+ struct ref_lock *lock;
+ int err, i, ret = 0, flag = 0;
+
+ lock = lock_ref_sha1_basic(refname, sha1, &flag);
+ if (!lock)
+ return 1;
+ if (!(flag & REF_ISPACKED)) {
+ /* loose */
+ i = strlen(lock->lk->filename) - 5; /* .lock */
+ lock->lk->filename[i] = 0;
+ err = unlink(lock->lk->filename);
+ if (err) {
+ ret = 1;
+ error("unlink(%s) failed: %s",
+ lock->lk->filename, strerror(errno));
+ }
+ lock->lk->filename[i] = '.';
+ }
+ /* removing the loose one could have resurrected an earlier
+ * packed one. Also, if it was not loose we need to repack
+ * without it.
+ */
+ ret |= repack_without_ref(refname);
+
+ err = unlink(lock->log_file);
+ if (err && errno != ENOENT)
+ fprintf(stderr, "warning: unlink(%s) failed: %s",
+ lock->log_file, strerror(errno));
+ invalidate_cached_refs();
+ unlock_ref(lock);
+ return ret;
+}
+
+int rename_ref(const char *oldref, const char *newref, const char *logmsg)
+{
+ static const char renamed_ref[] = "RENAMED-REF";
+ unsigned char sha1[20], orig_sha1[20];
+ int flag = 0, logmoved = 0;
+ struct ref_lock *lock;
+ struct stat loginfo;
+ int log = !lstat(git_path("logs/%s", oldref), &loginfo);
+
+ if (S_ISLNK(loginfo.st_mode))
+ return error("reflog for %s is a symlink", oldref);
+
+ if (!resolve_ref(oldref, orig_sha1, 1, &flag))
+ return error("refname %s not found", oldref);
+
+ if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
+ return 1;
+
+ if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
+ return 1;
+
+ lock = lock_ref_sha1_basic(renamed_ref, NULL, NULL);
+ if (!lock)
+ return error("unable to lock %s", renamed_ref);
+ lock->force_write = 1;
+ if (write_ref_sha1(lock, orig_sha1, logmsg))
+ return error("unable to save current sha1 in %s", renamed_ref);
+
+ if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
+ return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
+ oldref, strerror(errno));
+
+ if (delete_ref(oldref, orig_sha1)) {
+ error("unable to delete old %s", oldref);
+ goto rollback;
+ }
+
+ if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
+ if (errno==EISDIR) {
+ if (remove_empty_directories(git_path("%s", newref))) {
+ error("Directory not empty: %s", newref);
+ goto rollback;
+ }
+ } else {
+ error("unable to delete existing %s", newref);
+ goto rollback;
+ }
+ }
+
+ if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
+ error("unable to create directory for %s", newref);
+ goto rollback;
+ }
+
+ retry:
+ if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
+ if (errno==EISDIR) {
+ if (remove_empty_directories(git_path("logs/%s", newref))) {
+ error("Directory not empty: logs/%s", newref);
+ goto rollback;
+ }
+ goto retry;
+ } else {
+ error("unable to move logfile tmp-renamed-log to logs/%s: %s",
+ newref, strerror(errno));
+ goto rollback;
+ }
+ }
+ logmoved = log;
+
+ lock = lock_ref_sha1_basic(newref, NULL, NULL);
+ if (!lock) {
+ error("unable to lock %s for update", newref);
+ goto rollback;
+ }
+
+ lock->force_write = 1;
+ hashcpy(lock->old_sha1, orig_sha1);
+ if (write_ref_sha1(lock, orig_sha1, logmsg)) {
+ error("unable to write current sha1 into %s", newref);
+ goto rollback;
+ }
+
+ if (!strncmp(oldref, "refs/heads/", 11) &&
+ !strncmp(newref, "refs/heads/", 11)) {
+ char oldsection[1024], newsection[1024];
+
+ snprintf(oldsection, 1024, "branch.%s", oldref + 11);
+ snprintf(newsection, 1024, "branch.%s", newref + 11);
+ if (git_config_rename_section(oldsection, newsection) < 0)
+ return 1;
+ }
+
+ return 0;
+
+ rollback:
+ lock = lock_ref_sha1_basic(oldref, NULL, NULL);
+ if (!lock) {
+ error("unable to lock %s for rollback", oldref);
+ goto rollbacklog;
+ }
+
+ lock->force_write = 1;
+ flag = log_all_ref_updates;
+ log_all_ref_updates = 0;
+ if (write_ref_sha1(lock, orig_sha1, NULL))
+ error("unable to write current sha1 into %s", oldref);
+ log_all_ref_updates = flag;
+
+ rollbacklog:
+ if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
+ error("unable to restore logfile %s from %s: %s",
+ oldref, newref, strerror(errno));
+ if (!logmoved && log &&
+ rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
+ error("unable to restore logfile %s from tmp-renamed-log: %s",
+ oldref, strerror(errno));
+
+ return 1;