NPE in PageContext.getErrorData()

javax.servlet.jsp.PageContext#getErrorData() throws a NullPointerException if a JSP page is accessed but no javax.servlet.error.status_code attribute is available. This can occur when, say, a login page is sometimes triggered by an error (eg 401 unauthorized) and sometimes accessed directly (when there is no error).

The bug has been fixed in Tomcat for 5 years.
[https://bz.apache.org/bugzilla/show_bug.cgi?id=49196](https://bz.apache.org/bugzilla/show_bug.cgi?id=49196)
[https://bz.apache.org/bugzilla/attachment.cgi?id=25534&action=diff](https://bz.apache.org/bugzilla/attachment.cgi?id=25534&action=diff)
It would be nice to fix it here as well as I suspect this is the source that Jetty uses.
#### Affected Versions
[current]