Re: Private branch grafts

[David Reitter]

Eric,
Thanks for your work.  Is there a version of the converted repository that we 
can inspect?

Thanks,
David

On Mar 9, 2014, at 5:32 PM, Eric S. Raymond <address@hidden> wrote:

> I have built and tested some machinery to solve the Aquamacs
> problem. I am describing it on the Emacs list because other
> owners of private branches will need to know how it works.
> 
> The new feature involved here is "callouts". They solve a problemm
> with partial repository writes, in which commits contain mark
> references for which the corresponding parent commits are not in the
> selection set written out.
> 
> Previously, the write code would simply have dumped unaltered mark
> values, some of which would become meaningless outside the original repo
> context.  What reposurgeon now does in that case is replace any
> unresolved marks with callouts (which are just action stamps
> identifying a date and committer).
> 
> An import stream containing callouts cannot be loaded by
> git-fast-import.  What can happen, though is this: when a stream with
> callouts is grafted to another repo, the code tries to resolve all the
> callout links in the context of that repo. It looks for a committer
> and committer-date match for each callout and, in effect, replaces
> it with the corresponding parent mark.
> 
> The match attempt (and the graft) will fail if there is no matching 
> committer/committer-date pair in the repo, or more than one. In that
> case (which I expect to be rare and might not occur at all) the 
> offending callouts will need to be removed or hand-patched with ordinals,
> 
> What I will is locate each branch you want to preserve, write it
> out as a partial dump with callouts, and graft iyit onto the main
> repository in this way. 
> 
> -- 
>               <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>
> 
> The conclusion is thus inescapable that the history, concept, and 
> wording of the second amendment to the Constitution of the United 
> States, as well as its interpretation by every major commentator and 
> court in the first half-century after its ratification, indicates 
> that what is protected is an individual right of a private citizen 
> to own and carry firearms in a peaceful manner.
>         -- Report of the Subcommittee On The Constitution of the Committee On 
>            The Judiciary, United States Senate, 97th Congress, second session 
>            (February, 1982), SuDoc# Y4.J 89/2: Ar 5/5

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