QWebEngineView will crash when cursor leaves the QWebEngineView display area

Sub-class QWebEngineView to enable dragging. (See attached file qwebeng,tar)
Run the attached program.
Select the text with the mouse.
Press mouse left button to drag the text.
Drag it outside of the window.
Check the output of the program (console or QtCreator app window)
The thread within QWebEngine has crashed. (See callstack2.txt)
It crashes within WebViewImpl::dragTargetDragLeave because m_currentDragData is null.
It is null because WebViewImpl::dragTargetDragEnter, which creates m_currentDragData was never called.