Re: git help prune accuracy?

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 16, 2011, 00:04 UTC
Message-ID: <7vliqdl6vh.fsf@alter.siamese.dyndns.org>
In-Reply-To: <201112151601.52968.mfick@codeaurora.org>

Martin Fick <mfick@codeaurora.org> writes:

> ...  The summary line reads:
>
>   git-prune - Prune all unreachable objects from the object 
> database

Yea, prune itself has always been primarily about getting rid of unreachable objects. I suspect (I didn't check) that we did not even have a call to prune-packed in its original implementation and it was later added as "we are doing the pruning anyway, why not do this as well while at it".

Yeah, I just checked. Before 51890a6 (Call prune-packed from "git prune" as well., 2005-08-19), we didn't. And 2396ec8 (Add "git-prune-packed" that removes objects that exist in a pack., 2005-07-03) explains it rather nicely:

    Add "git-prune-packed" that removes objects that exist in a pack.
    
    This, together with "git repack" can be used to clean up unpacked
    git archives.

> I don't quite have an alternative suggestion for a better 
> summary, the best I could do (but don't like) is:
>
>   git-prune - Prune loose objects (unreachable or packed)

For a one-liner description, "Remove unnecessary or redundant loose objects" without parentheses may be better. Explaining "git prune" as "this prunes" does not add as much information as restating it using a different and more common verb.

The body text can clarify what we mean by "unnecessary" and "redundant". A loose object that is old may be unreachable from any of the refs, i.e. unused, and hence unnecessary. Or the same object as a loose one may be found in a pack, which would make the loose one redundant.