Hi All,
Please review a fix for an issue whereby
javax.swing.plaf.basic.BasicComboBoxUI.isPopupVisible returns
NullPointerException when called from a overridden method of getModel().
If a class extends JComboBox and overrides getModel() and then it calls
isPopupVisible() from the overriden getModel() it gets
NullPointerException the first time.
Because the popup variable in javax.swing.plaf.basic.BasicComboBoxUI is
not set yet.
Proposed fix is to guard against it by doing a null check for the
methods which can be overriden from JComboBox to access "popup" variable.
Bug: https://bugs.openjdk.java.net/browse/JDK-6709913
webrev: http://cr.openjdk.java.net/~psadhukhan/6709913/webrev.0/
Regards
Prasanta
