Index: awt/src/main/java/common/java/awt/KeyboardFocusManager.java =================================================================== --- awt/src/main/java/common/java/awt/KeyboardFocusManager.java (revision 485572) +++ awt/src/main/java/common/java/awt/KeyboardFocusManager.java (working copy) @@ -483,9 +483,15 @@ static void checkKeyStrokes(int[] traversalIDs, Map> traversalKeys, Integer kId, Set keystrokes) { - if (keystrokes == null || keystrokes.isEmpty()) { + if (keystrokes == null) { + throw new IllegalArgumentException(Messages.getString( + "awt.01", "keystrokes")); //$NON-NLS-1$ //$NON-NLS-2$ + } + + if (keystrokes.isEmpty()) { return; } + for (AWTKeyStroke key : keystrokes) { if (key == null) { // awt.79=cannot set null focus traversal key