FULL PRODUCT VERSION :
java version "1.8.0_40-ea"
Java(TM) SE Runtime Environment (build 1.8.0_40-ea-b06)
Java HotSpot(TM) Client VM (build 25.40-b10, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
Due to a missing AppContext in headless mode, the creation of various Swing components fails, where previously it succeeded

REGRESSION. Last worked in version 8u20

ADDITIONAL REGRESSION INFORMATION:
java version "1.8.0_40-ea"
Java(TM) SE Runtime Environment (build 1.8.0_40-ea-b06)
Java HotSpot(TM) Client VM (build 25.40-b10, mixed mode, sharing)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the attached program in headless mode (-Djava.awt.headless=true)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Program should execute without exceptions
ACTUAL -
An exception is thrown

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main" java.lang.NullPointerException
        at javax.swing.RepaintManager.currentManager(RepaintManager.java:262)
        at javax.swing.JComponent.repaint(JComponent.java:4799)
        at java.awt.Component.repaint(Component.java:3303)
        at javax.swing.AbstractButton.setModel(AbstractButton.java:1784)
        at javax.swing.JButton.<init>(JButton.java:134)
        at javax.swing.JButton.<init>(JButton.java:91)
        at bug.Bug.main(Bug.java:5)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.JButton;

public class Bug {
    public static void main(String... argv) throws Exception {
        new JButton();
    }
}
---------- END SOURCE ----------