Fix visual parent ownership with scenes that create windows

Commit 39540124dd0900e0c99dcda8c0ebdf4f3cea8d5e introduced the concept that
a visual parent marks its children, by recursively marking the children of
the root item in a QQuickView. This allowed for the removal of an ugly hack
in QtQuick Controls.

Unfortunately that fix is incomplete in the sense that it makes the incorrect
assumption that a QQuickView is always used. The use-case in the bug report is
to have child items inside a QtQuick.Window (a regular ApplicationWindow in
fact). That window - implemented by QQuickWindowQmlImpl - also needs to mark
its children, so this patch introduces the use of the same GC marking helper
class (which now operates on a QQuickWindow instead of a QQuickViewPrivate).

Task-number: QTBUG-37711
Change-Id: Id788e84dbb041ac8ba6ff23dc4ef56f6fe9e465a
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickitem/data/visualParentOwnershipWindow.qml b/tests/auto/quick/qquickitem/data/visualParentOwnershipWindow.qml
new file mode 100644
index 0000000000..30fc844d7a
--- /dev/null
+++ b/tests/auto/quick/qquickitem/data/visualParentOwnershipWindow.qml
@@ -0,0 +1,15 @@
+import QtQuick 2.0
+import QtQuick.Window 2.1
+
+Window {
+    Component {
+        id: factory
+        Item {}
+    }
+
+    property Item keepAliveProperty;
+
+    function createItemWithoutParent() {
+        return factory.createObject(/*parent*/ null);
+    }
+}