fixed #252.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@1932 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Functions.java

@@ -309,6 +309,7 @@ public class Functions {
     }
 
     public static boolean isMultiline(String s) {
+        if(s==null)     return false;
         return s.indexOf('\r')>=0 || s.indexOf('\n')>=0;
     }
 }