36260 2019-03-11 03:13:20 +0300 git rev-list is bad at detecting ancestors 2019-03-11 03:26:17 +0300 1 1 4 Development Sisyphus git-core unstable all Linux NEW P3 normal --- 1 imz placeholder glebfm ldv placeholder vt qa-sisyphus oldest_to_newest 179347 0 imz 2019-03-11 03:13:20 +0300 $ cd /gears/r/rpm-build.git/ $ git merge-base --is-ancestor 4.0.4-alt114 4.0.4-alt128 && echo yes yes $ git rev-list 4.0.4-alt114 ^4.0.4-alt128 | wc -l 163 $ rpm -q git-core git-core-2.19.2-alt1.x86_64 And this is also the method used in girar to detect an ancestor, which is broken (as we see) -- gb/gb-task-check-girar:76: if [ -z "$(GIT_ALTERNATE_OBJECT_DIRECTORIES="${1-}" git log -n1 --pretty=format:1 ^"$new_id" "$old_id")" ]; then "git log" works the same as "git rev-list": $ git --no-pager log -n1 --pretty=format:1 ^4.0.4-alt128 4.0.4-alt114 1 The expected correct result is an empty string. 179348 1 imz 2019-03-11 03:19:10 +0300 (In reply to comment #0) > $ cd /gears/r/rpm-build.git/ > $ git merge-base --is-ancestor 4.0.4-alt114 4.0.4-alt128 && echo yes > yes > $ git rev-list 4.0.4-alt114 ^4.0.4-alt128 | wc -l > 163 Here is the minimal example (using tags) in this repo: $ git rev-list 4.0.4-alt124 ^4.0.4-alt128 | wc -l 196 $ git rev-list 4.0.4-alt125 ^4.0.4-alt128 | wc -l 0 $ git rev-list 4.0.4-alt124 ^4.0.4-alt127 | wc -l 0 179349 2 imz 2019-03-11 03:26:17 +0300 (In reply to comment #1) > (In reply to comment #0) > > $ cd /gears/r/rpm-build.git/ > > $ git merge-base --is-ancestor 4.0.4-alt114 4.0.4-alt128 && echo yes > > yes > > $ git rev-list 4.0.4-alt114 ^4.0.4-alt128 | wc -l > > 163 > > Here is the minimal example (using tags) in this repo: > > $ git rev-list 4.0.4-alt124 ^4.0.4-alt128 | wc -l > 196 > $ git rev-list 4.0.4-alt125 ^4.0.4-alt128 | wc -l > 0 > $ git rev-list 4.0.4-alt124 ^4.0.4-alt127 | wc -l > 0 The commit where this happens: $ git rev-list 6d9d4fed64ef4d6763fffe5d72515fdb2427b417 ^4.0.4-alt128 | wc -l 0 $ git rev-list 6d9d4fed64ef4d6763fffe5d72515fdb2427b417^ ^4.0.4-alt128 | wc -l 196 $