--- a/jdk/src/share/classes/java/lang/ProcessBuilder.java	Tue Dec 22 17:56:58 2009 +0300
+++ b/jdk/src/share/classes/java/lang/ProcessBuilder.java	Tue Jan 12 12:13:48 2010 +0000
@@ -994,6 +994,8 @@
         // Must convert to array first -- a malicious user-supplied
         // list might try to circumvent the security check.
         String[] cmdarray = command.toArray(new String[command.size()]);
+        cmdarray = cmdarray.clone();
+
         for (String arg : cmdarray)
             if (arg == null)
                 throw new NullPointerException();