Fix regression with nested objects served by custom parsers

The following piece of code used to work and broke with Qt 5.3:

ListModel {
    property var conn: Connection {
        ...
    }
}

When validating the properties of the ListModel we would not validate
the Connection sub-object here, which meant the custom parser for the
connection object was never called.

We need to extend the logic for sub-object validation to recursive into
sub-objects when this is either an attached property (Component.onComplete on a
list model for example) or the object is assigned to an _existing_ property,
i.e. a property not deal with by the custom parser. In this case that's a
custom declared property.

Change-Id: Ic99f746f08771460cc6424a9e8a839c78a7eafd9
Task-number: QTBUG-45735
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

0 files changed, 0 insertions, 0 deletions