Index: src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java =================================================================== --- src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java (revision 490282) +++ src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java (working copy) @@ -524,6 +524,10 @@ } protected void installDefaults(final JFileChooser fc) { + if (fc == null) { + throw new NullPointerException(); + } + helpButtonMnemonic = UIManager.getInt("FileChooser.helpButtonMnemonic"); directoryOpenButtonMnemonic = UIManager.getInt("FileChooser.directoryOpenButtonMnemonic");