Merge remote-tracking branch 'origin/5.12' into 5.13

Change-Id: I59343fe228ca6b823b61577e5a0907e7381899c2

1 files changed, 20 insertions, 8 deletions

diff --git a/src/quick/items/qquickitemview.cpp b/src/quick/items/qquickitemview.cpp
index c20f778a8f..95f1229b92 100644
--- a/src/quick/items/qquickitemview.cpp
+++ b/src/quick/items/qquickitemview.cpp
@@ -1724,8 +1724,14 @@ void QQuickItemViewPrivate::refill()
 void QQuickItemViewPrivate::refill(qreal from, qreal to)
 {
     Q_Q(QQuickItemView);
-    if (!isValid() || !q->isComponentComplete())
+    if (!model || !model->isValid() || !q->isComponentComplete())
         return;
+    if (!model->count()) {
+        updateHeader();
+        updateFooter();
+        updateViewport();
+        return;
+    }
 
     do {
         bufferPause.stop();
@@ -1881,15 +1887,21 @@ void QQuickItemViewPrivate::layout()
 
         prepareVisibleItemTransitions();
 
-        for (QList<FxViewItem*>::Iterator it = releasePendingTransition.begin();
-             it != releasePendingTransition.end(); ) {
-            FxViewItem *item = *it;
-            if (prepareNonVisibleItemTransition(item, viewBounds)) {
-                ++it;
-            } else {
-                releaseItem(item);
+        for (auto it = releasePendingTransition.begin(); it != releasePendingTransition.end(); ) {
+            auto old_count = releasePendingTransition.count();
+            auto success = prepareNonVisibleItemTransition(*it, viewBounds);
+            // prepareNonVisibleItemTransition() may invalidate iterators while in fast flicking
+            // invisible animating items are kicked in or out the viewPort
+            // use old_count to test if the abrupt erasure occurs
+            if (old_count > releasePendingTransition.count()) {
+                continue;
+            }
+            if (!success) {
+                releaseItem(*it);
                 it = releasePendingTransition.erase(it);
+                continue;
             }
+            ++it;
         }
 
         for (int i=0; i<visibleItems.count(); i++)