QTabBar: Add testcase for tabs not scrolling

Verify that changing a tab's text doesn't scroll.

Fixes: QTBUG-45381
Task-number: QTBUG-113140
Pick-to: 6.5
Change-Id: I02ace9d3fcaa20d8ff5d87ccca5d96a4114b0fb0
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Santhosh Kumar <santhosh.kumar.selvaraj@qt.io>

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/auto/widgets/widgets/qtabbar/tst_qtabbar.cpp b/tests/auto/widgets/widgets/qtabbar/tst_qtabbar.cpp
index 7d47b744b1..6d5be7d558 100644
--- a/tests/auto/widgets/widgets/qtabbar/tst_qtabbar.cpp
+++ b/tests/auto/widgets/widgets/qtabbar/tst_qtabbar.cpp
@@ -98,6 +98,7 @@ private slots:
 
     void resizeKeepsScroll_data();
     void resizeKeepsScroll();
+    void changeTabTextKeepsScroll();
 
 private:
     void checkPositions(const TabBar &tabbar, const QList<int> &positions);
@@ -1426,5 +1427,30 @@ void tst_QTabBar::resizeKeepsScroll()
     }
 }
 
+void tst_QTabBar::changeTabTextKeepsScroll()
+{
+    QTabBar tabBar;
+    TabBarScrollingProxyStyle proxyStyle;
+    tabBar.setStyle(&proxyStyle);
+
+    for (int i = 0; i < 6; ++i)
+        tabBar.addTab(u"Tab Number %1"_s.arg(i));
+
+    const QSize fullSize = tabBar.sizeHint();
+    tabBar.resize(fullSize.width() / 2, fullSize.height());
+
+    tabBar.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&tabBar));
+
+    const auto getScrollOffset = [&]() -> int {
+        return static_cast<QTabBarPrivate *>(QObjectPrivate::get(&tabBar))->scrollOffset;
+    };
+
+    tabBar.setCurrentIndex(3);
+    const int scrollOffset = getScrollOffset();
+    tabBar.setTabText(3, "New title");
+    QCOMPARE(getScrollOffset(), scrollOffset);
+}
+
 QTEST_MAIN(tst_QTabBar)
 #include "tst_qtabbar.moc"