QQuickRepeater: Fix interaction with Package

Amends 3b806a18cc665b5ae0e12d45fe170bfc3f00352a.
Eric's change tried to tackle the issue by making the PartModel more
well-behaved. However, this still left some issues, as exhibited by the
linked bug. This time, we simply make the repeater more robust, and
setup d->deletables if it's not done yet.

Pick-to: 5.15
Fixes: QTBUG-71964
Change-Id: I58c80c84f73fddaea5d6030f92ffff219ecf2b71
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
(cherry picked from commit 28a31148ca02dbb530fd92dfafbcf71c64af4b70)

3 files changed, 52 insertions, 0 deletions

diff --git a/src/quick/items/qquickrepeater.cpp b/src/quick/items/qquickrepeater.cpp
index 20603720c5..6dc735d20b 100644
--- a/src/quick/items/qquickrepeater.cpp
+++ b/src/quick/items/qquickrepeater.cpp
@@ -417,6 +417,12 @@ void QQuickRepeater::createdItem(int index, QObject *)
 void QQuickRepeater::initItem(int index, QObject *object)
 {
     Q_D(QQuickRepeater);
+    if (index >= d->deletables.size()) {
+        // this can happen when Package is used
+        // calling regenerate does too much work, all we need is to call resize
+        // so that d->deletables[index] = item below works
+        d->deletables.resize(d->model->count() + 1);
+    }
     QQuickItem *item = qmlobject_cast<QQuickItem*>(object);
 
     if (!d->deletables.at(index)) {
diff --git a/tests/auto/quick/qquickrepeater/data/package2.qml b/tests/auto/quick/qquickrepeater/data/package2.qml
new file mode 100644
index 0000000000..0ceb34b362
--- /dev/null
+++ b/tests/auto/quick/qquickrepeater/data/package2.qml
@@ -0,0 +1,36 @@
+import QtQuick 2.0
+import QtQml.Models 2.2
+import QtQuick.Window 2.0
+
+Item {
+    width: 300
+    height: 300
+    visible: true    
+    DelegateModel {
+        id: mdl
+
+        model: 1
+        delegate: Package {
+            Item {
+                id: first
+                Package.name: "first"
+            }
+            Item{
+                id: second
+                Package.name: "second"
+            }
+        }
+    }
+
+    Repeater {
+        model: mdl.parts.first
+    }
+    Repeater {
+        model: mdl.parts.second
+    }
+
+    function setup():  bool {
+        mdl.model = 2
+        return true;
+    }
+}
diff --git a/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp b/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
index 33b8742170..35883339d7 100644
--- a/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
+++ b/tests/auto/quick/qquickrepeater/tst_qquickrepeater.cpp
@@ -1056,6 +1056,16 @@ void tst_QQuickRepeater::package()
         QCOMPARE(repeater2->count(), 1);
         QCOMPARE(repeater2->itemAt(0)->objectName(), "secondItem");
     }
+
+    {
+        QQmlComponent component(&engine, testFileUrl("package2.qml"));
+        QScopedPointer<QObject> root(component.create());
+        QVERIFY(root != nullptr);
+        bool returnedValue = false;
+        // calling setup should not crash
+        QMetaObject::invokeMethod(root.get(), "setup", Q_RETURN_ARG(bool, returnedValue));
+        QVERIFY(returnedValue);
+    }
 }
 
 void tst_QQuickRepeater::ownership()