Re: [PATCH 2/2] introduce "preciousObjects" repository extension

[Jeff King <peff@peff.net>]

On Tue, Jun 23, 2015 at 06:54:11AM -0400, Jeff King wrote:

> diff --git a/builtin/prune.c b/builtin/prune.c
> index 0c73246..fc0c8e8 100644
> --- a/builtin/prune.c
> +++ b/builtin/prune.c
> @@ -218,6 +218,9 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
>  		return 0;
>  	}
>  
> +	if (repository_format_precious_objects)
> +		die("cannot prune in a precious-objects repo");
> +

By the way, I originally wrote this patch on an older version of git,
and was surprised that `git gc` broke when I brought it forward. The
problem was that gc now runs `git prune --worktree`, and my die() was
affecting that case.

It really seems misplaced to me to make worktree-pruning part of
git-prune. I imagine the rationale was "well, we are pruning things, so
let's add an option to this command rather than make a new one". But I
do not think that follows our usual pattern with gc, which is:

  1. Individual areas of code handle their own cleanup. E.g., "reflog
     expire", "rerere gc".

  2. We tie them together with "git gc", not with "git prune".

So it seems weird that "git prune --worktree" is a fundamentally
different command than "git prune". I think by (1), it should be a
separate "git prune-worktree" (or better yet, "git worktree prune", as
the start of a command for manipulating the list of multiple-worktrees).

Not a _huge_ deal, but if we want to change it, it would be nice to do so
now before it is part of a release. Thoughts?

-Peff