2 files changed, 101 insertions, 1 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index 69e08d1..9892d36 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -1329,7 +1329,8 @@ void QGraphicsScenePrivate::mousePressEventHandler(QGraphicsSceneMouseEvent *mou
         // check if the item we are sending to are disabled (before we send the event)
         bool disabled = !item->isEnabled();
         bool isWindow = item->isWindow();
-        if (mouseEvent->type() == QEvent::GraphicsSceneMouseDoubleClick && item != lastMouseGrabberItem) {
+        if (mouseEvent->type() == QEvent::GraphicsSceneMouseDoubleClick
+            && item != lastMouseGrabberItem && lastMouseGrabberItem) {
             // If this item is different from the item that received the last
             // mouse event, and mouseEvent is a doubleclick event, then the
             // event is converted to a press. Known limitation:
diff --git a/tests/auto/qgraphicswidget/tst_qgraphicswidget.cpp b/tests/auto/qgraphicswidget/tst_qgraphicswidget.cpp
index 343aac6..a23ada9 100644
--- a/tests/auto/qgraphicswidget/tst_qgraphicswidget.cpp
+++ b/tests/auto/qgraphicswidget/tst_qgraphicswidget.cpp
@@ -149,6 +149,7 @@ private slots:
     void defaultSize();
     void explicitMouseGrabber();
     void implicitMouseGrabber();
+    void doubleClickAfterExplicitMouseGrab();
     void popupMouseGrabber();
     void windowFlags_data();
     void windowFlags();
@@ -1998,6 +1999,104 @@ void tst_QGraphicsWidget::implicitMouseGrabber()
     QCOMPARE(scene.mouseGrabberItem(), (QGraphicsItem *)0);
 }
 
+class GrabOnPressItem : public QGraphicsRectItem
+{
+public:
+    GrabOnPressItem(const QRectF &rect)
+        : QGraphicsRectItem(rect),
+          npress(0), nrelease(0), ndoubleClick(0),
+          ngrab(0), nungrab(0)
+    {
+    }
+    int npress;
+    int nrelease;
+    int ndoubleClick;
+    int ngrab;
+    int nungrab;
+protected:
+    bool sceneEvent(QEvent *event)
+    {
+        switch (event->type()) {
+        case QEvent::GrabMouse:
+            ++ngrab;
+            break;
+        case QEvent::UngrabMouse:
+            ++nungrab;
+            break;
+        default:
+            break;
+        }
+        return QGraphicsRectItem::sceneEvent(event);
+    }
+
+    void mousePressEvent(QGraphicsSceneMouseEvent *)
+    {
+        grabMouse();
+        ++npress;
+    }
+    void mouseReleaseEvent(QGraphicsSceneMouseEvent *)
+    {
+        ungrabMouse();
+        ++nrelease;
+    }
+    void mouseDoubleClickEvent(QGraphicsSceneMouseEvent *)
+    {
+        ++ndoubleClick;
+    }
+};
+
+void tst_QGraphicsWidget::doubleClickAfterExplicitMouseGrab()
+{
+    QGraphicsScene scene;
+    GrabOnPressItem *item = new GrabOnPressItem(QRectF(0, 0, 100, 100));
+    scene.addItem(item);
+
+    {
+        QGraphicsSceneMouseEvent event(QEvent::GraphicsSceneMousePress);
+        event.setButton(Qt::LeftButton);
+        event.setButtons(Qt::LeftButton);
+        event.ignore();
+        event.setScenePos(QPointF(50, 50));
+        qApp->sendEvent(&scene, &event);
+    }
+    QCOMPARE(scene.mouseGrabberItem(), (QGraphicsItem *)item);
+    QCOMPARE(item->npress, 1);
+    QCOMPARE(item->ngrab, 1);
+    {
+        QGraphicsSceneMouseEvent event(QEvent::GraphicsSceneMouseRelease);
+        event.setButton(Qt::LeftButton);
+        event.setButtons(0);
+        event.ignore();
+        event.setScenePos(QPointF(50, 50));
+        qApp->sendEvent(&scene, &event);
+    }
+    QCOMPARE(scene.mouseGrabberItem(), (QGraphicsItem *)0);
+    QCOMPARE(item->nrelease, 1);
+    QCOMPARE(item->nungrab, 1);
+    {
+        QGraphicsSceneMouseEvent event(QEvent::GraphicsSceneMouseDoubleClick);
+        event.setButton(Qt::LeftButton);
+        event.setButtons(Qt::LeftButton);
+        event.ignore();
+        event.setScenePos(QPointF(50, 50));
+        qApp->sendEvent(&scene, &event);
+    }
+    QCOMPARE(scene.mouseGrabberItem(), (QGraphicsItem *)item);
+    QCOMPARE(item->ndoubleClick, 1);
+    QCOMPARE(item->ngrab, 2);
+    {
+        QGraphicsSceneMouseEvent event(QEvent::GraphicsSceneMouseRelease);
+        event.setButton(Qt::LeftButton);
+        event.setButtons(0);
+        event.ignore();
+        event.setScenePos(QPointF(50, 50));
+        qApp->sendEvent(&scene, &event);
+    }
+    QCOMPARE(scene.mouseGrabberItem(), (QGraphicsItem *)0);
+    QCOMPARE(item->nrelease, 2);
+    QCOMPARE(item->nungrab, 2);
+}
+
 void tst_QGraphicsWidget::popupMouseGrabber()
 {
     QGraphicsScene scene;