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From: Derrick Stolee <stolee@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, peff@peff.net, jrnieder@gmail.com,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 0/5] Add a new "sparse" tree walk algorithm
Date: Wed, 28 Nov 2018 23:05:55 -0500
Message-ID: <d739ad00-d4f7-2a1b-7e03-3b69d74bdb5f@gmail.com> (raw)
In-Reply-To: <874lc0zw0p.fsf@evledraar.gmail.com>

On 11/28/2018 5:18 PM, Ævar Arnfjörð Bjarmason wrote:
> This is really interesting. I tested this with:
>
>      diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
>      index 124b1bafc4..5c7615f06c 100644
>      --- a/builtin/pack-objects.c
>      +++ b/builtin/pack-objects.c
>      @@ -3143 +3143 @@ static void get_object_list(int ac, const char **av)
>      -       mark_edges_uninteresting(&revs, show_edge, sparse);
>      +       mark_edges_uninteresting(&revs, show_edge, 1);
>
> To emulate having a GIT_TEST_* mode for this, which seems like a good
> idea since it turned up a lot of segfaults in pack-objects. I wasn't
> able to get a backtrace for that since it always happens indirectly, and
> I didn't dig enough to see how to manually invoke it the right way.

Thanks for double-checking this. I had run a similar test in my 
prototype implementation, but over-simplified some code when rewriting 
it for submission (and then forgot to re-run that test).

Specifically, these null checks are important:

diff --git a/list-objects.c b/list-objects.c
index 9bb93d1640..7e864b4db8 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -232,6 +232,10 @@ static void add_edge_parents(struct commit *commit,
         for (parents = commit->parents; parents; parents = parents->next) {
                 struct commit *parent = parents->item;
                 struct tree *tree = get_commit_tree(parent);
+
+               if (!tree)
+                       continue;
+
                 oidset_insert(set, &tree->object.oid);

                 if (!(parent->object.flags & UNINTERESTING))
@@ -261,6 +265,8 @@ void mark_edges_uninteresting(struct rev_info *revs,

                 if (sparse) {
                         struct tree *tree = get_commit_tree(commit);
+                       if (!tree)
+                               continue;

                         if (commit->object.flags & UNINTERESTING)
                                 tree->object.flags |= UNINTERESTING;

I will definitely include a GIT_TEST_* variable in v2.

Thanks,

-Stolee


  reply index

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-28 21:52 Derrick Stolee via GitGitGadget
2018-11-28 21:52 ` [PATCH 1/5] revision: add mark_tree_uninteresting_sparse Derrick Stolee via GitGitGadget
2018-11-28 21:52 ` [PATCH 2/5] list-objects: consume sparse tree walk Derrick Stolee via GitGitGadget
2018-11-28 21:52 ` [PATCH 3/5] pack-objects: add --sparse option Derrick Stolee via GitGitGadget
2018-11-28 22:11   ` Stefan Beller
2018-11-29 14:20     ` Derrick Stolee
2018-11-30  2:39       ` Junio C Hamano
2018-11-30 15:53         ` Derrick Stolee
2018-11-28 21:52 ` [PATCH 4/5] revision: implement sparse algorithm Derrick Stolee via GitGitGadget
2018-11-28 21:52 ` [PATCH 5/5] pack-objects: create pack.useSparse setting Derrick Stolee via GitGitGadget
2018-11-28 22:18 ` [PATCH 0/5] Add a new "sparse" tree walk algorithm Ævar Arnfjörð Bjarmason
2018-11-29  4:05   ` Derrick Stolee [this message]
2018-11-29 14:24 ` [PATCH v2 0/6] " Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 1/6] revision: add mark_tree_uninteresting_sparse Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 2/6] list-objects: consume sparse tree walk Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 3/6] pack-objects: add --sparse option Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 4/6] revision: implement sparse algorithm Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 5/6] pack-objects: create pack.useSparse setting Derrick Stolee via GitGitGadget
2018-11-29 14:24   ` [PATCH v2 6/6] pack-objects: create GIT_TEST_PACK_SPARSE Derrick Stolee via GitGitGadget
2018-12-10 16:42   ` [PATCH v3 0/6] Add a new "sparse" tree walk algorithm Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 1/6] revision: add mark_tree_uninteresting_sparse Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 2/6] list-objects: consume sparse tree walk Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 3/6] pack-objects: add --sparse option Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 4/6] revision: implement sparse algorithm Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 5/6] pack-objects: create pack.useSparse setting Derrick Stolee via GitGitGadget
2018-12-10 16:42     ` [PATCH v3 6/6] pack-objects: create GIT_TEST_PACK_SPARSE Derrick Stolee via GitGitGadget
2018-12-14 21:22     ` [PATCH v4 0/6] Add a new "sparse" tree walk algorithm Derrick Stolee via GitGitGadget
2018-12-14 21:22       ` [PATCH v4 1/6] revision: add mark_tree_uninteresting_sparse Derrick Stolee via GitGitGadget
2019-01-11 19:43         ` Junio C Hamano
2019-01-11 20:25           ` Junio C Hamano
2019-01-11 22:05             ` Derrick Stolee
2018-12-14 21:22       ` [PATCH v4 2/6] list-objects: consume sparse tree walk Derrick Stolee via GitGitGadget
2019-01-11 23:20         ` Junio C Hamano
2018-12-14 21:22       ` [PATCH v4 3/6] pack-objects: add --sparse option Derrick Stolee via GitGitGadget
2019-01-11 22:30         ` Junio C Hamano
2019-01-15 15:06           ` Derrick Stolee
2019-01-15 18:23             ` Junio C Hamano
2018-12-14 21:22       ` [PATCH v4 4/6] revision: implement sparse algorithm Derrick Stolee via GitGitGadget
2018-12-14 23:32         ` Ævar Arnfjörð Bjarmason
2018-12-17 14:20           ` Derrick Stolee
2018-12-17 14:26             ` Ævar Arnfjörð Bjarmason
2018-12-17 14:50               ` Derrick Stolee
2019-01-11 23:20         ` Junio C Hamano
2018-12-14 21:22       ` [PATCH v4 5/6] pack-objects: create pack.useSparse setting Derrick Stolee via GitGitGadget
2018-12-14 21:22       ` [PATCH v4 6/6] pack-objects: create GIT_TEST_PACK_SPARSE Derrick Stolee via GitGitGadget
2019-01-16 18:25       ` [PATCH v5 0/5] Add a new "sparse" tree walk algorithm Derrick Stolee via GitGitGadget
2019-01-16 18:25         ` [PATCH v5 2/5] list-objects: consume sparse tree walk Derrick Stolee via GitGitGadget
2019-01-16 18:25         ` [PATCH v5 1/5] revision: add mark_tree_uninteresting_sparse Derrick Stolee via GitGitGadget
2019-01-16 18:25         ` [PATCH v5 3/5] revision: implement sparse algorithm Derrick Stolee via GitGitGadget
2019-01-16 18:26         ` [PATCH v5 4/5] pack-objects: create pack.useSparse setting Derrick Stolee via GitGitGadget
2019-01-16 18:26         ` [PATCH v5 5/5] pack-objects: create GIT_TEST_PACK_SPARSE Derrick Stolee via GitGitGadget

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