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[PATCH] Re: push: point to 'git pull' and 'git push --force' in case of non-fast forward

From
NSNicolas Sebrecht <nicolas.s.dev@gmx.fr>
Date
Aug 6, 2009, 21:16 UTC
Message-ID
<20090806211610.GB12924@vidovic>
In-Reply-To
<7v7hxgk8c9.fsf@alter.siamese.dyndns.org>
The 06/08/09, Junio C Hamano wrote:
Show 23 quoted lines
>  Documentation/git-push.txt |   75 ++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 75 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
> index 2653388..c1ae82d 100644
> --- a/Documentation/git-push.txt
> +++ b/Documentation/git-push.txt
> @@ -195,6 +195,81 @@ reason::
>  	refs, no explanation is needed. For a failed ref, the reason for
>  	failure is described.
>  
> +Note about fast-forwards
> +------------------------
> +
> +When an update changes a branch (or more in general, a ref) that used to
> +point at commit A to point at another commit B, it is called a
> +fast-forward update if and only if B is a descendant of A.
> +
> +In a fast-forward update from A to B, the set of commits that the original
> +commit A built on top of is a subset of the commits the new commit B
> +builds on top of.  Hence, it does not lose any history.
> +
> +In contrast, a non-fast-forward update will lose history.

I believe that this sentence a bit too much scaring for the beginner. There are two kinds of update (push and pull). We loose history only when pushing. I know this applies to Documentation/git-push.txt but out of this context (and because we talk about pull near from here), I think it would be clearer to say something like:

	In contrast, a non-fast-forward push will loose history.
Show 12 quoted lines
>                                                             For example,
> +suppose you and somebody else started at the same commit X, and you built
> +a history leading to commit B while the other person built a history
> +leading to commit A.  The history looks like this:
> +
> +----------------
> +
> +      B
> +     /
> + ---X---A
> +
> +----------------
<...>
Show 12 quoted lines
> +Alternatively, you can rebase your change between X and B on top of A,
> +with "git pull --rebase", and push the result back.  The rebase will
> +create a new commit D that builds the change between X and B on top of
> +A.
> +
> +----------------
> +
> +      B   D
> +     /   /
> + ---X---A
> +
> +----------------
Wouldn't "git pull --rebase" loose B? Shouldn't we have this
  ----------------
  
            D
           /
   ---X---A
  
  ----------------
instead?
-- 
Nicolas Sebrecht
Previous: Junio C HamanoNext: Junio C Hamano
Message 6 of 48 in “push: point to 'git pull' and 'git push --force' in case of non-fast forward”
  1. push: point to 'git pull' and 'git push --force' in case of non-fast forwardMatthieu Moy, Aug 6, 2009
  2. Michael J GruberAug 6, 2009
  3. Matthieu MoyAug 7, 2009
  4. Michael J GruberAug 7, 2009
  5. Junio C HamanoAug 6, 2009
  6. Re: push: point to 'git pull' and 'git push --force' in case of non-fast forwardNicolas Sebrecht, Aug 6, 2009
  7. Junio C HamanoAug 6, 2009
  8. Matthieu MoyAug 7, 2009
  9. Junio C HamanoAug 7, 2009
  10. Matthieu MoyAug 7, 2009
  11. push: point to 'git pull' and 'git push --force' in case of non-fast forwardMatthieu Moy, Aug 8, 2009
  12. Teemu LikonenAug 8, 2009
  13. Matthieu MoyAug 8, 2009
  14. Junio C HamanoAug 8, 2009
  15. Re: push: point to 'git pull' and 'git push --force' in case of non-fast forwardNicolas Sebrecht, Aug 8, 2009
  16. Matthieu MoyAug 9, 2009
  17. Junio C HamanoAug 9, 2009
  18. Matthieu MoyAug 10, 2009
  19. Junio C HamanoAug 10, 2009
  20. Matthieu MoyAug 10, 2009
  21. Nanako ShiraishiAug 11, 2009
  22. 0/4 make helpful messages optionalJeff King, Sep 6, 2009
  23. 1/4 push: fix english in non-fast-forward messageJeff King, Sep 6, 2009
  24. 2/4 push: re-flow non-fast-forward messageJeff King, Sep 6, 2009
  25. 3/4 push: make non-fast-forward help message configurableJeff King, Sep 6, 2009
  26. Junio C HamanoSep 6, 2009
  27. Jeff KingSep 6, 2009
  28. Junio C HamanoSep 6, 2009
  29. Jeff KingSep 6, 2009
  30. Junio C HamanoSep 6, 2009
  31. Sverre RabbelierSep 6, 2009
  32. Nanako ShiraishiSep 7, 2009
  33. Johannes SixtSep 7, 2009
  34. Mike HommeySep 7, 2009
  35. Jeff KingSep 7, 2009
  36. Matthieu MoySep 7, 2009
  37. Jeff KingSep 7, 2009
  38. Matthieu MoySep 7, 2009
  39. Uri OkrentSep 8, 2009
  40. Jeff KingSep 9, 2009
  41. 0/2 configurable advice messagesJeff King, Sep 9, 2009
  42. 1/2 push: make non-fast-forward help message configurableJeff King, Sep 9, 2009
  43. Junio C HamanoSep 9, 2009
  44. Jeff KingSep 9, 2009
  45. Junio C HamanoSep 9, 2009
  46. 2/2 status: make "how to stage" messages optionalJeff King, Sep 9, 2009
  47. 4/4 status: make "how to stage" messages optionalJeff King, Sep 6, 2009
  48. Matthieu MoySep 6, 2009

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