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

@@ -397,10 +397,14 @@
 
     @Override
     public final PrintJob getPrintJob(Frame frame, String doctitle,
                                       JobAttributes jobAttributes,
                                       PageAttributes pageAttributes) {
+        if (frame == null) {
+            throw new NullPointerException("frame must not be null");
+        }
+        
         if (GraphicsEnvironment.isHeadless()) {
             throw new IllegalArgumentException();
         }
 
         PrintJob2D printJob = new PrintJob2D(frame, doctitle, jobAttributes, pageAttributes);