 being checked
  to be within the bounds of the file area specified by the arguments. If
  no disk_trailer was found then null is returned, and likewise we only
  accept a disk_trailer with a seekvalue that points to a disk_entry and
  both parts have valid PK-magic parts. Beyond some sanity check we try to
  catch a common brokeness with zip archives that still allows us to find
  the start of the zip central directory.
</p>
</td></tr><tr><td valign="top"><p>
  The <code>zzip_disk_findnext</code> function 