Please run the attached test; push "show dialog", "show frame" and "close" on Dialog. Window and Frame become minimized (on Linux - they don't; checked with Ubuntu 12.04).
To exit please push "close all" button.

If comment out the line:
  final Dialog dialog = new Dialog((Dialog) null);
and uncomment
  final Dialog dialog = new Dialog(frame);
then the windows wouldn't minimize.

I understand that the test case looks really weird but it arose when refactoring modality tests in compliance with JDK-8047367

Tested on Windows 7.
JDK version: 9-b14