From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 27 Apr 2016 21:15:16 GMT
Subject: Re: [PATCH 15/29] ref_transaction_create(): disallow recursive pruning
Message-ID: <xmqqvb327nyz.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <xmqqh9em93xo.fsf@gitster.mtv.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

> If a casual reader sees this code:
>
>     ref_transaction_delete(transaction, r->name, r->sha1,
> 			   REF_ISPRUNING | REF_NODEREF, NULL, &err)
>
> it gives an incorrect impression that there may also be a valid case
> to make a "delete" call with ISPRUNING alone without NODEREF, in
> other codepaths and under certain conditions, and write an incorrect
>
>     ref_transaction_delete(transaction, refname, sha1,
> 			   REF_ISPRUNING, NULL, &err)
>
> in her new code.  Or a careless programmer and reviewer may not even
> memorize and remember what the new world order is when they see such
> a code and let it pass.
>
> As I understand that we declare that "to prune a ref from set of
> loose refs is to prune the named one, never following a symbolic
> ref" is the new world order with this patch, making sure that
> ISPRUNING automatically and always mean NODEREF will eliminate the
> possibility that any new code makes an incorrect call to "delete",
> which I think is much better.

... but my understanding of the point of this patch may be flawed,
in which case I of course am willing to be enlightened ;-)