Add matching and parsing for fetch-side refspec rules

Also exports parse_ref_spec().

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

remote.c

@@ -208,6 +208,7 @@ static void read_branches_file(struct remote *remote)
 	}
 	add_uri(remote, p);
 	add_fetch_refspec(remote, branch);
+	remote->fetch_tags = 1; /* always auto-follow */
 }
 
 static int handle_config(const char *key, const char *value)
@@ -274,6 +275,9 @@ static int handle_config(const char *key, const char *value)
 			remote->uploadpack = xstrdup(value);
 		else
 			error("more than one uploadpack given, using the first");
+	} else if (!strcmp(subkey, ".tagopt")) {
+		if (!strcmp(value, "--no-tags"))
+			remote->fetch_tags = -1;
 	}
 	return 0;
 }
@@ -296,7 +300,7 @@ static void read_config(void)
 	git_config(handle_config);
 }
 
-static struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
+struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
 {
 	int i;
 	struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
@@ -352,6 +356,10 @@ struct remote *remote_get(const char *name)
 		add_uri(ret, name);
 	if (!ret->uri)
 		return NULL;
+	if (!strcmp(name, ".")) {
+		// we always fetch "refs/*:refs/*", which is trivial
+		add_fetch_refspec(ret, "refs/*:refs/*");
+	}
 	ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
 	ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
 	return ret;
@@ -454,6 +462,14 @@ struct ref *alloc_ref(unsigned namelen)
 	return ret;
 }
 
+static struct ref *copy_ref(struct ref *ref)
+{
+	struct ref *ret = xmalloc(sizeof(struct ref) + strlen(ref->name) + 1);
+	memcpy(ret, ref, sizeof(struct ref) + strlen(ref->name) + 1);
+	ret->next = NULL;
+	return ret;
+}
+
 void free_refs(struct ref *ref)
 {
 	struct ref *next;
@@ -771,3 +787,110 @@ int branch_merges(struct branch *branch, const char *refname)
 	}
 	return 0;
 }
+
+static struct ref *get_expanded_map(struct ref *remote_refs,
+				    const struct refspec *refspec)
+{
+	struct ref *ref;
+	struct ref *ret = NULL;
+	struct ref **tail = &ret;
+
+	int remote_prefix_len = strlen(refspec->src);
+	int local_prefix_len = strlen(refspec->dst);
+
+	for (ref = remote_refs; ref; ref = ref->next) {
+		if (strchr(ref->name, '^'))
+			continue; /* a dereference item */
+		if (!prefixcmp(ref->name, refspec->src)) {
+			char *match;
+			struct ref *cpy = copy_ref(ref);
+			match = ref->name + remote_prefix_len;
+
+			cpy->peer_ref = alloc_ref(local_prefix_len +
+						  strlen(match) + 1);
+			sprintf(cpy->peer_ref->name, "%s%s",
+				refspec->dst, match);
+			if (refspec->force)
+				cpy->peer_ref->force = 1;
+			*tail = cpy;
+			tail = &cpy->next;
+		}
+	}
+
+	return ret;
+}
+
+static struct ref *find_ref_by_name_abbrev(struct ref *refs, const char *name)
+{
+	struct ref *ref;
+	for (ref = refs; ref; ref = ref->next) {
+		if (ref_matches_abbrev(name, ref->name))
+			return ref;
+	}
+	return NULL;
+}
+
+struct ref *get_remote_ref(struct ref *remote_refs, const char *name)
+{
+	struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);
+
+	if (!ref)
+		die("Couldn't find remote ref %s\n", name);
+
+	return copy_ref(ref);
+}
+
+static struct ref *get_local_ref(const char *name)
+{
+	struct ref *ret;
+	if (!name)
+		return NULL;
+
+	if (!prefixcmp(name, "refs/")) {
+		ret = alloc_ref(strlen(name) + 1);
+		strcpy(ret->name, name);
+		return ret;
+	}
+
+	if (!prefixcmp(name, "heads/") ||
+	    !prefixcmp(name, "tags/") ||
+	    !prefixcmp(name, "remotes/")) {
+		ret = alloc_ref(strlen(name) + 6);
+		sprintf(ret->name, "refs/%s", name);
+		return ret;
+	}
+
+	ret = alloc_ref(strlen(name) + 12);
+	sprintf(ret->name, "refs/heads/%s", name);
+	return ret;
+}
+
+int get_fetch_map(struct ref *remote_refs,
+		  const struct refspec *refspec,
+		  struct ref ***tail)
+{
+	struct ref *ref_map, *rm;
+
+	if (refspec->pattern) {
+		ref_map = get_expanded_map(remote_refs, refspec);
+	} else {
+		ref_map = get_remote_ref(remote_refs,
+					 refspec->src[0] ?
+					 refspec->src : "HEAD");
+
+		ref_map->peer_ref = get_local_ref(refspec->dst);
+
+		if (refspec->force)
+			ref_map->peer_ref->force = 1;
+	}
+
+	for (rm = ref_map; rm; rm = rm->next) {
+		if (rm->peer_ref && check_ref_format(rm->peer_ref->name + 5))
+			die("* refusing to create funny ref '%s' locally",
+			    rm->peer_ref->name);
+	}
+
+	tail_link_ref(ref_map, tail);
+
+	return 0;
+}

remote.h

@@ -15,6 +15,14 @@ struct remote {
 	struct refspec *fetch;
 	int fetch_refspec_nr;
 
+	/*
+	 * -1 to never fetch tags
+	 * 0 to auto-follow tags on heuristic (default)
+	 * 1 to always auto-follow tags
+	 * 2 to always fetch tags
+	 */
+	int fetch_tags;
+
 	const char *receivepack;
 	const char *uploadpack;
 };
@@ -41,9 +49,25 @@ struct ref *alloc_ref(unsigned namelen);
  */
 void free_refs(struct ref *ref);
 
+struct refspec *parse_ref_spec(int nr_refspec, const char **refspec);
+
 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 	       int nr_refspec, char **refspec, int all);
 
+/*
+ * Given a list of the remote refs and the specification of things to
+ * fetch, makes a (separate) list of the refs to fetch and the local
+ * refs to store into.
+ *
+ * *tail is the pointer to the tail pointer of the list of results
+ * beforehand, and will be set to the tail pointer of the list of
+ * results afterward.
+ */
+int get_fetch_map(struct ref *remote_refs, const struct refspec *refspec,
+		  struct ref ***tail);
+
+struct ref *get_remote_ref(struct ref *remote_refs, const char *name);
+
 /*
  * For the given remote, reads the refspec's src and sets the other fields.
  */