Clarification of PERL_STASH_POST_DATA

[Paul J. Lucas]

        OK, so the documentation for PERL_STASH_POST_DATA reads:

                There is an experimental option for Makefile.PL
                called PERL_STASH_POST_DATA. If you turn it on,
                you can get at it again with $r->subprocess_env("POST_DATA").
                This is not on by default because it adds
                overhead.

        So I rebuilt Apache and mod_perl with PERL_STASH_POST_DATA=1
        on the perl Makefile.PL line; however:

        1. What *is* $r->subprocess_env("POST_DATA") ?  Just the entire
           posted data squished up into a single scalar?  What about
           file uploads?

        2. The $r->subprocess_env("POST_DATA") doesn't even seem to
           work.  I "warn" it to the log file and I get nothing there.

        The general problem is preserving POSTed data, including file
        uploads, for all handlers.

        - Paul