MouseArea signal handlers break when running successive QML tests

The was discovered in Qt Location tests. I have attached minimal example.

Test setup is a single test binary which runs two QML tests. Running the tests individually works as expected:

./declarative_ui First::test_spy
./declarative_ui Second::test_spy

Running both tests fails:

./declarative_ui

The failure is that the mouse parameter of the MouseArea::onClicked handler cannot be found. The following message is printed on the console:

QDEBUG : declarative_ui::Second::test_spy() arguments[0] is QQuickMouseEvent(0x7fff4299fd20)
QWARN : declarative_ui::Second::test_spy() file:///home/amccarthy/depot/qt5/qtlocation/tests/auto/declarative_ui/tst_second.qml:24: ReferenceError: mouse is not defined

Note that the argument is still available in the JavaScript arguments list as shown in the QDEBUG line above. It is the named parameter of the signal handler that fails to resolve.

The cause is the SignalSpy object in the first test. After commenting out the SignalSpy (and the compare) in tst_first.qml both tests pass. This test uses the QUICK_TEST_MAIN which reuses a single QQuickView for all run tests.

The same behaviour happens for other MouseArea signals with the same signature.