QCheckBox: Don't emit checkStateChanged when nothing changed

QCheckBox::checkStateChanged() was emitted with msvc even though the
check state was not changed due to a faulty comparison.
Amends: 37b47ebf946ef1a37573107375fbe5fc0eb1e6d2

Pick-to: 6.6
Fixes: QTBUG-118716
Task-number: QTBUG-104688
Change-Id: Iafeabeb9214f6c7510ea4ed87fabb7dc0ba175a6
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/auto/widgets/widgets/qcheckbox/tst_qcheckbox.cpp b/tests/auto/widgets/widgets/qcheckbox/tst_qcheckbox.cpp
index a8f8c03e02..23082485c2 100644
--- a/tests/auto/widgets/widgets/qcheckbox/tst_qcheckbox.cpp
+++ b/tests/auto/widgets/widgets/qcheckbox/tst_qcheckbox.cpp
@@ -16,6 +16,7 @@ private slots:
     void initTestCase();
 
     void setChecked();
+    void setCheckedSignal();
     void setTriState();
     void setText_data();
     void setText();
@@ -59,6 +60,25 @@ void tst_QCheckBox::setChecked()
     QVERIFY(!testWidget.isChecked());
 }
 
+void tst_QCheckBox::setCheckedSignal()
+{
+    QCheckBox testWidget;
+    testWidget.setCheckState(Qt::Unchecked);
+    QSignalSpy checkStateChangedSpy(&testWidget, &QCheckBox::checkStateChanged);
+    testWidget.setCheckState(Qt::Checked);
+    testWidget.setCheckState(Qt::Checked);
+    QTRY_COMPARE(checkStateChangedSpy.size(), 1);   // get signal only once
+    QCOMPARE(testWidget.checkState(), Qt::Checked);
+    testWidget.setCheckState(Qt::Unchecked);
+    testWidget.setCheckState(Qt::Unchecked);
+    QTRY_COMPARE(checkStateChangedSpy.size(), 2);   // get signal only once
+    QCOMPARE(testWidget.checkState(), Qt::Unchecked);
+    testWidget.setCheckState(Qt::PartiallyChecked);
+    testWidget.setCheckState(Qt::PartiallyChecked);
+    QTRY_COMPARE(checkStateChangedSpy.size(), 3);   // get signal only once
+    QCOMPARE(testWidget.checkState(), Qt::PartiallyChecked);
+}
+
 void tst_QCheckBox::setTriState()
 {
     QCheckBox testWidget;