[PATCH 5/6] refs.c: write to a lock file only once

[Stefan Beller <sbeller@google.com>]

Instead of having to call write_in_full_to_lock_file twice get a formatted
string such that we only need to invoke writing to the lock file once.

This is helpful for the next patch when we only open the file descriptors
as needed. The lock file API has a reopen_lock_file which currently
doesn't open for appending.

No functional changes intended.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 refs.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/refs.c b/refs.c
index 311599b..0161667 100644
--- a/refs.c
+++ b/refs.c
@@ -3078,8 +3078,8 @@ static ssize_t write_in_full_to_lockfile(struct lock_file *lock,
 static int write_ref_sha1(struct ref_lock *lock,
 	const unsigned char *sha1, const char *logmsg)
 {
-	static char term = '\n';
 	struct object *o;
+	const char *sha1_lf;
 
 	if (!lock) {
 		errno = EINVAL;
@@ -3104,8 +3104,9 @@ static int write_ref_sha1(struct ref_lock *lock,
 		errno = EINVAL;
 		return -1;
 	}
-	if (write_in_full_to_lockfile(lock->lk, sha1_to_hex(sha1), 40) != 40 ||
-	    write_in_full_to_lockfile(lock->lk, &term, 1) != 1 ||
+
+	sha1_lf = xstrfmt("%s\n",  sha1_to_hex(sha1));
+	if (write_in_full_to_lockfile(lock->lk, sha1_lf, 41) != 41 ||
 	    close_ref(lock) < 0) {
 		int save_errno = errno;
 		error("Couldn't write %s", lock->lk->filename.buf);
@@ -3113,6 +3114,7 @@ static int write_ref_sha1(struct ref_lock *lock,
 		errno = save_errno;
 		return -1;
 	}
+	free((void*)sha1_lf);
 	clear_loose_ref_cache(&ref_cache);
 	if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
 	    (strcmp(lock->ref_name, lock->orig_ref_name) &&
@@ -4081,13 +4083,13 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 	(*cleanup_fn)(cb.policy_cb);
 
 	if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
+		const char *sha1_lf = xstrfmt("%s\n",
+					      sha1_to_hex(cb.last_kept_sha1));
 		if (close_lock_file(&reflog_lock)) {
 			status |= error("couldn't write %s: %s", log_file,
 					strerror(errno));
 		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) &&
-			(write_in_full_to_lockfile(lock->lk,
-				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
-			 write_in_full_to_lockfile(lock->lk, "\n", 1) != 1 ||
+			(write_in_full_to_lockfile(lock->lk, sha1_lf, 41) != 41 ||
 			 close_ref(lock) < 0)) {
 			status |= error("couldn't write %s",
 					lock->lk->filename.buf);
@@ -4098,6 +4100,7 @@ int reflog_expire(const char *refname, const unsigned char *sha1,
 		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
 			status |= error("couldn't set %s", lock->ref_name);
 		}
+		free((void*)sha1_lf);
 	}
 	free(log_file);
 	unlock_ref(lock);
-- 
2.2.1.62.g3f15098