src/macosx/classes/sun/lwawt/macosx/CClipboard.java

@@ -55,10 +55,22 @@
     protected void clearNativeContext() {
         // Leaving Empty, as WClipboard.clearNativeContext is empty as well.
     }
 
     @Override
+    public synchronized Transferable getContents(Object requestor) {
+        checkPasteboardAndNotify();
+        return super.getContents(requestor);
+    }
+
+    @Override
+    protected synchronized Transferable getContextContents() {
+        checkPasteboardAndNotify();
+        return super.getContextContents();
+    }
+
+    @Override
     protected void setContentsNative(Transferable contents) {
         FlavorTable flavorMap = getDefaultFlavorTable();
         // Don't use delayed Clipboard rendering for the Transferable's data.
         // If we did that, we would call Transferable.getTransferData on
         // the Toolkit thread, which is a security hole.

@@ -114,17 +126,24 @@
     //protected Transferable createLocaleTransferable(long[] formats) throws IOException;
 
     private native void declareTypes(long[] formats, SunClipboard newOwner);
     private native void setData(byte[] data, long format);
 
+    void checkPasteboardAndNotify() {
+        if (checkPasteboardWithoutNotification()) {
+            notifyChanged();
+            lostOwnershipNow(null);
+        }
+    }
+
     /**
      * Invokes native check whether a change count on the general pasteboard is different
      * than when we set it. The different count value means the current owner lost
      * pasteboard ownership and someone else put data on the clipboard.
      * @since 1.7
      */
-    native void checkPasteboard();
+    native boolean checkPasteboardWithoutNotification();
 
     /*** Native Callbacks ***/
     private void notifyLostOwnership() {
         lostOwnershipImpl();
     }