This old test consistently fails on two dual screen Linux machines and does pass on a third, single screen host. Dumping the reference image from the test without other changes, one could see that the image is of the corner of desktop: rendering apparently is not finished. Adding a sync and delay makes the reference image correct but the test still fails.

I'm not sure if it is a test bug (I hope so) or a product one. Please try to reproduce.

RULE "closed/com/sun/java/swing/plaf/gtk/6492108/bug6492108.java" Exception java.lang.RuntimeException: Image comparison failed at (...,0) for image ...