src/java.desktop/share/classes/javax/swing/plaf/basic/BasicTreeUI.java

@@ -29,10 +29,11 @@
 import javax.swing.event.*;
 import java.awt.*;
 import java.awt.event.*;
 import java.awt.datatransfer.*;
 import java.beans.*;
+import static java.lang.Boolean.TRUE;
 import java.util.Enumeration;
 import java.util.Hashtable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;

@@ -4002,10 +4003,17 @@
 
                 // Preferably checkForClickInExpandControl could take
                 // the Event to do this it self!
                 if(SwingUtilities.isLeftMouseButton(e)) {
                     checkForClickInExpandControl(pressedPath, e.getX(), e.getY());
+                    
+                    if(tree.getClientProperty("Tree.enableDoubleClickOnExpandControl") == TRUE)
+                        // without this return statement, when double click on 
+                        // the expand control, only the first click is processed. 
+                        // used by WindowsNavigationTree
+                        if (isLocationInExpandControl(pressedPath, e.getX(), e.getY())) 
+                            return;
                 }
 
                 int x = e.getX();
 
                 // Perhaps they clicked the cell itself. If so,