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Re: Git commit generation numbers

From
Shawn Pearce <spearce@spearce.org>
Date
Jul 15, 2011, 16:18 UTC
Message-ID
<CAJo=hJtuxNLhSjn_sDJxG7xu5k2wbJ_QLf_n+Z1E=o2AndAuJQ@mail.gmail.com>
In-Reply-To
<CA+55aFzS3KDNvKt-dXvYpuAQwFwD3+GCj8y8bRQCycPvrynT8Q@mail.gmail.com>

On Fri, Jul 15, 2011 at 09:10, Linus Torvalds <torvalds@linux-foundation.org> wrote:

> Right now, we do *have* a "generation number". It's just that it's
> very easy to corrupt even by mistake. It's called "committer date". We
> could improve on it.
...
> If I had realized how small the patch was to add generation counters,
> and that it wouldn't have broken backwards compatibility (ie fsck
> doesn't start complaining). I would have done it originally, instead
> of all the crazy hacks we did for commit date verification.

What about going forward making the requirement that a new commit must have a committer date whose date is >= the maximum date of its parents?

We could also add a check during fast-forward merges to refuse to perform the merge if the incoming commit has a committer date too far forward in the future (e.g. more than 5 minutes). If you pull from a moron whose system clock is set such that the committer date isn't a proxy for generation number, Git would just refuse the merge, and you could ask them to fix their objects.

-- 
Shawn.
Previous: Linus TorvaldsNext: Linus Torvalds
Message 19 of 47 in “Git commit generation numbers”
  1. Linus TorvaldsJul 14, 2011
  2. Jeff KingJul 14, 2011
  3. Linus TorvaldsJul 14, 2011
  4. Linus TorvaldsJul 14, 2011
  5. Jeff KingJul 14, 2011
  6. Ted Ts'oJul 14, 2011
  7. Linus TorvaldsJul 14, 2011
  8. Jeff KingJul 14, 2011
  9. Ted Ts'oJul 14, 2011
  10. Jeff KingJul 14, 2011
  11. Linus TorvaldsJul 14, 2011
  12. Jeff KingJul 14, 2011
  13. Linus TorvaldsJul 14, 2011
  14. Jeff KingJul 14, 2011
  15. Linus TorvaldsJul 15, 2011
  16. Geert BoschJul 15, 2011
  17. Jeff KingJul 15, 2011
  18. Linus TorvaldsJul 15, 2011
  19. Shawn PearceJul 15, 2011
  20. Linus TorvaldsJul 15, 2011
  21. Ted Ts'oJul 15, 2011
  22. Linus TorvaldsJul 15, 2011
  23. Christian CouderJul 16, 2011
  24. Jeff KingJul 18, 2011
  25. Christian CouderJul 19, 2011
  26. Jeff KingJul 19, 2011
  27. Christian CouderJul 21, 2011
  28. Tony LuckJul 15, 2011
  29. Linus TorvaldsJul 15, 2011
  30. Jeff KingJul 15, 2011
  31. Jeff KingJul 15, 2011
  32. Linus TorvaldsJul 15, 2011
  33. Jeff KingJul 15, 2011
  34. Linus TorvaldsJul 15, 2011
  35. Linus TorvaldsJul 15, 2011
  36. Linus TorvaldsJul 15, 2011
  37. Jeff KingJul 16, 2011
  38. Jeff KingJul 16, 2011
  39. Jakub NarebskiJul 15, 2011
  40. Long, MartinJul 15, 2011
  41. Long, MartinJul 15, 2011
  42. Drew NorthupJul 15, 2011
  43. Linus TorvaldsJul 14, 2011
  44. Jakub NarebskiJul 14, 2011
  45. Junio C HamanoJul 14, 2011
  46. Jeff KingJul 14, 2011
  47. Junio C HamanoJul 14, 2011

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