Re: [PATCH] blame: drop unused parameter from maybe_changed_path

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> If the bloom filter also computes against an empty tree for root
> commits (I didn't check, but that would make sense), I think that AND
> could be an OR:
>
>    if (!origin->commit->parents ||
>        !oidcmp(...))
>
> though it probably doesn't matter that much in practice. Root commits
> are rather rare.

Correct.  I just followed the code from bloom.c::get_bloom_filter()
down, and for a root commit, diff_tree_oid() with NULL in the first
parameter (i.e. old_oid) is called.  This NULL pointer eventually
reaches tree-walk.c::fill_tree_descriptor() and the function just
gives an empty tree in that case, which is what we want.
>
> BTW, we could also be using oideq() here. I thought coccicheck would
> note this, but it doesn't seem to. I suspect we could also get away with
> a direct pointer comparison of "parent == origin->commit->parents->item"
> due to the way we allocate "struct commit", but I'd rather err on the
> safer and less subtle side. :)

True.  oideq() is probably an improvement; I agree that pointer
equality is taking it too far.