As Peff reported [1], the refactored can_all_from_reach_with_flags() method does not properly peel tags. Since the helper method can_all_from_reach() and code in t/helper/test-reach.c all peel tags before getting to this method, it is not super-simple to create a test that demonstrates this.
I modified t/helper/test-reach.c to allow calling can_all_from_reach_with_flags() directly, and added a test in t6600-test-reach.sh that demonstrates the segfault without the fix. For V2, I compared the loop that inspects the 'from' commits in commit ba3ca1edce "commit-reach: move can_all_from_reach_with_flags" to the version here and got the following diff: 3c3 < if (from_one->flags & assign_flag) --- > if (!from_one || from_one->flags & assign_flag) 5c5,7 < from_one = deref_tag(the_repository, from_one, "a from object", 0); --- > > from_one = deref_tag(the_repository, from_one, > "a from object", 0); 14a17,22 > > list[nr_commits] = (struct commit *)from_one; > if (parse_commit(list[nr_commits]) || > list[nr_commits]->generation < min_generation) > return 0; /* is this a leak? */ > nr_commits++; This diff includes the early termination we had before 'deref_tag' and the comment for why we can ignore non-commit objects. [1] https://public-inbox.org/git/0bf9103c-9377-506b-7ad7-e5273d8e9...@gmail.com/T/#u Derrick Stolee (1): commit-reach: properly peel tags commit-reach.c | 33 ++++++++++++++++++++++++++------- t/helper/test-reach.c | 22 +++++++++++++++++----- t/t6600-test-reach.sh | 30 ++++++++++++++++++++++++++++-- 3 files changed, 71 insertions(+), 14 deletions(-) base-commit: 6621c838743812aaba96e55cfec8524ea1144c2d Published-As: https://github.com/gitgitgadget/git/releases/tags/pr-39%2Fderrickstolee%2Ftag-fix-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-39/derrickstolee/tag-fix-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/39 Range-diff vs v1: 1: 948e222228 ! 1: 4bf21204dd commit-reach: properly peel tags @@ -36,9 +36,17 @@ - if (parse_commit(list[i]) || - list[i]->generation < min_generation) - return 0; ++ if (!from_one || from_one->flags & assign_flag) ++ continue; ++ + from_one = deref_tag(the_repository, from_one, + "a from object", 0); + if (!from_one || from_one->type != OBJ_COMMIT) { ++ /* no way to tell if this is reachable by ++ * looking at the ancestry chain alone, so ++ * leave a note to ourselves not to worry about ++ * this object anymore. ++ */ + from->objects[i].item->flags |= assign_flag; + continue; + } @@ -187,7 +195,7 @@ + echo "can_all_from_reach_with_flag(X,_,_,0,0):1" >expect && + test_three_modes can_all_from_reach_with_flag +' -+ ++ test_expect_success 'commit_contains:hit' ' cat >input <<-\EOF && A:commit-7-7 -- gitgitgadget
