Client: clear focus on touch cancel

When we get a touch_cancel event all touches should be treated as
lifted.

The next frame call focus is set, with no pending touch points but
without having gone through touch_up. We call mPendingTouchPoints.last()
without guards even though it is potentially now empty.

Change-Id: I3719f9507c5d397d8641692271d878076b7c23b8
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/client/qwaylandinputdevice.cpp b/src/client/qwaylandinputdevice.cpp
index c531699a6..9ff63b3b5 100644
--- a/src/client/qwaylandinputdevice.cpp
+++ b/src/client/qwaylandinputdevice.cpp
@@ -1412,6 +1412,7 @@ void QWaylandInputDevice::Touch::touch_cancel()
     if (touchExt)
         touchExt->touchCanceled();
 
+    mFocus = nullptr;
     QWindowSystemInterface::handleTouchCancelEvent(nullptr, mParent->mTouchDevice);
 }