Fix mod_autoindex bug where directories got a size of "0k" instead

of "-".  This was introduced by a bogus cleanup in rev 1.31; -1 was
changed to 0 to avoid storing -1 in a size_t, when the correct fix is
to change the size_t to an off_t.

Submitter's patch modified for correctness.

PR: 3130
Obtained from:
Submitted by:	Martin Plechsmid <plechsmi@karlin.mff.cuni.cz>
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82217 13f79535-47bb-0310-9956-ffa450edef68