additional navigation bug fixes.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@1688 71c3de6d-444a-0410-be80-ed276b4c234a

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

@@ -138,10 +138,7 @@ public class Functions {
             if(n ==null)
                 return null;
             else {
-                String url = contextPath + '/' + n.getUrl();
-                assert url.endsWith("/");
-                url = url.substring(0,url.length()-1);  // cut off the trailing '/'
-                return url+rest;
+                return basePortion+"/../"+n.getNumber()+rest;
             }
         }
     }