Fix QTreeModel calling beginRemoveRows twice

For items that are children of other items, removeRows calls
beginRemoveRows directly and then once again inside takeChild()
The signal blocker that dates back to the monolitic import from Nokia
prevents the model from emitting extra signals
but the persistent indexes are corrupted nonetheless.

Fixes: QTBUG-90030
Pick-to: 6.1 6.0 5.15
Change-Id: I5bc4b2598bf13247683b113faeec22471f1f04a4
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 7 insertions, 11 deletions

diff --git a/src/widgets/itemviews/qtreewidget.cpp b/src/widgets/itemviews/qtreewidget.cpp
index 12b39f3541..e1f7da6fcd 100644
--- a/src/widgets/itemviews/qtreewidget.cpp
+++ b/src/widgets/itemviews/qtreewidget.cpp
@@ -506,22 +506,18 @@ 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;
 }