Re: clone breaks replace

[Jonathan Nieder <jrnieder@gmail.com>]

Jeff King wrote:

> I think you are stuck with something manual
> like:
> 
>   # grab "view" from upstream and name it; let's imagine it links 2010
>   # history into 2009
>   git fetch origin refs/replace/$sha1 refs/views/2009/$sha1
> 
>   # now we feel like using them
>   git for-each-ref --shell --format='%(refname)' refs/views/2009 |
>     while read ref; do
>       git update-ref "refs/replace/${ref#refs/views/2009}" "$ref"
>     done
> 
> Which is a little overkill for the simple example you gave, but would
> also handle something as complex as a view like "pretend the foo/
> subtree never existed" or even "pretend the foo/ subtree existed all
> along".
> 
> Not that I'm sure such things are actually sane to do, performance-wise.
> The replace system is fast, but it was designed for a handful of
> objects, not hundreds or thousands.
> 
> Anyway. My point is that we don't have the porcelain to do something
> like managing views or enabling/disabling them in a sane manner.

Maybe something like

	git fetch origin refs/views/2009/*:refs/replace/*

except that that does not provide a nice way to remove to replace
refs when done.

A potential usability enhancement might be to allow additional
replacement hierarchies to be requested on a per command basis, like

	GIT_REPLACE_REFS=refs/remotes/origin/views/2009 gitk --all

along the lines of GIT_NOTES_REF.