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>

2 files changed, 23 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmllanguage/data/nestedCustomParsers.qml b/tests/auto/qml/qqmllanguage/data/nestedCustomParsers.qml
new file mode 100644
index 0000000000..77b93e8594
--- /dev/null
+++ b/tests/auto/qml/qqmllanguage/data/nestedCustomParsers.qml
@@ -0,0 +1,8 @@
+import Test 1.0
+import QtQml 2.0
+SimpleObjectWithCustomParser {
+    customProperty: 42
+    property var nested: SimpleObjectWithCustomParser {
+        customNestedProperty: 42
+    }
+}
diff --git a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
index 922abd9761..0405b2905b 100644
--- a/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
+++ b/tests/auto/qml/qqmllanguage/tst_qqmllanguage.cpp
@@ -229,6 +229,7 @@ private slots:
     void customParserEvaluateEnum();
     void customParserProperties();
     void customParserWithExtendedObject();
+    void nestedCustomParsers();
 
     void preservePropertyCacheOnGroupObjects();
     void propertyCacheInSync();
@@ -3930,6 +3931,20 @@ void tst_qqmllanguage::customParserWithExtendedObject()
     QCOMPARE(returnValue.toInt(), 1584);
 }
 
+void tst_qqmllanguage::nestedCustomParsers()
+{
+    QQmlComponent component(&engine, testFile("nestedCustomParsers.qml"));
+    VERIFY_ERRORS(0);
+    QScopedPointer<QObject> o(component.create());
+    QVERIFY(!o.isNull());
+    SimpleObjectWithCustomParser *testObject = qobject_cast<SimpleObjectWithCustomParser*>(o.data());
+    QVERIFY(testObject);
+    QCOMPARE(testObject->customBindingsCount(), 1);
+    SimpleObjectWithCustomParser *nestedObject = qobject_cast<SimpleObjectWithCustomParser*>(testObject->property("nested").value<QObject*>());
+    QVERIFY(nestedObject);
+    QCOMPARE(nestedObject->customBindingsCount(), 1);
+}
+
 void tst_qqmllanguage::preservePropertyCacheOnGroupObjects()
 {
     QQmlComponent component(&engine, testFile("preservePropertyCacheOnGroupObjects.qml"));