Make *ItemBoundingRect modes work with custom shapes.

Currently, calling
QGraphicsScene::items(QPointF(0, 0), Qt::IntersectsItemBoundingRect) or
QGraphicsScene::items(QPointF(0, 0), Qt::ContainsItemBoundingRect)
will exclude items whose shape does not contain QPointF(0, 0). This is
because QGraphicsSceneIndexPointIntersector::intersect() also checks if
the point is contained within the shape, instead of just checking
if it is contained within the bounding rect.

Task-number: QTBUG-19036

Change-Id: Ie701af2a5694d40cf9b3c9c19adbb09a53a4e398
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Andreas Aardal Hanssen <andreas@hanssen.name>

src/widgets/graphicsview/qgraphicssceneindex.cpp

@@ -151,7 +151,7 @@ public:
                                                         itemd->sceneTransform.dy())
                                      : itemd->sceneTransform.mapRect(brect);
             keep = sceneBoundingRect.intersects(QRectF(scenePoint, QSizeF(1, 1)));
-            if (keep) {
+            if (keep && (mode == Qt::ContainsItemShape || mode == Qt::IntersectsItemShape)) {
                 QPointF p = itemd->sceneTransformTranslateOnly
                           ? QPointF(scenePoint.x() - itemd->sceneTransform.dx(),
                                     scenePoint.y() - itemd->sceneTransform.dy())

tests/auto/widgets/graphicsview/qgraphicssceneindex/tst_qgraphicssceneindex.cpp

@@ -61,6 +61,8 @@ private slots:
     void movingItems();
     void connectedToSceneRectChanged();
     void items();
+    void boundingRectPointIntersection_data();
+    void boundingRectPointIntersection();
     void removeItems();
     void clear();
 
@@ -233,6 +235,56 @@ void tst_QGraphicsSceneIndex::items()
     QCOMPARE(scene.items().size(), 3);
 }
 
+class CustomShapeItem : public QGraphicsItem
+{
+public:
+    CustomShapeItem(const QPainterPath &shape) : QGraphicsItem(0), mShape(shape) {}
+
+    QPainterPath shape() const { return mShape; }
+    QRectF boundingRect() const { return mShape.boundingRect(); }
+    void paint(QPainter*, const QStyleOptionGraphicsItem*, QWidget*) {}
+private:
+    QPainterPath mShape;
+};
+
+Q_DECLARE_METATYPE(Qt::ItemSelectionMode)
+Q_DECLARE_METATYPE(QPainterPath)
+
+void tst_QGraphicsSceneIndex::boundingRectPointIntersection_data()
+{
+    QTest::addColumn<QPainterPath>("itemShape");
+    QTest::addColumn<Qt::ItemSelectionMode>("mode");
+
+    QTest::newRow("zero shape - intersects rect") << QPainterPath() << Qt::IntersectsItemBoundingRect;
+    QTest::newRow("zero shape - contains rect") << QPainterPath() << Qt::ContainsItemBoundingRect;
+
+    QPainterPath triangle;
+    triangle.moveTo(50, 0);
+    triangle.lineTo(0, 50);
+    triangle.lineTo(100, 50);
+    triangle.lineTo(50, 0);
+    QTest::newRow("triangle shape - intersects rect") << triangle << Qt::IntersectsItemBoundingRect;
+    QTest::newRow("triangle shape - contains rect") << triangle << Qt::ContainsItemBoundingRect;
+
+    QPainterPath rect;
+    rect.addRect(QRectF(0, 0, 100, 100));
+    QTest::newRow("rectangle shape - intersects rect") << rect << Qt::IntersectsItemBoundingRect;
+    QTest::newRow("rectangle shape - contains rect") << rect << Qt::ContainsItemBoundingRect;
+}
+
+void tst_QGraphicsSceneIndex::boundingRectPointIntersection()
+{
+    QFETCH(QPainterPath, itemShape);
+    QFETCH(Qt::ItemSelectionMode, mode);
+
+    QGraphicsScene scene;
+    CustomShapeItem *item = new CustomShapeItem(itemShape);
+    scene.addItem(item);
+    QList<QGraphicsItem*> items = scene.items(QPointF(0, 0), mode, Qt::AscendingOrder);
+    QVERIFY(!items.isEmpty());
+    QCOMPARE(items.first(), item);
+}
+
 class RectWidget : public QGraphicsWidget
 {
     Q_OBJECT