QFile (fileengine) and QFileSystemWatcher don't play nicely together (Linux inotify)

Using QFileSystemWatcher on a directory is supposed to notify when changes to files happen in that directory. If a file is 'touched' this is the case but if a file is written to using QFile then this does not happen.

I have attached small sample programs that demonstrate the problem.

If QFileSystemWatcher monitors the file it gets the notifications as expected. If it monitors the directory then 'touch' triggers a notification but using QFile to write to the files does not trigger a notification.