Merge branch 'bc/hash-transition-interop-part-1'

SHA-256 transition.

* bc/hash-transition-interop-part-1:
  hex: print objects using the hash algorithm member
  hex: default to the_hash_algo on zero algorithm value
  builtin/pack-objects: avoid using struct object_id for pack hash
  commit-graph: don't store file hashes as struct object_id
  builtin/show-index: set the algorithm for object IDs
  hash: provide per-algorithm null OIDs
  hash: set, copy, and use algo field in struct object_id
  builtin/pack-redundant: avoid casting buffers to struct object_id
  Use the final_oid_fn to finalize hashing of object IDs
  hash: add a function to finalize object IDs
  http-push: set algorithm when reading object ID
  Always use oidread to read into struct object_id
  hash: add an algo member to struct object_id

1 files changed, 15 insertions, 5 deletions

diff --git a/hex.c b/hex.c
index da51e64929..4f64d34696 100644
--- a/hex.c
+++ b/hex.c
@@ -69,7 +69,10 @@ int get_sha1_hex(const char *hex, unsigned char *sha1)
 int get_oid_hex_algop(const char *hex, struct object_id *oid,
 		      const struct git_hash_algo *algop)
 {
-	return get_hash_hex_algop(hex, oid->hash, algop);
+	int ret = get_hash_hex_algop(hex, oid->hash, algop);
+	if (!ret)
+		oid_set_algo(oid, algop);
+	return ret;
 }
 
 /*
@@ -80,7 +83,7 @@ int get_oid_hex_any(const char *hex, struct object_id *oid)
 {
 	int i;
 	for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
-		if (!get_hash_hex_algop(hex, oid->hash, &hash_algos[i]))
+		if (!get_oid_hex_algop(hex, oid, &hash_algos[i]))
 			return i;
 	}
 	return GIT_HASH_UNKNOWN;
@@ -95,7 +98,7 @@ int parse_oid_hex_algop(const char *hex, struct object_id *oid,
 			const char **end,
 			const struct git_hash_algo *algop)
 {
-	int ret = get_hash_hex_algop(hex, oid->hash, algop);
+	int ret = get_oid_hex_algop(hex, oid, algop);
 	if (!ret)
 		*end = hex + algop->hexsz;
 	return ret;
@@ -121,6 +124,13 @@ char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
 	char *buf = buffer;
 	int i;
 
+	/*
+	 * Our struct object_id has been memset to 0, so default to printing
+	 * using the default hash.
+	 */
+	if (algop == &hash_algos[0])
+		algop = the_hash_algo;
+
 	for (i = 0; i < algop->rawsz; i++) {
 		unsigned int val = *hash++;
 		*buf++ = hex[val >> 4];
@@ -133,7 +143,7 @@ char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
 
 char *oid_to_hex_r(char *buffer, const struct object_id *oid)
 {
-	return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
+	return hash_to_hex_algop_r(buffer, oid->hash, &hash_algos[oid->algo]);
 }
 
 char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
@@ -151,5 +161,5 @@ char *hash_to_hex(const unsigned char *hash)
 
 char *oid_to_hex(const struct object_id *oid)
 {
-	return hash_to_hex_algop(oid->hash, the_hash_algo);
+	return hash_to_hex_algop(oid->hash, &hash_algos[oid->algo]);
 }