Cull removed items from QQuickItemView

Amends a20132c326f6d2c5fec848efb98dd86afb320e2a, which fixed a crash,
but also prevented the item from being culled. This is fixed by
narrowing the scope of the condition to affect only the caching related
part.

Fixes: QTBUG-84604
Change-Id: I9b8a1a148d6538a18280475d89b87a4049ff3465
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
(cherry picked from commit ab03621516630991c7cc0fea3be79879efed23a8)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

3 files changed, 63 insertions, 2 deletions

diff --git a/src/quick/items/qquickitemview.cpp b/src/quick/items/qquickitemview.cpp
index 7fb392233e..2b4ca9e256 100644
--- a/src/quick/items/qquickitemview.cpp
+++ b/src/quick/items/qquickitemview.cpp
@@ -2452,14 +2452,15 @@ bool QQuickItemViewPrivate::releaseItem(FxViewItem *item, QQmlInstanceModel::Reu
     QQmlInstanceModel::ReleaseFlags flags = {};
     if (model && item->item) {
         flags = model->release(item->item, reusableFlag);
-        if (!flags && !isClearing) {
+        if (!flags) {
             // item was not destroyed, and we no longer reference it.
             if (item->item->parentItem() == contentItem) {
                 // Only cull the item if its parent item is still our contentItem.
                 // One case where this can happen is moving an item out of one ObjectModel and into another.
                 QQuickItemPrivate::get(item->item)->setCulled(true);
             }
-            unrequestedItems.insert(item->item, model->indexOf(item->item, q));
+            if (!isClearing)
+                unrequestedItems.insert(item->item, model->indexOf(item->item, q));
         } else if (flags & QQmlInstanceModel::Destroyed) {
             item->item->setParentItem(nullptr);
         } else if (flags & QQmlInstanceModel::Pooled) {
diff --git a/tests/auto/quick/qquicklistview/data/objectModelCulling.qml b/tests/auto/quick/qquicklistview/data/objectModelCulling.qml
new file mode 100644
index 0000000000..c0a70ec485
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/objectModelCulling.qml
@@ -0,0 +1,35 @@
+import QtQuick 2.12
+
+import QtQml.Models 2.12
+
+Item {
+
+    ObjectModel {
+        id: model1
+        objectName: "model1"
+
+        Rectangle {
+           color: "red"
+           objectName: "redRect"
+           height: 30; width: 80;
+        }
+    }
+
+    ObjectModel {
+        id: model2
+        objectName: "model2"
+
+        Rectangle {
+           color: "green"
+           height: 30; width: 80;
+           x:10
+        }
+    }
+
+    ListView {
+        id: listView
+        objectName: "lv"
+
+        anchors.fill: parent 
+    }
+}
diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 4e49344bc0..f63793ca80 100644
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -294,6 +294,7 @@ private slots:
     void reuse_checkThatItemsAreReused();
     void moveObjectModelItemToAnotherObjectModel();
     void changeModelAndDestroyTheOldOne();
+    void objectModelCulling();
 
     void requiredObjectListModel();
 
@@ -9988,6 +9989,30 @@ void tst_QQuickListView::changeModelAndDestroyTheOldOne()  // QTBUG-80203
     // no crash
 }
 
+void tst_QQuickListView::objectModelCulling()
+{
+    QScopedPointer<QQuickView> window(createView());
+    window->setSource(testFileUrl("objectModelCulling.qml"));
+    window->resize(640, 480);
+    window->show();
+    QVERIFY(QTest::qWaitForWindowExposed(window.data()));
+    QObject *root = window->rootObject();
+    QVERIFY(root);
+    auto listView = root->findChild<QQuickListView *>("lv");
+    QVERIFY(listView);
+    auto model1 = root->findChild<QObject *>("model1");
+    QVERIFY(model1);
+    auto model2 = root->findChild<QObject *>("model2");
+    QVERIFY(model2);
+    auto redRect = root->findChild<QQuickItem *>("redRect");
+    QVERIFY(redRect);
+    auto redRectPriv = QQuickItemPrivate::get(redRect);
+    listView->setModel(QVariant::fromValue(model1));
+    QVERIFY(!redRectPriv->culled);
+    listView->setModel(QVariant::fromValue(model2));
+    QTRY_VERIFY(redRectPriv->culled);
+}
+
 class DataObject : public QObject
 {
     Q_OBJECT