2 files changed, 10 insertions, 12 deletions
diff --git a/src/widgets/itemviews/qtreeview.cpp b/src/widgets/itemviews/qtreeview.cpp
index b778ef9a47..69ab0bb958 100644
--- a/src/widgets/itemviews/qtreeview.cpp
+++ b/src/widgets/itemviews/qtreeview.cpp
@@ -1448,7 +1448,8 @@ void QTreeViewPrivate::adjustViewOptionsForIndex(QStyleOptionViewItem *option, c
 void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
 {
     Q_D(const QTreeView);
-    const QVector<QTreeViewItem> viewItems = d->viewItems;
+    // d->viewItems changes when posted layouts are executed in itemDecorationAt, so don't copy
+    const QVector<QTreeViewItem> &viewItems = d->viewItems;
 
     QStyleOptionViewItem option = d->viewOptionsV1();
     const QStyle::State state = option.state;
@@ -3459,6 +3460,7 @@ int QTreeViewPrivate::indentationForItem(int item) const
 
 int QTreeViewPrivate::itemHeight(int item) const
 {
+    Q_ASSERT(item < viewItems.count());
     if (uniformRowHeights)
         return defaultItemHeight;
     if (viewItems.isEmpty())
diff --git a/src/widgets/itemviews/qtreewidget.cpp b/src/widgets/itemviews/qtreewidget.cpp
index b795b79c28..81aed27361 100644
--- a/src/widgets/itemviews/qtreewidget.cpp
+++ b/src/widgets/itemviews/qtreewidget.cpp
@@ -508,22 +508,18 @@ bool QTreeModel::insertColumns(int column, int count, const QModelIndex &parent)
 bool QTreeModel::removeRows(int row, int count, const QModelIndex &parent) {
     if (count < 1 || row < 0 || (row + count) > rowCount(parent))
         return false;
-
-    beginRemoveRows(parent, row, row + count - 1);
-
-    QSignalBlocker blocker(this);
-
-    QTreeWidgetItem *itm = item(parent);
+    QTreeWidgetItem *parentItem = item(parent);
+    // if parentItem is valid, begin/end RemoveRows is handled by takeChild below
+    if (!parentItem)
+        beginRemoveRows(parent, row, row + count - 1);
     for (int i = row + count - 1; i >= row; --i) {
-        QTreeWidgetItem *child = itm ? itm->takeChild(i) : rootItem->children.takeAt(i);
+        QTreeWidgetItem *child = parentItem ? parentItem->takeChild(i) : rootItem->children.takeAt(i);
         Q_ASSERT(child);
         child->view = nullptr;
         delete child;
-        child = nullptr;
     }
-    blocker.unblock();
-
-    endRemoveRows();
+    if (!parentItem)
+        endRemoveRows();
     return true;
 }