QTimer: extend property tests and fix binding loop

The bindable property tests were not using the QTestPrivate helpers, so
add a new test which uses them.

The new tests revealed a binding loop for the interval property.
Fix it in a usual way by explicitly removing the binding and using
{set}ValueBypassingBindings() in the setter.

Task-number: QTBUG-116346
Change-Id: If94f57938da449a68e3527aead5ebd55ba410adb
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
(cherry picked from commit 7d70edd31cb4c55471ad96e3a1d7114e2c081cf6)

src/corelib/kernel/qtimer.cpp

@@ -622,8 +622,9 @@ QBindable<bool> QTimer::bindableSingleShot()
 void QTimer::setInterval(int msec)
 {
     Q_D(QTimer);
-    const bool intervalChanged = msec != d->inter;
-    d->inter.setValue(msec);
+    d->inter.removeBindingUnlessInWrapper();
+    const bool intervalChanged = msec != d->inter.valueBypassingBindings();
+    d->inter.setValueBypassingBindings(msec);
     if (d->id != QTimerPrivate::INV_TIMER) { // create new timer
         QObject::killTimer(d->id);                        // restart timer
         d->id = QObject::startTimer(std::chrono::milliseconds{msec}, d->type);

tests/auto/corelib/kernel/qtimer/CMakeLists.txt

@@ -14,6 +14,7 @@ qt_internal_add_test(tst_qtimer
         tst_qtimer.cpp
     LIBRARIES
         Qt::CorePrivate
+        Qt::TestPrivate
 )
 
 ## Scopes:

tests/auto/corelib/kernel/qtimer/tst_qtimer.cpp

@@ -11,6 +11,7 @@
 #include <QtCore/private/qglobal_p.h>
 #include <QTest>
 #include <QSignalSpy>
+#include <QtTest/private/qpropertytesthelper_p.h>
 
 #include <qtimer.h>
 #include <qthread.h>
@@ -75,6 +76,7 @@ private slots:
 
     void bindToTimer();
     void bindTimer();
+    void automatedBindingTests();
 };
 
 void tst_QTimer::zeroTimer()
@@ -1312,6 +1314,42 @@ void tst_QTimer::bindTimer()
     QCOMPARE(timer.timerType(), Qt::VeryCoarseTimer);
 }
 
+void tst_QTimer::automatedBindingTests()
+{
+    QTimer timer;
+
+    QVERIFY(!timer.isSingleShot());
+    QTestPrivate::testReadWritePropertyBasics(timer, true, false, "singleShot");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::singleShot");
+        return;
+    }
+
+    QCOMPARE_NE(timer.interval(), 10);
+    QTestPrivate::testReadWritePropertyBasics(timer, 10, 20, "interval");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::interval");
+        return;
+    }
+
+    QCOMPARE_NE(timer.timerType(), Qt::PreciseTimer);
+    QTestPrivate::testReadWritePropertyBasics(timer, Qt::PreciseTimer, Qt::CoarseTimer,
+                                              "timerType");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::timerType");
+        return;
+    }
+
+    timer.start(1000);
+    QVERIFY(timer.isActive());
+    QTestPrivate::testReadOnlyPropertyBasics(timer, true, false, "active",
+                                             [&timer]() { timer.stop(); });
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::active");
+        return;
+    }
+}
+
 class OrderHelper : public QObject
 {
     Q_OBJECT

tests/auto/gui/kernel/qguitimer/CMakeLists.txt

@@ -11,4 +11,5 @@ qt_internal_add_test(tst_qguitimer
     LIBRARIES
         Qt::CorePrivate
         Qt::Gui
+        Qt::TestPrivate
 )