Fix some major brokenness.  We were not validating that the autoindex
  subrequest'ed file was valid, and did not check a subrequest at all if
  the user didn't use FancyIndexing.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89899 13f79535-47bb-0310-9956-ffa450edef68