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Re: clone breaks replace

From
Johannes Sixt <j6t@kdbg.org>
Date
Jan 11, 2011, 19:48 UTC
Message-ID
<201101112048.57326.j6t@kdbg.org>
In-Reply-To
<20110111173922.GB1833@sigill.intra.peff.net>
On Dienstag, 11. Januar 2011, Jeff King wrote:
Show 8 quoted lines
> On Tue, Jan 11, 2011 at 10:24:01AM -0500, Phillip Susi wrote:
> > Yes, either a new branch or separate historical repository could be
> > published to pull the original history from, or git would need to pass
> > the --no-replace-objects flag to git-upload-pack on the server, causing
> > it to ignore the replace and send the original history.
>
> AFAIK, git can't pass --no-replace-objects to the server over git:// (or
> smart http). You would need a protocol extension.
Why would you have to? git-upload-pack never looks at replacement objects.
Show 13 quoted lines
> And here's another corner case I thought of:
>
> Suppose you have some server S1 with this history:
>
>   A--B--C--D
>
> and a replace object truncating history to look like:
>
>   B'--C--D
>
> You clone from S1 and have only commits B', C, and D (or maybe even B,
> depending on the implementation). But definitely not A, nor its
> associated tree and blobs.

Why so? Cloning transfers the database using git-upload-pack, git-pack-objects, git-index-pack, and git-unpack-objects. All of them have object replacements disabled. (And AFAICS, there is no possibility to *enable* it.)

Therefore, after cloning you get
 A--B--C--D
and perhaps also the replacement object B'.
Hint: git grep read_replace_refs
-- Hannes
Previous: Jeff KingNext: Jeff King
Message 27 of 34 in “clone breaks replace”
  1. Phillip SusiJan 6, 2011
  2. Jonathan NiederJan 6, 2011
  3. Junio C HamanoJan 6, 2011
  4. Phillip SusiJan 7, 2011
  5. Jonathan NiederJan 7, 2011
  6. Stephen BashJan 7, 2011
  7. Jonathan NiederJan 7, 2011
  8. Phillip SusiJan 7, 2011
  9. Jonathan NiederJan 7, 2011
  10. Phillip SusiJan 7, 2011
  11. Jeff KingJan 7, 2011
  12. Junio C HamanoJan 7, 2011
  13. Jeff KingJan 11, 2011
  14. Junio C HamanoJan 11, 2011
  15. Jeff KingJan 11, 2011
  16. Jonathan NiederJan 11, 2011
  17. Jeff KingJan 11, 2011
  18. Christian CouderJan 11, 2011
  19. Phillip SusiJan 8, 2011
  20. Jeff KingJan 11, 2011
  21. Jonathan NiederJan 11, 2011
  22. Phillip SusiJan 11, 2011
  23. Jonathan NiederJan 11, 2011
  24. Phillip SusiJan 11, 2011
  25. Phillip SusiJan 11, 2011
  26. Jeff KingJan 11, 2011
  27. Johannes SixtJan 11, 2011
  28. Jeff KingJan 11, 2011
  29. Johannes SixtJan 11, 2011
  30. Phillip SusiJan 11, 2011
  31. Jonathan NiederJan 11, 2011
  32. Phillip SusiJan 12, 2011
  33. small downloads and immutable history (Re: clone breaks replace)Jonathan Nieder, Jan 14, 2011
  34. Phillip SusiJan 15, 2011

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