Running it in valgrind gives a clue:
==19941== Invalid read of size 4
==19941==at 0x6604DA4: ??? (in
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5.5.1)
==19941==by 0x1877174F: ???
==19941==by 0xFFFD: ???
==19941==by 0x2483D3FE: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x27C117AB: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x27C36ADC: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x27C3DDD3: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x27C3E1A8: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x24861F42: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x24861FF8: ??? (in
/usr/lib/x86_64-linux-gnu/libOxideQtCore.so.0)
==19941==by 0x2414E312:
QScopedPointerDeleter::cleanup(oxide::qt::WebViewProxy*)
(in /usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x2414D996: QScopedPointer >::~QScopedPointer() (in
/usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x241467FB:
OxideQQuickWebViewPrivate::~OxideQQuickWebViewPrivate() (in
/usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x24146847:
OxideQQuickWebViewPrivate::~OxideQQuickWebViewPrivate() (in
/usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x2414E4D6:
QScopedPointerDeleter::cleanup(OxideQQuickWebViewPrivate*)
(in /usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x2414DED6: QScopedPointer >::~QScopedPointer() (in
/usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x24147E1C: OxideQQuickWebView::~OxideQQuickWebView() (in
/usr/lib/x86_64-linux-gnu/libOxideQtQuick.so.0)
==19941==by 0x240855BD:
QQmlPrivate::QQmlElement::~QQmlElement() (in
/usr/lib/x86_64-linux-gnu/qt5/qml/com/canonical/Oxide/libqmloxideplugin.so)
==19941==by 0x240855F3:
QQmlPrivate::QQmlElement::~QQmlElement() (in
/usr/lib/x86_64-linux-gnu/qt5/qml/com/canonical/Oxide/libqmloxideplugin.so)
==19941==by 0x64BE52A: QObjectPrivate::deleteChildren() (in
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5.5.1)
==19941==by 0x64C7D9F: QObject::~QObject() (in
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5.5.1)
==19941==by 0x5DBD028: QWindow::~QWindow() (in
/usr/lib/x86_64-linux-gnu/libQt5Gui.so.5.5.1)
==19941==by 0x4FD26E8: QQuickWindow::~QQuickWindow() (in
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.5.1)
==19941==by 0x50AA74C:
QQmlPrivate::QQmlElement::~QQmlElement() (in
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.5.1)
==19941==by 0x405115: main (in /usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene)
==19941== Address 0x151bcd9e is 18 bytes before a block of size 664 alloc'd
==19941==at 0x4C2E0EF: operator new(unsigned long) (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==19941==by 0x50A96E9: QQuickWindowQmlImpl::QQuickWindowQmlImpl(QWindow*)
(in /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.5.1)
==19941==by 0x50AA78F: void
QQmlPrivate::createInto(void*) (in
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.5.1)
==19941==by 0x547B71A: QQmlType::create() const (in
/usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.5.1)
==19941==by 0x54DCE23: QQmlObjectCreator::createInstance(int, QObject*,
bool) (in /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.5.1)
==19941==by 0x54DD8CE: QQmlObjectCreator::create(int, QObject*,
QQmlInstantiationInterrupt*) (in /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.5.1)
==19941==by 0x5465B04: QQmlComponentPrivate::beginCreate(QQmlContextData*)
(in /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.5.1)
==19941==by 0x546378E: QQmlComponent::create(QQmlContext*) (in
/usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.5.1)
==19941==by 0x404F0F: main (in /usr/lib/x86_64-linux-gnu/qt5/bin/qmlscene)
So we're accessing the window after it's been deleted.
Some stepping through in gdb shows that this access occurs here:
oxide::qt::InputMethodContext::FocusedNodeChanged (this=0xb426d0) at
../../oxide/qt/core/browser/input/oxide_qt_input_method_context.cc:236
236 QGuiApplication::focusWindow()->focusObject()) {
(gdb) bt
#0 0x7fffb699d3fe in oxide::qt::InputMethodContext::FocusedNodeChanged()
(this=0xb426d0) at
../../oxide/qt/core/browser/input/oxide_qt_input_method_context.cc:236
#1 0x7fffb8edf9fc in
oxide::ImeBridgeImpl::SetContext(oxide::InputMethodContext*) (this=0xaea948,
context=0x0) at ../../oxide/shared/browser/input/oxide_ime_bridge_impl.cc:109
#2 0x7fffb8f04d4d in
oxide::WebContentsView::SetClient(oxide::WebContentsViewClient*)
(this=0xcbe100, client=) at
../../oxide/shared/browser/oxide_web_contents_view.cc:786
#3 0x7fffb8f09790 in oxide::WebView::~WebView() (this=0xb62660,
__in_chrg=) at ../../oxide/shared/browser/oxide_web_view.cc:984
#4 0x7fffb8f098f9 in oxide::WebView::~WebView() (this=0xb62660,
__in_chrg=) at ../../oxide/shared/browser/oxide_web_view.cc:998
#5 0x7fffb69c126e in oxide::qt::WebView::~WebView() (this=,
__