Fix QQWinPriv::deliverSinglePointEventUntilAccepted for wheel, gestures

WheelHandler was only reacting to one wheel event between mouse moves,
because it got added to the QQPointerHandlerPriv::deviceDeliveryTargets()
vector, and was not removed at the beginning of delivery of subsequent
events, as QQuickWindowPrivate::deliverPointerEvent() does.  (In Qt 5
the equivalent vector was cleared in QQuickPointerMouseEvent::reset().)
Wheel events are delivered via deliverSinglePointEventUntilAccepted()
(grabbing the wheel is still not implemented).  Native gesture events
are delivered that way too; and sure enough, the same bug happens on the
macOS trackpad, whether you are attempting to do pinch zoom or just
two-finger-flick.

tst_QQuickWheelHandler::nestedHandler() sends multiple wheel events
in a row, so we do have some test coverage, and hopefully this issue
explains why it needed to be blacklisted.

Fixes: QTBUG-88428
Task-number: QTBUG-86729
Change-Id: Id1ed4a38dfa3eb2253c4a60f09f80aea0f69707e
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index b283f56ab9..4dab3b731d 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -2209,6 +2209,7 @@ bool QQuickWindowPrivate::deliverHoverEvent(QQuickItem *item, const QPointF &sce
 bool QQuickWindowPrivate::deliverSinglePointEventUntilAccepted(QPointerEvent *event)
 {
     Q_ASSERT(event->points().count() == 1);
+    QQuickPointerHandlerPrivate::deviceDeliveryTargets(event->pointingDevice()).clear();
     QEventPoint &point = event->point(0);
     QVector<QQuickItem *> targetItems = pointerTargets(contentItem, event, point, false, false);
     point.setAccepted(false);