From: Mathias Rav Date: Wed, 11 Mar 2026 06:44:06 GMT Subject: [PATCH v2] merge-file: fix BUG when --object-id is used in a worktree Message-ID: In-Reply-To: The `--object-id` option was added in commit e1068f0ad4 (merge-file: add an option to process object IDs, 2023-11-01) together with a call to setup_git_directory() to avoid crashing when run outside a repository. However, the call to setup_git_directory() is redundant when run inside a repository, as merge-file runs with RUN_SETUP_GENTLY, so the repository has already been set up. The redundant call is harmless when linked worktrees are not used, but in a linked worktree, the repo_set_gitdir() function ends up being called twice. Calling repo_set_gitdir() used to be silently accepted, but commit 2816b748e5 (odb: handle changing a repository's commondir, 2025-11-19) changed this to a BUG in repository.c with the error message: "cannot reinitialize an already-initialized object directory". Guard the redundant call to setup_git_directory() behind a repo pointer check, to ensure that we continue to give the correct "not a git repo" error whilst avoiding the BUG when running in a linked worktree. Signed-off-by: Mathias Rav --- Thanks Karthik, Patrick, Kristoffer and Junio for your feedback. I've incorporated the sum of it all in this PATCH v2: - Check !repo before object_id and add a comment - Use term "linked worktree" instead of just "worktree" throughout - Use git -C instead of a subshell in test - Remove gitk's quotes from the commit references in the commit message As for the quotes in the commit references, I use gitk's "Copy commit reference" daily and am personally used to the quotes. Since SubmittingPatches seems to give equal preference to --pretty=reference and "Copy commit reference" I didn't think that the quotes were a problem. (I wonder how controversial it would be to remove the quotes in gitk.) builtin/merge-file.c | 5 +++-- t/t6403-merge-file.sh | 9 +++++++++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/builtin/merge-file.c b/builtin/merge-file.c index 46775d0c79..cc8fda3b5b 100644 --- a/builtin/merge-file.c +++ b/builtin/merge-file.c @@ -60,7 +60,7 @@ static int diff_algorithm_cb(const struct option *opt, int cmd_merge_file(int argc, const char **argv, const char *prefix, - struct repository *repo UNUSED) + struct repository *repo) { const char *names[3] = { 0 }; mmfile_t mmfs[3] = { 0 }; @@ -110,7 +110,8 @@ int cmd_merge_file(int argc, return error_errno("failed to redirect stderr to /dev/null"); } - if (object_id) + if (!repo && object_id) + /* emit the correct "not a git repo" error in this case */ setup_git_directory(); for (i = 0; i < 3; i++) { diff --git a/t/t6403-merge-file.sh b/t/t6403-merge-file.sh index 06ab4d7aed..ed7eec8f93 100755 --- a/t/t6403-merge-file.sh +++ b/t/t6403-merge-file.sh @@ -506,6 +506,15 @@ test_expect_success '--object-id fails without repository' ' grep "not a git repository" err ' +test_expect_success 'run in a linked worktree with --object-id' ' + empty="$(test_oid empty_blob)" && + git worktree add work && + git -C work merge-file --object-id $empty $empty $empty >actual && + git worktree remove work && + git merge-file --object-id $empty $empty $empty >expected && + test_cmp actual expected +' + test_expect_success 'merging C files with "myers" diff algorithm creates some spurious conflicts' ' cat >expect.c <<-\EOF && int g(size_t u) -- 2.53.0