refs: introduce REF_SKIP_OID_VERIFICATION flag

This lets the ref-store test helper write non-existent or unparsable objects
into the ref storage.

Use this to make t1006 and t3800 independent of the files storage backend.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 29 insertions, 21 deletions

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 37329b9..d0019fc 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1353,7 +1353,8 @@ static int rename_tmp_log(struct files_ref_store *refs, const char *newrefname)
 }
 
 static int write_ref_to_lockfile(struct ref_lock *lock,
-				 const struct object_id *oid, struct strbuf *err);
+				 const struct object_id *oid,
+				 int skip_oid_verification, struct strbuf *err);
 static int commit_ref_update(struct files_ref_store *refs,
 			     struct ref_lock *lock,
 			     const struct object_id *oid, const char *logmsg,
@@ -1500,7 +1501,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 	}
 	oidcpy(&lock->old_oid, &orig_oid);
 
-	if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
+	if (write_ref_to_lockfile(lock, &orig_oid, 0, &err) ||
 	    commit_ref_update(refs, lock, &orig_oid, logmsg, &err)) {
 		error("unable to write current sha1 into %s: %s", newrefname, err.buf);
 		strbuf_release(&err);
@@ -1520,7 +1521,7 @@ static int files_copy_or_rename_ref(struct ref_store *ref_store,
 
 	flag = log_all_ref_updates;
 	log_all_ref_updates = LOG_REFS_NONE;
-	if (write_ref_to_lockfile(lock, &orig_oid, &err) ||
+	if (write_ref_to_lockfile(lock, &orig_oid, 0, &err) ||
 	    commit_ref_update(refs, lock, &orig_oid, NULL, &err)) {
 		error("unable to write current sha1 into %s: %s", oldrefname, err.buf);
 		strbuf_release(&err);
@@ -1756,26 +1757,31 @@ static int files_log_ref_write(struct files_ref_store *refs,
  * errors, rollback the lockfile, fill in *err and return -1.
  */
 static int write_ref_to_lockfile(struct ref_lock *lock,
-				 const struct object_id *oid, struct strbuf *err)
+				 const struct object_id *oid,
+				 int skip_oid_verification, struct strbuf *err)
 {
 	static char term = '\n';
 	struct object *o;
 	int fd;
 
-	o = parse_object(the_repository, oid);
-	if (!o) {
-		strbuf_addf(err,
-			    "trying to write ref '%s' with nonexistent object %s",
-			    lock->ref_name, oid_to_hex(oid));
-		unlock_ref(lock);
-		return -1;
-	}
-	if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
-		strbuf_addf(err,
-			    "trying to write non-commit object %s to branch '%s'",
-			    oid_to_hex(oid), lock->ref_name);
-		unlock_ref(lock);
-		return -1;
+	if (!skip_oid_verification) {
+		o = parse_object(the_repository, oid);
+		if (!o) {
+			strbuf_addf(
+				err,
+				"trying to write ref '%s' with nonexistent object %s",
+				lock->ref_name, oid_to_hex(oid));
+			unlock_ref(lock);
+			return -1;
+		}
+		if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
+			strbuf_addf(
+				err,
+				"trying to write non-commit object %s to branch '%s'",
+				oid_to_hex(oid), lock->ref_name);
+			unlock_ref(lock);
+			return -1;
+		}
 	}
 	fd = get_lock_file_fd(&lock->lk);
 	if (write_in_full(fd, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
@@ -2189,7 +2195,7 @@ static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 }
 
 static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
-				   struct object_id *peeled)
+				      struct object_id *peeled)
 {
 	BUG("ref_iterator_peel() called for reflog_iterator");
 }
@@ -2575,8 +2581,10 @@ static int lock_ref_for_update(struct files_ref_store *refs,
 			 * The reference already has the desired
 			 * value, so we don't need to write it.
 			 */
-		} else if (write_ref_to_lockfile(lock, &update->new_oid,
-						 err)) {
+		} else if (write_ref_to_lockfile(
+				   lock, &update->new_oid,
+				   update->flags & REF_SKIP_OID_VERIFICATION,
+				   err)) {
 			char *write_err = strbuf_detach(err, NULL);
 
 			/*