From: Jeff King <peff@xxxxxxxx> After we run parse_object_buffer() to get an object's contents, we try to check that the return value wasn't NULL. However, since our "struct object" is a pointer-to-pointer, and we assign like: *obj = parse_object_buffer(...); it's not correct to check: if (!obj) That will always be true, since our double pointer will continue to point to the single pointer (which is itself NULL). This is a regression that was introduced by aa46a0da30 (ref-filter: use oid_object_info() to get object, 2018-07-17); since that commit we'll segfault on a parse failure, as we try to look at the NULL object pointer. There are many ways a parse could fail, but most of them are hard to set up in the tests (it's easy to make a bogus object, but update-ref will refuse to point to it). A minimal stand-alone test can be found at, but let's use the newly amended t3800-mktag.sh tests to test these cases exhaustively on all sorts of bad tags. 1. http://lore.kernel.org/git/YGWFGMdGcKeaqCQF@xxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jeff King <peff@xxxxxxxx> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> --- ref-filter.c | 2 +- t/t3800-mktag.sh | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/ref-filter.c b/ref-filter.c index f0bd32f7141..a0adb4551d8 100644 --- a/ref-filter.c +++ b/ref-filter.c @@ -1608,7 +1608,7 @@ static int get_object(struct ref_array_item *ref, int deref, struct object **obj if (oi->info.contentp) { *obj = parse_object_buffer(the_repository, &oi->oid, oi->type, oi->size, oi->content, &eaten); - if (!obj) { + if (!*obj) { if (!eaten) free(oi->content); return strbuf_addf_ret(err, -1, _("parse_object_buffer failed on %s for %s"), diff --git a/t/t3800-mktag.sh b/t/t3800-mktag.sh index 10e4fde28de..b175d639013 100755 --- a/t/t3800-mktag.sh +++ b/t/t3800-mktag.sh @@ -64,7 +64,7 @@ check_verify_failure () { git -C bad-tag for-each-ref "$tag_ref" >actual && test_cmp expected actual && # segfaults! - ! git -C bad-tag for-each-ref --format="%(*objectname)" + test_must_fail git -C bad-tag for-each-ref --format="%(*objectname)" ' } -- 2.31.1.474.g72d45d12706
