Subject: Re: [PATCH 2/2] fetch: handle overlaping refspecs on --prune

From: Michael Haggerty <[email-masked]>
Date: Thu, 27 Feb 2014 11:21:53 +0100

On 02/27/2014 10:00 AM, Carlos Martín Nieto wrote:
> From: Carlos Martín Nieto <[email-masked]>
> 
> We need to consider that a remote-tracking branch may match more than
> one rhs of a fetch refspec. In such a case, it is not enough to stop at
> the first match but look at all of the matches in order to determine
> whether a head is stale.
> 
> To this goal, introduce a variant of query_refspecs which returns all of
> the matching refspecs and loop over those answers to check for
> staleness.
> 
> Signed-off-by: Carlos Martín Nieto <[email-masked]>
> ---
> 
> There is an unfortunate duplication of code here, as
> query_refspecs_multiple is mostly query_refspecs but we only care
> about the other side of matching refspecs and disregard the 'force'
> information which query_refspecs does want.
> 
> I thought about putting both together via callbacks and having
> query_refspecs stop at the first one, but I'm not sure that it would
> make it easier to read or manage.
> 
>  remote.c         | 52 +++++++++++++++++++++++++++++++++++++++++++++++-----
>  t/t5510-fetch.sh |  2 +-
>  2 files changed, 48 insertions(+), 6 deletions(-)
> 
> diff --git a/remote.c b/remote.c
> index 9f1a8aa..26140c7 100644
> --- a/remote.c
> +++ b/remote.c
> @@ -821,6 +821,33 @@ static int match_name_with_pattern(const char *key, const char *name,
>  	return ret;
>  }
>  
> +static void query_refspecs_multiple(struct refspec *refs, int ref_count, struct refspec *query, struct string_list *results)
> +{
> +	int i;
> +	int find_src = !query->src;
> +
> +	if (find_src && !query->dst)
> +		error("query_refspecs_multiple: need either src or dst");
> +
> +	for (i = 0; i < ref_count; i++) {
> +		struct refspec *refspec = &refs[i];
> +		const char *key = find_src ? refspec->dst : refspec->src;
> +		const char *value = find_src ? refspec->src : refspec->dst;
> +		const char *needle = find_src ? query->dst : query->src;
> +		char **result = find_src ? &query->src : &query->dst;
> +
> +		if (!refspec->dst)
> +			continue;
> +		if (refspec->pattern) {
> +			if (match_name_with_pattern(key, needle, value, result)) {
> +				string_list_append_nodup(results, *result);
> +			}
> +		} else if (!strcmp(needle, key)) {
> +			string_list_append(results, value);
> +		}
> +	}
> +}
> +
>  static int query_refspecs(struct refspec *refs, int ref_count, struct refspec *query)
>  {
>  	int i;
> @@ -1954,25 +1981,40 @@ static int get_stale_heads_cb(const char *refname,
>  	const unsigned char *sha1, int flags, void *cb_data)
>  {
>  	struct stale_heads_info *info = cb_data;
> +	struct string_list matches = STRING_LIST_INIT_DUP;
>  	struct refspec query;
> +	int i, stale = 1;
>  	memset(&query, 0, sizeof(struct refspec));
>  	query.dst = (char *)refname;
>  
> -	if (query_refspecs(info->refs, info->ref_count, &query))
> +	query_refspecs_multiple(info->refs, info->ref_count, &query, &matches);
> +	if (matches.nr == 0)
>  		return 0; /* No matches */
>  
>  	/*
>  	 * If we did find a suitable refspec and it's not a symref and
>  	 * it's not in the list of refs that currently exist in that
> -	 * remote we consider it to be stale.
> +	 * remote we consider it to be stale. In order to deal with
> +	 * overlapping refspecs, we need to go over all of the
> +	 * matching refs.
>  	 */
> -	if (!((flags & REF_ISSYMREF) ||
> -	      string_list_has_string(info->ref_names, query.src))) {
> +	if (flags & REF_ISSYMREF)
> +		return 0;
> +
> +	for (i = 0; i < matches.nr; i++) {
> +		if (string_list_has_string(info->ref_names, matches.items[i].string)) {
> +			stale = 0;
> +			break;
> +		}
> +	}
> +
> +	string_list_clear(&matches, 0);
> +
> +	if (stale) {
>  		struct ref *ref = make_linked_ref(refname, &info->stale_refs_tail);
>  		hashcpy(ref->new_sha1, sha1);
>  	}
>  
> -	free(query.src);
>  	return 0;
>  }

I didn't have time to review this fully, but I think you are missing
calls to string_list_clear(&matches) on a couple of code paths.

Michael

-- 
Michael Haggerty
[email-masked]
http://softwareswirl.blogspot.com/