Index: src/main/java/common/javax/swing/plaf/basic/BasicComboBoxUI.java =================================================================== --- src/main/java/common/javax/swing/plaf/basic/BasicComboBoxUI.java (revision 493699) +++ src/main/java/common/javax/swing/plaf/basic/BasicComboBoxUI.java (working copy) @@ -475,6 +475,9 @@ public int getAccessibleChildrenCount(final JComponent c) { + if (comboBox == null) { + throw new NullPointerException("comboBox is null"); + } return 0; }