Make QML composite types inherit enums

Problem: in Qt Quick Controls 2, enums declared in the abstract
C++ base types were not accessible with the concrete QML type name,
but had to be referenced using the base type name:

    Slider {
        snapMode: AbstractSlider.SnapOnRelease
    }

Solution: this change resolves the C++ base type and creates the
missing link between the composite type and its base type's meta-
object. This allows referencing enums using the concrete/composite
QML type name:

    Slider {
        snapMode: Slider.SnapOnRelease
    }

Change-Id: Icefdec91b012b12728367fd54b4d16796233ee12
Task-number: QTBUG-43582
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index f371a369a1..171fa048ce 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1101,6 +1101,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
     if (customParser) {
         QHash<int, QBitArray>::ConstIterator customParserBindings = compiledData->customParserBindings.constFind(index);
         if (customParserBindings != compiledData->customParserBindings.constEnd()) {
+            customParser->engine = QQmlEnginePrivate::get(engine);
             customParser->imports = compiledData->importCache;
 
             QList<const QV4::CompiledData::Binding *> bindings;
@@ -1110,6 +1111,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
                     bindings << obj->bindingTable() + i;
             customParser->applyBindings(instance, compiledData, bindings);
 
+            customParser->engine = 0;
             customParser->imports = (QQmlTypeNameCache*)0;
             bindingsToSkip = *customParserBindings;
         }