Avoid double deletion when deleting an incubating component.

The guard in QQmlIncubatorPrivate::clear() was invalidated by clearing
the guards in QQmlIncubatorPrivate::incubate() when a deletion was
detected.

If we detect a deletion, leave the guards in place, to be handled in
QQmlIncubatorPrivate::clear().

Task-number: QTBUG-40685
Change-Id: I1bf7422fda97745f1f7a3b42285a399244c09a1f
Reviewed-by: Alan Alpert <aalpert@blackberry.com>
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/qml/qml/qqmlincubator.cpp b/src/qml/qml/qqmlincubator.cpp
index 4cdeb19719..098a664ded 100644
--- a/src/qml/qml/qqmlincubator.cpp
+++ b/src/qml/qml/qqmlincubator.cpp
@@ -292,10 +292,7 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
     QQmlEngine *engine = compiledData->engine;
     QQmlEnginePrivate *enginePriv = QQmlEnginePrivate::get(engine);
 
-    bool guardOk = vmeGuard.isOK();
-    vmeGuard.clear();
-
-    if (!guardOk) {
+    if (!vmeGuard.isOK()) {
         QQmlError error;
         error.setUrl(compiledData->url);
         error.setDescription(QQmlComponent::tr("Object destroyed during incubation"));
@@ -305,6 +302,8 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
         goto finishIncubate;
     }
 
+    vmeGuard.clear();
+
     if (progress == QQmlIncubatorPrivate::Execute) {
         enginePriv->referenceScarceResources();
         QObject *tresult = 0;