Re: [PATCH] refs: cleanup directories when deleting packed ref

> Subject: [PATCH v2] refs: cleanup directories when deleting packed ref
> 
> When deleting a packed ref via 'update-ref -d', a lockfile is made in
> the directory that would contain the loose copy of that ref, creating
> any directories in the ref's path that do not exist. When the
> transaction completes, the lockfile is deleted, but any empty parent
> directories made when creating the lockfile are left in place.  These
> empty directories are not removed by 'pack-refs' or other housekeeping
> tasks and will accumulate over time.
> 
> When deleting a loose ref, we remove all empty parent directories at the
> end of the transaction.
> 
> This commit applies the parent directory cleanup logic used when
> deleting loose refs to packed refs as well.
> 
> Signed-off-by: Will Chandler <wfc@wfchandler.org>
> ---
>   refs/files-backend.c  | 12 ++++++------
>   t/t1400-update-ref.sh |  9 +++++++++
>   2 files changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/refs/files-backend.c b/refs/files-backend.c
> index 119972ee16..49e6ee069a 100644
> --- a/refs/files-backend.c
> +++ b/refs/files-backend.c
> @@ -45,10 +45,10 @@
>   #define REF_UPDATE_VIA_HEAD (1 << 8)
>   
>   /*
> - * Used as a flag in ref_update::flags when the loose reference has
> - * been deleted.
> + * Used as a flag in ref_update::flags when a reference has been
> + * deleted and the ref's parent directories may need cleanup.
>    */
> -#define REF_DELETED_LOOSE (1 << 9)
> +#define REF_DELETED_RMDIR (1 << 9)
>   
>   struct ref_lock {
>   	char *ref_name;
> @@ -2852,6 +2852,7 @@ static int files_transaction_finish(struct ref_store *ref_store,
>   
>   		if (update->flags & REF_DELETING &&
>   		    !(update->flags & REF_LOG_ONLY)) {
> +			update->flags |= REF_DELETED_RMDIR;
>   			if (!(update->type & REF_ISPACKED) ||
>   			    update->type & REF_ISSYMREF) {
>   				/* It is a loose reference. */
> @@ -2861,7 +2862,6 @@ static int files_transaction_finish(struct ref_store *ref_store,
>   					ret = TRANSACTION_GENERIC_ERROR;
>   					goto cleanup;
>   				}
> -				update->flags |= REF_DELETED_LOOSE;
>   			}
>   		}
>   	}
> @@ -2874,9 +2874,9 @@ static int files_transaction_finish(struct ref_store *ref_store,
>   	for (i = 0; i < transaction->nr; i++) {
>   		struct ref_update *update = transaction->updates[i];
>   
> -		if (update->flags & REF_DELETED_LOOSE) {
> +		if (update->flags & REF_DELETED_RMDIR) {
>   			/*
> -			 * The loose reference was deleted. Delete any
> +			 * The reference was deleted. Delete any
>   			 * empty parent directories. (Note that this
>   			 * can only work because we have already
>   			 * removed the lockfile.)
> diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
> index e31f65f381..4506cd435b 100755
> --- a/t/t1400-update-ref.sh
> +++ b/t/t1400-update-ref.sh
> @@ -1598,4 +1598,13 @@ test_expect_success 'transaction cannot restart ongoing transaction' '
>   	test_must_fail git show-ref --verify refs/heads/restart
>   '
>   
> +test_expect_success 'directory not created deleting packed ref' '
> +	git branch d1/d2/r1 HEAD &&
> +	git pack-refs --all &&
> +	test_path_is_missing .git/refs/heads/d1/d2 &&
> +	git update-ref -d refs/heads/d1/d2/r1 &&
> +	test_path_is_missing .git/refs/heads/d1/d2 &&
> +	test_path_is_missing .git/refs/heads/d1
> +'
> +
>   test_done
>