Re: [RFC] git gc "--prune=now" semantics considered harmful

[Linus Torvalds <torvalds@linux-foundation.org>]

On Fri, Jun 1, 2018 at 2:04 AM Jeff King <peff@peff.net> wrote:
>
> We'd also accept relative times like "5.minutes.ago" (in fact, the
> default is a relative 2.weeks.ago, though it's long enough that the
> difference between "2 weeks" and "2 weeks plus 5 minutes" may not matter
> much). So we probably ought to just normalize _everything_ without even
> bothering to match "now". It's a noop for non-relative times, but that's
> OK.

Heh. That's what I tried to do at first.

It's surprisingly hard.

You can't normalize it as a date, because we have a few times that
aren't expressible as dates because they are just the maximum value
(ie "all").

And then I tried to just express it just as a standard numerical
value, which we accept on input. But we *only* accept that if it's
more than eight digits.

And regardless, you need to special-case "now", since
parse_expiry_date() special cases it.

Or you'd need to just make another version of parse_expiry_date() entirely.

End result: I only special-cased "now".

> There are still possibilities for a race, even with the grace period.

Agreed. But you *really* have to work at it.

              Linus