Merge branch 'mh/ref-remove-empty-directory'
Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
once there no longer is any other branch whose name begins with
"foo/", but we didn't do so so far. Now we do.
* mh/ref-remove-empty-directory: (23 commits)
files_transaction_commit(): clean up empty directories
try_remove_empty_parents(): teach to remove parents of reflogs, too
try_remove_empty_parents(): don't trash argument contents
try_remove_empty_parents(): rename parameter "name" -> "refname"
delete_ref_loose(): inline function
delete_ref_loose(): derive loose reference path from lock
log_ref_write_1(): inline function
log_ref_setup(): manage the name of the reflog file internally
log_ref_write_1(): don't depend on logfile argument
log_ref_setup(): pass the open file descriptor back to the caller
log_ref_setup(): improve robustness against races
log_ref_setup(): separate code for create vs non-create
log_ref_write(): inline function
rename_tmp_log(): improve error reporting
rename_tmp_log(): use raceproof_create_file()
lock_ref_sha1_basic(): use raceproof_create_file()
lock_ref_sha1_basic(): inline constant
raceproof_create_file(): new function
safe_create_leading_directories(): set errno on SCLD_EXISTS
safe_create_leading_directories_const(): preserve errno
...