Process the drop event in the same process, block processing in the local event, close and destroy the window that initiated the event, qt crashed

In my application, I open two windows A and B. Both windows have a QListView control. Drag and drop the elements of QListView in window A to QListView in window B. In the dropevent event handler of QListView in window B.  Create a local event loop QEventLoop to process some logic, but this logic takes a long time to process. When the event loop has not ended, close window A and destroy window A. After the event loop ends, qt crashes. There is a demo written by me in the attachment.