"brian m. carlson" <sandals@xxxxxxxxxxxxxxxxxxxx> writes:
> If a user is cloning a SHA-1 repository with GIT_DEFAULT_HASH set to
> "sha256", then we can end up with a repository where the repository
> format version is 0 but the extensions.objectformat key is set to
> "sha256". This is both wrong (the user has a SHA-1 repository) and
> nonfunctional (because the extension cannot be used in a v0 repository).
>
> This happens because in a clone, we initially set up the repository, and
> then change its algorithm based on what the remote side tells us it's
> using. We've initially set up the repository as SHA-256 in this case,
> and then later on reset the repository version without clearing the
> extension.
>
> We could just always set the extension in this case, but that would mean
> that our SHA-1 repositories weren't compatible with older Git versions,
> even though there's no reason why they shouldn't be. And we also don't
> want to initialize the repository as SHA-1 initially, since that means
> if we're cloning an empty repository, we'll have failed to honor the
> GIT_DEFAULT_HASH variable and will end up with a SHA-1 repository, not a
> SHA-256 repository.
>
> Neither of those are appealing, so let's tell the repository
> initialization code if we're doing a reinit like this, and if so, to
> clear the extension if we're using SHA-1. This makes sure we produce a
> valid and functional repository and doesn't break any of our other use
> cases.
>
> Reported-by: Matheus Tavares <matheus.bernardino@xxxxxx>
> Signed-off-by: brian m. carlson <sandals@xxxxxxxxxxxxxxxxxxxx>
> ---
> Changes since v1:
> * Use git_config_set_gently to make things work with SHA-1 repos as well
> as SHA-256 repos.
Hmph, the reason why v1's bug weren't caught was because it was only
tested with GIT_TEST_DEFAULT_HASH=sha256, right? I am wondering if
adding two new tests that run the same end-user scenario except
for the choice of hash algorithms would be a good way to ensure this
will stay fixed. Am I mistaken?
Thanks anyway for a quick turnaround.
> Diff-intervalle contre v1 :
> 1: 32d3357460 ! 1: 1becbbbb50 builtin/clone: avoid failure with GIT_DEFAULT_HASH
> @@ builtin/init-db.c: void initialize_repository_version(int hash_algo)
> git_config_set("extensions.objectformat",
> hash_algos[hash_algo].name);
> + else if (reinit)
> -+ git_config_set("extensions.objectformat", NULL);
> ++ git_config_set_gently("extensions.objectformat", NULL);
> }
>
> static int create_default_files(const char *template_path,
>
> builtin/clone.c | 2 +-
> builtin/init-db.c | 6 ++++--
> cache.h | 2 +-
> t/t5601-clone.sh | 10 ++++++++++
> 4 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/builtin/clone.c b/builtin/clone.c
> index b087ee40c2..925a2e3dd6 100644
> --- a/builtin/clone.c
> +++ b/builtin/clone.c
> @@ -1235,7 +1235,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
> * Now that we know what algorithm the remote side is using,
> * let's set ours to the same thing.
> */
> - initialize_repository_version(hash_algo);
> + initialize_repository_version(hash_algo, 1);
> repo_set_hash_algo(the_repository, hash_algo);
>
> mapped_refs = wanted_peer_refs(refs, &remote->fetch);
> diff --git a/builtin/init-db.c b/builtin/init-db.c
> index cd3e760541..01bc648d41 100644
> --- a/builtin/init-db.c
> +++ b/builtin/init-db.c
> @@ -179,7 +179,7 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree)
> return 1;
> }
>
> -void initialize_repository_version(int hash_algo)
> +void initialize_repository_version(int hash_algo, int reinit)
> {
> char repo_version_string[10];
> int repo_version = GIT_REPO_VERSION;
> @@ -195,6 +195,8 @@ void initialize_repository_version(int hash_algo)
> if (hash_algo != GIT_HASH_SHA1)
> git_config_set("extensions.objectformat",
> hash_algos[hash_algo].name);
> + else if (reinit)
> + git_config_set_gently("extensions.objectformat", NULL);
> }
>
> static int create_default_files(const char *template_path,
> @@ -277,7 +279,7 @@ static int create_default_files(const char *template_path,
> free(ref);
> }
>
> - initialize_repository_version(fmt->hash_algo);
> + initialize_repository_version(fmt->hash_algo, 0);
>
> /* Check filemode trustability */
> path = git_path_buf(&buf, "config");
> diff --git a/cache.h b/cache.h
> index cee8aa5dc3..c0072d43b1 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -629,7 +629,7 @@ int path_inside_repo(const char *prefix, const char *path);
> int init_db(const char *git_dir, const char *real_git_dir,
> const char *template_dir, int hash_algo,
> const char *initial_branch, unsigned int flags);
> -void initialize_repository_version(int hash_algo);
> +void initialize_repository_version(int hash_algo, int reinit);
>
> void sanitize_stdfds(void);
> int daemonize(void);
> diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
> index 15fb64c18d..570d989795 100755
> --- a/t/t5601-clone.sh
> +++ b/t/t5601-clone.sh
> @@ -631,6 +631,16 @@ test_expect_success CASE_INSENSITIVE_FS 'colliding file detection' '
> test_i18ngrep "the following paths have collided" icasefs/warning
> '
>
> +test_expect_success 'clone with GIT_DEFAULT_HASH' '
> + (
> + sane_unset GIT_DEFAULT_HASH &&
> + git init test
> + ) &&
> + test_commit -C test foo &&
> + git clone test test-clone &&
> + git -C test-clone status
> +'
> +
> partial_clone_server () {
> SERVER="$1" &&
>
