<Swing Dev> [12] Review Request: 8198339 Test javax/swing/border/Test6981576.java is unstable

[Sergey Bylokhov]

Hello.
Please review the fix for jdk 12.

Bug: https://bugs.openjdk.java.net/browse/JDK-8198339
Webrev: http://cr.openjdk.java.net/~serb/8198339/webrev.00

The reason of instability was an intermittent HeadlessException in the headless mode.
But in most cases the test passed, because the test code was not executed on EDT.
The root issues was the usage of sequence of invokeLater().

After the fix the test will run the test code sequentially for each LookAndFeel in a loop
and will not use System.exit(). The test also marked as "@key headful" because now it will always
throw HeadlessException.

I also confirm that the updated test still can be used for verification of "@bug 6981576".

-- 
Best regards, Sergey.