QQuickItem: detect loop in KeyNavigation chain

Task-number: QTBUG-47229
Change-Id: I22dbe5ee1fff4e9a8de4fa69b43e4d9a87677192
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>

3 files changed, 66 insertions, 1 deletions

diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index ab93974f60..fbea3a0ee1 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -724,6 +724,7 @@ void QQuickKeyNavigationAttached::setFocusNavigation(QQuickItem *currentItem, co
 {
     QQuickItem *initialItem = currentItem;
     bool isNextItem = false;
+    QVector<QQuickItem *> visitedItems;
     do {
         isNextItem = false;
         if (currentItem->isVisible() && currentItem->isEnabled()) {
@@ -734,13 +735,14 @@ void QQuickKeyNavigationAttached::setFocusNavigation(QQuickItem *currentItem, co
             if (attached) {
                 QQuickItem *tempItem = qvariant_cast<QQuickItem*>(attached->property(dir));
                 if (tempItem) {
+                    visitedItems.append(currentItem);
                     currentItem = tempItem;
                     isNextItem = true;
                 }
             }
         }
     }
-    while (currentItem != initialItem && isNextItem);
+    while (currentItem != initialItem && isNextItem && !visitedItems.contains(currentItem));
 }
 
 struct SigMap {
diff --git a/tests/auto/quick/qquickitem2/data/keynavigationtest_loop.qml b/tests/auto/quick/qquickitem2/data/keynavigationtest_loop.qml
new file mode 100644
index 0000000000..dfac1549f9
--- /dev/null
+++ b/tests/auto/quick/qquickitem2/data/keynavigationtest_loop.qml
@@ -0,0 +1,37 @@
+import QtQuick 2.0
+
+Column {
+    width: 50; height: 200
+    Rectangle {
+        id: item1
+        objectName: "item1"
+        focus: true
+        width: 50; height: 50
+        color: focus ? "red" : "lightgray"
+        KeyNavigation.down: item2
+    }
+    Rectangle {
+        id: item2
+        objectName: "item2"
+        enabled: false
+        width: 50; height: 50
+        color: focus ? "red" : "lightgray"
+        KeyNavigation.down: item3
+    }
+    Rectangle {
+        id: item3
+        objectName: "item3"
+        enabled: false
+        width: 50; height: 50
+        color: focus ? "red" : "lightgray"
+        KeyNavigation.down: item4
+    }
+    Rectangle {
+        id: item4
+        objectName: "item4"
+        enabled: false
+        width: 50; height: 50
+        color: focus ? "red" : "lightgray"
+        KeyNavigation.down: item3
+    }
+}
diff --git a/tests/auto/quick/qquickitem2/tst_qquickitem.cpp b/tests/auto/quick/qquickitem2/tst_qquickitem.cpp
index 69c7250134..f3333df60d 100644
--- a/tests/auto/quick/qquickitem2/tst_qquickitem.cpp
+++ b/tests/auto/quick/qquickitem2/tst_qquickitem.cpp
@@ -85,6 +85,7 @@ private slots:
     void keyNavigation_skipNotVisible();
     void keyNavigation_implicitSetting();
     void keyNavigation_focusReason();
+    void keyNavigation_loop();
     void layoutMirroring();
     void layoutMirroringIllegalParent();
     void smooth();
@@ -2026,6 +2027,31 @@ void tst_QQuickItem::keyNavigation_focusReason()
     delete window;
 }
 
+void tst_QQuickItem::keyNavigation_loop()
+{
+    // QTBUG-47229
+    QQuickView *window = new QQuickView(0);
+    window->setBaseSize(QSize(240,320));
+
+    window->setSource(testFileUrl("keynavigationtest_loop.qml"));
+    window->show();
+    window->requestActivate();
+
+    QVERIFY(QTest::qWaitForWindowActive(window));
+    QCOMPARE(QGuiApplication::focusWindow(), window);
+
+    QQuickItem *item = findItem<QQuickItem>(window->rootObject(), "item1");
+    QVERIFY(item);
+    QVERIFY(item->hasActiveFocus());
+
+    QKeyEvent key = QKeyEvent(QEvent::KeyPress, Qt::Key_Down, Qt::NoModifier, "", false, 1);
+    QGuiApplication::sendEvent(window, &key);
+    QVERIFY(key.isAccepted());
+    QVERIFY(item->hasActiveFocus());
+
+    delete window;
+}
+
 void tst_QQuickItem::smooth()
 {
     QQmlComponent component(&engine);