Kill box in tree dialog box makes dialog dispose of itself

CHANGES.txt

@@ -1,5 +1,9 @@
 ANTLR v4 Honey Badger
 
+November 4, 2012
+
+* Kill box in tree dialog box makes dialog dispose of itself
+
 October 29, 2012
 
 * Sam fixes nongreedy more.

runtime/Java/src/org/antlr/v4/runtime/tree/gui/TreeViewer.java

@@ -303,6 +303,7 @@ public class TreeViewer extends JComponent {
 		bottomPanel.add(scaleSlider, BorderLayout.CENTER);
 
 		// make viz
+		dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
 		dialog.pack();
 		dialog.setLocationRelativeTo(null);
 		dialog.setVisible(true);