moc: put the QPrivateSignal argument in the arg array

Even if it is normaly not used, templated code might still try to access it

Task-number: QTBUG-59414
Change-Id: I9f7aadd714843059c8f89cdac48c60a3e2ca7294
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/auto/tools/moc/tst_moc.cpp b/tests/auto/tools/moc/tst_moc.cpp
index 2d7ec2f0b5..7c05b388dc 100644
--- a/tests/auto/tools/moc/tst_moc.cpp
+++ b/tests/auto/tools/moc/tst_moc.cpp
@@ -2837,6 +2837,21 @@ void tst_Moc::privateSignalConnection()
     // We can't use function pointer connections to private signals which are overloaded because we would have to cast in this case to:
     //   static_cast<void (ClassWithPrivateSignals::*)(int, ClassWithPrivateSignals::QPrivateSignal)>(&ClassWithPrivateSignals::overloadedMaybePrivate)
     // Which doesn't work as ClassWithPrivateSignals::QPrivateSignal is private.
+
+    // Connecting from one private signal to another
+    {
+        ClassWithPrivateSignals classWithPrivateSignals1;
+        ClassWithPrivateSignals classWithPrivateSignals2;
+        SignalConnectionTester tester;
+        QObject::connect(&classWithPrivateSignals1, &ClassWithPrivateSignals::privateSignal1,
+                         &classWithPrivateSignals2, &ClassWithPrivateSignals::privateSignal1);
+        QObject::connect(&classWithPrivateSignals2, &ClassWithPrivateSignals::privateSignal1,
+                         &tester, &SignalConnectionTester::testSlot);
+
+        QVERIFY(!tester.testPassed);
+        classWithPrivateSignals1.emitPrivateSignals();
+        QVERIFY(tester.testPassed);
+    }
 }
 
 void tst_Moc::finalClasses_data()