6604109: javax.print.PrintServiceLookup.lookupPrintServices fails SOMETIMES for Cups

Reviewed-by: bae, prr

src/solaris/classes/sun/print/UnixPrintServiceLookup.java

@@ -189,7 +189,7 @@ public class UnixPrintServiceLookup extends PrintServiceLookup
         if (printServices == null) {
             return new PrintService[0];
         } else {
-            return printServices;
+            return (PrintService[])printServices.clone();
         }
     }