NPE when debug level logging enabled.

When log level is set to debug level for "org.hippoecm.frontend", the following NPE occurred:

09.05.2011 15:32:50 ERROR [org.apache.wicket.RequestCycle.detach():1126] there was an error cleaning up target [BookmarkablePageRequestTarget@773648156 pageClass=org.hippoecm.frontend.PageExpiredErrorPage].
java.lang.NullPointerException
at org.hippoecm.frontend.ResourceRewriteFilter$FilteredRequest.getPathTranslated(ResourceRewriteFilter.java:63)
at org.apache.wicket.protocol.http.servlet.ServletWebRequest.toString(ServletWebRequest.java:556)
at java.lang.String.valueOf(String.java:2826)
at java.lang.StringBuilder.append(StringBuilder.java:115)
at org.apache.wicket.Page.onDetach(Page.java:1568)
at org.hippoecm.frontend.Home.onDetach(Home.java:224)
at org.apache.wicket.Component.detach(Component.java:1225)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.detach(BookmarkablePageRequestTarget.java:142)
at org.apache.wicket.RequestCycle.detach(RequestCycle.java:1122)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1462)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:486)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:319)
...

#61: String stripped = stripPrefix(superPath);
#62: if (log.isDebugEnabled()) {
#63: if (!stripped.equals(superPath)) {

stipped variable can be null, so you should check null in #63.