bucket length parameter is apr_size_t, which isn't always signed,

so be careful when comparing with the special value -1

Submitted by:	Allan Edwards <ake@us.ibm.com>
Reviewed by:	Jeff Trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97569 13f79535-47bb-0310-9956-ffa450edef68