hash: provide per-algorithm null OIDs

Up until recently, object IDs did not have an algorithm member, only a
hash.  Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms.  Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.

Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
brian m. carlson
2021-04-26 01:02:56 +00:00
committed by Junio C Hamano
parent 5a6dce70d7
commit 14228447c9
42 changed files with 119 additions and 95 deletions

View File

@ -106,8 +106,8 @@ static int post_checkout_hook(struct commit *old_commit, struct commit *new_comm
int changed)
{
return run_hook_le(NULL, "post-checkout",
oid_to_hex(old_commit ? &old_commit->object.oid : &null_oid),
oid_to_hex(new_commit ? &new_commit->object.oid : &null_oid),
oid_to_hex(old_commit ? &old_commit->object.oid : null_oid()),
oid_to_hex(new_commit ? &new_commit->object.oid : null_oid()),
changed ? "1" : "0", NULL);
/* "new_commit" can be NULL when checking out from the index before
a commit exists. */
@ -638,7 +638,7 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
opts.src_index = &the_index;
opts.dst_index = &the_index;
init_checkout_metadata(&opts.meta, info->refname,
info->commit ? &info->commit->object.oid : &null_oid,
info->commit ? &info->commit->object.oid : null_oid(),
NULL);
parse_tree(tree);
init_tree_desc(&tree_desc, tree->buffer, tree->size);