UPDATE for V2: We now know the full repro, and a test is added. Thanks Szeder and Peff for your insights! UPDATE in V3: Cleaned up the commit messages and some test details. UPDATE in V4: There is an unfortunate interaction with GIT_TEST_COMMIT_GRAPH that requires an update to the test. Sorry for not noticing this earlier. Thanks, Johannes for pointing it out! While dogfooding, Johannes found a bug in the fetch.writeCommitGraph config behavior. While his example initially happened during a clone with --recurse-submodules, (UPDATE) and the submodule is important, but --recurse-submodules is not: $ git clone <url> test $ cd test $ git -c fetch.writeCommitGraph=true fetch origin Computing commit graph generation numbers: 100% (12/12), done. BUG: commit-graph.c:886: missing parent <hash1> for commit <hash2> Aborted (core dumped) In the repo I had cloned, there were really 60 commits to scan, but only 12 were in the list to write when calling compute_generation_numbers(). A commit in the list expects to see a parent, but that parent is not in the list. The simple example I used for my testing was https://github.com/derrickstolee/numbers. Thie repo HAS A SUBMODULE, I just forgot. Sorry for derailing the investigation somewhat. The details above are the start of the commit message for [PATCH 1/2], including a test that fails when fetching after cloning a repo with a submodule. In [PATCH 2/2], I actually have the fix. I tried to include as much detail as I could for how I investigated the problem and why I think this is the right solution. I added details that have come from the on-list discussion, including what the submodule code is doing and why REACHABLE is no longer used in commit-reach.c. Thanks, -Stolee Derrick Stolee (2): t5510-fetch.sh: demonstrate fetch.writeCommitGraph bug commit-graph: fix writing first commit-graph during fetch commit-graph.c | 11 +++++++---- commit-reach.c | 1 - object.h | 3 ++- t/t5510-fetch.sh | 16 ++++++++++++++++ 4 files changed, 25 insertions(+), 6 deletions(-) base-commit: d966095db01190a2196e31195ea6fa0c722aa732 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-415%2Fderrickstolee%2Ffetch-first-write-fail-v4 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-415/derrickstolee/fetch-first-write-fail-v4 Pull-Request: https://github.com/gitgitgadget/git/pull/415 Range-diff vs v3: 1: ce53b5a7bf ! 1: 8150108471 t5510-fetch.sh: demonstrate fetch.writeCommitGraph bug @@ -20,7 +20,10 @@ parent, but that parent is not in the list. A follow-up will fix the bug, but first we create a test that - demonstrates the problem. + demonstrates the problem. This test must be careful about an existing + commit-graph file, since GIT_TEST_COMMIT_GRAPH=1 will cause the repo we + are cloning to already have one. This then prevents the incremtnal + commit-graph write during the first 'git fetch'. Helped-by: Jeff King <peff@xxxxxxxx> Helped-by: Johannes Schindelin <johannes.schindelin@xxxxxx> @@ -44,7 +47,7 @@ + git clone "super" super-clone && + ( + cd super-clone && -+ test_path_is_missing .git/objects/info/commit-graphs/commit-graph-chain && ++ rm -rf .git/objects/info && + git -c fetch.writeCommitGraph=true fetch origin && + test_path_is_file .git/objects/info/commit-graphs/commit-graph-chain + ) 2: edacfff490 = 2: 6d01e90591 commit-graph: fix writing first commit-graph during fetch -- gitgitgadget
