Fix bindings to when property of States not always working

The "when" property is of type QQmlBinding* and we special case that type when
writing property bindings. However in order for that to work, the meta-type for
QQmlBinding* needs to be registered at the point in time when resolving
properties in the type compiler. In Qt 5.1/5.2 this worked by accident due to
a different code paths that implicitly registered the meta-type earlier from a
different location.

There are a couple of property types for which we have special handling, such as
QQmlV4Handler and QJSvalue, besides QQmlBinding*. We do register them explicitly
at engine initialization time, and therefore we should also initialize the meta-type
for QQmlBinding* there.

Task-number: QTBUG-39421
Change-Id: Iec8609848b632afa52aa42cf0b807330c74f6f3a
Reviewed-by: Joona Petrell <joona.petrell@jollamobile.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 610bbcfe1e..0424c57f97 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -812,6 +812,7 @@ void QQmlEnginePrivate::init()
     qRegisterMetaType<QList<QObject*> >();
     qRegisterMetaType<QList<int> >();
     qRegisterMetaType<QQmlV4Handle>();
+    qRegisterMetaType<QQmlBinding*>();
 
     v8engine()->setEngine(q);