QSortFilterProxyModel call to mapToSource random crash

Please refer to the attached sample, there is a random crash when QFileSystemModel is used with QSortFilterProxyModel. When user selects the folder by clicking on a folder from folder list, and then presses "select" button, maptoSource() is crashing even the index is valid.

Observation: If folder structure is say, C:\Folder\test. click on folder once, don't click on test folder. Just launch the app, click on C:\ and then click folder (try by clicking on empty space on left), and then press "select"

Attaching the stack trace also.