Allow helper to map private ref names into normal names

This allows a helper to say that, when it handles "import
refs/heads/topic", the script it outputs will actually write to
refs/svn/origin/branches/topic; therefore, transport-helper should
read it from the latter location after git-fast-import completes.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/remote.c b/remote.c
index 09bb79c..1f7870d 100644
--- a/remote.c
+++ b/remote.c
@@ -673,6 +673,16 @@
 	return parse_refspec_internal(nr_refspec, refspec, 0, 0);
 }
 
+void free_refspec(int nr_refspec, struct refspec *refspec)
+{
+	int i;
+	for (i = 0; i < nr_refspec; i++) {
+		free(refspec[i].src);
+		free(refspec[i].dst);
+	}
+	free(refspec);
+}
+
 static int valid_remote_nick(const char *name)
 {
 	if (!name[0] || is_dot_or_dotdot(name))
@@ -811,6 +821,23 @@
 	return ret;
 }
 
+char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
+		     const char *name)
+{
+	int i;
+	char *ret = NULL;
+	for (i = 0; i < nr_refspec; i++) {
+		struct refspec *refspec = refspecs + i;
+		if (refspec->pattern) {
+			if (match_name_with_pattern(refspec->src, name,
+						    refspec->dst, &ret))
+				return ret;
+		} else if (!strcmp(refspec->src, name))
+			return strdup(refspec->dst);
+	}
+	return NULL;
+}
+
 int remote_find_tracking(struct remote *remote, struct refspec *refspec)
 {
 	int find_src = refspec->src == NULL;