[PATCH 18/32] object-file-convert: convert commit objects when writing

From

Eric W. Biederman <ebiederm@xmission.com>

Date

Sep 8, 2023, 23:10 UTC

Message-ID

<20230908231049.2035003-18-ebiederm@xmission.com>

In-Reply-To

<87sf7ol0z3.fsf@email.froward.int.ebiederm.org>

From: "brian m. carlson" <sandals@crustytoothpaste.net>

****
- made static and moved to object-file-convert.c
- Renamed the variable compat_oid to mapped_oid for clarity
- Replaced repo_map_object with oid_to_algop
-- EWB

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 object-file-convert.c | 44 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/object-file-convert.c b/object-file-convert.c
index f266c8c6cc95..9c715a9864d5 100644
--- a/object-file-convert.c
+++ b/object-file-convert.c
@@ -83,6 +83,48 @@ static int convert_tree_object(struct strbuf *out,
 	return 0;
 }
 
+static int convert_commit_object(struct strbuf *out,
+				 const struct git_hash_algo *from,
+				 const struct git_hash_algo *to,
+				 const char *buffer, size_t size)
+{
+	const char *tail = buffer;
+	const char *bufptr = buffer;
+	const int tree_entry_len = from->hexsz + 5;
+	const int parent_entry_len = from->hexsz + 7;
+	struct object_id oid, mapped_oid;
+	const char *p;
+
+	tail += size;
+	if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
+			bufptr[tree_entry_len] != '\n')
+		return error("bogus commit object");
+	if (parse_oid_hex_algop(bufptr + 5, &oid, &p, from) < 0)
+		return error("bad tree pointer");
+
+	if (repo_oid_to_algop(the_repository, &oid, to, &mapped_oid))
+		return error("unable to map tree %s in commit object",
+			     oid_to_hex(&oid));
+	strbuf_addf(out, "tree %s\n", oid_to_hex(&mapped_oid));
+	bufptr = p + 1;
+
+	while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
+		if (tail <= bufptr + parent_entry_len + 1 ||
+		    parse_oid_hex_algop(bufptr + 7, &oid, &p, from) ||
+		    *p != '\n')
+			return error("bad parents in commit");
+
+		if (repo_oid_to_algop(the_repository, &oid, to, &mapped_oid))
+			return error("unable to map parent %s in commit object",
+				     oid_to_hex(&oid));
+
+		strbuf_addf(out, "parent %s\n", oid_to_hex(&mapped_oid));
+		bufptr = p + 1;
+	}
+	strbuf_add(out, bufptr, tail - bufptr);
+	return 0;
+}
+
 int convert_object_file(struct strbuf *outbuf,
 			const struct git_hash_algo *from,
 			const struct git_hash_algo *to,
@@ -101,6 +143,8 @@ int convert_object_file(struct strbuf *outbuf,
 		ret = convert_tree_object(outbuf, from, to, buf, len);
 		break;
 	case OBJ_COMMIT:
+		ret = convert_commit_object(outbuf, from, to, buf, len);
+		break;
 	case OBJ_TAG:
 	default:
 		/* Not implemented yet, so fail. */

-- 
2.41.0