From c3c17bf10725149e2f806c73aceb522509afcc83 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 19 Mar 2015 16:37:09 -0400 Subject: [PATCH] filter_ref: make a copy of extra "sought" entries If the server supports allow_tip_sha1_in_want, we add any unmatched raw-sha1 entries in our "sought" list of refs to the list of refs we will ask the other side for. We do so by inserting the original "struct ref" directly into our list, rather than making a copy. This has several problems. The most minor problem is that one cannot ever free the resulting list; it contains structs that are copies of the remote refs (made earlier by fetch_pack) along with sought refs that are referenced elsewhere. But more importantly that we set the ref->next pointer to NULL, chopping off the remainder of any existing list that the ref was a part of. We get the set of "sought" refs in an array rather than a linked list, but that array is often in turn generated from a list. The test modification in t5516 demonstrates this. Rather than fetching just an exact sha1, we fetch that sha1 plus another ref: - we build a linked list of refs to fetch when do_fetch calls get_ref_map; the exact sha1 is first, followed by the named ref ("refs/heads/extra" in this case). - we pass that linked list to transport_fetch_ref, which squashes it into an array of pointers - that array goes to fetch_pack, which calls filter_ref. There we generate the want list from a mix of what the remote side has advertised, and the "sought" entry for the exact sha1. We set the sought entry's "next" pointer to NULL. - after we return from transport_fetch_refs, we then try to update the refs by following the linked list. But our list is now truncated, and we do not update refs/heads/extra at all. We can fix this by making a copy of the ref. There's nothing that fetch_pack does to it that must be reflected in the original "sought" list (and indeed, if that were the case we would have a serious bug, because it is only exact-sha1 entries which are treated this way). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- fetch-pack.c | 5 ++--- t/t5516-fetch-push.sh | 13 ++++++++++--- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/fetch-pack.c b/fetch-pack.c index 058c25837d..84d5a66967 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -555,9 +555,8 @@ static void filter_refs(struct fetch_pack_args *args, continue; ref->matched = 1; - *newtail = ref; - ref->next = NULL; - newtail = &ref->next; + *newtail = copy_ref(ref); + newtail = &(*newtail)->next; } } *refs = newlist; diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh index f4da20aa9b..f7947315ba 100755 --- a/t/t5516-fetch-push.sh +++ b/t/t5516-fetch-push.sh @@ -1107,9 +1107,16 @@ test_expect_success 'fetch exact SHA1' ' git config uploadpack.allowtipsha1inwant true ) && - git fetch -v ../testrepo $the_commit:refs/heads/copy && - result=$(git rev-parse --verify refs/heads/copy) && - test "$the_commit" = "$result" + git fetch -v ../testrepo $the_commit:refs/heads/copy master:refs/heads/extra && + cat >expect <<-EOF && + $the_commit + $the_first_commit + EOF + { + git rev-parse --verify refs/heads/copy && + git rev-parse --verify refs/heads/extra + } >actual && + test_cmp expect actual ) ' -- 2.11.4.GIT