Fix warnings about uninitialized variables

qtbase/src/corelib/kernel/qmetatype.cpp: In static member function ‘static void QMetaType::destroy(int, void*)’:
qtbase/src/corelib/kernel/qmetatype.cpp:2599:27: error: ‘info.QMetaType::m_destructor’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     if (m_typedDestructor && !m_destructor)
         ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
qtbase/src/corelib/kernel/qmetatype.cpp:1868:15: note: ‘info.QMetaType::m_destructor’ was declared here
     QMetaType info(type);
               ^~~~
qtbase/src/corelib/kernel/qmetatype.cpp:2600:26: error: ‘info.QMetaType::m_typedDestructor’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
         m_typedDestructor(m_typeId, data);
         ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
qtbase/src/corelib/kernel/qmetatype.cpp:1868:15: note: ‘info.QMetaType::m_typedDestructor’ was declared here
     QMetaType info(type);
               ^~~~

The extended (not inlined) function may be called on a half
initialized invalid instance.

Change-Id: I26d677a8ad2bd0c5846233f06393e774d377936d
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
index 5d9b5ca95c..e6fac74ccc 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
@@ -123,6 +123,7 @@ private slots:
     void compareCustomType();
     void compareCustomEqualOnlyType();
     void customDebugStream();
+    void unknownType();
 };
 
 struct BaseGenericType
@@ -2529,6 +2530,16 @@ void tst_QMetaType::customDebugStream()
     qDebug() << v1;
 }
 
+void tst_QMetaType::unknownType()
+{
+    QMetaType invalid(QMetaType::UnknownType);
+    QVERIFY(!invalid.create());
+    QVERIFY(!invalid.sizeOf());
+    QVERIFY(!invalid.metaObject());
+    int buffer = 0xBAD;
+    invalid.construct(&buffer);
+    QCOMPARE(buffer, 0xBAD);
+}
 // Compile-time test, it should be possible to register function pointer types
 class Undefined;