Mail archive indexes are broken, URLs too

When Marc fixed the message-boundary pattern and regenerated the
archives, many of the existing messages changed URLs because they
got assigned slightly different numbers. I notice that the archive
search engine hasn't yet tracked this change --- if you do a search
and click on a link to a message, you'll arrive at a message close
to the one you want but probably not quite it.

Regenerating the archive indexes is presumably not hard, but there's
a bigger problem: for awhile now many of us have been in the habit
of citing old discussions by archive URLs. All those links are now
broken too, and I can't think of any easy way to fix them. And then
there's Google etc.

I wonder if it'd be better to revert the regeneration of the archives,
and only apply the new message-boundary pattern to future messages.

regards, tom lane