src/java.desktop/macosx/classes/sun/lwawt/LWWindowPeer.java

*** 1294,1303 ****
--- 1294,1309 ----
              // ungrab a simple window if its owner looses activation.
              grabbingWindow.ungrab();
          }
  
          KeyboardFocusManagerPeer kfmPeer = LWKeyboardFocusManagerPeer.getInstance();
+ 
+         if (!becomesFocused && kfmPeer.getCurrentFocusedWindow() != getTarget()) {
+             // late window focus lost event - ingoring
+             return;
+         }
+ 
          kfmPeer.setCurrentFocusedWindow(becomesFocused ? getTarget() : null);
  
          int eventID = becomesFocused ? WindowEvent.WINDOW_GAINED_FOCUS : WindowEvent.WINDOW_LOST_FOCUS;
          WindowEvent windowEvent = new TimedWindowEvent(getTarget(), eventID, opposite, System.currentTimeMillis());