builtin/clone: avoid failure with GIT_DEFAULT_HASH
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@usp.br>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/clone.c b/builtin/clone.c
index fbfd656..391aa41 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1233,7 +1233,7 @@
* 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 cd3e760..01bc648 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -179,7 +179,7 @@
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 @@
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 @@
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 cee8aa5..c0072d4 100644
--- a/cache.h
+++ b/cache.h
@@ -629,7 +629,7 @@
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 15fb64c..b6c8312 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -631,6 +631,20 @@
test_i18ngrep "the following paths have collided" icasefs/warning
'
+test_expect_success 'clone with GIT_DEFAULT_HASH' '
+ (
+ sane_unset GIT_DEFAULT_HASH &&
+ git init --object-format=sha1 test-sha1 &&
+ git init --object-format=sha256 test-sha256
+ ) &&
+ test_commit -C test-sha1 foo &&
+ test_commit -C test-sha256 foo &&
+ GIT_DEFAULT_HASH=sha1 git clone test-sha256 test-clone-sha256 &&
+ GIT_DEFAULT_HASH=sha256 git clone test-sha1 test-clone-sha1 &&
+ git -C test-clone-sha1 status &&
+ git -C test-clone-sha256 status
+'
+
partial_clone_server () {
SERVER="$1" &&
