moc: add a test for Q_FLAG getter/setter on integers

This is legacy behavior from Qt 3, before we had QFlags and before
QVariant could support user types. I cannot find any instance of a
getter returning an integer in current Qt or Qt Creator code. And note
this only compiles if the flags type with Q_FLAG - not Q_ENUM.

The content is wrapped as Qt 6.x only so it can be removed in Qt
7.0. The deprecation warning will come in a later commit, for 6.9.

Change-Id: Ie3ddd8025e3b4387866efffd8e8d46c3daa0dff2
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
(cherry picked from commit 939f7f5)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/tools/moc/CMakeLists.txt

@@ -92,6 +92,10 @@ qt_internal_extend_target(tst_moc CONDITION CMAKE_CROSSCOMPILING
         MOC_CROSS_COMPILED
 )
 
+if (${PROJECT_VERSION_MAJOR} LESS 7)
+    qt_internal_extend_target(tst_moc SOURCES flags-property-integer-access.h)
+endif()
+
 if (UNIX AND (CLANG OR GCC OR QCC))
     qt_wrap_cpp(os9_moc os9-newlines.h)
 endif()

tests/auto/tools/moc/flags-property-integer-access.h

@@ -0,0 +1,23 @@
+// Copyright (C) 2024 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#ifndef FLAGS_PROPERTY_INTEGER_ACCESS
+#define FLAGS_PROPERTY_INTEGER_ACCESS
+#include <QtCore/qobject.h>
+
+class ClassWithFlagsAccessAsInteger : public QObject
+{
+    Q_OBJECT
+public:
+    enum Flag { F1 = 1, F2 = 2 };
+    Q_DECLARE_FLAGS(Flags, Flag)
+    Q_FLAG(Flags)
+    Q_PROPERTY(Flags flagsValue READ flagsValue WRITE setFlagsValue)
+    uint flagsValue() const { return f; }
+    void setFlagsValue(uint v) { f = v; }
+
+private:
+    uint f = 0;
+};
+
+#endif // FLAGS_PROPERTY_INTEGER_ACCESS

tests/auto/tools/moc/tst_moc.cpp

@@ -777,6 +777,9 @@ private slots:
     void uLongLong();
     void inputFileNameWithDotsButNoExtension();
     void userProperties();
+#if QT_VERSION <= QT_VERSION_CHECK(7, 0, 0)
+    void integerAccessFlagsProperties();
+#endif
     void supportConstSignals();
     void task87883();
     void multilineComments();
@@ -1077,6 +1080,25 @@ void tst_Moc::userProperties()
     QVERIFY(!property.isUser());
 }
 
+#if QT_VERSION <= QT_VERSION_CHECK(7, 0, 0)
+#include "flags-property-integer-access.h"
+
+void tst_Moc::integerAccessFlagsProperties()
+{
+    ClassWithFlagsAccessAsInteger o;
+
+    const QMetaObject *mobj = &ClassWithFlagsAccessAsInteger::staticMetaObject;
+    QMetaProperty property = mobj->property(mobj->indexOfProperty("flagsValue"));
+    QVERIFY(property.isValid());
+    QCOMPARE(property.metaType(), QMetaType::fromType<ClassWithFlagsAccessAsInteger::Flags>());
+
+    QVariant v = property.read(&o);
+    QCOMPARE(v, 0);
+    property.write(&o, QVariant::fromValue(ClassWithFlagsAccessAsInteger::F2));
+    QCOMPARE(o.flagsValue(), ClassWithFlagsAccessAsInteger::F2);
+}
+#endif
+
 void tst_Moc::supportConstSignals()
 {
     QSignalSpy spy1(this, SIGNAL(constSignal1()));