QMetaObjectBuilder: Always set Data::metatypes

The array of metatypes should always contain at least one entry (for the
metatype of the current metaobject itself).
This prevents crashes in the case of a metaobject without meta-methods
and properties (as observed in Qt for Python).

Pick-to: 6.2 6.3
Change-Id: I7a6fb316eea48c4852b6f1c26e0a930aeba4c799
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp b/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
index 188a5a6626..9e96d0e02c 100644
--- a/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
+++ b/tests/auto/corelib/kernel/qmetaobjectbuilder/tst_qmetaobjectbuilder.cpp
@@ -67,6 +67,8 @@ private slots:
 
     void cleanupTestCase();
 
+    void ownMetaTypeNoProperties();
+
 private:
     static bool checkForSideEffects
         (const QMetaObjectBuilder& builder,
@@ -1657,6 +1659,16 @@ void tst_QMetaObjectBuilder::propertyMetaType()
     free(mo);
 }
 
+void tst_QMetaObjectBuilder::ownMetaTypeNoProperties()
+{
+    QMetaObjectBuilder builder;
+    builder.setClassName("NoProperties");
+    auto mo = builder.toMetaObject();
+    auto cleanup = qScopeGuard([&](){ free(mo); });
+    // own metatype should be invalid, as the dynamic metaobject has not been registered
+    QVERIFY(!mo->metaType().isValid());// should not crash
+}
+
 void tst_QMetaObjectBuilder::cleanupTestCase()
 {
     for (QMetaObject *obj: dynamicMetaObjectsPendingFree)