Re: [RFC/PATCH 5/5] fetch: fix regression with transport helpers

> Commit e198b3a740 changed the behavior of fetch with regards to tags.
> Before, null oids where not ignored, now they are, regardless of whether
> the refs have been explicitly cleared or not.
>
>   e198b3a740 (fetch: replace string-list used as a look-up table with a hashmap)
>
> When using a transport helper the oids can certainly be null. So now
> tags are ignored and fetching them is impossible.
>
> This patch fixes that by having a specific flag that is set only when we
> explicitly want to ignore the refs, restoring the original behavior.
>
> Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
> ---
>  builtin/fetch.c           | 5 +++--
>  t/t5801-remote-helpers.sh | 2 +-
>  2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/fetch.c b/builtin/fetch.c
> index 9dc551551e..f2be50a4a3 100644
> --- a/builtin/fetch.c
> +++ b/builtin/fetch.c
> @@ -239,6 +239,7 @@ static int will_fetch(struct ref **head, const unsigned char *sha1)
>  struct refname_hash_entry {
>  	struct hashmap_entry ent; /* must be the first member */
>  	struct object_id oid;
> +	int ignore;
>  	char refname[FLEX_ARRAY];
>  };
>  
> @@ -289,7 +290,7 @@ static int refname_hash_exists(struct hashmap *map, const char *refname)
>  
>  static void clear_item(struct refname_hash_entry *item)
>  {
> -	oidclr(&item->oid);
> +	item->ignore = 1;
>  }
>  
>  static void find_non_local_tags(const struct ref *refs,
> @@ -374,7 +375,7 @@ static void find_non_local_tags(const struct ref *refs,
>  			BUG("unseen remote ref?");
>  
>  		/* Unless we have already decided to ignore this item... */
> -		if (is_null_oid(&item->oid))
> +		if (item->ignore)
>  			continue;