Index: src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java =================================================================== --- src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java (revision 507874) +++ src/main/java/common/javax/swing/plaf/basic/BasicFileChooserUI.java (working copy) @@ -684,6 +684,10 @@ } public int getApproveButtonMnemonic(final JFileChooser fc) { + if (fc == null) { + throw new NullPointerException(); + } + return approveButtonMnemonic; }