Reported on http://forum.joomla.org/viewtopic.php?f=728&t=903739
How to test:
Test 1:
The image field is now empty again.
Test 2:
The image field displays the original image again
Confirmed ... I tested on existing 3.4.8 that was updated with Weblinks and Jstaging with Weblinks freshly installed
Referenced issue has been closed (PR merged).
I can confirm this and having the same issue myself on 3.4.8 core.