Fix crash when binding to QML component

As the properties were missing their context, we could not get the
correct QMetaObject and would trigger an assertion in canConvert. We now
always set the context when creating QQmlProperties in qqmlbind.

Fixes: QTBUG-40487
Change-Id: I766c5697dc33fc1e18c2316e28d944975e84ae3c
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 22 insertions, 0 deletions

diff --git a/tests/auto/qml/qqmlbinding/data/MyComponent.qml b/tests/auto/qml/qqmlbinding/data/MyComponent.qml
new file mode 100644
index 0000000000..5892539a5d
--- /dev/null
+++ b/tests/auto/qml/qqmlbinding/data/MyComponent.qml
@@ -0,0 +1,2 @@
+import QtQuick 2.3
+QtObject { property real p: 0 }
diff --git a/tests/auto/qml/qqmlbinding/data/bindToQMLComponent.qml b/tests/auto/qml/qqmlbinding/data/bindToQMLComponent.qml
new file mode 100644
index 0000000000..471db9023b
--- /dev/null
+++ b/tests/auto/qml/qqmlbinding/data/bindToQMLComponent.qml
@@ -0,0 +1,12 @@
+import QtQuick 2.0
+
+Item {
+    id: root
+    property MyComponent myProperty
+    Binding {
+        target: root
+        property: "myProperty"
+        value: myObject
+    }
+    MyComponent { id: myObject }
+}
diff --git a/tests/auto/qml/qqmlbinding/tst_qqmlbinding.cpp b/tests/auto/qml/qqmlbinding/tst_qqmlbinding.cpp
index 717fd5dbd1..9b66cd828a 100644
--- a/tests/auto/qml/qqmlbinding/tst_qqmlbinding.cpp
+++ b/tests/auto/qml/qqmlbinding/tst_qqmlbinding.cpp
@@ -54,6 +54,7 @@ private slots:
     void disabledOnReadonlyProperty();
     void delayed();
     void bindingOverwriting();
+    void bindToQmlComponent();
 
 private:
     QQmlEngine engine;
@@ -394,6 +395,13 @@ void tst_qqmlbinding::bindingOverwriting()
     QCOMPARE(messageHandler.messages().count(), 2);
 }
 
+void tst_qqmlbinding::bindToQmlComponent()
+{
+    QQmlEngine engine;
+    QQmlComponent c(&engine, testFileUrl("bindToQMLComponent.qml"));
+    QVERIFY(c.create());
+}
+
 QTEST_MAIN(tst_qqmlbinding)
 
 #include "tst_qqmlbinding.moc"