JAL-3784 null the right overview reference when it is closed

diff --git a/src/jalview/gui/AlignFrame.java b/src/jalview/gui/AlignFrame.java
index 42c0df0..2c079b8 100644 (file)
--- a/src/jalview/gui/AlignFrame.java
+++ b/src/jalview/gui/AlignFrame.java
@@ -3402,6 +3402,7 @@ public class AlignFrame extends GAlignFrame implements DropTargetListener,
             true, true);
     frame.pack();
     frame.setLayer(JLayeredPane.PALETTE_LAYER);
+    final AlignmentPanel thePanel = this.alignPanel; 
     frame.addInternalFrameListener(
             new javax.swing.event.InternalFrameAdapter()
             {
@@ -3410,7 +3411,7 @@ public class AlignFrame extends GAlignFrame implements DropTargetListener,
                       javax.swing.event.InternalFrameEvent evt)
               {
                 overview.dispose();
-                alignPanel.setOverviewPanel(null);
+                thePanel.setOverviewPanel(null);
               }
             });
     if (getKeyListeners().length > 0)