The recently (5.10) added QAbstractItemView::isPersistentEditorOpen() is not checking the persistent editor list and it is returning true even if the index has a regular (non persistent) editor.

I'm attaching a simple test case but it should be obvious by looking at the source code:

(from http://code.qt.io/cgit/qt/qtbase.git/tree/src/widgets/itemviews/qabstractitemview.cpp)

bool QAbstractItemView::isPersistentEditorOpen(const QModelIndex &index) const
{
     Q_D(const QAbstractItemView);
     return d->editorForIndex(index).widget;
}

I'd expect the method to do something similar to this instead:

bool QAbstractItemView::isPersistentEditorOpen(const QModelIndex &index) const
{
    Q_D(const QAbstractItemView);
    return d->persistent.contains(d->editorForIndex(index).widget);
}

PS: the issue appears to affect Qt 6 as well.