[PATCHv3 5/6] refs.c: remove unlock_ref and commit_ref from write_ref_sha1

[Stefan Beller <sbeller@google.com>]

This makes write_ref_sha1 only write the the lock file, committing
needs to be done outside of that function. This will help us change
the ref_transaction_commit in a later patch.

Also instead of calling unlock_ref before each return in write_ref_sha1
we can call this after the call. This is a first step to split up
write_ref_sha1 into the write and commit phase which is done in a
later patch.

There is a call in each code path after write_ref_sha1 now. Even in
the last hunk in the error case, the 'goto cleanup;' will make sure
there is a call to unlock_ref.

Signed-off-by: Stefan Beller <sbeller@google.com>
---

Notes:
    new in v3

 refs.c | 40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/refs.c b/refs.c
index f1eefc7..1bfc84b 100644
--- a/refs.c
+++ b/refs.c
@@ -2815,8 +2815,11 @@ static int close_ref(struct ref_lock *lock)
 	return 0;
 }
 
-static int commit_ref(struct ref_lock *lock)
+static int commit_ref(struct ref_lock *lock, const unsigned char *sha1)
 {
+	if (!lock->force_write && !hashcmp(lock->old_sha1, sha1))
+		return 0;
+
 	if (commit_lock_file(lock->lk))
 		return -1;
 	return 0;
@@ -2879,10 +2882,13 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 	}
 	lock->force_write = 1;
 	hashcpy(lock->old_sha1, orig_sha1);
-	if (write_ref_sha1(lock, orig_sha1, logmsg)) {
+	if (write_ref_sha1(lock, orig_sha1, logmsg)
+	    || commit_ref(lock, orig_sha1)) {
+		unlock_ref(lock);
 		error("unable to write current sha1 into %s", newrefname);
 		goto rollback;
 	}
+	unlock_ref(lock);
 
 	return 0;
 
@@ -2896,8 +2902,11 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 	lock->force_write = 1;
 	flag = log_all_ref_updates;
 	log_all_ref_updates = 0;
-	if (write_ref_sha1(lock, orig_sha1, NULL))
+	if (write_ref_sha1(lock, orig_sha1, NULL)
+	    || commit_ref(lock, orig_sha1))
 		error("unable to write current sha1 into %s", oldrefname);
+
+	unlock_ref(lock);
 	log_all_ref_updates = flag;
 
  rollbacklog:
@@ -3067,22 +3076,19 @@ static int write_ref_sha1(struct ref_lock *lock,
 		errno = EINVAL;
 		return -1;
 	}
-	if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
-		unlock_ref(lock);
+	if (!lock->force_write && !hashcmp(lock->old_sha1, sha1))
 		return 0;
-	}
+
 	o = parse_object(sha1);
 	if (!o) {
 		error("Trying to write ref %s with nonexistent object %s",
 			lock->ref_name, sha1_to_hex(sha1));
-		unlock_ref(lock);
 		errno = EINVAL;
 		return -1;
 	}
 	if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
 		error("Trying to write non-commit object %s to branch %s",
 			sha1_to_hex(sha1), lock->ref_name);
-		unlock_ref(lock);
 		errno = EINVAL;
 		return -1;
 	}
@@ -3091,7 +3097,6 @@ static int write_ref_sha1(struct ref_lock *lock,
 	    close_ref(lock) < 0) {
 		int save_errno = errno;
 		error("Couldn't write %s", lock->lk->filename.buf);
-		unlock_ref(lock);
 		errno = save_errno;
 		return -1;
 	}
@@ -3099,7 +3104,6 @@ static int write_ref_sha1(struct ref_lock *lock,
 	if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
 	    (strcmp(lock->ref_name, lock->orig_ref_name) &&
 	     log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
-		unlock_ref(lock);
 		return -1;
 	}
 	if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
@@ -3124,12 +3128,6 @@ static int write_ref_sha1(struct ref_lock *lock,
 		    !strcmp(head_ref, lock->ref_name))
 			log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
 	}
-	if (commit_ref(lock)) {
-		error("Couldn't set %s", lock->ref_name);
-		unlock_ref(lock);
-		return -1;
-	}
-	unlock_ref(lock);
 	return 0;
 }
 
@@ -3762,14 +3760,15 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 
 		if (!is_null_sha1(update->new_sha1)) {
 			if (write_ref_sha1(update->lock, update->new_sha1,
-					   update->msg)) {
-				update->lock = NULL; /* freed by write_ref_sha1 */
+					   update->msg)
+			    || commit_ref(update->lock, update->new_sha1)) {
 				strbuf_addf(err, "Cannot update the ref '%s'.",
 					    update->refname);
 				ret = TRANSACTION_GENERIC_ERROR;
 				goto cleanup;
 			}
-			update->lock = NULL; /* freed by write_ref_sha1 */
+			unlock_ref(update->lock);
+			update->lock = NULL;
 		}
 	}
 
@@ -4053,7 +4052,8 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 		} else if (commit_lock_file(&reflog_lock)) {
 			status |= error("unable to commit reflog '%s' (%s)",
 					log_file, strerror(errno));
-		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
+		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF)
+			    && commit_ref(lock, cb.last_kept_sha1)) {
 			status |= error("couldn't set %s", lock->ref_name);
 		}
 	}
-- 
2.2.1.62.g3f15098