While working with another fullscreen issue (6500686), I added a couple of lines to the setFullScreenWindow as suggested in the evaluation for 6500686. The lines included the storing of the new window 'resizable' state and restoring this state for the old window, if any. No synchronization was added.

However, after I compiled the code and run the test, a deadlock was found - see attached file. The stack trace doesn't contain my added lines, it happens after all the resizability changes, in super.setFullScreenWindow(). Thus, I suspect the same deadlock may be reproduced if resizing some window while another window is going fullscreen.