- if (write_cache(fd, active_cache, active_nr) ||
- commit_locked_index(&index_lock))
- die("unable to write new_index file");
+ if (active_cache_changed) {
+ if (write_cache(fd, active_cache, active_nr) ||
+ commit_locked_index(&index_lock))
+ die("unable to write new_index file");
+ } else {
+ rollback_lock_file(&index_lock);
+ }