokia.com>
+
+        Reviewed by Kenneth Rohde Christiansen.
+
+        Canvas's getContext() must return null when called with an invalid/unsupported parameter.
+        (HTML5 spec 4.8.11): http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-canvas-getcontext
+
+        https://bugs.webkit.org/show_bug.cgi?id=39150
+
+        Test: fast/canvas/canvas-getContext-invalid.html
+
+        * bindings/js/JSHTMLCanvasElementCustom.cpp:
+        (WebCore::JSHTMLCanvasElement::getContext):
+        * bindings/v8/custom/V8HTMLCanvasElementCustom.cpp:
+        (WebCore::V8HTMLCanvasElement::getContextCallback):
+
 2010-05-17  Kenneth Rohde Christiansen  <kenneth@webkit.org>
 
         Reviewed by Laszlo Gombos.
diff --git a/src/3rdparty/webkit/WebCore/bindings/js/JSHTMLCanvasElementCustom.cpp b/src/3rdparty/webkit/WebCore/bindings/js/JSHTMLCanvasElementCustom.cpp
index 80634f7..8f241f9 100644
--- a/src/3rdparty/webkit/WebCore/bindings/js/JSHTMLCanvasElementCustom.cpp
+++ b/src/3rdparty/webkit/WebCore/bindings/js/JSHTMLCanvasElementCustom.cpp
@@ -78,7 +78,10 @@ JSValue JSHTMLCanvasElement::getContext(ExecState* exec, const ArgList& args)
         }
     }
 #endif
-    return toJS(exec, globalObject(), WTF::getPtr(canvas->getContext(contextId, attrs.get())));
+    CanvasRenderingContext* context = canvas->getContext(contextId, attrs.get());
+    if (!context)
+        return jsNull();
+    return toJS(exec, globalObject(), WTF::getPtr(context));
 }
 
 } // namespace WebCore
diff --git a/src/3rdparty/webkit/WebCore/html/HTMLCanvasElement.cpp b/src/3rdparty/webkit/WebCore/html/HTMLCanvasElement.cpp
index 30a620c..0c5159d 100644
--- a/src/3rdparty/webkit/WebCore/html/HTMLCanvasElement.cpp
+++ b/src/3rdparty/webkit/WebCore/html/HTMLCanvasElement.cpp
@@ -143,10 +143,12 @@ String HTMLCanvasElement::toDataURL(const String& mimeType, ExceptionCode& ec)
     if (m_size.isEmpty() || !buffer())
         return String("data:,");
 
-    if (mimeType.isNull() || !MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType))
+    String lowercaseMimeType = mimeType.lower();
+
+    if (mimeType.isNull() || !MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(lowercaseMimeType))
         return buffer()->toDataURL("image/png");
 
-    return buffer()->toDataURL(mimeType);
+    return buffer()->toDataURL(lowercaseMimeType);
 }
 
 CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, CanvasContextAttributes* attrs)
diff --git a/src/3rdparty/webkit/WebCore/page/ChromeClient.h b/src/3rdparty/webkit/WebCore/page/ChromeClient.h
index 0bfdbaf..a01eef1 100644
--- a/src/3rdparty/webkit/WebCore/page/ChromeClient.h
+++ b/src/3rdparty/webkit/WebCore/page/ChromeClient.h
@@ -222,7 +222,11 @@ namespace WebCore {
         virtual bool supportsFullscreenForNode(const Node*) { return false; }
         virtual void enterFullscreenForNode(Node*) { }
         virtual void exitFullscreenForNode(Node*) { }
-        
+
+#if ENABLE(TILED_BACKING_STORE)
+        virtual IntRect visibleRectForTiledBackingStore() const { return IntRect(); }
+#endif
+
 #if PLATFORM(MAC)
         virtual KeyboardUIMode keyboardUIMode() { return KeyboardAccessDefault; }
 
diff --git a/src/3rdparty/webkit/WebCore/page/Frame.cpp b/src/3rdparty/webkit/WebCore/page/Frame.cpp
index 6dbca69..379bf7d 100644
--- a/src/3rdparty/webkit/WebCore/page/Frame.cpp
+++ b/src/3rdparty/webkit/WebCore/page/Frame.cpp
@@ -37,6 +37,7 @@
 #include "CSSPropertyNames.h"
 #include "CachedCSSStyleSheet.h"
 #include "Chrome.h"
+#include "ChromeClient.h"
 #include "DOMWindow.h"
 #include "DocLoader.h"
 #include "DocumentType.h"
@@ -1853,6 +1854,13 @@ IntRect Frame::tiledBackingStoreContentsRect()
         return IntRect();
     return IntRect(IntPoint(), m_view->contentsSize());
 }
+
+IntRect Frame::tiledBackingStoreVisibleRect()
+{
+    if (!m_page)
+        return IntRect();
+    return m_page->chrome()->client()->visibleRectForTiledBackingStore();
+}
 #endif
 
 } // namespace WebCore
diff --git a/src/3rdparty/webkit/WebCore/page/Frame.h b/src/3rdparty/webkit/WebCore/page/Frame.h
index 67761f9..a654cd7 100644
--- a/src/3rdparty/webkit/WebCore/page/Frame.h
+++ b/src/3rdparty/webkit/WebCore/page/Frame.h
@@ -288,6 +288,7 @@ namespace WebCore {
         virtual void tiledBackingStorePaint(GraphicsContext*, const IntRect&);
         virtual void tiledBackingStorePaintEnd(const Vector<IntRect>& paintedArea);
         virtual IntRect tiledBackingStoreContentsRect();
+        virtual IntRect tiledBackingStoreVisibleRect();
 #endif
 
     #if PLATFORM(MAC)
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.cpp b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.cpp
index 6214f1b..f00e792 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.cpp
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.cpp
@@ -129,13 +129,12 @@ void TiledBackingStore::paint(GraphicsContext* context, const IntRect& rect)
     context->restore();
 }
 
-void TiledBackingStore::viewportChanged(const IntRect& contentsViewport)
+void TiledBackingStore::adjustVisibleRect()
 {
-    IntRect viewport = mapFromContents(contentsViewport);
-    if (m_viewport == viewport)
+    IntRect visibleRect = mapFromContents(m_client->tiledBackingStoreVisibleRect());
+    if (m_previousVisibleRect == visibleRect)
         return;
-
-    m_viewport = viewport;
+    m_previousVisibleRect = visibleRect;
 
     startTileCreationTimer();
 }
@@ -177,24 +176,27 @@ void TiledBackingStore::createTiles()
 {
     if (m_contentsFrozen)
         return;
+    
+    IntRect visibleRect = mapFromContents(m_client->tiledBackingStoreVisibleRect());
+    m_previousVisibleRect = visibleRect;
 
-    if (m_viewport.isEmpty())
+    if (visibleRect.isEmpty())
         return;
 
     // Remove tiles that extend outside the current contents rect.
     dropOverhangingTiles();
 
     // FIXME: Make configurable/adapt to memory.
-    IntRect keepRect = m_viewport;
-    keepRect.inflateX(m_viewport.width());
-    keepRect.inflateY(3 * m_viewport.height());
+    IntRect keepRect = visibleRect;
+    keepRect.inflateX(visibleRect.width());
+    keepRect.inflateY(3 * visibleRect.height());
     keepRect.intersect(contentsRect());
     
     dropTilesOutsideRect(keepRect);
     
-    IntRect coverRect = m_viewport;
-    coverRect.inflateX(m_viewport.width() / 2);
-    coverRect.inflateY(2 * m_viewport.height());
+    IntRect coverRect = visibleRect;
+    coverRect.inflateX(visibleRect.width() / 2);
+    coverRect.inflateY(2 * visibleRect.height());
     coverRect.intersect(contentsRect());
     
     // Search for the tile position closest to the viewport center that does not yet contain a tile. 
@@ -211,7 +213,7 @@ void TiledBackingStore::createTiles()
                 continue;
             ++requiredTileCount;
             // Distance is 0 for all currently visible tiles.
-            double distance = tileDistance(m_viewport, currentCoordinate);
+            double distance = tileDistance(visibleRect, currentCoordinate);
             if (distance > shortestDistance)
                 continue;
             if (distance < shortestDistance) {
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.h b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.h
index 8ed4336..d12f191 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.h
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStore.h
@@ -41,7 +41,7 @@ public:
     TiledBackingStore(TiledBackingStoreClient*);
     ~TiledBackingStore();
 
-    void viewportChanged(const IntRect& viewportRect);
+    void adjustVisibleRect();
     
     float contentsScale() { return m_contentsScale; }
     void setContentsScale(float);
@@ -95,7 +95,7 @@ private:
 
     IntSize m_tileSize;
     
-    IntRect m_viewport;
+    IntRect m_previousVisibleRect;
     float m_contentsScale;
     float m_pendingScale;
 
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStoreClient.h b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStoreClient.h
index 4adbbab..c5845b9 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStoreClient.h
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/TiledBackingStoreClient.h
@@ -29,6 +29,7 @@ public:
     virtual void tiledBackingStorePaint(GraphicsContext*, const IntRect&) = 0;
     virtual void tiledBackingStorePaintEnd(const Vector<IntRect>& paintedArea) = 0;
     virtual IntRect tiledBackingStoreContentsRect() = 0;
+    virtual IntRect tiledBackingStoreVisibleRect() = 0;
 };
 
 #else
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp b/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp
index 0100b72..69121c8 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/qt/GraphicsContextQt.cpp
@@ -167,10 +167,13 @@ static inline Qt::FillRule toQtFillRule(WindRule rule)
 }
 
 struct TransparencyLayer : FastAllocBase {
-    TransparencyLayer(const QPainter* p, const QRect &rect)
+    TransparencyLayer(const QPainter* p, const QRect &rect, qreal opacity, QPixmap& alphaMask)
         : pixmap(rect.width(), rect.height())
+        , opacity(opacity)
+        , alphaMask(alphaMask)
+        , saveCounter(1) // see the comment for saveCounter
     {
-        offset = rect.topLeft();
+        offset = p->transform().mapRect(rect).topLeft();
         pixmap.fill(Qt::transparent);
         painter.begin(&pixmap);
         painter.setRenderHint(QPainter::Antialiasing, p->testRenderHint(QPainter::Antialiasing));
@@ -182,7 +185,9 @@ struct TransparencyLayer : FastAllocBase {
         painter.setFont(p->font());
         if (painter.paintEngine()->hasFeature(QPaintEngine::PorterDuff))
             painter.setCompositionMode(p->compositionMode());
-        painter.setClipPath(p->clipPath());
+        // if the path is an empty region, this assignment disables all painting
+        if (!p->clipPath().isEmpty())
+            painter.setClipPath(p->clipPath());
     }
 
     TransparencyLayer()
@@ -193,6 +198,11 @@ struct TransparencyLayer : FastAllocBase {
     QPoint offset;
     QPainter painter;
     qreal opacity;
+    // for clipToImageBuffer
+    QPixmap alphaMask;
+    // saveCounter is only used in combination with alphaMask
+    // otherwise, its value is unspecified
+    int saveCounter;
 private:
     TransparencyLayer(const TransparencyLayer &) {}
     TransparencyLayer & operator=(const TransparencyLayer &) { return *this; }
@@ -217,6 +227,9 @@ public:
     bool antiAliasingForRectsAndLines;
 
     QStack<TransparencyLayer*> layers;
+    // Counting real layers. Required by inTransparencyLayer() calls
+    // For example, layers with valid alphaMask are not real layers
+    int layerCount;
     QPainter* redirect;
 
     // reuse this brush for solid color (to prevent expensive QBrush construction)
@@ -235,6 +248,7 @@ private:
 GraphicsContextPlatformPrivate::GraphicsContextPlatformPrivate(QPainter* p)
 {
     painter = p;
+    layerCount = 0;
     redirect = 0;
 
     solidColor = QBrush(Qt::black);
@@ -289,11 +303,17 @@ AffineTransform GraphicsContext::getCTM() const
 
 void GraphicsContext::savePlatformState()
 {
+    if (!m_data->layers.isEmpty() && !m_data->layers.top()->alphaMask.isNull())
+        ++m_data->layers.top()->saveCounter;
     m_data->p()->save();
 }
 
 void GraphicsContext::restorePlatformState()
 {
+    if (!m_data->layers.isEmpty() && !m_data->layers.top()->alphaMask.isNull())
+        if (!--m_data->layers.top()->saveCounter)
+            endTransparencyLayer();
+
     m_data->p()->restore();
 
     if (!m_data->currentPath.isEmpty() && m_common->state.pathTransform.isInvertible()) {
@@ -678,7 +698,7 @@ void GraphicsContext::addPath(const Path& path)
 
 bool GraphicsContext::inTransparencyLayer() const
 {
-    return !m_data->layers.isEmpty();
+    return m_data->layerCount;
 }
 
 PlatformPath* GraphicsContext::currentPath()
@@ -837,10 +857,9 @@ void GraphicsContext::beginTransparencyLayer(float opacity)
     w = int(qBound(qreal(0), deviceClip.width(), (qreal)w) + 2);
     h = int(qBound(qreal(0), deviceClip.height(), (qreal)h) + 2);
 
-    TransparencyLayer * layer = new TransparencyLayer(m_data->p(), QRect(x, y, w, h));
-
-    layer->opacity = opacity;
-    m_data->layers.push(layer);
+    QPixmap emptyAlphaMask;
+    m_data->layers.push(new TransparencyLayer(m_data->p(), QRect(x, y, w, h), opacity, emptyAlphaMask));
+    ++m_data->layerCount;
 }
 
 void GraphicsContext::endTransparencyLayer()
@@ -849,6 +868,12 @@ void GraphicsContext::endTransparencyLayer()
         return;
 
     TransparencyLayer* layer = m_data->layers.pop();
+    if (!layer->alphaMask.isNull()) {
+        layer->painter.resetTransform();
+        layer->painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
+        layer->painter.drawPixmap(QPoint(), layer->alphaMask);
+    } else
+        --m_data->layerCount; // see the comment for layerCount
     layer->painter.end();
 
     QPainter* p = m_data->p();
@@ -1086,9 +1111,21 @@ void GraphicsContext::clipOutEllipseInRect(const IntRect& rect)
     }
 }
 
-void GraphicsContext::clipToImageBuffer(const FloatRect&, const ImageBuffer*)
+void GraphicsContext::clipToImageBuffer(const FloatRect& floatRect, const ImageBuffer* image)
 {
-    notImplemented();
+    if (paintingDisabled())
+        return;
+
+    QPixmap* nativeImage = image->image()->nativeImageForCurrentFrame();
+    if (!nativeImage)
+        return;
+
+    IntRect rect(floatRect);
+    QPixmap alphaMask = *nativeImage;
+    if (alphaMask.width() != rect.width() || alphaMask.height() != rect.height())
+        alphaMask = alphaMask.scaled(rect.width(), rect.height());
+
+    m_data->layers.push(new TransparencyLayer(m_data->p(), rect, 1.0, alphaMask));
 }
 
 void GraphicsContext::addInnerRoundedRectClip(const IntRect& rect,
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/qt/ImageBufferQt.cpp b/src/3rdparty/webkit/WebCore/platform/graphics/qt/ImageBufferQt.cpp
index d831566..eafdcf0 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/qt/ImageBufferQt.cpp
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/qt/ImageBufferQt.cpp
@@ -46,12 +46,19 @@ namespace WebCore {
 
 ImageBufferData::ImageBufferData(const IntSize& size)
     : m_pixmap(size)
+    , m_painter(0)
 {
+    if (m_pixmap.isNull())
+        return;
+
     m_pixmap.fill(QColor(Qt::transparent));
 
-    QPainter* painter = new QPainter(&m_pixmap);
+    QPainter* painter = new QPainter;
     m_painter.set(painter);
 
+    if (!painter->begin(&m_pixmap))
+        return;
+
     // Since ImageBuffer is used mainly for Canvas, explicitly initialize
     // its painter's pen and brush with the corresponding canvas defaults
     // NOTE: keep in sync with CanvasRenderingContext2D::State
@@ -72,8 +79,11 @@ ImageBuffer::ImageBuffer(const IntSize& size, ImageColorSpace, bool& success)
     : m_data(size)
     , m_size(size)
 {
+    success = m_data.m_painter && m_data.m_painter->isActive();
+    if (!success)
+        return;
+
     m_context.set(new GraphicsContext(m_data.m_painter.get()));
-    success = true;
 }
 
 ImageBuffer::~ImageBuffer()
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/qt/PathQt.cpp b/src/3rdparty/webkit/WebCore/platform/graphics/qt/PathQt.cpp
index 4b0c21f..a7351a0 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/qt/PathQt.cpp
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/qt/PathQt.cpp
@@ -298,9 +298,10 @@ void Path::addArc(const FloatPoint& p, float r, float sar, float ear, bool antic
         span += ea - sa;
     }
 
-    // connect to the previous point by a straight line
-    m_path.lineTo(QPointF(xc + radius  * cos(sar),
-                          yc - radius  * sin(sar)));
+    // If the path is empty, move to where the arc will start to avoid painting a line from (0,0)
+    // NOTE: QPainterPath::isEmpty() won't work here since it ignores a lone MoveToElement
+    if (!m_path.elementCount())
+        m_path.arcMoveTo(xs, ys, width, height, sa);
 
     m_path.arcTo(xs, ys, width, height, sa, span);
 
diff --git a/src/3rdparty/webkit/WebCore/platform/qt/QWebPageClient.h b/src/3rdparty/webkit/WebCore/platform/qt/QWebPageClient.h
index 467941f..8e48d1f 100644
--- a/src/3rdparty/webkit/WebCore/platform/qt/QWebPageClient.h
+++ b/src/3rdparty/webkit/WebCore/platform/qt/QWebPageClient.h
@@ -89,6 +89,8 @@ public:
 
     virtual QStyle* style() const = 0;
 
+    virtual QRectF graphicsItemVisibleRect() const { return QRectF(); }
+
 protected:
 #ifndef QT_NO_CURSOR
     virtual QCursor cursor() const = 0;