Test connecting to virtual function pointer

The C++ standard says that the comparison between pointer to virtual
function is unspecified (C++11 $5.10.2)
But we still may rely on it for the Qt::UniqueConnection and the
disconnection

So test if it works while using the same function.
Using function from different classes works for me, but we should
probably not assume it works. I left it commented in the test for
reference.

Change-Id: I1d9b91d4cc1a424d4f43ef2ee4981b8573f1e86f
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 15353a3764..9628bb3faa 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -134,6 +134,7 @@ private slots:
     void returnValue();
     void returnValue2_data();
     void returnValue2();
+    void connectVirtualSlots();
 };
 
 class SenderObject : public QObject
@@ -5150,6 +5151,52 @@ void tst_QObject::returnValue2()
     }
 }
 
+class VirtualSlotsObjectBase : public QObject {
+    Q_OBJECT
+public slots:
+    virtual void slot1() {
+        base_counter1++;
+    }
+public:
+    VirtualSlotsObjectBase() : base_counter1(0) {}
+    int base_counter1;
+signals:
+    void signal1();
+};
+
+class VirtualSlotsObject : public VirtualSlotsObjectBase {
+    Q_OBJECT
+public slots:
+    virtual void slot1() {
+        derived_counter1++;
+    }
+public:
+    VirtualSlotsObject() : derived_counter1(0) {}
+    int derived_counter1;
+};
+
+void tst_QObject::connectVirtualSlots()
+{
+    VirtualSlotsObject obj;
+    QVERIFY( QObject::connect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObjectBase::slot1, Qt::UniqueConnection));
+    QVERIFY(!QObject::connect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObjectBase::slot1, Qt::UniqueConnection));
+
+    emit obj.signal1();
+    QCOMPARE(obj.base_counter1, 0);
+    QCOMPARE(obj.derived_counter1, 1);
+
+    QVERIFY(QObject::disconnect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObjectBase::slot1));
+    QVERIFY(!QObject::disconnect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObjectBase::slot1));
+
+    emit obj.signal1();
+    QCOMPARE(obj.base_counter1, 0);
+    QCOMPARE(obj.derived_counter1, 1);
+
+    /* the C++ standard say the comparison between pointer to virtual member function is unspecified
+    QVERIFY( QObject::connect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObjectBase::slot1, Qt::UniqueConnection));
+    QVERIFY(!QObject::connect(&obj, &VirtualSlotsObjectBase::signal1, &obj, &VirtualSlotsObject::slot1, Qt::UniqueConnection));
+    */
+}
 
 QTEST_MAIN(tst_QObject)
 #include "tst_qobject.moc"