Re: [PATCH 1/2] pack-objects: break out of want_object loop early

From

Junio C Hamano <gitster@pobox.com>

Date

Jul 26, 2016, 20:38 UTC

Message-ID

<xmqqshuwyw14.fsf@gitster.mtv.corp.google.com>

In-Reply-To

<20160725221411.GA14131@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

>> I do not mind too much about having to check two bools twice.  But
>> given that the reason why I was confused was because I didn't see
>> why we need to pass the two "return 0" conditions at least once
>> before we decide that we do not need the "return 0" thing at all,
>> and started constructing a case where this might break by writing
>> "Suppose you have two packs, one remote and one local in packed_git
>> list in this order, and ..." before I realized that the new "early
>> break" can be hoisted up like the above, I definitely feel that "we
>> found one, and we aren't conditionally pretending that this thing
>> does not need to be packed at all, so return early and say we want
>> to pack it" is easier to understand before the two existing "if"
>> statements.
>
> Ah, right. Now you had me second-guessing for a moment that there might
> be a bad case in hoisting it up where we would want to return 0 but
> would break out early to the "return 1".
>
> But it cannot be the case, because the break is mutually exclusive with
> the two conditions.

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index a2f8cfd..a46bf5b 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -977,6 +977,21 @@ static int want_object_in_pack(const unsigned char *sha1,
 				return 1;
 			if (incremental)
 				return 0;
+
+			/*
+			 * When asked to do --local (do not include an
+			 * object that appears in a pack we borrow
+			 * from elsewhere) or --honor-pack-keep (do not
+			 * include an object that appears in a pack marked
+			 * with .keep), we need to make sure no copy of this
+			 * object come from in _any_ pack that causes us to
+			 * omit it, and need to complete this loop.  When
+			 * neither option is in effect, we know the object
+			 * we just found is going to be packed, so break
+			 * out of the loop to return 1 now.
+			 */
+			if (!ignore_packed_keep && !local)
+				break;
 			if (local && !p->pack_local)
 				return 0;
 			if (ignore_packed_keep && p->pack_local && p->pack_keep)