[mythtv-users] Shows did not record?

[f-myth-users at media.mit.edu]

    > Date: Mon, 10 Mar 2008 17:55:15 -0400
    > From: "Michael T. Dean" <mtdean at thirdcontact.com>

    > Most likely there was when it aired, and your listings have since changed.

I hang onto the last couple of weeks of raw XML downloaded from SD,
exactly so I can retrospectively investigate weirdnesses.  It's turned
out to be absolutely invaluable a few times.

All I did was to take the script I was already running that called
tv_grab_na_dd and have it preserve whatever it downloaded (and the
"massaged" version before it was inhaled by mythfilldatabase) in a
directory that named them by the date of download and deleted any that
were too old (and compressed them, since they can be large but very
compressible).

I originally did this because I was running a hacked downloader that
could take SD data and stuff it into my 0.18.1 build, so I didn't have
to jump a couple releases on a schedule I didn't control.  Part of the
rationale was debugging this hack, and part was because I had
occasionally (pre-SD, I believe) received an update in which one of
the days had -no- data and it wiped out that day's listing in Myth
(yes, I know that more recent Myths have some sanity checking in that
regard).  But it's also allowed me to figure out whether it was pilot
error or listing issues when things didn't record or had strange info,
etc, especially since Mythweb doesn't display farther back than a day
(even if I'm keeping 7 days in the DB) and sometimes I needed to check
more than 7 days back in the listings...

The question:  under 0.21, assuming I'm using the default mechanism
for doing SD downloads, is there some easy way of preserving the
pre-mfdb grabbed data externally?  I'm basically looking for a hook to
let me get at the data (so I can do the preservation) without having
to actually go to a source-based install and hack up the source.  (Or
should I just stay with using tv_grab_na_dd as I've been doing and
just not change anything, except to -not- massage the data since 0.21
understands SD's schema natively?)