src/macosx/classes/com/apple/laf/AquaComboBoxUI.java

*** 279,288 ****
--- 279,290 ----
          actionMap.put("aquaSelectHome", highlightFirstAction);
          actionMap.put("aquaSelectEnd", highlightLastAction);
          actionMap.put("aquaSelectPageUp", highlightPageUpAction);
          actionMap.put("aquaSelectPageDown", highlightPageDownAction);
  
+         actionMap.put("aquaHidePopup", hideAction);
+ 
          SwingUtilities.replaceUIActionMap(comboBox, actionMap);
      }
  
      abstract class ComboBoxAction extends AbstractAction {
          public void actionPerformed(final ActionEvent e) {
*** 386,395 ****
--- 388,405 ----
              listBox.ensureIndexIsVisible(target);
              listBox.setSelectedIndex(target);
          }
      };
  
+     Action hideAction = new ComboBoxAction() {
+         @Override
+         void performComboBoxAction(final AquaComboBoxUI ui) {
+             comboBox.firePopupMenuCanceled();
+             comboBox.setPopupVisible(false);
+         }
+     };
+ 
      // For <rdar://problem/3759984> Java 1.4.2_5: Serializing Swing components not working
      // Inner classes were using a this reference and then trying to serialize the AquaComboBoxUI
      // We shouldn't do that. But we need to be able to get the popup from other classes, so we need
      // a public accessor.
      public ComboPopup getPopup() {