in this case there's also an existing math error in privsep.c while
computing the size of the imsg: sizeof(struct ...) already accounts for
the hash digest, so no need to add to it.

commit 259994d85b8a255b5d9b1176870695cd5350bb19 (main)
from: Omar Polo <op@omarpolo.com>
date: Wed Jul 10 16:15:14 2024 UTC
 
 use proper type for got_imsg_enumerated_commit
 
diff 0f9ed2af036df203ad7b7e5b7e54756bf36a7c4c 259994d85b8a255b5d9b1176870695cd5350bb19
commit - 0f9ed2af036df203ad7b7e5b7e54756bf36a7c4c
commit + 259994d85b8a255b5d9b1176870695cd5350bb19
blob - 86c780f1b39bd6593b1deb94215ecf9405b05740
blob + 7511786325d8e67359b25d6e5a6983eaf0f84457
--- lib/got_lib_privsep.h
+++ lib/got_lib_privsep.h
@@ -592,7 +592,7 @@ struct got_imsg_traversed_commits {
 
 /* Structure for GOT_IMSG_ENUMERATED_COMMIT  */
 struct got_imsg_enumerated_commit {
-	uint8_t id[SHA1_DIGEST_LENGTH];
+	struct got_object_id id;
 	time_t mtime;
 } __attribute__((__packed__));
 
blob - 337a7e73209bcce74e47b6f588ebc9eef0119ae9
blob + e51908c9bc07441fc896089ee1c96ad436e9c94a
--- lib/privsep.c
+++ lib/privsep.c
@@ -2824,12 +2824,12 @@ got_privsep_send_enumerated_commit(struct imsgbuf *ibu
 	struct ibuf *wbuf;
 
 	wbuf = imsg_create(ibuf, GOT_IMSG_ENUMERATED_COMMIT, 0, 0,
-	    sizeof(struct got_imsg_enumerated_commit) + SHA1_DIGEST_LENGTH);
+	    sizeof(struct got_imsg_enumerated_commit));
 	if (wbuf == NULL)
 		return got_error_from_errno("imsg_create ENUMERATED_COMMIT");
 
 	/* Keep in sync with struct got_imsg_enumerated_commit! */
-	if (imsg_add(wbuf, id, SHA1_DIGEST_LENGTH) == -1)
+	if (imsg_add(wbuf, id, sizeof(*id)) == -1)
 		return got_error_from_errno("imsg_add ENUMERATED_COMMIT");
 	if (imsg_add(wbuf, &mtime, sizeof(mtime)) == -1)
 		return got_error_from_errno("imsg_add ENUMERATED_COMMIT");
@@ -2880,7 +2880,7 @@ got_privsep_recv_enumerated_objects(int *found_all_obj
 				break;
 			}
 			icommit = (struct got_imsg_enumerated_commit *)imsg.data;
-			memcpy(commit_id.sha1, icommit->id, SHA1_DIGEST_LENGTH);
+			memcpy(&commit_id, &icommit->id, sizeof(commit_id));
 			mtime = icommit->mtime;
 			have_commit = 1;
 			break;