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

*** 735,744 ****
--- 735,753 ----
          CWrapper.NSWindow.setOpaque(getNSWindowPtr(), isOpaque);
          if (!isOpaque) {
              long clearColor = CWrapper.NSColor.clearColor();
              CWrapper.NSWindow.setBackgroundColor(getNSWindowPtr(), clearColor);
          }
+ 
+         //This is a temporary workaround. Looks like after 7124236 will be fixed
+         //the correct place for invalidateShadow() is CGLayer.drawInCGLContext.
+         SwingUtilities.invokeLater(new Runnable() {
+             @Override
+             public void run() {
+                 invalidateShadow();
+             }
+         });
      }
  
      @Override
      public void enterFullScreenMode() {
          isFullScreenMode = true;
*** 803,812 ****
--- 812,825 ----
          }
  
          nativeSetEnabled(getNSWindowPtr(), !blocked);
      }
  
+     public final void invalidateShadow(){
+         nativeRevalidateNSWindowShadow(getNSWindowPtr());
+     }
+ 
      // ----------------------------------------------------------------------
      //                          UTILITY METHODS
      // ----------------------------------------------------------------------
  
      /*