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

*** 182,191 ****
--- 182,193 ----
       *
       * @see #createItemListener
       */
      protected ItemListener             itemListener;
  
+     private MouseWheelListener         scrollerMouseWheelListener;
+ 
      /**
       * This protected field is implementation specific. Do not access directly
       * or override.
       */
      protected Timer                    autoscrollTimer;
*** 309,318 ****
--- 311,321 ----
              comboBox.removeItemListener( itemListener );
          }
          uninstallComboBoxModelListeners(comboBox.getModel());
          uninstallKeyboardActions();
          uninstallListListeners();
+         uninstallScrollerListeners();
          // We do this, otherwise the listener the ui installs on
          // the model (the combobox model in this case) will keep a
          // reference to the list, causing the list (and us) to never get gced.
          list.setModel(EmptyListModel);
      }
*** 606,615 ****
--- 609,619 ----
       */
      protected void configureScroller() {
          scroller.setFocusable( false );
          scroller.getVerticalScrollBar().setFocusable( false );
          scroller.setBorder( null );
+         installScrollerListeners();
      }
  
      /**
       * Configures the popup portion of the combo box. This method is called
       * when the UI class is created.
*** 622,631 ****
--- 626,649 ----
          add( scroller );
          setDoubleBuffered( true );
          setFocusable( false );
      }
  
+     private void installScrollerListeners() {
+         scrollerMouseWheelListener = getHandler();
+         if (scrollerMouseWheelListener != null) {
+             scroller.addMouseWheelListener(scrollerMouseWheelListener);
+         }
+     }
+ 
+     private void uninstallScrollerListeners() {
+         if (scrollerMouseWheelListener != null) {
+             scroller.removeMouseWheelListener(scrollerMouseWheelListener);
+             scrollerMouseWheelListener = null;
+         }
+     }
+ 
      /**
       * This method adds the necessary listeners to the JComboBox.
       */
      protected void installComboBoxListeners() {
          if ((propertyChangeListener = createPropertyChangeListener()) != null) {
*** 833,844 ****
          }
      }
  
  
      private class Handler implements ItemListener, MouseListener,
!                           MouseMotionListener, PropertyChangeListener,
!                           Serializable {
          //
          // MouseListener
          // NOTE: this is added to both the JList and JComboBox
          //
          public void mouseClicked(MouseEvent e) {
--- 851,862 ----
          }
      }
  
  
      private class Handler implements ItemListener, MouseListener,
!                           MouseMotionListener, MouseWheelListener,
!                           PropertyChangeListener, Serializable {
          //
          // MouseListener
          // NOTE: this is added to both the JList and JComboBox
          //
          public void mouseClicked(MouseEvent e) {
*** 1022,1031 ****
--- 1040,1056 ----
                  @SuppressWarnings("unchecked")
                  JComboBox<Object> comboBox = (JComboBox)e.getSource();
                  setListSelection(comboBox.getSelectedIndex());
              }
          }
+ 
+         //
+         // MouseWheelListener
+         //
+         public void mouseWheelMoved(MouseWheelEvent e) {
+             e.consume();
+         }
      }
  
      //
      // end Event Listeners
      //=================================================================