The fix for 6806217 introduced the following failure reported in SDN comments.

The testcase:

public class Failure {
  public static void main(String[] args) {
    java.awt.KeyboardFocusManager.getCurrentKeyboardFocusManager();
  }
}

The problem:

java -showversion -Djava.awt.headless=true Failure
java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b55)
Java HotSpot(TM) 64-Bit Server VM (build 15.0-b05, mixed mode)

Exception in thread "main" java.awt.HeadlessException
at sun.awt.HeadlessToolkit.createKeyboardFocusManagerPeer(HeadlessToolkit.java:184)
at java.awt.KeyboardFocusManager.initPeer(KeyboardFocusManager.java:454)
at java.awt.KeyboardFocusManager.<init>(KeyboardFocusManager.java:448)
at java.awt.DefaultKeyboardFocusManager.<init>(DefaultKeyboardFocusManager.java:64)
at java.awt.KeyboardFocusManager.getCurrentKeyboardFocusManager(KeyboardFocusManager.java:218)
at java.awt.KeyboardFocusManager.getCurrentKeyboardFocusManager(KeyboardFocusManager.java:209)
at Failure.main(Failure.java:3)